Welcome to the new info.aerosensor website!

Get the most out of your Aerosensor devices in our dedicated support hub. You can find all the latest documentation and downloads.

If you have any questions, please contact us at support@aerosensor.tech and we’ll be happy to help!

Aerosensor

Quickstart

What follows outlines the basic setup of Aerosensor.  For more detailed information please refer to the other articles on the left hand side. 

ACS Installation

Download the ACS app to your Garmin.  Go to Garmin ConnectIQ store and search for “Aerosensor” or use link below.

https://apps.garmin.com/en-US/apps/0170243b-0384-4072-9e85-57030e4949a6

ACS screen layout

  1. FIT file recording status:
    Red square = not recording.
    Green triangle = recording.
  2. Aerobody connection and battery status.
  3. Aerosensor connection status.
  4. Aerosensor power and speed or speed/cadence sensor connection status: Green = Connected. Orange = Searching. Red = Disconnected.
  5. Aerosensor battery status.
  6. Back key Use in menus use to go back a step, or on data screens exists app. This may be a button instead of touch screen icon depending on your Garmin Edge model.
  7. Menu key. This may be a button instead of touch screen icon depending on your Garmin Edge model.

Aerosensor Setup

  1. Install Aerosensor securely, level, and centred on the bike using a go-pro mount.
  2. Pair your power meter speed sensor to Garmin.  We recommend dual sided power meter, and magnet based speed sensor.
  3. Calibrate power meter in Garmin, and set crank length if necessary.
  4. Open ACS CIQ app on your Garmin bike computer.
  5. Choose test type:
    1. Road: for general road cycling.
    2. Out and back: for cycling out and back along a stretch of road.
    3. Velodrome trackless: for velodrome use without Aerodrome lap trigger.
    4. Velodrome tracked: for velodrome use with Aerodrome lap trigger.
  6. Connect Aerosensor to CIQ app.
    1. Turn on Aerosensor.  It should connect automatically.  If not:
    2. Menu > Connections > Aerosensor.
    3. Wait for CIQ app to find device, then click on it to connect.
  7. Input key parameters Menu > Aerosensor Settings > Parameters > Edit Parameters. Most important parameters to set are:
    1. Aero device calibration: Start with a value of 1.4.
    2. Total mass (your total mass i.e. you + bike + clothing)
    3. Wheel circumference You can get from speed sensor info in Garmin, or roll out wheel and measure distance on ground.
    4. Power meter scaling This accounts for drive train losses. Typically use 0.98 for all but hub based PMs
    5. CTF calibration offset Only necessary if using an SRM PM7 or earlier Power meter.  This is the value reported when you calibrate your power meter on the Garmin.
    Be sure to “Push Parameters” after exiting this menu to save any changes.
  8. Check connections, and start activity
    1. Make sure your power meter and speed sensor are on, by rotating wheel and pedals.
    2. If paired then “PWR” and “SPD” icons in top right go green.  If not see ACS instructions.
  9. Start activity
  10. Press the start activity button on Garmin to start recording to FIT file.  Note the red square in the top right corner turns to a green triangle.

That’s it!  You are now ready to go aero testing.  For accurate results be sure to calibrate your aerosensor every time you change bike or make a substantial change in your position. Don’t worry, you can do this at the same time as testing and post-correct your data, so no specific runs are necessary.  See next section.

Calibration

The air “sees” you coming towards it due to high pressure build up ahead of you. For this reason the air at Aerosensor’s location on your bike is slower than freestream. We need to correct for this.
  1. Perform at least two out/backs or 4 laps of velodrome. Be sure to start activity before starting this, and stop activity at the end.
  2. Select valid laps. Go to page 9 of the CIQ app, press menu, then either press up or down arrows or swipe up or down to select laps.  Press menu again to toggle valid (“X”) or invalid (no “X”).
  3. Read the average cal value (“Avg_Cal”).  You can either see this at the top of the lap page, or on page 10.
  4. Post-correct your CdA values by dividing them by this value.
    CdA_corrected = CdA_reported / Avg_cal
  5. Calculate new calibration factor
    AeroCal_New = AeroCal_Old x Avg_cal
  6. Enter new “Aero device calibration” in Aerosensor Settings.
    Menu > Aerosensor Settings > Parameters > Edit Parameters.

Aero testing guidance

Reliable aerodynamic testing is reliant on good testing protocols, focus on the following:

  • CdA data is only as accurate as the inputs. Make sure you check Aerosensor’s settings in the ACS app before every test.
  • Always calibrate power sensor before starting testing, and ideally before each set of laps or out-backs. Small calibration offsets can result in a big error in CdA measurement.
  • Always start and end your test block with a baseline repeat.
  • Try to maintain a constant speed through each run.
  • For out and back testing we recommend a stretch between 600 and 1000m.
  • The more out and backs you do, the better the repeatability will be.

Data Analysis

Data is recorded to FIT file.  You can view the data via various platforms:
  • Aerosensor Excel Analysis Tool
    Automated in-depth analysis in a macro-enabled Excel workbook, available from the downloads section.
  • Aerotune
    Online platform tailored for Aerosensor analysis. See Aerotune website.
  • Garmin Connect
    All Aerosensor data is visible as “Developer fields” on the Garmin Connect website, after your head units has synced.
  • WKO
    Workbook available from downloads section of our website.
  • Golden Cheetah
    We are working with Golden Cheetah developers to better support aero testing. Watch this space!

Important notes & prerequisites

Important notes

Aerosensor is designed for outdoor paved roads or velodrome use in dry conditions and is therefore not suitable for wet conditions.

The device is not waterproof as it has holes to allow pressure measurement.

Aerosensor must be removed in wet conditions. If you think it will rain whilst you are out riding or the road may be wet in places then take a 3mm hex key with you so you can remove the device and put it in your jersey pocket for the rest of your ride.

Aerosensor will vibrate on rough paved roads. This has no negative impact on measurement quality. However if excessive vibrations occur, or if Aerosensor pitches down after use, please check the got-pro mount screw was sufficiently tight.

Clean Aerosensor with a soft, dry cloth. Avoid using abrasive materials or harsh chemicals that may damage the product’s surface.

Prerequisites

Aerosensor requires an ANT+ power and either bike speed or bike speed + cadence sensor. It also requires a Garmin cycling computer.

Bike Computer

Currently to use the ACS you will need a Garmin bike computer that can run Garmin Connect IQ applications at a minimum of SDK 3.1.0. A full list of compatible devices is available on the link below – be sure to check that the device has the “A” symbol, meaning apps.

https://developer.garmin.com/connect-iq/compatible-devices/ 

We will make data fields in the future, allowing you to see data in the standard Garmin context, and also on the Edge 130.

Power Meter (PWR)

Aerosensor requires a quality power meter. Single sided pedal-based power meters are not sufficiently accurate for good aerodynamic data. Remember that the aero data you get will only be as accurate as the power meter used.  

Speed (SPD) or Speed/Cadence (BSC) Sensor

For the best accuracy we highly recommend a magnet-based speed sensor. Hub mounted speed sensors or GPS based speed sensors do not have the time resolution necessary for high quality aerodynamic data.

Device mounts

Aerosensor has been designed to work on a variety of different bike bar types, notably the following:

  1. Drop handlebars – usually standard on road bikes and track bikes.
  2. Clip-on time-trial (TT) bars – additions to road and track bikes.
  3. Integrated TT handlebar/cockpit – mostly seen on TT and triathlon specific bikes.

A go-pro mount is required to install Aerosensor – for example one underneath a bike computer mount (sold separately, available on our website in Accessories).

Whilst Aerosensor can be used on most bike setups, there will be some bar variants that may be trickier to setup. Please do not hesitate to contact us at hello@Aerosensor.tech with any questions or for advice on how to best mount onto your bike.

Device basics

Specifications

Dimensions (H x W x D)

135 x 57 x 85mm

Mass

66g

Battery Life

57 hours

Wind speed resolution

+/- 0.1%

Wind angle resolution

+/- 0.1°

Altitude resolution

+/- 10cm

Layout

  1. LED
  2. Power button
  3. Reset button
  4. USB-C bung & charging port
  5. Stem
  6. Height/yaw adjustment screw
  7. Go-pro mount

Button functions

  • Power button:
    • Press and release to turn on.
    • Press and hold until LED turns off then release to shut down.
    • Press and hold, push reset button, then release for full factory reset. This resets the internal settings used to calculate CdA.
  • Reset button:
    • To be used in case the device becomes unresponsive. Resets device without erasing settings.

LED significance

The multi-colour LED indicates the device state as shown below:

Colour

Flashing

State

USB

Charge

Aqua

Normal

On

Unplugged

Normal

Red

Normal

On

Unplugged

Low

Amber

Slow

Off

Plugged in

Charging

Amber

Solid

On

Plugged in

Charging

Green

Slow

Off

Plugged in

Charged

Green

Solid

On

Plugged in

Charged

Note: Do not use sharp objects or tools to press buttons, this may result in damage. 

Installation

Use the go-pro mount itself to adjust pitch, then the yaw by loosening the height/yaw screw on Aerosensor’s stem (height adjuster) and rotating the unit. 

Do not use the aerosensor base to pivot, this can cause damage to the stem.

When installing, it is important to have Aerosensor as far forward and low as possible that the stem allows to minimise influence of rider position.

  • The base must be at least 20mm above the front wheel.
  • It should be centred on the bike and facing forwards. Use the front wheel as a reference for yaw alignment.
  • Aerosensor should be level – use a horizontal object to the side of the bike (like floor markings), and visually align the bottom of Aerosensor with the horizontal line. An example is shown below, where a horizontal line on the wall is used. Note that the device is tolerant to pitch misalignment within +/-5°.

CIQ App

Aerosensor Connection

Make sure that Aerosensor is switched on.

1.    Press the menu button on the Garmin head unit.

2.    Select “Connections” -> “Aerosensor”.

ACS-2

3. Select the device you want to connect to. Note: it is worth keeping a note of the Device ID for your Aerosensor and Aerobody for your records, especially if you are a coach and have multiple devices for your riders.

Pass-pairing

Pass-pairing is where ACS transmits the power meter and speed sensor ANT+ connection details to Aerosensor, allowing it to connect to them directly. 

For this to work the Garmin unit should already be paired with the ANT+ sensors you are using.

Note that Aerosensor requires a power meter (PWR) AND EITHER a speed sensor (SPD) OR speed + cadence sensor (BSC).

The CIQ app should automatically pass on the sensor connections to Aerosensor.  In case this does not work, or you have multiple sensors on the bike, follow these steps:

  1. Ensure that a power meter and speed sensor are installed on the bike and paired with the Garmin. Make sure they are on by rotating the wheel and/or pedals/crank, depending on the power meter.
  2. In the ACS menu, select “Connections”->”Pass pair” which will bring up the following screen:
ACS-3

3. Either select the devices individually or select the bottom “Enter to sync” button in purple above. After a short period, the status bar at the bottom of the screen should go green to show Aerosensor matches the Garmin device.  Aerosensor connection status icons should go from red to green.

ACS-4

Aerosensor Parameters

To accurately calculate aerodynamic drag, Aerosensor requires some information about you and your bike:

  1. Aero device calibration: This accounts for the fact that the wind slows as it approaches the bike, so the wind speed measured by Aerosensor is always slower than the air far upstream of the bike. Start with a value of 1.4. Typically we see values beweeen 1.1 and 1.45. See ‘Quickstart’ section for more information.
  2. Total mass (kg): includes rider + bike + all accessories used whilst riding with Aerosensor.
  3. Wheel Circumference (mm). If unknown, you can go into the speed sensor settings on the Garmin and you will find the wheel circumference in there once you have ridden far enough for the Garmin to calibrate against GPS.
  4. Power meter scaling: Default value is 1.0. If using pedals or crank we need to account for drivetrain losses.  A typical value would be 0.98, i.e. 2% drivetrain loss.
  5. CTF calibration offset: Used for CTF power meters.
  6. Time av period: This is the time period used by Aerosensor to average the CdA value, default is 30 seconds.
  7. Reference Crr: Rolling resistance coefficient (used if known), default 0.004. For an indoor velodrome you should use 0.002 (half the road value).  You can find typical crr values for a range of tyres at https://www.bicyclerollingresistance.com/
  8. Valid speed min: minimum speed (kph) for valid CdA automatic lapping. The CdA calculation is started when you go above this speed, and stopped when you slow down below this speed.  The device automatically creates laps for each CdA measurement period.

Editing Parameters:

It is important you check these frequently, especially total mass and wheel circumference if changing between bikes for example.

Velodrome testing – Track layout

When Aerosensor is in track calculation mode it uses lap distance and speed to calculate lean angle to compensate for centre of gravity location.  This only works when Aerodrome is being used. A typical track layout is shown below, of which you can input the track measurements by editing parameters directly in the CIQ app.

You can measure the track by measuring relative distance of corner start and end, using the distance markers along the track. This does not need to be very accurate – within a few meters is fine.

Measuring the track:

  1. Measure the distance from the tapeswitch location to the start and end of each corner.
  2. Use these to calculate the total distance of the two straight sections.
  3. Corner length = track length – total straight lengths
  4. Corner radius = corner length / pi
  5. Transition length is the distance it takes for the rider to transition from the straight to the corner. Typical value is 10m.

Example:

  • Total track length = 250m.
  • C1 start = 10m
  • C1 end = 95m
  • C2 start = 135m
  • C2 end = 220m
  • Corner length = C1 end – C1 start – transition= 95 – 10 – 10 = 75m
  • Corner radius = 75/pi = 23.9m

Editing Parameters:

Velodrome testing – Calculation mode

At the velodrome Aerosensor can ignore the barometer, since elevation is roughly constant, and should use the track map. If the track map is not known, or Aerodrome is not available, you can use the trackless mode. To use Velodrome mode:
  1. Go to Menu-> Aerosensor Settings->Calculation Mode.
  2. Select the model you require:
    1. Road
      For road riding.
    2. Velodrome Trackless
      Assumes constant elevation but ignores track layout. This is for when you are not using a lap trigger (Aerodrome) or the track layout is unknown.
    3. Velodrome Tracked
      Assumes constant elevation AND uses the track layout. This is for when you are using Aerodrome and know the track layout, as entered in ‘Aerosensor Settings->Track’.
  3. Wait until the mode changes as required, in the menu heading.
Screen sequence shown below:

Aerosensor demo mode

This is for diagnostic purposes and can generally be ignored.

Aerosensor information

Go to Menu -> Aerosensor settings -> about

Here you can see information about your Aerosensor device, including battery level, firmware version and serial number. Battery voltage is also included as it is useful for diagnostic purposes.

Aerobody

Quickstart

What follows outlines the basic setup of Aerobody.  For more detailed information please refer to the other articles on the left hand side. 

ACS Installation

Download the ACS app to your Garmin.  Go to Garmin ConnectIQ store and search for “Aerosensor” or use link below.

https://apps.garmin.com/en-US/apps/0170243b-0384-4072-9e85-57030e4949a6

ACS screen layout

  1. FIT file recording status:
    Red square = not recording.
    Green triangle = recording.
  2. Aerobody connection and battery status.
  3. Aerosensor connection status.
  4. Aerosensor power and speed or speed/cadence sensor connection status: Green = Connected. Orange = Searching. Red = Disconnected.
  5. Aerosensor battery status.
  6. Back key Use in menus use to go back a step, or on data screens exists app. This may be a button instead of touch screen icon depending on your Garmin Edge model.
  7. Menu key. This may be a button instead of touch screen icon depending on your Garmin Edge model.

Aerobody setup

 

1.    Install device using Garmin ¼-turn mount.

2.    Position device. Using your hand to check, rotate Aerobody so the head sensor is picking up your chin. Tighten mount screw to lock in position.

3.    Open either ACS or Aerobody datafield on Garmin device.

4.    Connect Aerobody to CIQ app.

a. Turn on Aerobody.  It should connect automatically.  If not:

b. Menu > Connections > Aerobody.

c. Wait for CIQ app to find device, then click on it to connect.

5.      Set your datum position using the app or datafield.

Data Analysis

Data is recorded to FIT file.  You can view the data via various platforms:
  • Aerosensor Excel Analysis Tool
    Automated in-depth analysis in a macro-enabled Excel workbook, available from the downloads section.
  • Aerotune
    Online platform tailored for Aerosensor analysis. See Aerotune website.
  • Garmin Connect
    All Aerosensor data is visible as “Developer fields” on the Garmin Connect website, after your head units has synced.
  • WKO
    Workbook available from downloads section of our website.
  • Golden Cheetah
    We are working with Golden Cheetah developers to better support aero testing. Watch this space!

Device basics

Specifications

Dimensions (H x W x D)

36 x 32 x 64mm

Mass

37g

Battery Life

9 hours

Head position resolution

+/- 1mm

Chest position resolution

+/- 1mm

Layout

  1. LED
  2. Power button
  3. Reset button
  4. USB-C bung & charging port
  5. Head sensor
  6. Chest sensor
  7. Quarter-turn mount

Button functions

  • Power button:
    • Press and release to turn on.
    • Press and hold until LED turns off then release to shut down.
  • Reset button:
    • To be used in case the device becomes unresponsive.

LED significance

The multi-colour LED indicates the device state as shown below:

Colour

Flashing

State

USB

Charge

Aqua

Normal

On

Unplugged

Normal

Red

Normal

On

Unplugged

Low

Amber

Slow

Off

Plugged in

Charging

Amber

Solid

On

Plugged in

Charging

Green

Slow

Off

Plugged in

Charged

Green

Solid

On

Plugged in

Charged

Note: Do not use sharp objects or tools to press buttons, this may result in damage. 

Important notes & prerequisites

Important notes

Aerobody uses optical sensors for measuring your body position, so keeping the sensor lenses clean and free from debris is critical for good performance.

The USB port should be kept dry and free from debris. After charging, please ensure that the bung is replaced firmly.

Although Aerobody is splashproof, it is not designed to operate in wet conditions. Please ensure it is removed if outdoors and raining.

Clean Aerobody with a soft, dry cloth. Avoid using abrasive materials or harsh chemicals that may damage the product’s surface.

Prerequisites

Aerobody doesn’t require any other devices to work; you will need a Garmin cycling computer however.

Device mounts

Aerobody has been designed to work on a variety of different bike bar types, notably the following:

  1. Drop handlebars – usually standard on road bikes and track bikes.
  2. Clip-on time-trial (TT) bars – additions to road and track bikes.
  3. Integrated TT handlebar/cockpit – mostly seen on TT and triathlon specific bikes.

Aerobody is supplied with a quarter-turn mount suitable for most bike setups.

Whilst Aerobody can be used on most bike setups, there will be some bar variants that may be trickier to setup. Please do not hesitate to contact us at hello@Aerosensor.tech with any questions or for advice on how to best mount onto your bike.

Installation

Aerobody has a standard Garmin quarter-turn mount. It should be positioned on the stem using a compatible bike mount adapter such as the one supplied with the unit. The screw on the quarter-turn mount allows pitch adjustment of the entire unit.

The forward (head) sensor should be aligned approximately with the chin and the chest sensor points at the chest.

To align, support the bike either in a turbo trainer, or by asking someone to support the bike.  Sitting on the bike in your normal riding position watch the display whilst moving two fingers up and down from your chin towards the unit, and ensure that the measurement tracks movement of your fingers.

CIQ App

Aerobody Connection

Make sure that Aerobody is switched on.

  1. Press the menu button on the Garmin head unit.
  2. Select “Connections” -> “Aerobody”.
4. Connect device

3. Select the device you want to connect to. Note: it is worth keeping a note of the Device ID for your Aerobody for your records, especially if you are a coach and have multiple devices for your riders.

Set Reference

The CIQ app shows your body position relative to a reference which you can set as follows:

  1. Got to Menu-> Aerobody Settings->Set Reference.
  2. Get into your ideal position on the bike. To do this support the bike in a turbo trainer, or ask someone to support it for you, and get into your normal riding position.
  3. Select “Measure”. This will give you a 5 second countdown to get in position, then will take a 2 second average of your position. When complete the measurements will show in red to indicate the new values are unsaved, and the “Save” button will be highlighted.
  4. Click “Save” to send the new position to Aerobody. Wait for the head and chest display to update to green, and the save button to turn grey and show “Saved”.
5. Set datum
AEROBODY QUICKSTART-8

Set Null Zone

The body position fields in the CIQ app will turn red if you are higher, or blue if you are lower, than your reference position. It will be white if you are within a set “null zone” around your reference position. As an example, a 1.5cm null zone means that the rider moving between -1.5cm and +1.5cm of their reference head or chest position will remain white whilst riding. Anything outside of these values are considered “out of position” will be red or blue depending if you are too high or too low.

The null zone may be set as follows:

  1. Got to Menu-> Aerobody Settings->Set Null Zone.
  2. The buttons can be used to adjust in multiples of 1cm and 0.1cm as necessary.
  3. Click “Save” to send the new position to Aerobody.

Aerobody information

Got to Menu -> Aerobody settings -> About

Here you can see information about your Aerobody device, including battery level, firmware version and serial number. Battery voltage is also included as it is useful for diagnostic purposes.

CIQ Datafield

Please refer to the Aerobody CIQ Datafield section here.

Aerodrome

Quickstart

What follows outlines the basic setup of Aerodrome. For more detailed information please refer to the other articles on the left hand side. 

ACS Installation

Download the ACS app to your Garmin.  Go to Garmin ConnectIQ store and search for “Aerosensor” or use link below.

https://apps.garmin.com/en-US/apps/0170243b-0384-4072-9e85-57030e4949a6

ACS screen layout

  1. FIT file recording status:
    Red square = not recording.
    Green triangle = recording.
  2. Aerobody connection and battery status.
  3. Aerosensor connection status.
  4. Aerosensor power and speed or speed/cadence sensor connection status: Green = Connected. Orange = Searching. Red = Disconnected.
  5. Aerosensor battery status.
  6. Back key Use in menus use to go back a step, or on data screens exists app. This may be a button instead of touch screen icon depending on your Garmin Edge model.
  7. Menu key. This may be a button instead of touch screen icon depending on your Garmin Edge model.

Aerodrome Setup

  1. Install tapeswitch across track, securing with duck tape.
  2. Position Aerodrome about 1-2 meters downstream of the tapeswitch, close to track, oriented so that the buttons are closest to the track as shown.
  3. Ensure Aerodrome blue light is flashing
    When Aerosensor is on and within a few meters of the Aerodrome the light will flash to show it is able to communicate with it. This ensures radio signal is strong enough to work.  It only needs to pick up Aerosensor’s signal for 1-2 meters after the tapeswitch is crossed.
  4. Open ACS in “Velodrome Tracked” mode.
    This assumes no elevation changes, and uses the trackmap to correct for cyclist lean angle.
  5. Edit track map in ACS.
    See section in CIQ app documentation.
Remember to start an activity on the Garmin before starting to ride. Aerosensor will automatically create new laps every time you cross the tapeswitch. Note that the data appears on the Garmin a couple of seconds after the end of lap, once Aerosensor has finished averaging data for the lap.

Aero testing guidance

Reliable aerodynamic testing is reliant on good testing protocols.  Here are a few tips for best results.
  • CdA data is only as accurate as the inputs. Make sure you check Aerosensor’s settings in the ACS app before every test.
  • Always calibrate power sensor before starting testing. Small calibration offsets can result in a big error in CdA measurement.
  • Always start and end your test block with a baseline repeat.
  • Try to maintain a constant speed through each run.
  • For velodrome testing we recommend 6-8 laps per configuration.
  • The more laps you do, the better the repeatability will be.

Data Analysis

Data is recorded to FIT file.  You can view the data via various platforms:
  • Aerosensor Excel Analysis Tool
    Automated in-depth analysis in a macro-enabled Excel workbook, available from the downloads section.
  • Aerotune
    Online platform tailored for Aerosensor analysis. See Aerotune website.
  • Garmin Connect
    All Aerosensor data is visible as “Developer fields” on the Garmin Connect website, after your head units has synced.
  • WKO
    Workbook available from downloads section of our website.
  • Golden Cheetah
    We are working with Golden Cheetah developers to better support aero testing. Watch this space!

Device basics

Specifications

Dimensions (H x W x D)

34 x 76 x 76mm

Mass

66g

Battery Life

28 hours

Timing resolution

+/- 1ms

Layout

  1. Power button
  2. LED
  3. Reset button
  4. USB-C charging port
  5. Tapeswitch port

Button functions

  • Power button:
    • Press and release to turn on.
    • Press and release to shut down.
  • Reset button:
    • To be used in case the device becomes unresponsive.

LED significance

The multi-colour LED indicates the device state as shown below:

Colour

Flashing

State

USB

Charge

Cyan

Solid

On

Unplugged

Normal

Lilac

Solid

Trigger

N/A

N/A

Amber

Solid

On

Charger

Low

Green

Solid

Off

Charger

Charging

Blue

Solid

On

Computer

Charging

Light blue

Solid

Off

Computer

Charged

Any

Flash

On

Aerosensor connected

Note: Do not use sharp objects or tools to press buttons, this may result in damage. 

Important notes & prerequisites

Important notes

Aerodrome uses a Tapeswitch cable as a lap trigger – the cable should not be pinched or bent. Bending with a bend radius less than 4mm will permanently damage the product.

The USB port and Tapeswitch port should be kept dry and free from debris.

Although Aerodrome is splashproof, it is not designed to operate in wet conditions.  Please ensure it is not used outdoors when it is raining.

Clean Aerodrome with a soft, dry cloth. Avoid using abrasive materials or harsh chemicals that may damage the product’s surface.

Prerequisites

Aerodrome requires Aerosensor device and a Garmin cycling computer.

Installation

As Aerodrome will likely be used on a live track or a public road, it is critical that you have permission to use the device and/or have taken appropriate measures to ensure not only the safety of you and other riders, but also to prolong the life of the device itself.

The tapeswitch should be placed so that the flat side is against the track or road, and the ridge on the upper side. Using duck tape, secure the tapeswitch across the line the cyclist will be following, be it on the track or the road. Secure at the far ends with tape, and placing a further piece of tape along the length, just holding down the upstream side of the tapeswitch.

Tape along the tapeswitch, not across it (as below).

Aerodrome listens for Aerosensor and the LED flashes when it receives data. It is only able to transmit the lap trigger when this is happening.

For optimal radio performance, make sure Aerodrome is situated in a position where it can receive data from Aerosensor when bike is at or just past the Tapeswitch. It is normally best to position 1-2m downstream of where the lap trigger is placed.  Orient the device so that the buttons are closest to the track, as shown in images below.

Plug the tapeswitch plug into the Aerodrome socket and turn on. The power light should illuminate.  You can check it is working by pressing on the tapeswitch. The LED will turn purple for 1 second to indicate a lap trigger.

Aerodrome should be placed on the floor well clear of any area the rider is likely to pass.  Secure the tapeswitch cable to the floor with duck tape to avoid trip hazards.

Note that currently Aerodrome cannot distinguish between multiple Aerosensor’s running on track.  It will only work correctly when a single rider is on track.

1. Install tapeswitch
2. Position Aerodrome

CIQ App

Aerodrome Connection

Aerodrome uses Aerosensor, so no specific settings are required in the CIQ App.

Please refer to the Aerosensor section here.

Garmin CIQ Apps & Datafields

Aerosensor Cycling System CIQ App

Overview

The Aerosensor Aerodynamic Cycling System (ACS) Connect IQ app is required to seamlessly integrate our devices with your Garmin bike computer, providing real-time aerodynamic data and further insights during your ride, and recording your data to a FIT file for further analysis.

Installation

  1. The Aerosensor ACS CIQ app can be downloaded from the Garmin Connect IQ website:

https://apps.garmin.com/

  1. Simply search for “Aerosensor” and the app will come up, or use this link:

https://apps.garmin.com/en-US/apps/0170243b-0384-4072-9e85-57030e4949a6

  1. Install to the Garmin head unit as per the instructions on the CIQ app website.
  2. Start ACS by going to the Connect IQ menu on your Garmin (see Garmin instructions) and then selecting “Aerosensor ACS”.

ACS screen layout

  1. FIT file recording status:
    Red square = not recording
    Green triangle = recording.
  2. Aerobody connection and battery status.
  3. Aerosensor connection status.
  4. Aerosensor power and speed or speed/cadence sensor connection status:
    Green = Connected.
    Orange = Searching.
    Red = Disconnected.
  5. Aerosensor battery status.
  6. Back key
    Use in menus use to go back a step, or on data screens exists app. This may be a button instead of touch screen icon depending on your Garmin Edge model.
  7. Menu key.
    This may be a button instead of touch screen icon depending on your Garmin Edge model.

Aerobody CIQ Datafield

Overview

Aerobody is a device that mounts on your stem and measures the distance to your head and chest. This is a good indication of your overall body position.

The Aerobody datafield allows you to view your body position data in the context of your normal Garmin views. You can add it in the same way you would add any other data such as speed, power, time etc. It also adds your aerobody data to the fit file so you can view it after your ride.

Installation

Search for Aerobody on the ConnectIQ store and follow instructions to install. 

  • Once installed, on your Garmin select the data screen (in your chosen activity profile) and edit the field where you want the data to appear.
  • Select Connect IQ from the list.
  • Select Aerobody from the list.

Note that aerobody really needs a full screen width field to display correctly as it displays both head and chest positions.

Pairing

Turn on your Aerobody device.

The Aerobody datafield will automatically connect to the first Aerobody signal it picks up.  It saves this so that next time it will look for the same physical device.

If you need to switch to a different Aerobody device, firstly make sure that only that one is switched on and in range (roughly 10m) of the Garmin unit, the follow the following steps.

  • Make sure that Garmin Connect app is installed on your phone and paired with your Edge unit.
  • Turn on your Garmin and the Aerobody device.
  • In either Garmin Connect or the Garmin ConnectIQ app, select your device, then go find the datafield app. Open settings.
  • Move the slider next to “Reset paired device” to the right.
  • Click “Save”. The display on the Garmin should show “Reconnecting” for 3 seconds then switch back to the data view.  Ensure that a surface is within 300mm of the Aerobody device in order to make sure it is reading data.
AEROBODY DATAFIELD-4
AEROBODY DATAFIELD-5
AEROBODY DATAFIELD-6

Setting datum

Aerobody allows you to set a datum, which you can think of as a target position for you to maintain whilst riding. The head and chest fields will go red if you go above this; blue if below, outside of a “null zone”, the dimensions of which you can modify in the settings.  You can also set an audible alert to warn you when you are outside of your target range. By default the relative position is shown in the fields, which is the distance between your current position and the datum.  This can be changed to absolute position in the datafield settings.
To set your datum, follow these steps:
  • Get on the bike, ready to get into position. Use a turbo-trainer or friend to support it.
  • In settings, put the “Set datum” slider to the right. Click “Save”.
  • On the datafield it will give you a countdown of 3 seconds to get into position.
  • The datafield It will then average your position and save it.
Now when you are in the correct position the display should have an uncoloured background.  If you are too low it goes blue; too high it goes red.
AEROBODY DATAFIELD-7
AEROBODY DATAFIELD-8
AEROBODY DATAFIELD-9

Testing

General Riding

Riding with Aerosensor

Always make sure you calibrate your power meter before starting a ride.  You must do this on the Garmin outside of the CIQ app.

Always run the CIQ app whilst riding to view and record your Aerosensor or Aerobody data.

Press the “start/stop activity” button on the Garmin to start recording data to fit file.

When your cycling speed exceeds the preset “Valid speed min” speed a new lap will be started and the CdA field will show a countdown to when data will be available. If the averaging time is set to 30s then this will count down from 30s to zero.  When it reaches zero the live CdA value will be shown.

As well as CdA, a “lap CdA” value is shown on some screens. This shows the average CdA over the current lap, and is available from 10 seconds after the valid speed is hit.

When you slow down again the lap will be finished, either by dropping below the minimum speed, or by braking hard. The lap CdA for the last lap will be available.

Don’t forget to press the “start/stop activity” button again to end the recording.

Out-back / road testing

Overview

  • For more accurate aerodynamic testing outdoors, when a track is not available, you should ride in both directions along an ideally quiet section of road.  The wind generated by passing traffic will degrade the measurement.
  • The road section does not need to be straight, but tight corners should be avoided.  You should aim to be able to ride at a roughly constant speed and power during the test.
  • The more out and backs you perform, the more accurate your CdA will be.

Protocol

  1. Press the “start/stop activity” button on the Garmin to start recording data to fit file.
  2. You should ride in one direction along the road stretch for between 500m and 1km. The longer the better.  At the end of your segment, brake sharply, turn around and then ride back the other way back to your starting point. For the turnaround ride slowly (below your preset minimum speed) for at least ten seconds to ensure the lapping process works properly.
  3. During each out or back segment, aim to maintain a constant position on the bike, and ideally a constant speed.
  4. Don’t forget to press the “start/stop activity” button again to end the recording.

The more out and backs you perform, the more accurate your CdA will be.

Calibration

For each out and back segment, Aerosensor calculates a “Cal factor”, shown on page 6 of the display as “Prev cal factor” for the most recent segment.  Average these values for all of your out and back segments to get your calibration factor.  This should then be multiplied by the aero device calibration factor set in the CIQ app to get the new calibration factor.  You can then set the aero cal parameter to this new value.

For example, lets say you perform two out and backs.  Your aero cal parameter set in the CIQ app is 1.18.  The values you get are as follows.  Note that typically the odd laps will be acceleration and turnaround segments.  Because of ambient wind the value in one direction will generally by higher than in the other.

Lap 2   1.05

Lap 4   1.15

Lap 6   1.03

Lap 7   1.14

The average of these values is 1.09.  1.09 x 1.18 = 1.29.  You should go into Aerosensor settings -> parameters and enter this new value.

This value varies a little with your body position so for accurate CdA data periodically repeat this process.

Lap / Velodrome testing

Overview

  • For best results, calibrate the power meter before starting each run.
  • The more laps you ride, the more accurate the average for the run will be, as shown on page 9 of the CIQ app.

Protocol

  1. Once you have set everything up, press the start/stop activity button on your gamin to start recording.
  2. Ride at least 4 full laps, (i.e. out lap, 4 test laps, in lap).  Whilst testing try to maintain a constant power output and body position.  You must ride above the preset minimum speed.
  3. Data for each lap is shown in the page 8 of the CIQ app.
  4. Don’t forget to press the “start/stop activity” button again to end the recording.

Aerodynamic testing protocols

Overview

Aerodynamic testing is inherently difficult. There are many variables involved and the final CdA values are only as accurate as the least accurate measurement.
For this is reason it is important to use dual-sided power meters, and magnet-based speed sensors.

Terminology

A baseline is the first and last test you perform to determine data confidence levels, likely in a standard position or with standard equipment.

The baseline confidence delta is the % difference between the baseline and repeat baseline CdA – this determines data confidence levels.

A configuration is your bike setup with a change that you’d like to test, say a new helmet, new wheel etc

A run is one interval using a configuration (e.g. one lap on velodrome, or one out and back on the road)

A test is made up of multiple runs which are then averaged to give the overall measurement data for the tested configuration (e.g. multiple laps on velodrome or multiple out and backs on road)

A session is comprised of a baseline, one or more tests, and ideally a final baseline.

For velodrome testing we recommend doing at least 6 laps for a test.

For road testing we recommend at least 3 out and back runs for a test.  The distance over which you should ride for each individual out or back should be between 600 and 1000m.

Remember the more runs you do, the more accurate the data.

Baseline control

You should start and end each test session with a baseline repeat.
Example
For helmet testing, start with your usual helmet (baseline), then do one test for each helmet.  Finally do a one more test with your baseline helmet.  The variation in CdA between the first and last tests tells you what your repeatability is.  If this difference is 0.0015 then you know that any measured difference greater than this is a reliable result.

Equipment

Keeping track of the variables in your control isn’t just limited to your aerodynamic testing plan or your body position – it includes your bike.
It is worth getting into the habit of logging your clothing, shoes, bike geometry, wheels etc when aero testing – we would recommend photos of your configurations too to add to your post processed data. You can never have too much information in a diary – we recommend using Aerotune’s web platform for this.
In addition make sure your bike is routinely maintained, including a clean and well-lubed drivetrain, and that you have correctly inflated tyres.
We can’t stress enough that aerodynamic testing is made accessible with Aerosensor, but there the data will only be as reliable as the testing. Think about everything you do to make sure you are being as consistent as possible between each test.

Case studies

Case Study 1

Testing a new rear wheel at the velodrome:

  1. Perform at least 6 laps with current/base wheels – this is the baseline.
  2. Swap rear wheel to perform another 6 laps – this is test 1.
  3. Return to the current wheels for a final 6 laps – this is the repeat baseline.
  4.  Conclusion:
    • Looking at the data, there is a 0.4% difference between the first baseline and the repeat baseline CdA, this means that anything larger than 0.4% on test 1 can be resolved and conclusions can be taken.
    • New rear wheel test yielded a reduction in CdA of 1.3% – this is larger than the baseline confidence delta, therefore with confidence we can say that the new rear wheel reduces the rider’s CdA. Larger differences increase the confidence.

Case Study 2

Testing four different helmets on a straight, flat, quiet road:

  1. Perform 3 1000m out and back runs with a current helmet – this is the baseline
  2. For four subsequent tests, the rider changes between the four test helmets – these are tests 1-4
  3. Return to the current helmet and perform the same 3 1km out and back runs – this is the repeat baseline.
  4.  Conclusion:
    • Looking at the data, there is a large 4% increase in CdA on the repeat baseline – this baseline confidence delta is too large to draw any conclusions from the tests. Speed, distance, and wind conditions are all much less than 4% different – so something else must be at play.
    • It is noticeable that, after looking at head and chest position data from Aerobody, there has been a 15mm increase in average head position from the baseline to the repeat baseline – this almost certainly explains the large CdA increase.
    • The test helmet data also backs this up, there were expectations pre-session that all helmets would reduce drag compared to the current helmet, however that data says this is not the case, even saying the performance is worse in some cases – this is because the head positions also were different for each test, and therefore ruined the results.
    • This means the rider did not keep a consistent body position throughout the session and implies that the rider couldn’t sustain the position for that length of time – which is itself a useful conclusion for the rider.

Trackside Lap Logger

Overview

The Aerosensor Lap Logger is a piece of software that allows a coach to view data from the ACS Connect IQ app trackside. The ConnectIQ app transmits data from the previous lap continuously, allowing an ANT dongle equipped computer to display and log the data, meaning that the coach can make quick decisions on the results, knowing what to do next with the rider before they come off the track.

Installation

The software is only compatible with a Windows based computer.

The application can be downloaded from the downloads section here.

To operate an ANT+ dongle is required, such as the one below:

https://www.garmin.com/en-GB/p/10997

Other manufacturers offer similar products at lower prices, although quality may vary.

For optimal reception it is recommended that a USB extension lead is used, ideally 2m long, and the dongle is placed high up somewhere.

Operation

  1. Open the application from the start menu (search for “ANT_Lap_Logger”) or use the shortcut on the desktop.
  2. Click “Browse” and select a folder to save log files to.
  3. Click “Connect” and ensure that “Sensor opened” shows.
    In the “Messages” window, when ACS is open on the Garmin you should see data packets coming through. If nothing appears, click “Close” then “Open” again to reset the connection.
  4. For each set of laps:
    1. Click “Reset” to remove any data from the “LapData” grid from previous runs.
    2. Enter the run description in the “Description” field.
    3. Click on “Start log” to start logging the data to a file.
  5. As each lap comes in, you can click on the checkbox under the “Flag” column in the lap data to activate or deactivate laps. The average of all active laps is displayed under session data.
  6. Click “Stop log” at the end of the session, which will save the data and close the log file.
  7. The log file is a simple .csv comma delimited file which can be opened directly in Microsoft Excel.

Data analysis

Aerodynamic basics

What is aerodynamic drag?

Aerodynamic drag is the force of the air acting to slow down a cyclist moving through it.

It is made up of two major components – pressure drag and skin friction drag.

  • Pressure drag is related to the size and shape of the bike and rider. As you cycle forwards you hit air particles out of the way. These are compressed on impact but then space out as they pass over and past you – the difference between these two air pressures is pressure drag. This is why getting into an aerodynamic position and allowing the oncoming air to flow smoothly around you, reduces your overall aerodynamic drag and makes it easier to cycle.
  • Skin friction is related to the roughness or texture of the surface on the bike and rider, a smooth (laminar) surface allows air particles to have consistent trajectories (pathlines). A rough (turbulent) surface causes irregular pathlines. Something to note however is surface roughness can be used to keep flow attached longer (for example a textured should on a skinsuit) which increases skin friction drag, but reduces pressure drag (of which is a larger component and therefore can reduce overall drag.

How do we measure aerodynamic drag?

There are five forces acting on a cyclist. Aerosensor works by measuring or estimating forces (or power) from the rider (FR), kinetic (FK), gravitational (FG) and friction (FF) to find the fifth, aerodynamic drag (FD).

The sum of these sources (positive) and sinks (negative) plus the aerodynamic drag (sink) must equal zero:

F_{R} \pm F_{K} \pm F_{G}-F_{F}-F_{D}=0

Aerodynamic drag is comprised of the product of dynamic pressure (pDyn, directly measured by Aerosensor), coefficient of drag (Cd, a constant for a given body position/setup) and frontal area (A). In cycling, the coefficient of drag and frontal area are commonly combined as the term CdA:

F_{D} = p_{\text{Dyn}} \times C_{d}A

Combining these two equations gives you a relationship between CdA and the other bike forces:

C_{d}A = \frac{{F_{R} \pm F_{K} \pm F_{G} – F_{F}}}{{p_{\text{Dyn}}}}

This is what your Aerosensor calculates in real-time!

Why is aerodynamic drag important?

Although aerodynamic drag increases with speed, friction does not – so at high speeds aerodynamic drag dominates.

Above you can see that at 5kph just 10% of your power goes into overcoming aerodynamic drag, and at 40kph this increases to over 80% – ie 80% of your power is used only to push you through the air.

Say you’re taking part in a flat 40km TT, how can reducing your CdA (and therefore aerodynamic drag) affect your race time?

In this example, reducing your CdA by around 10% can save over 1 minute and 30 seconds. The great news about aerodynamic testing is that you can make huge strides in making yourself faster and/or saving more energy for when it matters.

Garmin Connect

Section currently in construction. 

Excel Tools

Section currently in construction. 

WKO

Section currently in construction. 

Golden Cheetah

Section currently in construction. 

Aerotune

Section currently in construction. 

Troubleshooting

Aerosensor

We have a known issue where Aerosensor can become unresponsive.

  • Make sure device has charge by plugging into USB-C.
  • Press reset button. You can find instructions on where to find it in the quickstart.

In addition, our device works on a standard 5V power supply.  Some laptop/phone charges are “smart chargers” that communicate with device to charge at a higher voltage.  These just flat out don’t work, so please try the following:

  • Try a different power source. A computer USB port is usually a safe bet.
  • Try a different USB cable, just in case that is the problem.  Rare but it has happened that the USB cable isn’t suitable.

If the LED doesn’t come on after this, please reach out to our support team.

It is likely that Aerosensor is not correctly paired to your ANT+ sensors.

  • BLE/ANT+ sensors transmit as both BLE and ANT+ separately. You may have paired to the BLE sensor. In the Garmin go to the sensor, and check that you are paired to the ANT+ sensor.
  • Check that the ANT+ power meter AND EITHER speed OR speed and cadence sensor is paired properly. Ensure the sensors are on by rotating pedals/crank/wheel then check pass-pairing (in CIQ app go to Connections->Pass Pairing). When properly paired the SPD and PWR icons in the top right hand corner of the CIQ app will show green.

There are a few reasons Aerosensor may report an incorrect CdA value.

  • Check that you have entered an appropriate Aero Calibration factor in the CIQ app (Aerosensor settings->Parameters->Edit Parameters). For instructions on how to get this value see the quickstart guide.
  • Make sure you have calibrated the power meter.
  • Make sure that other Aerosensor parameters (in particular Total Mass, Wheel Circumference, Power meter scaling, Reference Crr) are correct.
  • If using a pedal based power meter, ensure that the crank length is set correctly in the Garmin Power Meter sensor settings.

If Aerosensor is not able to connect to the aerosensor updater then it is likely the USB-C cable is power only, not power + data. Try a different cable.

We have also noticed that USB-C to USB-C chargers don’t work for updater for this reason.

Aerobody

Aerodrome

If, when using Aerodrome, more laps are shown than expected, it is likely that you are experiencing drop-outs in the speed sensor.

This means that Aerosensor sporadically auto-laps independent of Aerodrome.

Try moving your magnet speed sensor to the front wheel, this should fix the issue.

Tutorial Videos

This area is currently in construction – stay tuned for more videos soon! 

Aerosensor Setup

In this video we show you how to setup our cycling aerodynamic drag measurement device, Aerosensor: From unboxing through to testing the setup on a turbo trainer.

Aerobody Setup

In this video we show you how to set Aerobody up on the bike, and use both the ACS Connect IQ (CIQ) app, and the Aerobody Datafield to set it up and view the data.

Excel Analysis Tool

Find out how to use our Aerosensor Excel Analysis Tool, enabling you to get the most of your aerodynamic cycling data and make conclusions about your testing quickly and with confidence.

This video takes you from installation on your Windows or Mac computers, through to loading, editing, and analysing the data.

Downloads

Demo FIT Files

Out-back FIT files

Download demo FIT files to try out-back analysis using our excel tool and other platforms.

Updated 20th February 2024.

Garmin Connect IQ Apps & Datafields

ACS App

Aerosensor Cycling System app lets you get the most from our unique system of aerodynamic development devices.

Aerobody Datafield

View your body position as you ride, in the context of your favourite data screens with a datafield dedicated to Aerobody.

Excel Tools

Excel tools for Windows and Mac

Import Aerosensor FIT files directly to excel, and perform basic out-back and velodrome analysis. V4.7 Now available!

Updated 29th February 2024.

Fit to CSV for Windows

Simple tool to convert FIT files directly into CSV files for import into excel or other software.

Trackside Lap Logger

Aerosensor lap logger

View and log lap data trackside on a Windows computer.

Updated 8th January 2024.

ANT+ dongle driver

Windows driver for ANT+ USB dongle.

Firmware Updater

Aerosensor Updater for Windows

Update your aerosensor and aerodrome firmware to the latest version using a Windows laptop or desktop computer.

  • Install .msi file
  • Run ‘AerosensorUpdater’
  • Plug in Aerosensor device via USB-C and click update.

Updated 28th March 2024 to V1.4

Aerosensor Updater for macOS

Update your aerosensor and aerodrome firmware to the latest version using an Apple Mac laptop or desktop computer.

 

Updated 11th April 2024 to V1.12

WKO Charts

WKO CHART

Chart layout for viewing Aerosensor data in WKO V4 or V5.

(01.11.23 Update)

Note that WKO does not show the lap or session data, only the record data, which is the time history.

CAD Files

The CAD files are provided for free use; however, users assume all associated risks. Aerosensor disclaims any responsibility for loss or injury resulting from the use of these files.

Current Aerosensor stay

Includes stay and fairing, plus assembly.

Updated Aerosensor stay

One-piece stay released February 2024.

Contact Us

We’re here to help and answer any questions you may have – please email us or ask the Aerosensor community on our discord forum. 

email
Email
support@aerosensor.tech
community
Discord

Members only discord forum

Aerosensor Store

Quickstart

What follows outlines the basic setup of Aerosensor.  For more detailed information please refer to the other articles on the left hand side. 

ACS Installation

Download the ACS app to your Garmin.  Go to Garmin ConnectIQ store and search for “Aerosensor” or use link below.

https://apps.garmin.com/en-US/apps/0170243b-0384-4072-9e85-57030e4949a6

ACS screen layout

  1. FIT file recording status:
    Red square = not recording.
    Green triangle = recording.
  2. Aerobody connection and battery status.
  3. Aerosensor connection status.
  4. Aerosensor power and speed or speed/cadence sensor connection status: Green = Connected. Orange = Searching. Red = Disconnected.
  5. Aerosensor battery status.
  6. Back key Use in menus use to go back a step, or on data screens exists app. This may be a button instead of touch screen icon depending on your Garmin Edge model.
  7. Menu key. This may be a button instead of touch screen icon depending on your Garmin Edge model.

Aerosensor Setup

  1. Install Aerosensor securely, level, and centred on the bike using a go-pro mount.
  2. Pair your power meter speed sensor to Garmin.  We recommend dual sided power meter, and magnet based speed sensor.
  3. Calibrate power meter in Garmin, and set crank length if necessary.
  4. Open ACS CIQ app on your Garmin bike computer.
  5. Choose test type:
    1. Road: for general road cycling.
    2. Out and back: for cycling out and back along a stretch of road.
    3. Velodrome trackless: for velodrome use without Aerodrome lap trigger.
    4. Velodrome tracked: for velodrome use with Aerodrome lap trigger.
  6. Connect Aerosensor to CIQ app.
    1. Turn on Aerosensor.  It should connect automatically.  If not:
    2. Menu > Connections > Aerosensor.
    3. Wait for CIQ app to find device, then click on it to connect.
  7. Input key parameters Menu > Aerosensor Settings > Parameters > Edit Parameters. Most important parameters to set are:
    1. Aero device calibration: Start with a value of 1.4.
    2. Total mass (your total mass i.e. you + bike + clothing)
    3. Wheel circumference You can get from speed sensor info in Garmin, or roll out wheel and measure distance on ground.
    4. Power meter scaling This accounts for drive train losses. Typically use 0.98 for all but hub based PMs
    5. CTF calibration offset Only necessary if using an SRM PM7 or earlier Power meter.  This is the value reported when you calibrate your power meter on the Garmin.
    Be sure to “Push Parameters” after exiting this menu to save any changes.
  8. Check connections, and start activity
    1. Make sure your power meter and speed sensor are on, by rotating wheel and pedals.
    2. If paired then “PWR” and “SPD” icons in top right go green.  If not see ACS instructions.
  9. Start activity
  10. Press the start activity button on Garmin to start recording to FIT file.  Note the red square in the top right corner turns to a green triangle.

That’s it!  You are now ready to go aero testing.  For accurate results be sure to calibrate your aerosensor every time you change bike or make a substantial change in your position. Don’t worry, you can do this at the same time as testing and post-correct your data, so no specific runs are necessary.  See next section.

Calibration

The air “sees” you coming towards it due to high pressure build up ahead of you. For this reason the air at Aerosensor’s location on your bike is slower than freestream. We need to correct for this.
  1. Perform at least two out/backs or 4 laps of velodrome. Be sure to start activity before starting this, and stop activity at the end.
  2. Select valid laps. Go to page 9 of the CIQ app, press menu, then either press up or down arrows or swipe up or down to select laps.  Press menu again to toggle valid (“X”) or invalid (no “X”).
  3. Read the average cal value (“Avg_Cal”).  You can either see this at the top of the lap page, or on page 10.
  4. Post-correct your CdA values by dividing them by this value.
    CdA_corrected = CdA_reported / Avg_cal
  5. Calculate new calibration factor
    AeroCal_New = AeroCal_Old x Avg_cal
  6. Enter new “Aero device calibration” in Aerosensor Settings.
    Menu > Aerosensor Settings > Parameters > Edit Parameters.

Aero testing guidance

Reliable aerodynamic testing is reliant on good testing protocols, focus on the following:

  • CdA data is only as accurate as the inputs. Make sure you check Aerosensor’s settings in the ACS app before every test.
  • Always calibrate power sensor before starting testing, and ideally before each set of laps or out-backs. Small calibration offsets can result in a big error in CdA measurement.
  • Always start and end your test block with a baseline repeat.
  • Try to maintain a constant speed through each run.
  • For out and back testing we recommend a stretch between 600 and 1000m.
  • The more out and backs you do, the better the repeatability will be.

Data Analysis

Data is recorded to FIT file.  You can view the data via various platforms:
  • Aerosensor Excel Analysis Tool
    Automated in-depth analysis in a macro-enabled Excel workbook, available from the downloads section.
  • Aerotune
    Online platform tailored for Aerosensor analysis. See Aerotune website.
  • Garmin Connect
    All Aerosensor data is visible as “Developer fields” on the Garmin Connect website, after your head units has synced.
  • WKO
    Workbook available from downloads section of our website.
  • Golden Cheetah
    We are working with Golden Cheetah developers to better support aero testing. Watch this space!

Aerosensor

Quickstart

What follows outlines the basic setup of Aerosensor.  For more detailed information please refer to the other articles on the left hand side. 

ACS Installation

Download the ACS app to your Garmin.  Go to Garmin ConnectIQ store and search for “Aerosensor” or use link below.

https://apps.garmin.com/en-US/apps/0170243b-0384-4072-9e85-57030e4949a6

ACS screen layout

  1. FIT file recording status:
    Red square = not recording.
    Green triangle = recording.
  2. Aerobody connection and battery status.
  3. Aerosensor connection status.
  4. Aerosensor power and speed or speed/cadence sensor connection status: Green = Connected. Orange = Searching. Red = Disconnected.
  5. Aerosensor battery status.
  6. Back key Use in menus use to go back a step, or on data screens exists app. This may be a button instead of touch screen icon depending on your Garmin Edge model.
  7. Menu key. This may be a button instead of touch screen icon depending on your Garmin Edge model.

Aerosensor Setup

  1. Install Aerosensor securely, level, and centred on the bike using a go-pro mount.
  2. Pair your power meter speed sensor to Garmin.  We recommend dual sided power meter, and magnet based speed sensor.
  3. Calibrate power meter in Garmin, and set crank length if necessary.
  4. Open ACS CIQ app on your Garmin bike computer.
  5. Choose test type:
    1. Road: for general road cycling.
    2. Out and back: for cycling out and back along a stretch of road.
    3. Velodrome trackless: for velodrome use without Aerodrome lap trigger.
    4. Velodrome tracked: for velodrome use with Aerodrome lap trigger.
  6. Connect Aerosensor to CIQ app.
    1. Turn on Aerosensor.  It should connect automatically.  If not:
    2. Menu > Connections > Aerosensor.
    3. Wait for CIQ app to find device, then click on it to connect.
  7. Input key parameters Menu > Aerosensor Settings > Parameters > Edit Parameters. Most important parameters to set are:
    1. Aero device calibration: Start with a value of 1.4.
    2. Total mass (your total mass i.e. you + bike + clothing)
    3. Wheel circumference You can get from speed sensor info in Garmin, or roll out wheel and measure distance on ground.
    4. Power meter scaling This accounts for drive train losses. Typically use 0.98 for all but hub based PMs
    5. CTF calibration offset Only necessary if using an SRM PM7 or earlier Power meter.  This is the value reported when you calibrate your power meter on the Garmin.
    Be sure to “Push Parameters” after exiting this menu to save any changes.
  8. Check connections, and start activity
    1. Make sure your power meter and speed sensor are on, by rotating wheel and pedals.
    2. If paired then “PWR” and “SPD” icons in top right go green.  If not see ACS instructions.
  9. Start activity
  10. Press the start activity button on Garmin to start recording to FIT file.  Note the red square in the top right corner turns to a green triangle.

That’s it!  You are now ready to go aero testing.  For accurate results be sure to calibrate your aerosensor every time you change bike or make a substantial change in your position. Don’t worry, you can do this at the same time as testing and post-correct your data, so no specific runs are necessary.  See next section.

Calibration

The air “sees” you coming towards it due to high pressure build up ahead of you. For this reason the air at Aerosensor’s location on your bike is slower than freestream. We need to correct for this.
  1. Perform at least two out/backs or 4 laps of velodrome. Be sure to start activity before starting this, and stop activity at the end.
  2. Select valid laps. Go to page 9 of the CIQ app, press menu, then either press up or down arrows or swipe up or down to select laps.  Press menu again to toggle valid (“X”) or invalid (no “X”).
  3. Read the average cal value (“Avg_Cal”).  You can either see this at the top of the lap page, or on page 10.
  4. Post-correct your CdA values by dividing them by this value.
    CdA_corrected = CdA_reported / Avg_cal
  5. Calculate new calibration factor
    AeroCal_New = AeroCal_Old x Avg_cal
  6. Enter new “Aero device calibration” in Aerosensor Settings.
    Menu > Aerosensor Settings > Parameters > Edit Parameters.

Aero testing guidance

Reliable aerodynamic testing is reliant on good testing protocols, focus on the following:

  • CdA data is only as accurate as the inputs. Make sure you check Aerosensor’s settings in the ACS app before every test.
  • Always calibrate power sensor before starting testing, and ideally before each set of laps or out-backs. Small calibration offsets can result in a big error in CdA measurement.
  • Always start and end your test block with a baseline repeat.
  • Try to maintain a constant speed through each run.
  • For out and back testing we recommend a stretch between 600 and 1000m.
  • The more out and backs you do, the better the repeatability will be.

Data Analysis

Data is recorded to FIT file.  You can view the data via various platforms:
  • Aerosensor Excel Analysis Tool
    Automated in-depth analysis in a macro-enabled Excel workbook, available from the downloads section.
  • Aerotune
    Online platform tailored for Aerosensor analysis. See Aerotune website.
  • Garmin Connect
    All Aerosensor data is visible as “Developer fields” on the Garmin Connect website, after your head units has synced.
  • WKO
    Workbook available from downloads section of our website.
  • Golden Cheetah
    We are working with Golden Cheetah developers to better support aero testing. Watch this space!

Important notes & prerequisites

Important notes

Aerosensor is designed for outdoor paved roads or velodrome use in dry conditions and is therefore not suitable for wet conditions.

The device is not waterproof as it has holes to allow pressure measurement.

Aerosensor must be removed in wet conditions. If you think it will rain whilst you are out riding or the road may be wet in places then take a 3mm hex key with you so you can remove the device and put it in your jersey pocket for the rest of your ride.

Aerosensor will vibrate on rough paved roads. This has no negative impact on measurement quality. However if excessive vibrations occur, or if Aerosensor pitches down after use, please check the got-pro mount screw was sufficiently tight.

Clean Aerosensor with a soft, dry cloth. Avoid using abrasive materials or harsh chemicals that may damage the product’s surface.

Prerequisites

Aerosensor requires an ANT+ power and either bike speed or bike speed + cadence sensor. It also requires a Garmin cycling computer.

Bike Computer

Currently to use the ACS you will need a Garmin bike computer that can run Garmin Connect IQ applications at a minimum of SDK 3.1.0. A full list of compatible devices is available on the link below – be sure to check that the device has the “A” symbol, meaning apps.

https://developer.garmin.com/connect-iq/compatible-devices/ 

We will make data fields in the future, allowing you to see data in the standard Garmin context, and also on the Edge 130.

Power Meter (PWR)

Aerosensor requires a quality power meter. Single sided pedal-based power meters are not sufficiently accurate for good aerodynamic data. Remember that the aero data you get will only be as accurate as the power meter used.  

Speed (SPD) or Speed/Cadence (BSC) Sensor

For the best accuracy we highly recommend a magnet-based speed sensor. Hub mounted speed sensors or GPS based speed sensors do not have the time resolution necessary for high quality aerodynamic data.

Device mounts

Aerosensor has been designed to work on a variety of different bike bar types, notably the following:

  1. Drop handlebars – usually standard on road bikes and track bikes.
  2. Clip-on time-trial (TT) bars – additions to road and track bikes.
  3. Integrated TT handlebar/cockpit – mostly seen on TT and triathlon specific bikes.

A go-pro mount is required to install Aerosensor – for example one underneath a bike computer mount (sold separately, available on our website in Accessories).

Whilst Aerosensor can be used on most bike setups, there will be some bar variants that may be trickier to setup. Please do not hesitate to contact us at hello@Aerosensor.tech with any questions or for advice on how to best mount onto your bike.

Device basics

Specifications

Dimensions (H x W x D)

135 x 57 x 85mm

Mass

66g

Battery Life

57 hours

Wind speed resolution

+/- 0.1%

Wind angle resolution

+/- 0.1°

Altitude resolution

+/- 10cm

Layout

  1. LED
  2. Power button
  3. Reset button
  4. USB-C bung & charging port
  5. Stem
  6. Height/yaw adjustment screw
  7. Go-pro mount

Button functions

  • Power button:
    • Press and release to turn on.
    • Press and hold until LED turns off then release to shut down.
    • Press and hold, push reset button, then release for full factory reset. This resets the internal settings used to calculate CdA.
  • Reset button:
    • To be used in case the device becomes unresponsive. Resets device without erasing settings.

LED significance

The multi-colour LED indicates the device state as shown below:

Colour

Flashing

State

USB

Charge

Aqua

Normal

On

Unplugged

Normal

Red

Normal

On

Unplugged

Low

Amber

Slow

Off

Plugged in

Charging

Amber

Solid

On

Plugged in

Charging

Green

Slow

Off

Plugged in

Charged

Green

Solid

On

Plugged in

Charged

Note: Do not use sharp objects or tools to press buttons, this may result in damage. 

Installation

Use the go-pro mount itself to adjust pitch, then the yaw by loosening the height/yaw screw on Aerosensor’s stem (height adjuster) and rotating the unit. 

Do not use the aerosensor base to pivot, this can cause damage to the stem.

When installing, it is important to have Aerosensor as far forward and low as possible that the stem allows to minimise influence of rider position.

  • The base must be at least 20mm above the front wheel.
  • It should be centred on the bike and facing forwards. Use the front wheel as a reference for yaw alignment.
  • Aerosensor should be level – use a horizontal object to the side of the bike (like floor markings), and visually align the bottom of Aerosensor with the horizontal line. An example is shown below, where a horizontal line on the wall is used. Note that the device is tolerant to pitch misalignment within +/-5°.

CIQ App

Aerosensor Connection

Make sure that Aerosensor is switched on.

1.    Press the menu button on the Garmin head unit.

2.    Select “Connections” -> “Aerosensor”.

ACS-2

3. Select the device you want to connect to. Note: it is worth keeping a note of the Device ID for your Aerosensor and Aerobody for your records, especially if you are a coach and have multiple devices for your riders.

Pass-pairing

Pass-pairing is where ACS transmits the power meter and speed sensor ANT+ connection details to Aerosensor, allowing it to connect to them directly. 

For this to work the Garmin unit should already be paired with the ANT+ sensors you are using.

Note that Aerosensor requires a power meter (PWR) AND EITHER a speed sensor (SPD) OR speed + cadence sensor (BSC).

The CIQ app should automatically pass on the sensor connections to Aerosensor.  In case this does not work, or you have multiple sensors on the bike, follow these steps:

  1. Ensure that a power meter and speed sensor are installed on the bike and paired with the Garmin. Make sure they are on by rotating the wheel and/or pedals/crank, depending on the power meter.
  2. In the ACS menu, select “Connections”->”Pass pair” which will bring up the following screen:
ACS-3

3. Either select the devices individually or select the bottom “Enter to sync” button in purple above. After a short period, the status bar at the bottom of the screen should go green to show Aerosensor matches the Garmin device.  Aerosensor connection status icons should go from red to green.

ACS-4

Aerosensor Parameters

To accurately calculate aerodynamic drag, Aerosensor requires some information about you and your bike:

  1. Aero device calibration: This accounts for the fact that the wind slows as it approaches the bike, so the wind speed measured by Aerosensor is always slower than the air far upstream of the bike. Start with a value of 1.4. Typically we see values beweeen 1.1 and 1.45. See ‘Quickstart’ section for more information.
  2. Total mass (kg): includes rider + bike + all accessories used whilst riding with Aerosensor.
  3. Wheel Circumference (mm). If unknown, you can go into the speed sensor settings on the Garmin and you will find the wheel circumference in there once you have ridden far enough for the Garmin to calibrate against GPS.
  4. Power meter scaling: Default value is 1.0. If using pedals or crank we need to account for drivetrain losses.  A typical value would be 0.98, i.e. 2% drivetrain loss.
  5. CTF calibration offset: Used for CTF power meters.
  6. Time av period: This is the time period used by Aerosensor to average the CdA value, default is 30 seconds.
  7. Reference Crr: Rolling resistance coefficient (used if known), default 0.004. For an indoor velodrome you should use 0.002 (half the road value).  You can find typical crr values for a range of tyres at https://www.bicyclerollingresistance.com/
  8. Valid speed min: minimum speed (kph) for valid CdA automatic lapping. The CdA calculation is started when you go above this speed, and stopped when you slow down below this speed.  The device automatically creates laps for each CdA measurement period.

Editing Parameters:

It is important you check these frequently, especially total mass and wheel circumference if changing between bikes for example.

Velodrome testing – Track layout

When Aerosensor is in track calculation mode it uses lap distance and speed to calculate lean angle to compensate for centre of gravity location.  This only works when Aerodrome is being used. A typical track layout is shown below, of which you can input the track measurements by editing parameters directly in the CIQ app.

You can measure the track by measuring relative distance of corner start and end, using the distance markers along the track. This does not need to be very accurate – within a few meters is fine.

Measuring the track:

  1. Measure the distance from the tapeswitch location to the start and end of each corner.
  2. Use these to calculate the total distance of the two straight sections.
  3. Corner length = track length – total straight lengths
  4. Corner radius = corner length / pi
  5. Transition length is the distance it takes for the rider to transition from the straight to the corner. Typical value is 10m.

Example:

  • Total track length = 250m.
  • C1 start = 10m
  • C1 end = 95m
  • C2 start = 135m
  • C2 end = 220m
  • Corner length = C1 end – C1 start – transition= 95 – 10 – 10 = 75m
  • Corner radius = 75/pi = 23.9m

Editing Parameters:

Velodrome testing – Calculation mode

At the velodrome Aerosensor can ignore the barometer, since elevation is roughly constant, and should use the track map. If the track map is not known, or Aerodrome is not available, you can use the trackless mode. To use Velodrome mode:
  1. Go to Menu-> Aerosensor Settings->Calculation Mode.
  2. Select the model you require:
    1. Road
      For road riding.
    2. Velodrome Trackless
      Assumes constant elevation but ignores track layout. This is for when you are not using a lap trigger (Aerodrome) or the track layout is unknown.
    3. Velodrome Tracked
      Assumes constant elevation AND uses the track layout. This is for when you are using Aerodrome and know the track layout, as entered in ‘Aerosensor Settings->Track’.
  3. Wait until the mode changes as required, in the menu heading.
Screen sequence shown below:

Aerosensor demo mode

This is for diagnostic purposes and can generally be ignored.

Aerosensor information

Go to Menu -> Aerosensor settings -> about

Here you can see information about your Aerosensor device, including battery level, firmware version and serial number. Battery voltage is also included as it is useful for diagnostic purposes.

Aerosensor Setup

In this video we show you how to setup our cycling aerodynamic drag measurement device, Aerosensor: From unboxing through to testing the setup on a turbo trainer.

Important notes & prerequisites

Important notes

Aerosensor is designed for outdoor paved roads or velodrome use in dry conditions and is therefore not suitable for wet conditions.

The device is not waterproof as it has holes to allow pressure measurement.

Aerosensor must be removed in wet conditions. If you think it will rain whilst you are out riding or the road may be wet in places then take a 3mm hex key with you so you can remove the device and put it in your jersey pocket for the rest of your ride.

Aerosensor will vibrate on rough paved roads. This has no negative impact on measurement quality. However if excessive vibrations occur, or if Aerosensor pitches down after use, please check the got-pro mount screw was sufficiently tight.

Clean Aerosensor with a soft, dry cloth. Avoid using abrasive materials or harsh chemicals that may damage the product’s surface.

Prerequisites

Aerosensor requires an ANT+ power and either bike speed or bike speed + cadence sensor. It also requires a Garmin cycling computer.

Bike Computer

Currently to use the ACS you will need a Garmin bike computer that can run Garmin Connect IQ applications at a minimum of SDK 3.1.0. A full list of compatible devices is available on the link below – be sure to check that the device has the “A” symbol, meaning apps.

https://developer.garmin.com/connect-iq/compatible-devices/ 

We will make data fields in the future, allowing you to see data in the standard Garmin context, and also on the Edge 130.

Power Meter (PWR)

Aerosensor requires a quality power meter. Single sided pedal-based power meters are not sufficiently accurate for good aerodynamic data. Remember that the aero data you get will only be as accurate as the power meter used.  

Speed (SPD) or Speed/Cadence (BSC) Sensor

For the best accuracy we highly recommend a magnet-based speed sensor. Hub mounted speed sensors or GPS based speed sensors do not have the time resolution necessary for high quality aerodynamic data.

Device mounts

Aerosensor has been designed to work on a variety of different bike bar types, notably the following:

  1. Drop handlebars – usually standard on road bikes and track bikes.
  2. Clip-on time-trial (TT) bars – additions to road and track bikes.
  3. Integrated TT handlebar/cockpit – mostly seen on TT and triathlon specific bikes.

A go-pro mount is required to install Aerosensor – for example one underneath a bike computer mount (sold separately, available on our website in Accessories).

Whilst Aerosensor can be used on most bike setups, there will be some bar variants that may be trickier to setup. Please do not hesitate to contact us at hello@Aerosensor.tech with any questions or for advice on how to best mount onto your bike.

Aerobody Setup

In this video we show you how to set Aerobody up on the bike, and use both the ACS Connect IQ (CIQ) app, and the Aerobody Datafield to set it up and view the data.

Aerobody

Quickstart

What follows outlines the basic setup of Aerobody.  For more detailed information please refer to the other articles on the left hand side. 

ACS Installation

Download the ACS app to your Garmin.  Go to Garmin ConnectIQ store and search for “Aerosensor” or use link below.

https://apps.garmin.com/en-US/apps/0170243b-0384-4072-9e85-57030e4949a6

ACS screen layout

  1. FIT file recording status:
    Red square = not recording.
    Green triangle = recording.
  2. Aerobody connection and battery status.
  3. Aerosensor connection status.
  4. Aerosensor power and speed or speed/cadence sensor connection status: Green = Connected. Orange = Searching. Red = Disconnected.
  5. Aerosensor battery status.
  6. Back key Use in menus use to go back a step, or on data screens exists app. This may be a button instead of touch screen icon depending on your Garmin Edge model.
  7. Menu key. This may be a button instead of touch screen icon depending on your Garmin Edge model.

Aerobody setup

 

1.    Install device using Garmin ¼-turn mount.

2.    Position device. Using your hand to check, rotate Aerobody so the head sensor is picking up your chin. Tighten mount screw to lock in position.

3.    Open either ACS or Aerobody datafield on Garmin device.

4.    Connect Aerobody to CIQ app.

a. Turn on Aerobody.  It should connect automatically.  If not:

b. Menu > Connections > Aerobody.

c. Wait for CIQ app to find device, then click on it to connect.

5.      Set your datum position using the app or datafield.

Data Analysis

Data is recorded to FIT file.  You can view the data via various platforms:
  • Aerosensor Excel Analysis Tool
    Automated in-depth analysis in a macro-enabled Excel workbook, available from the downloads section.
  • Aerotune
    Online platform tailored for Aerosensor analysis. See Aerotune website.
  • Garmin Connect
    All Aerosensor data is visible as “Developer fields” on the Garmin Connect website, after your head units has synced.
  • WKO
    Workbook available from downloads section of our website.
  • Golden Cheetah
    We are working with Golden Cheetah developers to better support aero testing. Watch this space!

Device basics

Specifications

Dimensions (H x W x D)

36 x 32 x 64mm

Mass

37g

Battery Life

9 hours

Head position resolution

+/- 1mm

Chest position resolution

+/- 1mm

Layout

  1. LED
  2. Power button
  3. Reset button
  4. USB-C bung & charging port
  5. Head sensor
  6. Chest sensor
  7. Quarter-turn mount

Button functions

  • Power button:
    • Press and release to turn on.
    • Press and hold until LED turns off then release to shut down.
  • Reset button:
    • To be used in case the device becomes unresponsive.

LED significance

The multi-colour LED indicates the device state as shown below:

Colour

Flashing

State

USB

Charge

Aqua

Normal

On

Unplugged

Normal

Red

Normal

On

Unplugged

Low

Amber

Slow

Off

Plugged in

Charging

Amber

Solid

On

Plugged in

Charging

Green

Slow

Off

Plugged in

Charged

Green

Solid

On

Plugged in

Charged

Note: Do not use sharp objects or tools to press buttons, this may result in damage. 

Important notes & prerequisites

Important notes

Aerobody uses optical sensors for measuring your body position, so keeping the sensor lenses clean and free from debris is critical for good performance.

The USB port should be kept dry and free from debris. After charging, please ensure that the bung is replaced firmly.

Although Aerobody is splashproof, it is not designed to operate in wet conditions. Please ensure it is removed if outdoors and raining.

Clean Aerobody with a soft, dry cloth. Avoid using abrasive materials or harsh chemicals that may damage the product’s surface.

Prerequisites

Aerobody doesn’t require any other devices to work; you will need a Garmin cycling computer however.

Device mounts

Aerobody has been designed to work on a variety of different bike bar types, notably the following:

  1. Drop handlebars – usually standard on road bikes and track bikes.
  2. Clip-on time-trial (TT) bars – additions to road and track bikes.
  3. Integrated TT handlebar/cockpit – mostly seen on TT and triathlon specific bikes.

Aerobody is supplied with a quarter-turn mount suitable for most bike setups.

Whilst Aerobody can be used on most bike setups, there will be some bar variants that may be trickier to setup. Please do not hesitate to contact us at hello@Aerosensor.tech with any questions or for advice on how to best mount onto your bike.

Installation

Aerobody has a standard Garmin quarter-turn mount. It should be positioned on the stem using a compatible bike mount adapter such as the one supplied with the unit. The screw on the quarter-turn mount allows pitch adjustment of the entire unit.

The forward (head) sensor should be aligned approximately with the chin and the chest sensor points at the chest.

To align, support the bike either in a turbo trainer, or by asking someone to support the bike.  Sitting on the bike in your normal riding position watch the display whilst moving two fingers up and down from your chin towards the unit, and ensure that the measurement tracks movement of your fingers.

CIQ App

Aerobody Connection

Make sure that Aerobody is switched on.

  1. Press the menu button on the Garmin head unit.
  2. Select “Connections” -> “Aerobody”.
4. Connect device

3. Select the device you want to connect to. Note: it is worth keeping a note of the Device ID for your Aerobody for your records, especially if you are a coach and have multiple devices for your riders.

Set Reference

The CIQ app shows your body position relative to a reference which you can set as follows:

  1. Got to Menu-> Aerobody Settings->Set Reference.
  2. Get into your ideal position on the bike. To do this support the bike in a turbo trainer, or ask someone to support it for you, and get into your normal riding position.
  3. Select “Measure”. This will give you a 5 second countdown to get in position, then will take a 2 second average of your position. When complete the measurements will show in red to indicate the new values are unsaved, and the “Save” button will be highlighted.
  4. Click “Save” to send the new position to Aerobody. Wait for the head and chest display to update to green, and the save button to turn grey and show “Saved”.
5. Set datum
AEROBODY QUICKSTART-8

Set Null Zone

The body position fields in the CIQ app will turn red if you are higher, or blue if you are lower, than your reference position. It will be white if you are within a set “null zone” around your reference position. As an example, a 1.5cm null zone means that the rider moving between -1.5cm and +1.5cm of their reference head or chest position will remain white whilst riding. Anything outside of these values are considered “out of position” will be red or blue depending if you are too high or too low.

The null zone may be set as follows:

  1. Got to Menu-> Aerobody Settings->Set Null Zone.
  2. The buttons can be used to adjust in multiples of 1cm and 0.1cm as necessary.
  3. Click “Save” to send the new position to Aerobody.

Aerobody information

Got to Menu -> Aerobody settings -> About

Here you can see information about your Aerobody device, including battery level, firmware version and serial number. Battery voltage is also included as it is useful for diagnostic purposes.

CIQ Datafield

Please refer to the Aerobody CIQ Datafield section here.

Aerodrome

Quickstart

What follows outlines the basic setup of Aerodrome. For more detailed information please refer to the other articles on the left hand side. 

ACS Installation

Download the ACS app to your Garmin.  Go to Garmin ConnectIQ store and search for “Aerosensor” or use link below.

https://apps.garmin.com/en-US/apps/0170243b-0384-4072-9e85-57030e4949a6

ACS screen layout

  1. FIT file recording status:
    Red square = not recording.
    Green triangle = recording.
  2. Aerobody connection and battery status.
  3. Aerosensor connection status.
  4. Aerosensor power and speed or speed/cadence sensor connection status: Green = Connected. Orange = Searching. Red = Disconnected.
  5. Aerosensor battery status.
  6. Back key Use in menus use to go back a step, or on data screens exists app. This may be a button instead of touch screen icon depending on your Garmin Edge model.
  7. Menu key. This may be a button instead of touch screen icon depending on your Garmin Edge model.

Aerodrome Setup

  1. Install tapeswitch across track, securing with duck tape.
  2. Position Aerodrome about 1-2 meters downstream of the tapeswitch, close to track, oriented so that the buttons are closest to the track as shown.
  3. Ensure Aerodrome blue light is flashing
    When Aerosensor is on and within a few meters of the Aerodrome the light will flash to show it is able to communicate with it. This ensures radio signal is strong enough to work.  It only needs to pick up Aerosensor’s signal for 1-2 meters after the tapeswitch is crossed.
  4. Open ACS in “Velodrome Tracked” mode.
    This assumes no elevation changes, and uses the trackmap to correct for cyclist lean angle.
  5. Edit track map in ACS.
    See section in CIQ app documentation.
Remember to start an activity on the Garmin before starting to ride. Aerosensor will automatically create new laps every time you cross the tapeswitch. Note that the data appears on the Garmin a couple of seconds after the end of lap, once Aerosensor has finished averaging data for the lap.

Aero testing guidance

Reliable aerodynamic testing is reliant on good testing protocols.  Here are a few tips for best results.
  • CdA data is only as accurate as the inputs. Make sure you check Aerosensor’s settings in the ACS app before every test.
  • Always calibrate power sensor before starting testing. Small calibration offsets can result in a big error in CdA measurement.
  • Always start and end your test block with a baseline repeat.
  • Try to maintain a constant speed through each run.
  • For velodrome testing we recommend 6-8 laps per configuration.
  • The more laps you do, the better the repeatability will be.

Data Analysis

Data is recorded to FIT file.  You can view the data via various platforms:
  • Aerosensor Excel Analysis Tool
    Automated in-depth analysis in a macro-enabled Excel workbook, available from the downloads section.
  • Aerotune
    Online platform tailored for Aerosensor analysis. See Aerotune website.
  • Garmin Connect
    All Aerosensor data is visible as “Developer fields” on the Garmin Connect website, after your head units has synced.
  • WKO
    Workbook available from downloads section of our website.
  • Golden Cheetah
    We are working with Golden Cheetah developers to better support aero testing. Watch this space!

Device basics

Specifications

Dimensions (H x W x D)

34 x 76 x 76mm

Mass

66g

Battery Life

28 hours

Timing resolution

+/- 1ms

Layout

  1. Power button
  2. LED
  3. Reset button
  4. USB-C charging port
  5. Tapeswitch port

Button functions

  • Power button:
    • Press and release to turn on.
    • Press and release to shut down.
  • Reset button:
    • To be used in case the device becomes unresponsive.

LED significance

The multi-colour LED indicates the device state as shown below:

Colour

Flashing

State

USB

Charge

Cyan

Solid

On

Unplugged

Normal

Lilac

Solid

Trigger

N/A

N/A

Amber

Solid

On

Charger

Low

Green

Solid

Off

Charger

Charging

Blue

Solid

On

Computer

Charging

Light blue

Solid

Off

Computer

Charged

Any

Flash

On

Aerosensor connected

Note: Do not use sharp objects or tools to press buttons, this may result in damage. 

Important notes & prerequisites

Important notes

Aerodrome uses a Tapeswitch cable as a lap trigger – the cable should not be pinched or bent. Bending with a bend radius less than 4mm will permanently damage the product.

The USB port and Tapeswitch port should be kept dry and free from debris.

Although Aerodrome is splashproof, it is not designed to operate in wet conditions.  Please ensure it is not used outdoors when it is raining.

Clean Aerodrome with a soft, dry cloth. Avoid using abrasive materials or harsh chemicals that may damage the product’s surface.

Prerequisites

Aerodrome requires Aerosensor device and a Garmin cycling computer.

Installation

As Aerodrome will likely be used on a live track or a public road, it is critical that you have permission to use the device and/or have taken appropriate measures to ensure not only the safety of you and other riders, but also to prolong the life of the device itself.

The tapeswitch should be placed so that the flat side is against the track or road, and the ridge on the upper side. Using duck tape, secure the tapeswitch across the line the cyclist will be following, be it on the track or the road. Secure at the far ends with tape, and placing a further piece of tape along the length, just holding down the upstream side of the tapeswitch.

Tape along the tapeswitch, not across it (as below).

Aerodrome listens for Aerosensor and the LED flashes when it receives data. It is only able to transmit the lap trigger when this is happening.

For optimal radio performance, make sure Aerodrome is situated in a position where it can receive data from Aerosensor when bike is at or just past the Tapeswitch. It is normally best to position 1-2m downstream of where the lap trigger is placed.  Orient the device so that the buttons are closest to the track, as shown in images below.

Plug the tapeswitch plug into the Aerodrome socket and turn on. The power light should illuminate.  You can check it is working by pressing on the tapeswitch. The LED will turn purple for 1 second to indicate a lap trigger.

Aerodrome should be placed on the floor well clear of any area the rider is likely to pass.  Secure the tapeswitch cable to the floor with duck tape to avoid trip hazards.

Note that currently Aerodrome cannot distinguish between multiple Aerosensor’s running on track.  It will only work correctly when a single rider is on track.

1. Install tapeswitch
2. Position Aerodrome

CIQ App

Aerodrome Connection

Aerodrome uses Aerosensor, so no specific settings are required in the CIQ App.

Please refer to the Aerosensor section here.

Device basics

Specifications

Dimensions (H x W x D)

135 x 57 x 85mm

Mass

66g

Battery Life

57 hours

Wind speed resolution

+/- 0.1%

Wind angle resolution

+/- 0.1°

Altitude resolution

+/- 10cm

Layout

  1. LED
  2. Power button
  3. Reset button
  4. USB-C bung & charging port
  5. Stem
  6. Height/yaw adjustment screw
  7. Go-pro mount

Button functions

  • Power button:
    • Press and release to turn on.
    • Press and hold until LED turns off then release to shut down.
    • Press and hold, push reset button, then release for full factory reset. This resets the internal settings used to calculate CdA.
  • Reset button:
    • To be used in case the device becomes unresponsive. Resets device without erasing settings.

LED significance

The multi-colour LED indicates the device state as shown below:

Colour

Flashing

State

USB

Charge

Aqua

Normal

On

Unplugged

Normal

Red

Normal

On

Unplugged

Low

Amber

Slow

Off

Plugged in

Charging

Amber

Solid

On

Plugged in

Charging

Green

Slow

Off

Plugged in

Charged

Green

Solid

On

Plugged in

Charged

Note: Do not use sharp objects or tools to press buttons, this may result in damage. 

Garmin CIQ Apps & Datafields

Aerosensor Cycling System CIQ App

Overview

The Aerosensor Aerodynamic Cycling System (ACS) Connect IQ app is required to seamlessly integrate our devices with your Garmin bike computer, providing real-time aerodynamic data and further insights during your ride, and recording your data to a FIT file for further analysis.

Installation

  1. The Aerosensor ACS CIQ app can be downloaded from the Garmin Connect IQ website:

https://apps.garmin.com/

  1. Simply search for “Aerosensor” and the app will come up, or use this link:

https://apps.garmin.com/en-US/apps/0170243b-0384-4072-9e85-57030e4949a6

  1. Install to the Garmin head unit as per the instructions on the CIQ app website.
  2. Start ACS by going to the Connect IQ menu on your Garmin (see Garmin instructions) and then selecting “Aerosensor ACS”.

ACS screen layout

  1. FIT file recording status:
    Red square = not recording
    Green triangle = recording.
  2. Aerobody connection and battery status.
  3. Aerosensor connection status.
  4. Aerosensor power and speed or speed/cadence sensor connection status:
    Green = Connected.
    Orange = Searching.
    Red = Disconnected.
  5. Aerosensor battery status.
  6. Back key
    Use in menus use to go back a step, or on data screens exists app. This may be a button instead of touch screen icon depending on your Garmin Edge model.
  7. Menu key.
    This may be a button instead of touch screen icon depending on your Garmin Edge model.

Aerobody CIQ Datafield

Overview

Aerobody is a device that mounts on your stem and measures the distance to your head and chest. This is a good indication of your overall body position.

The Aerobody datafield allows you to view your body position data in the context of your normal Garmin views. You can add it in the same way you would add any other data such as speed, power, time etc. It also adds your aerobody data to the fit file so you can view it after your ride.

Installation

Search for Aerobody on the ConnectIQ store and follow instructions to install. 

  • Once installed, on your Garmin select the data screen (in your chosen activity profile) and edit the field where you want the data to appear.
  • Select Connect IQ from the list.
  • Select Aerobody from the list.

Note that aerobody really needs a full screen width field to display correctly as it displays both head and chest positions.

Pairing

Turn on your Aerobody device.

The Aerobody datafield will automatically connect to the first Aerobody signal it picks up.  It saves this so that next time it will look for the same physical device.

If you need to switch to a different Aerobody device, firstly make sure that only that one is switched on and in range (roughly 10m) of the Garmin unit, the follow the following steps.

  • Make sure that Garmin Connect app is installed on your phone and paired with your Edge unit.
  • Turn on your Garmin and the Aerobody device.
  • In either Garmin Connect or the Garmin ConnectIQ app, select your device, then go find the datafield app. Open settings.
  • Move the slider next to “Reset paired device” to the right.
  • Click “Save”. The display on the Garmin should show “Reconnecting” for 3 seconds then switch back to the data view.  Ensure that a surface is within 300mm of the Aerobody device in order to make sure it is reading data.
AEROBODY DATAFIELD-4
AEROBODY DATAFIELD-5
AEROBODY DATAFIELD-6

Setting datum

Aerobody allows you to set a datum, which you can think of as a target position for you to maintain whilst riding. The head and chest fields will go red if you go above this; blue if below, outside of a “null zone”, the dimensions of which you can modify in the settings.  You can also set an audible alert to warn you when you are outside of your target range. By default the relative position is shown in the fields, which is the distance between your current position and the datum.  This can be changed to absolute position in the datafield settings.
To set your datum, follow these steps:
  • Get on the bike, ready to get into position. Use a turbo-trainer or friend to support it.
  • In settings, put the “Set datum” slider to the right. Click “Save”.
  • On the datafield it will give you a countdown of 3 seconds to get into position.
  • The datafield It will then average your position and save it.
Now when you are in the correct position the display should have an uncoloured background.  If you are too low it goes blue; too high it goes red.
AEROBODY DATAFIELD-7
AEROBODY DATAFIELD-8
AEROBODY DATAFIELD-9

Excel Analysis Tool

Find out how to use our Aerosensor Excel Analysis Tool, enabling you to get the most of your aerodynamic cycling data and make conclusions about your testing quickly and with confidence.

This video takes you from installation on your Windows or Mac computers, through to loading, editing, and analysing the data.

Installation

Use the go-pro mount itself to adjust pitch, then the yaw by loosening the height/yaw screw on Aerosensor’s stem (height adjuster) and rotating the unit. 

Do not use the aerosensor base to pivot, this can cause damage to the stem.

When installing, it is important to have Aerosensor as far forward and low as possible that the stem allows to minimise influence of rider position.

  • The base must be at least 20mm above the front wheel.
  • It should be centred on the bike and facing forwards. Use the front wheel as a reference for yaw alignment.
  • Aerosensor should be level – use a horizontal object to the side of the bike (like floor markings), and visually align the bottom of Aerosensor with the horizontal line. An example is shown below, where a horizontal line on the wall is used. Note that the device is tolerant to pitch misalignment within +/-5°.

Testing

General Riding

Riding with Aerosensor

Always make sure you calibrate your power meter before starting a ride.  You must do this on the Garmin outside of the CIQ app.

Always run the CIQ app whilst riding to view and record your Aerosensor or Aerobody data.

Press the “start/stop activity” button on the Garmin to start recording data to fit file.

When your cycling speed exceeds the preset “Valid speed min” speed a new lap will be started and the CdA field will show a countdown to when data will be available. If the averaging time is set to 30s then this will count down from 30s to zero.  When it reaches zero the live CdA value will be shown.

As well as CdA, a “lap CdA” value is shown on some screens. This shows the average CdA over the current lap, and is available from 10 seconds after the valid speed is hit.

When you slow down again the lap will be finished, either by dropping below the minimum speed, or by braking hard. The lap CdA for the last lap will be available.

Don’t forget to press the “start/stop activity” button again to end the recording.

Out-back / road testing

Overview

  • For more accurate aerodynamic testing outdoors, when a track is not available, you should ride in both directions along an ideally quiet section of road.  The wind generated by passing traffic will degrade the measurement.
  • The road section does not need to be straight, but tight corners should be avoided.  You should aim to be able to ride at a roughly constant speed and power during the test.
  • The more out and backs you perform, the more accurate your CdA will be.

Protocol

  1. Press the “start/stop activity” button on the Garmin to start recording data to fit file.
  2. You should ride in one direction along the road stretch for between 500m and 1km. The longer the better.  At the end of your segment, brake sharply, turn around and then ride back the other way back to your starting point. For the turnaround ride slowly (below your preset minimum speed) for at least ten seconds to ensure the lapping process works properly.
  3. During each out or back segment, aim to maintain a constant position on the bike, and ideally a constant speed.
  4. Don’t forget to press the “start/stop activity” button again to end the recording.

The more out and backs you perform, the more accurate your CdA will be.

Calibration

For each out and back segment, Aerosensor calculates a “Cal factor”, shown on page 6 of the display as “Prev cal factor” for the most recent segment.  Average these values for all of your out and back segments to get your calibration factor.  This should then be multiplied by the aero device calibration factor set in the CIQ app to get the new calibration factor.  You can then set the aero cal parameter to this new value.

For example, lets say you perform two out and backs.  Your aero cal parameter set in the CIQ app is 1.18.  The values you get are as follows.  Note that typically the odd laps will be acceleration and turnaround segments.  Because of ambient wind the value in one direction will generally by higher than in the other.

Lap 2   1.05

Lap 4   1.15

Lap 6   1.03

Lap 7   1.14

The average of these values is 1.09.  1.09 x 1.18 = 1.29.  You should go into Aerosensor settings -> parameters and enter this new value.

This value varies a little with your body position so for accurate CdA data periodically repeat this process.

Lap / Velodrome testing

Overview

  • For best results, calibrate the power meter before starting each run.
  • The more laps you ride, the more accurate the average for the run will be, as shown on page 9 of the CIQ app.

Protocol

  1. Once you have set everything up, press the start/stop activity button on your gamin to start recording.
  2. Ride at least 4 full laps, (i.e. out lap, 4 test laps, in lap).  Whilst testing try to maintain a constant power output and body position.  You must ride above the preset minimum speed.
  3. Data for each lap is shown in the page 8 of the CIQ app.
  4. Don’t forget to press the “start/stop activity” button again to end the recording.

Aerodynamic testing protocols

Overview

Aerodynamic testing is inherently difficult. There are many variables involved and the final CdA values are only as accurate as the least accurate measurement.
For this is reason it is important to use dual-sided power meters, and magnet-based speed sensors.

Terminology

A baseline is the first and last test you perform to determine data confidence levels, likely in a standard position or with standard equipment.

The baseline confidence delta is the % difference between the baseline and repeat baseline CdA – this determines data confidence levels.

A configuration is your bike setup with a change that you’d like to test, say a new helmet, new wheel etc

A run is one interval using a configuration (e.g. one lap on velodrome, or one out and back on the road)

A test is made up of multiple runs which are then averaged to give the overall measurement data for the tested configuration (e.g. multiple laps on velodrome or multiple out and backs on road)

A session is comprised of a baseline, one or more tests, and ideally a final baseline.

For velodrome testing we recommend doing at least 6 laps for a test.

For road testing we recommend at least 3 out and back runs for a test.  The distance over which you should ride for each individual out or back should be between 600 and 1000m.

Remember the more runs you do, the more accurate the data.

Baseline control

You should start and end each test session with a baseline repeat.
Example
For helmet testing, start with your usual helmet (baseline), then do one test for each helmet.  Finally do a one more test with your baseline helmet.  The variation in CdA between the first and last tests tells you what your repeatability is.  If this difference is 0.0015 then you know that any measured difference greater than this is a reliable result.

Equipment

Keeping track of the variables in your control isn’t just limited to your aerodynamic testing plan or your body position – it includes your bike.
It is worth getting into the habit of logging your clothing, shoes, bike geometry, wheels etc when aero testing – we would recommend photos of your configurations too to add to your post processed data. You can never have too much information in a diary – we recommend using Aerotune’s web platform for this.
In addition make sure your bike is routinely maintained, including a clean and well-lubed drivetrain, and that you have correctly inflated tyres.
We can’t stress enough that aerodynamic testing is made accessible with Aerosensor, but there the data will only be as reliable as the testing. Think about everything you do to make sure you are being as consistent as possible between each test.

Case studies

Case Study 1

Testing a new rear wheel at the velodrome:

  1. Perform at least 6 laps with current/base wheels – this is the baseline.
  2. Swap rear wheel to perform another 6 laps – this is test 1.
  3. Return to the current wheels for a final 6 laps – this is the repeat baseline.
  4.  Conclusion:
    • Looking at the data, there is a 0.4% difference between the first baseline and the repeat baseline CdA, this means that anything larger than 0.4% on test 1 can be resolved and conclusions can be taken.
    • New rear wheel test yielded a reduction in CdA of 1.3% – this is larger than the baseline confidence delta, therefore with confidence we can say that the new rear wheel reduces the rider’s CdA. Larger differences increase the confidence.

Case Study 2

Testing four different helmets on a straight, flat, quiet road:

  1. Perform 3 1000m out and back runs with a current helmet – this is the baseline
  2. For four subsequent tests, the rider changes between the four test helmets – these are tests 1-4
  3. Return to the current helmet and perform the same 3 1km out and back runs – this is the repeat baseline.
  4.  Conclusion:
    • Looking at the data, there is a large 4% increase in CdA on the repeat baseline – this baseline confidence delta is too large to draw any conclusions from the tests. Speed, distance, and wind conditions are all much less than 4% different – so something else must be at play.
    • It is noticeable that, after looking at head and chest position data from Aerobody, there has been a 15mm increase in average head position from the baseline to the repeat baseline – this almost certainly explains the large CdA increase.
    • The test helmet data also backs this up, there were expectations pre-session that all helmets would reduce drag compared to the current helmet, however that data says this is not the case, even saying the performance is worse in some cases – this is because the head positions also were different for each test, and therefore ruined the results.
    • This means the rider did not keep a consistent body position throughout the session and implies that the rider couldn’t sustain the position for that length of time – which is itself a useful conclusion for the rider.

Trackside Lap Logger

Overview

The Aerosensor Lap Logger is a piece of software that allows a coach to view data from the ACS Connect IQ app trackside. The ConnectIQ app transmits data from the previous lap continuously, allowing an ANT dongle equipped computer to display and log the data, meaning that the coach can make quick decisions on the results, knowing what to do next with the rider before they come off the track.

Installation

The software is only compatible with a Windows based computer.

The application can be downloaded from the downloads section here.

To operate an ANT+ dongle is required, such as the one below:

https://www.garmin.com/en-GB/p/10997

Other manufacturers offer similar products at lower prices, although quality may vary.

For optimal reception it is recommended that a USB extension lead is used, ideally 2m long, and the dongle is placed high up somewhere.

Operation

  1. Open the application from the start menu (search for “ANT_Lap_Logger”) or use the shortcut on the desktop.
  2. Click “Browse” and select a folder to save log files to.
  3. Click “Connect” and ensure that “Sensor opened” shows.
    In the “Messages” window, when ACS is open on the Garmin you should see data packets coming through. If nothing appears, click “Close” then “Open” again to reset the connection.
  4. For each set of laps:
    1. Click “Reset” to remove any data from the “LapData” grid from previous runs.
    2. Enter the run description in the “Description” field.
    3. Click on “Start log” to start logging the data to a file.
  5. As each lap comes in, you can click on the checkbox under the “Flag” column in the lap data to activate or deactivate laps. The average of all active laps is displayed under session data.
  6. Click “Stop log” at the end of the session, which will save the data and close the log file.
  7. The log file is a simple .csv comma delimited file which can be opened directly in Microsoft Excel.

CIQ App

Aerosensor Connection

Make sure that Aerosensor is switched on.

1.    Press the menu button on the Garmin head unit.

2.    Select “Connections” -> “Aerosensor”.

ACS-2

3. Select the device you want to connect to. Note: it is worth keeping a note of the Device ID for your Aerosensor and Aerobody for your records, especially if you are a coach and have multiple devices for your riders.

Pass-pairing

Pass-pairing is where ACS transmits the power meter and speed sensor ANT+ connection details to Aerosensor, allowing it to connect to them directly. 

For this to work the Garmin unit should already be paired with the ANT+ sensors you are using.

Note that Aerosensor requires a power meter (PWR) AND EITHER a speed sensor (SPD) OR speed + cadence sensor (BSC).

The CIQ app should automatically pass on the sensor connections to Aerosensor.  In case this does not work, or you have multiple sensors on the bike, follow these steps:

  1. Ensure that a power meter and speed sensor are installed on the bike and paired with the Garmin. Make sure they are on by rotating the wheel and/or pedals/crank, depending on the power meter.
  2. In the ACS menu, select “Connections”->”Pass pair” which will bring up the following screen:
ACS-3

3. Either select the devices individually or select the bottom “Enter to sync” button in purple above. After a short period, the status bar at the bottom of the screen should go green to show Aerosensor matches the Garmin device.  Aerosensor connection status icons should go from red to green.

ACS-4

Aerosensor Parameters

To accurately calculate aerodynamic drag, Aerosensor requires some information about you and your bike:

  1. Aero device calibration: This accounts for the fact that the wind slows as it approaches the bike, so the wind speed measured by Aerosensor is always slower than the air far upstream of the bike. Start with a value of 1.4. Typically we see values beweeen 1.1 and 1.45. See ‘Quickstart’ section for more information.
  2. Total mass (kg): includes rider + bike + all accessories used whilst riding with Aerosensor.
  3. Wheel Circumference (mm). If unknown, you can go into the speed sensor settings on the Garmin and you will find the wheel circumference in there once you have ridden far enough for the Garmin to calibrate against GPS.
  4. Power meter scaling: Default value is 1.0. If using pedals or crank we need to account for drivetrain losses.  A typical value would be 0.98, i.e. 2% drivetrain loss.
  5. CTF calibration offset: Used for CTF power meters.
  6. Time av period: This is the time period used by Aerosensor to average the CdA value, default is 30 seconds.
  7. Reference Crr: Rolling resistance coefficient (used if known), default 0.004. For an indoor velodrome you should use 0.002 (half the road value).  You can find typical crr values for a range of tyres at https://www.bicyclerollingresistance.com/
  8. Valid speed min: minimum speed (kph) for valid CdA automatic lapping. The CdA calculation is started when you go above this speed, and stopped when you slow down below this speed.  The device automatically creates laps for each CdA measurement period.

Editing Parameters:

It is important you check these frequently, especially total mass and wheel circumference if changing between bikes for example.

Velodrome testing – Track layout

When Aerosensor is in track calculation mode it uses lap distance and speed to calculate lean angle to compensate for centre of gravity location.  This only works when Aerodrome is being used. A typical track layout is shown below, of which you can input the track measurements by editing parameters directly in the CIQ app.

You can measure the track by measuring relative distance of corner start and end, using the distance markers along the track. This does not need to be very accurate – within a few meters is fine.

Measuring the track:

  1. Measure the distance from the tapeswitch location to the start and end of each corner.
  2. Use these to calculate the total distance of the two straight sections.
  3. Corner length = track length – total straight lengths
  4. Corner radius = corner length / pi
  5. Transition length is the distance it takes for the rider to transition from the straight to the corner. Typical value is 10m.

Example:

  • Total track length = 250m.
  • C1 start = 10m
  • C1 end = 95m
  • C2 start = 135m
  • C2 end = 220m
  • Corner length = C1 end – C1 start – transition= 95 – 10 – 10 = 75m
  • Corner radius = 75/pi = 23.9m

Editing Parameters:

Velodrome testing – Calculation mode

At the velodrome Aerosensor can ignore the barometer, since elevation is roughly constant, and should use the track map. If the track map is not known, or Aerodrome is not available, you can use the trackless mode. To use Velodrome mode:
  1. Go to Menu-> Aerosensor Settings->Calculation Mode.
  2. Select the model you require:
    1. Road
      For road riding.
    2. Velodrome Trackless
      Assumes constant elevation but ignores track layout. This is for when you are not using a lap trigger (Aerodrome) or the track layout is unknown.
    3. Velodrome Tracked
      Assumes constant elevation AND uses the track layout. This is for when you are using Aerodrome and know the track layout, as entered in ‘Aerosensor Settings->Track’.
  3. Wait until the mode changes as required, in the menu heading.
Screen sequence shown below:

Aerosensor demo mode

This is for diagnostic purposes and can generally be ignored.

Aerosensor information

Go to Menu -> Aerosensor settings -> about

Here you can see information about your Aerosensor device, including battery level, firmware version and serial number. Battery voltage is also included as it is useful for diagnostic purposes.

Quickstart

What follows outlines the basic setup of Aerobody.  For more detailed information please refer to the other articles on the left hand side. 

ACS Installation

Download the ACS app to your Garmin.  Go to Garmin ConnectIQ store and search for “Aerosensor” or use link below.

https://apps.garmin.com/en-US/apps/0170243b-0384-4072-9e85-57030e4949a6

ACS screen layout

  1. FIT file recording status:
    Red square = not recording.
    Green triangle = recording.
  2. Aerobody connection and battery status.
  3. Aerosensor connection status.
  4. Aerosensor power and speed or speed/cadence sensor connection status: Green = Connected. Orange = Searching. Red = Disconnected.
  5. Aerosensor battery status.
  6. Back key Use in menus use to go back a step, or on data screens exists app. This may be a button instead of touch screen icon depending on your Garmin Edge model.
  7. Menu key. This may be a button instead of touch screen icon depending on your Garmin Edge model.

Aerobody setup

 

1.    Install device using Garmin ¼-turn mount.

2.    Position device. Using your hand to check, rotate Aerobody so the head sensor is picking up your chin. Tighten mount screw to lock in position.

3.    Open either ACS or Aerobody datafield on Garmin device.

4.    Connect Aerobody to CIQ app.

a. Turn on Aerobody.  It should connect automatically.  If not:

b. Menu > Connections > Aerobody.

c. Wait for CIQ app to find device, then click on it to connect.

5.      Set your datum position using the app or datafield.

Data Analysis

Data is recorded to FIT file.  You can view the data via various platforms:
  • Aerosensor Excel Analysis Tool
    Automated in-depth analysis in a macro-enabled Excel workbook, available from the downloads section.
  • Aerotune
    Online platform tailored for Aerosensor analysis. See Aerotune website.
  • Garmin Connect
    All Aerosensor data is visible as “Developer fields” on the Garmin Connect website, after your head units has synced.
  • WKO
    Workbook available from downloads section of our website.
  • Golden Cheetah
    We are working with Golden Cheetah developers to better support aero testing. Watch this space!

Data analysis

Aerodynamic basics

What is aerodynamic drag?

Aerodynamic drag is the force of the air acting to slow down a cyclist moving through it.

It is made up of two major components – pressure drag and skin friction drag.

  • Pressure drag is related to the size and shape of the bike and rider. As you cycle forwards you hit air particles out of the way. These are compressed on impact but then space out as they pass over and past you – the difference between these two air pressures is pressure drag. This is why getting into an aerodynamic position and allowing the oncoming air to flow smoothly around you, reduces your overall aerodynamic drag and makes it easier to cycle.
  • Skin friction is related to the roughness or texture of the surface on the bike and rider, a smooth (laminar) surface allows air particles to have consistent trajectories (pathlines). A rough (turbulent) surface causes irregular pathlines. Something to note however is surface roughness can be used to keep flow attached longer (for example a textured should on a skinsuit) which increases skin friction drag, but reduces pressure drag (of which is a larger component and therefore can reduce overall drag.

How do we measure aerodynamic drag?

There are five forces acting on a cyclist. Aerosensor works by measuring or estimating forces (or power) from the rider (FR), kinetic (FK), gravitational (FG) and friction (FF) to find the fifth, aerodynamic drag (FD).

The sum of these sources (positive) and sinks (negative) plus the aerodynamic drag (sink) must equal zero:

F_{R} \pm F_{K} \pm F_{G}-F_{F}-F_{D}=0

Aerodynamic drag is comprised of the product of dynamic pressure (pDyn, directly measured by Aerosensor), coefficient of drag (Cd, a constant for a given body position/setup) and frontal area (A). In cycling, the coefficient of drag and frontal area are commonly combined as the term CdA:

F_{D} = p_{\text{Dyn}} \times C_{d}A

Combining these two equations gives you a relationship between CdA and the other bike forces:

C_{d}A = \frac{{F_{R} \pm F_{K} \pm F_{G} – F_{F}}}{{p_{\text{Dyn}}}}

This is what your Aerosensor calculates in real-time!

Why is aerodynamic drag important?

Although aerodynamic drag increases with speed, friction does not – so at high speeds aerodynamic drag dominates.

Above you can see that at 5kph just 10% of your power goes into overcoming aerodynamic drag, and at 40kph this increases to over 80% – ie 80% of your power is used only to push you through the air.

Say you’re taking part in a flat 40km TT, how can reducing your CdA (and therefore aerodynamic drag) affect your race time?

In this example, reducing your CdA by around 10% can save over 1 minute and 30 seconds. The great news about aerodynamic testing is that you can make huge strides in making yourself faster and/or saving more energy for when it matters.

Garmin Connect

Section currently in construction. 

Excel Tools

Section currently in construction. 

WKO

Section currently in construction. 

Golden Cheetah

Section currently in construction. 

Aerotune

Section currently in construction. 

Troubleshooting

Aerosensor

We have a known issue where Aerosensor can become unresponsive.

  • Make sure device has charge by plugging into USB-C.
  • Press reset button. You can find instructions on where to find it in the quickstart.

In addition, our device works on a standard 5V power supply.  Some laptop/phone charges are “smart chargers” that communicate with device to charge at a higher voltage.  These just flat out don’t work, so please try the following:

  • Try a different power source. A computer USB port is usually a safe bet.
  • Try a different USB cable, just in case that is the problem.  Rare but it has happened that the USB cable isn’t suitable.

If the LED doesn’t come on after this, please reach out to our support team.

It is likely that Aerosensor is not correctly paired to your ANT+ sensors.

  • BLE/ANT+ sensors transmit as both BLE and ANT+ separately. You may have paired to the BLE sensor. In the Garmin go to the sensor, and check that you are paired to the ANT+ sensor.
  • Check that the ANT+ power meter AND EITHER speed OR speed and cadence sensor is paired properly. Ensure the sensors are on by rotating pedals/crank/wheel then check pass-pairing (in CIQ app go to Connections->Pass Pairing). When properly paired the SPD and PWR icons in the top right hand corner of the CIQ app will show green.

There are a few reasons Aerosensor may report an incorrect CdA value.

  • Check that you have entered an appropriate Aero Calibration factor in the CIQ app (Aerosensor settings->Parameters->Edit Parameters). For instructions on how to get this value see the quickstart guide.
  • Make sure you have calibrated the power meter.
  • Make sure that other Aerosensor parameters (in particular Total Mass, Wheel Circumference, Power meter scaling, Reference Crr) are correct.
  • If using a pedal based power meter, ensure that the crank length is set correctly in the Garmin Power Meter sensor settings.

If Aerosensor is not able to connect to the aerosensor updater then it is likely the USB-C cable is power only, not power + data. Try a different cable.

We have also noticed that USB-C to USB-C chargers don’t work for updater for this reason.

Aerobody

Aerodrome

If, when using Aerodrome, more laps are shown than expected, it is likely that you are experiencing drop-outs in the speed sensor.

This means that Aerosensor sporadically auto-laps independent of Aerodrome.

Try moving your magnet speed sensor to the front wheel, this should fix the issue.

Device basics

Specifications

Dimensions (H x W x D)

36 x 32 x 64mm

Mass

37g

Battery Life

9 hours

Head position resolution

+/- 1mm

Chest position resolution

+/- 1mm

Layout

  1. LED
  2. Power button
  3. Reset button
  4. USB-C bung & charging port
  5. Head sensor
  6. Chest sensor
  7. Quarter-turn mount

Button functions

  • Power button:
    • Press and release to turn on.
    • Press and hold until LED turns off then release to shut down.
  • Reset button:
    • To be used in case the device becomes unresponsive.

LED significance

The multi-colour LED indicates the device state as shown below:

Colour

Flashing

State

USB

Charge

Aqua

Normal

On

Unplugged

Normal

Red

Normal

On

Unplugged

Low

Amber

Slow

Off

Plugged in

Charging

Amber

Solid

On

Plugged in

Charging

Green

Slow

Off

Plugged in

Charged

Green

Solid

On

Plugged in

Charged

Note: Do not use sharp objects or tools to press buttons, this may result in damage. 

Important notes & prerequisites

Important notes

Aerobody uses optical sensors for measuring your body position, so keeping the sensor lenses clean and free from debris is critical for good performance.

The USB port should be kept dry and free from debris. After charging, please ensure that the bung is replaced firmly.

Although Aerobody is splashproof, it is not designed to operate in wet conditions. Please ensure it is removed if outdoors and raining.

Clean Aerobody with a soft, dry cloth. Avoid using abrasive materials or harsh chemicals that may damage the product’s surface.

Prerequisites

Aerobody doesn’t require any other devices to work; you will need a Garmin cycling computer however.

Device mounts

Aerobody has been designed to work on a variety of different bike bar types, notably the following:

  1. Drop handlebars – usually standard on road bikes and track bikes.
  2. Clip-on time-trial (TT) bars – additions to road and track bikes.
  3. Integrated TT handlebar/cockpit – mostly seen on TT and triathlon specific bikes.

Aerobody is supplied with a quarter-turn mount suitable for most bike setups.

Whilst Aerobody can be used on most bike setups, there will be some bar variants that may be trickier to setup. Please do not hesitate to contact us at hello@Aerosensor.tech with any questions or for advice on how to best mount onto your bike.

Tutorial Videos

This area is currently in construction – stay tuned for more videos soon! 

Aerosensor Setup

In this video we show you how to setup our cycling aerodynamic drag measurement device, Aerosensor: From unboxing through to testing the setup on a turbo trainer.

Aerobody Setup

In this video we show you how to set Aerobody up on the bike, and use both the ACS Connect IQ (CIQ) app, and the Aerobody Datafield to set it up and view the data.

Excel Analysis Tool

Find out how to use our Aerosensor Excel Analysis Tool, enabling you to get the most of your aerodynamic cycling data and make conclusions about your testing quickly and with confidence.

This video takes you from installation on your Windows or Mac computers, through to loading, editing, and analysing the data.

Installation

Aerobody has a standard Garmin quarter-turn mount. It should be positioned on the stem using a compatible bike mount adapter such as the one supplied with the unit. The screw on the quarter-turn mount allows pitch adjustment of the entire unit.

The forward (head) sensor should be aligned approximately with the chin and the chest sensor points at the chest.

To align, support the bike either in a turbo trainer, or by asking someone to support the bike.  Sitting on the bike in your normal riding position watch the display whilst moving two fingers up and down from your chin towards the unit, and ensure that the measurement tracks movement of your fingers.

CIQ App

Aerobody Connection

Make sure that Aerobody is switched on.

  1. Press the menu button on the Garmin head unit.
  2. Select “Connections” -> “Aerobody”.
4. Connect device

3. Select the device you want to connect to. Note: it is worth keeping a note of the Device ID for your Aerobody for your records, especially if you are a coach and have multiple devices for your riders.

Set Reference

The CIQ app shows your body position relative to a reference which you can set as follows:

  1. Got to Menu-> Aerobody Settings->Set Reference.
  2. Get into your ideal position on the bike. To do this support the bike in a turbo trainer, or ask someone to support it for you, and get into your normal riding position.
  3. Select “Measure”. This will give you a 5 second countdown to get in position, then will take a 2 second average of your position. When complete the measurements will show in red to indicate the new values are unsaved, and the “Save” button will be highlighted.
  4. Click “Save” to send the new position to Aerobody. Wait for the head and chest display to update to green, and the save button to turn grey and show “Saved”.
5. Set datum
AEROBODY QUICKSTART-8

Set Null Zone

The body position fields in the CIQ app will turn red if you are higher, or blue if you are lower, than your reference position. It will be white if you are within a set “null zone” around your reference position. As an example, a 1.5cm null zone means that the rider moving between -1.5cm and +1.5cm of their reference head or chest position will remain white whilst riding. Anything outside of these values are considered “out of position” will be red or blue depending if you are too high or too low.

The null zone may be set as follows:

  1. Got to Menu-> Aerobody Settings->Set Null Zone.
  2. The buttons can be used to adjust in multiples of 1cm and 0.1cm as necessary.
  3. Click “Save” to send the new position to Aerobody.

Aerobody information

Got to Menu -> Aerobody settings -> About

Here you can see information about your Aerobody device, including battery level, firmware version and serial number. Battery voltage is also included as it is useful for diagnostic purposes.

Downloads

Demo FIT Files

Out-back FIT files

Download demo FIT files to try out-back analysis using our excel tool and other platforms.

Updated 20th February 2024.

Garmin Connect IQ Apps & Datafields

ACS App

Aerosensor Cycling System app lets you get the most from our unique system of aerodynamic development devices.

Aerobody Datafield

View your body position as you ride, in the context of your favourite data screens with a datafield dedicated to Aerobody.

Excel Tools

Excel tools for Windows and Mac

Import Aerosensor FIT files directly to excel, and perform basic out-back and velodrome analysis. V4.7 Now available!

Updated 29th February 2024.

Fit to CSV for Windows

Simple tool to convert FIT files directly into CSV files for import into excel or other software.

Trackside Lap Logger

Aerosensor lap logger

View and log lap data trackside on a Windows computer.

Updated 8th January 2024.

ANT+ dongle driver

Windows driver for ANT+ USB dongle.

Firmware Updater

Aerosensor Updater for Windows

Update your aerosensor and aerodrome firmware to the latest version using a Windows laptop or desktop computer.

  • Install .msi file
  • Run ‘AerosensorUpdater’
  • Plug in Aerosensor device via USB-C and click update.

Updated 28th March 2024 to V1.4

Aerosensor Updater for macOS

Update your aerosensor and aerodrome firmware to the latest version using an Apple Mac laptop or desktop computer.

 

Updated 11th April 2024 to V1.12

WKO Charts

WKO CHART

Chart layout for viewing Aerosensor data in WKO V4 or V5.

(01.11.23 Update)

Note that WKO does not show the lap or session data, only the record data, which is the time history.

CAD Files

The CAD files are provided for free use; however, users assume all associated risks. Aerosensor disclaims any responsibility for loss or injury resulting from the use of these files.

Current Aerosensor stay

Includes stay and fairing, plus assembly.

Updated Aerosensor stay

One-piece stay released February 2024.

Contact Us

We’re here to help and answer any questions you may have – please email us or ask the Aerosensor community on our discord forum. 

email
Email
support@aerosensor.tech
community
Discord

Members only discord forum

CIQ Datafield

Please refer to the Aerobody CIQ Datafield section here.

Quickstart

What follows outlines the basic setup of Aerodrome. For more detailed information please refer to the other articles on the left hand side. 

ACS Installation

Download the ACS app to your Garmin.  Go to Garmin ConnectIQ store and search for “Aerosensor” or use link below.

https://apps.garmin.com/en-US/apps/0170243b-0384-4072-9e85-57030e4949a6

ACS screen layout

  1. FIT file recording status:
    Red square = not recording.
    Green triangle = recording.
  2. Aerobody connection and battery status.
  3. Aerosensor connection status.
  4. Aerosensor power and speed or speed/cadence sensor connection status: Green = Connected. Orange = Searching. Red = Disconnected.
  5. Aerosensor battery status.
  6. Back key Use in menus use to go back a step, or on data screens exists app. This may be a button instead of touch screen icon depending on your Garmin Edge model.
  7. Menu key. This may be a button instead of touch screen icon depending on your Garmin Edge model.

Aerodrome Setup

  1. Install tapeswitch across track, securing with duck tape.
  2. Position Aerodrome about 1-2 meters downstream of the tapeswitch, close to track, oriented so that the buttons are closest to the track as shown.
  3. Ensure Aerodrome blue light is flashing
    When Aerosensor is on and within a few meters of the Aerodrome the light will flash to show it is able to communicate with it. This ensures radio signal is strong enough to work.  It only needs to pick up Aerosensor’s signal for 1-2 meters after the tapeswitch is crossed.
  4. Open ACS in “Velodrome Tracked” mode.
    This assumes no elevation changes, and uses the trackmap to correct for cyclist lean angle.
  5. Edit track map in ACS.
    See section in CIQ app documentation.
Remember to start an activity on the Garmin before starting to ride. Aerosensor will automatically create new laps every time you cross the tapeswitch. Note that the data appears on the Garmin a couple of seconds after the end of lap, once Aerosensor has finished averaging data for the lap.

Aero testing guidance

Reliable aerodynamic testing is reliant on good testing protocols.  Here are a few tips for best results.
  • CdA data is only as accurate as the inputs. Make sure you check Aerosensor’s settings in the ACS app before every test.
  • Always calibrate power sensor before starting testing. Small calibration offsets can result in a big error in CdA measurement.
  • Always start and end your test block with a baseline repeat.
  • Try to maintain a constant speed through each run.
  • For velodrome testing we recommend 6-8 laps per configuration.
  • The more laps you do, the better the repeatability will be.

Data Analysis

Data is recorded to FIT file.  You can view the data via various platforms:
  • Aerosensor Excel Analysis Tool
    Automated in-depth analysis in a macro-enabled Excel workbook, available from the downloads section.
  • Aerotune
    Online platform tailored for Aerosensor analysis. See Aerotune website.
  • Garmin Connect
    All Aerosensor data is visible as “Developer fields” on the Garmin Connect website, after your head units has synced.
  • WKO
    Workbook available from downloads section of our website.
  • Golden Cheetah
    We are working with Golden Cheetah developers to better support aero testing. Watch this space!

Aerosensor Store

Device basics

Specifications

Dimensions (H x W x D)

34 x 76 x 76mm

Mass

66g

Battery Life

28 hours

Timing resolution

+/- 1ms

Layout

  1. Power button
  2. LED
  3. Reset button
  4. USB-C charging port
  5. Tapeswitch port

Button functions

  • Power button:
    • Press and release to turn on.
    • Press and release to shut down.
  • Reset button:
    • To be used in case the device becomes unresponsive.

LED significance

The multi-colour LED indicates the device state as shown below:

Colour

Flashing

State

USB

Charge

Cyan

Solid

On

Unplugged

Normal

Lilac

Solid

Trigger

N/A

N/A

Amber

Solid

On

Charger

Low

Green

Solid

Off

Charger

Charging

Blue

Solid

On

Computer

Charging

Light blue

Solid

Off

Computer

Charged

Any

Flash

On

Aerosensor connected

Note: Do not use sharp objects or tools to press buttons, this may result in damage. 

Important notes & prerequisites

Important notes

Aerodrome uses a Tapeswitch cable as a lap trigger – the cable should not be pinched or bent. Bending with a bend radius less than 4mm will permanently damage the product.

The USB port and Tapeswitch port should be kept dry and free from debris.

Although Aerodrome is splashproof, it is not designed to operate in wet conditions.  Please ensure it is not used outdoors when it is raining.

Clean Aerodrome with a soft, dry cloth. Avoid using abrasive materials or harsh chemicals that may damage the product’s surface.

Prerequisites

Aerodrome requires Aerosensor device and a Garmin cycling computer.

Installation

As Aerodrome will likely be used on a live track or a public road, it is critical that you have permission to use the device and/or have taken appropriate measures to ensure not only the safety of you and other riders, but also to prolong the life of the device itself.

The tapeswitch should be placed so that the flat side is against the track or road, and the ridge on the upper side. Using duck tape, secure the tapeswitch across the line the cyclist will be following, be it on the track or the road. Secure at the far ends with tape, and placing a further piece of tape along the length, just holding down the upstream side of the tapeswitch.

Tape along the tapeswitch, not across it (as below).

Aerodrome listens for Aerosensor and the LED flashes when it receives data. It is only able to transmit the lap trigger when this is happening.

For optimal radio performance, make sure Aerodrome is situated in a position where it can receive data from Aerosensor when bike is at or just past the Tapeswitch. It is normally best to position 1-2m downstream of where the lap trigger is placed.  Orient the device so that the buttons are closest to the track, as shown in images below.

Plug the tapeswitch plug into the Aerodrome socket and turn on. The power light should illuminate.  You can check it is working by pressing on the tapeswitch. The LED will turn purple for 1 second to indicate a lap trigger.

Aerodrome should be placed on the floor well clear of any area the rider is likely to pass.  Secure the tapeswitch cable to the floor with duck tape to avoid trip hazards.

Note that currently Aerodrome cannot distinguish between multiple Aerosensor’s running on track.  It will only work correctly when a single rider is on track.

1. Install tapeswitch
2. Position Aerodrome

CIQ App

Aerodrome Connection

Aerodrome uses Aerosensor, so no specific settings are required in the CIQ App.

Please refer to the Aerosensor section here.

Aerosensor Cycling System CIQ App

Overview

The Aerosensor Aerodynamic Cycling System (ACS) Connect IQ app is required to seamlessly integrate our devices with your Garmin bike computer, providing real-time aerodynamic data and further insights during your ride, and recording your data to a FIT file for further analysis.

Installation

  1. The Aerosensor ACS CIQ app can be downloaded from the Garmin Connect IQ website:

https://apps.garmin.com/

  1. Simply search for “Aerosensor” and the app will come up, or use this link:

https://apps.garmin.com/en-US/apps/0170243b-0384-4072-9e85-57030e4949a6

  1. Install to the Garmin head unit as per the instructions on the CIQ app website.
  2. Start ACS by going to the Connect IQ menu on your Garmin (see Garmin instructions) and then selecting “Aerosensor ACS”.

ACS screen layout

  1. FIT file recording status:
    Red square = not recording
    Green triangle = recording.
  2. Aerobody connection and battery status.
  3. Aerosensor connection status.
  4. Aerosensor power and speed or speed/cadence sensor connection status:
    Green = Connected.
    Orange = Searching.
    Red = Disconnected.
  5. Aerosensor battery status.
  6. Back key
    Use in menus use to go back a step, or on data screens exists app. This may be a button instead of touch screen icon depending on your Garmin Edge model.
  7. Menu key.
    This may be a button instead of touch screen icon depending on your Garmin Edge model.

Aerobody CIQ Datafield

Overview

Aerobody is a device that mounts on your stem and measures the distance to your head and chest. This is a good indication of your overall body position.

The Aerobody datafield allows you to view your body position data in the context of your normal Garmin views. You can add it in the same way you would add any other data such as speed, power, time etc. It also adds your aerobody data to the fit file so you can view it after your ride.

Installation

Search for Aerobody on the ConnectIQ store and follow instructions to install. 

  • Once installed, on your Garmin select the data screen (in your chosen activity profile) and edit the field where you want the data to appear.
  • Select Connect IQ from the list.
  • Select Aerobody from the list.

Note that aerobody really needs a full screen width field to display correctly as it displays both head and chest positions.

Pairing

Turn on your Aerobody device.

The Aerobody datafield will automatically connect to the first Aerobody signal it picks up.  It saves this so that next time it will look for the same physical device.

If you need to switch to a different Aerobody device, firstly make sure that only that one is switched on and in range (roughly 10m) of the Garmin unit, the follow the following steps.

  • Make sure that Garmin Connect app is installed on your phone and paired with your Edge unit.
  • Turn on your Garmin and the Aerobody device.
  • In either Garmin Connect or the Garmin ConnectIQ app, select your device, then go find the datafield app. Open settings.
  • Move the slider next to “Reset paired device” to the right.
  • Click “Save”. The display on the Garmin should show “Reconnecting” for 3 seconds then switch back to the data view.  Ensure that a surface is within 300mm of the Aerobody device in order to make sure it is reading data.
AEROBODY DATAFIELD-4
AEROBODY DATAFIELD-5
AEROBODY DATAFIELD-6

Setting datum

Aerobody allows you to set a datum, which you can think of as a target position for you to maintain whilst riding. The head and chest fields will go red if you go above this; blue if below, outside of a “null zone”, the dimensions of which you can modify in the settings.  You can also set an audible alert to warn you when you are outside of your target range. By default the relative position is shown in the fields, which is the distance between your current position and the datum.  This can be changed to absolute position in the datafield settings.
To set your datum, follow these steps:
  • Get on the bike, ready to get into position. Use a turbo-trainer or friend to support it.
  • In settings, put the “Set datum” slider to the right. Click “Save”.
  • On the datafield it will give you a countdown of 3 seconds to get into position.
  • The datafield It will then average your position and save it.
Now when you are in the correct position the display should have an uncoloured background.  If you are too low it goes blue; too high it goes red.
AEROBODY DATAFIELD-7
AEROBODY DATAFIELD-8
AEROBODY DATAFIELD-9

General Riding

Riding with Aerosensor

Always make sure you calibrate your power meter before starting a ride.  You must do this on the Garmin outside of the CIQ app.

Always run the CIQ app whilst riding to view and record your Aerosensor or Aerobody data.

Press the “start/stop activity” button on the Garmin to start recording data to fit file.

When your cycling speed exceeds the preset “Valid speed min” speed a new lap will be started and the CdA field will show a countdown to when data will be available. If the averaging time is set to 30s then this will count down from 30s to zero.  When it reaches zero the live CdA value will be shown.

As well as CdA, a “lap CdA” value is shown on some screens. This shows the average CdA over the current lap, and is available from 10 seconds after the valid speed is hit.

When you slow down again the lap will be finished, either by dropping below the minimum speed, or by braking hard. The lap CdA for the last lap will be available.

Don’t forget to press the “start/stop activity” button again to end the recording.

Out-back / road testing

Overview

  • For more accurate aerodynamic testing outdoors, when a track is not available, you should ride in both directions along an ideally quiet section of road.  The wind generated by passing traffic will degrade the measurement.
  • The road section does not need to be straight, but tight corners should be avoided.  You should aim to be able to ride at a roughly constant speed and power during the test.
  • The more out and backs you perform, the more accurate your CdA will be.

Protocol

  1. Press the “start/stop activity” button on the Garmin to start recording data to fit file.
  2. You should ride in one direction along the road stretch for between 500m and 1km. The longer the better.  At the end of your segment, brake sharply, turn around and then ride back the other way back to your starting point. For the turnaround ride slowly (below your preset minimum speed) for at least ten seconds to ensure the lapping process works properly.
  3. During each out or back segment, aim to maintain a constant position on the bike, and ideally a constant speed.
  4. Don’t forget to press the “start/stop activity” button again to end the recording.

The more out and backs you perform, the more accurate your CdA will be.

Calibration

For each out and back segment, Aerosensor calculates a “Cal factor”, shown on page 6 of the display as “Prev cal factor” for the most recent segment.  Average these values for all of your out and back segments to get your calibration factor.  This should then be multiplied by the aero device calibration factor set in the CIQ app to get the new calibration factor.  You can then set the aero cal parameter to this new value.

For example, lets say you perform two out and backs.  Your aero cal parameter set in the CIQ app is 1.18.  The values you get are as follows.  Note that typically the odd laps will be acceleration and turnaround segments.  Because of ambient wind the value in one direction will generally by higher than in the other.

Lap 2   1.05

Lap 4   1.15

Lap 6   1.03

Lap 7   1.14

The average of these values is 1.09.  1.09 x 1.18 = 1.29.  You should go into Aerosensor settings -> parameters and enter this new value.

This value varies a little with your body position so for accurate CdA data periodically repeat this process.

Lap / Velodrome testing

Overview

  • For best results, calibrate the power meter before starting each run.
  • The more laps you ride, the more accurate the average for the run will be, as shown on page 9 of the CIQ app.

Protocol

  1. Once you have set everything up, press the start/stop activity button on your gamin to start recording.
  2. Ride at least 4 full laps, (i.e. out lap, 4 test laps, in lap).  Whilst testing try to maintain a constant power output and body position.  You must ride above the preset minimum speed.
  3. Data for each lap is shown in the page 8 of the CIQ app.
  4. Don’t forget to press the “start/stop activity” button again to end the recording.

Aerodynamic testing protocols

Overview

Aerodynamic testing is inherently difficult. There are many variables involved and the final CdA values are only as accurate as the least accurate measurement.
For this is reason it is important to use dual-sided power meters, and magnet-based speed sensors.

Terminology

A baseline is the first and last test you perform to determine data confidence levels, likely in a standard position or with standard equipment.

The baseline confidence delta is the % difference between the baseline and repeat baseline CdA – this determines data confidence levels.

A configuration is your bike setup with a change that you’d like to test, say a new helmet, new wheel etc

A run is one interval using a configuration (e.g. one lap on velodrome, or one out and back on the road)

A test is made up of multiple runs which are then averaged to give the overall measurement data for the tested configuration (e.g. multiple laps on velodrome or multiple out and backs on road)

A session is comprised of a baseline, one or more tests, and ideally a final baseline.

For velodrome testing we recommend doing at least 6 laps for a test.

For road testing we recommend at least 3 out and back runs for a test.  The distance over which you should ride for each individual out or back should be between 600 and 1000m.

Remember the more runs you do, the more accurate the data.

Baseline control

You should start and end each test session with a baseline repeat.
Example
For helmet testing, start with your usual helmet (baseline), then do one test for each helmet.  Finally do a one more test with your baseline helmet.  The variation in CdA between the first and last tests tells you what your repeatability is.  If this difference is 0.0015 then you know that any measured difference greater than this is a reliable result.

Equipment

Keeping track of the variables in your control isn’t just limited to your aerodynamic testing plan or your body position – it includes your bike.
It is worth getting into the habit of logging your clothing, shoes, bike geometry, wheels etc when aero testing – we would recommend photos of your configurations too to add to your post processed data. You can never have too much information in a diary – we recommend using Aerotune’s web platform for this.
In addition make sure your bike is routinely maintained, including a clean and well-lubed drivetrain, and that you have correctly inflated tyres.
We can’t stress enough that aerodynamic testing is made accessible with Aerosensor, but there the data will only be as reliable as the testing. Think about everything you do to make sure you are being as consistent as possible between each test.

Case studies

Case Study 1

Testing a new rear wheel at the velodrome:

  1. Perform at least 6 laps with current/base wheels – this is the baseline.
  2. Swap rear wheel to perform another 6 laps – this is test 1.
  3. Return to the current wheels for a final 6 laps – this is the repeat baseline.
  4.  Conclusion:
    • Looking at the data, there is a 0.4% difference between the first baseline and the repeat baseline CdA, this means that anything larger than 0.4% on test 1 can be resolved and conclusions can be taken.
    • New rear wheel test yielded a reduction in CdA of 1.3% – this is larger than the baseline confidence delta, therefore with confidence we can say that the new rear wheel reduces the rider’s CdA. Larger differences increase the confidence.

Case Study 2

Testing four different helmets on a straight, flat, quiet road:

  1. Perform 3 1000m out and back runs with a current helmet – this is the baseline
  2. For four subsequent tests, the rider changes between the four test helmets – these are tests 1-4
  3. Return to the current helmet and perform the same 3 1km out and back runs – this is the repeat baseline.
  4.  Conclusion:
    • Looking at the data, there is a large 4% increase in CdA on the repeat baseline – this baseline confidence delta is too large to draw any conclusions from the tests. Speed, distance, and wind conditions are all much less than 4% different – so something else must be at play.
    • It is noticeable that, after looking at head and chest position data from Aerobody, there has been a 15mm increase in average head position from the baseline to the repeat baseline – this almost certainly explains the large CdA increase.
    • The test helmet data also backs this up, there were expectations pre-session that all helmets would reduce drag compared to the current helmet, however that data says this is not the case, even saying the performance is worse in some cases – this is because the head positions also were different for each test, and therefore ruined the results.
    • This means the rider did not keep a consistent body position throughout the session and implies that the rider couldn’t sustain the position for that length of time – which is itself a useful conclusion for the rider.

Trackside Lap Logger

Overview

The Aerosensor Lap Logger is a piece of software that allows a coach to view data from the ACS Connect IQ app trackside. The ConnectIQ app transmits data from the previous lap continuously, allowing an ANT dongle equipped computer to display and log the data, meaning that the coach can make quick decisions on the results, knowing what to do next with the rider before they come off the track.

Installation

The software is only compatible with a Windows based computer.

The application can be downloaded from the downloads section here.

To operate an ANT+ dongle is required, such as the one below:

https://www.garmin.com/en-GB/p/10997

Other manufacturers offer similar products at lower prices, although quality may vary.

For optimal reception it is recommended that a USB extension lead is used, ideally 2m long, and the dongle is placed high up somewhere.

Operation

  1. Open the application from the start menu (search for “ANT_Lap_Logger”) or use the shortcut on the desktop.
  2. Click “Browse” and select a folder to save log files to.
  3. Click “Connect” and ensure that “Sensor opened” shows.
    In the “Messages” window, when ACS is open on the Garmin you should see data packets coming through. If nothing appears, click “Close” then “Open” again to reset the connection.
  4. For each set of laps:
    1. Click “Reset” to remove any data from the “LapData” grid from previous runs.
    2. Enter the run description in the “Description” field.
    3. Click on “Start log” to start logging the data to a file.
  5. As each lap comes in, you can click on the checkbox under the “Flag” column in the lap data to activate or deactivate laps. The average of all active laps is displayed under session data.
  6. Click “Stop log” at the end of the session, which will save the data and close the log file.
  7. The log file is a simple .csv comma delimited file which can be opened directly in Microsoft Excel.

Aerodynamic basics

What is aerodynamic drag?

Aerodynamic drag is the force of the air acting to slow down a cyclist moving through it.

It is made up of two major components – pressure drag and skin friction drag.

  • Pressure drag is related to the size and shape of the bike and rider. As you cycle forwards you hit air particles out of the way. These are compressed on impact but then space out as they pass over and past you – the difference between these two air pressures is pressure drag. This is why getting into an aerodynamic position and allowing the oncoming air to flow smoothly around you, reduces your overall aerodynamic drag and makes it easier to cycle.
  • Skin friction is related to the roughness or texture of the surface on the bike and rider, a smooth (laminar) surface allows air particles to have consistent trajectories (pathlines). A rough (turbulent) surface causes irregular pathlines. Something to note however is surface roughness can be used to keep flow attached longer (for example a textured should on a skinsuit) which increases skin friction drag, but reduces pressure drag (of which is a larger component and therefore can reduce overall drag.

How do we measure aerodynamic drag?

There are five forces acting on a cyclist. Aerosensor works by measuring or estimating forces (or power) from the rider (FR), kinetic (FK), gravitational (FG) and friction (FF) to find the fifth, aerodynamic drag (FD).

The sum of these sources (positive) and sinks (negative) plus the aerodynamic drag (sink) must equal zero:

F_{R} \pm F_{K} \pm F_{G}-F_{F}-F_{D}=0

Aerodynamic drag is comprised of the product of dynamic pressure (pDyn, directly measured by Aerosensor), coefficient of drag (Cd, a constant for a given body position/setup) and frontal area (A). In cycling, the coefficient of drag and frontal area are commonly combined as the term CdA:

F_{D} = p_{\text{Dyn}} \times C_{d}A

Combining these two equations gives you a relationship between CdA and the other bike forces:

C_{d}A = \frac{{F_{R} \pm F_{K} \pm F_{G} – F_{F}}}{{p_{\text{Dyn}}}}

This is what your Aerosensor calculates in real-time!

Why is aerodynamic drag important?

Although aerodynamic drag increases with speed, friction does not – so at high speeds aerodynamic drag dominates.

Above you can see that at 5kph just 10% of your power goes into overcoming aerodynamic drag, and at 40kph this increases to over 80% – ie 80% of your power is used only to push you through the air.

Say you’re taking part in a flat 40km TT, how can reducing your CdA (and therefore aerodynamic drag) affect your race time?

In this example, reducing your CdA by around 10% can save over 1 minute and 30 seconds. The great news about aerodynamic testing is that you can make huge strides in making yourself faster and/or saving more energy for when it matters.

Garmin Connect

Section currently in construction. 

Excel Tools

Section currently in construction. 

WKO

Section currently in construction. 

Golden Cheetah

Section currently in construction. 

Aerotune

Section currently in construction. 

Aerosensor

We have a known issue where Aerosensor can become unresponsive.

  • Make sure device has charge by plugging into USB-C.
  • Press reset button. You can find instructions on where to find it in the quickstart.

In addition, our device works on a standard 5V power supply.  Some laptop/phone charges are “smart chargers” that communicate with device to charge at a higher voltage.  These just flat out don’t work, so please try the following:

  • Try a different power source. A computer USB port is usually a safe bet.
  • Try a different USB cable, just in case that is the problem.  Rare but it has happened that the USB cable isn’t suitable.

If the LED doesn’t come on after this, please reach out to our support team.

It is likely that Aerosensor is not correctly paired to your ANT+ sensors.

  • BLE/ANT+ sensors transmit as both BLE and ANT+ separately. You may have paired to the BLE sensor. In the Garmin go to the sensor, and check that you are paired to the ANT+ sensor.
  • Check that the ANT+ power meter AND EITHER speed OR speed and cadence sensor is paired properly. Ensure the sensors are on by rotating pedals/crank/wheel then check pass-pairing (in CIQ app go to Connections->Pass Pairing). When properly paired the SPD and PWR icons in the top right hand corner of the CIQ app will show green.

There are a few reasons Aerosensor may report an incorrect CdA value.

  • Check that you have entered an appropriate Aero Calibration factor in the CIQ app (Aerosensor settings->Parameters->Edit Parameters). For instructions on how to get this value see the quickstart guide.
  • Make sure you have calibrated the power meter.
  • Make sure that other Aerosensor parameters (in particular Total Mass, Wheel Circumference, Power meter scaling, Reference Crr) are correct.
  • If using a pedal based power meter, ensure that the crank length is set correctly in the Garmin Power Meter sensor settings.

If Aerosensor is not able to connect to the aerosensor updater then it is likely the USB-C cable is power only, not power + data. Try a different cable.

We have also noticed that USB-C to USB-C chargers don’t work for updater for this reason.

Aerobody

Aerodrome

If, when using Aerodrome, more laps are shown than expected, it is likely that you are experiencing drop-outs in the speed sensor.

This means that Aerosensor sporadically auto-laps independent of Aerodrome.

Try moving your magnet speed sensor to the front wheel, this should fix the issue.

Demo FIT Files

Out-back FIT files

Download demo FIT files to try out-back analysis using our excel tool and other platforms.

Updated 20th February 2024.

Garmin Connect IQ Apps & Datafields

ACS App

Aerosensor Cycling System app lets you get the most from our unique system of aerodynamic development devices.

Aerobody Datafield

View your body position as you ride, in the context of your favourite data screens with a datafield dedicated to Aerobody.

Excel Tools

Excel tools for Windows and Mac

Import Aerosensor FIT files directly to excel, and perform basic out-back and velodrome analysis. V4.7 Now available!

Updated 29th February 2024.

Fit to CSV for Windows

Simple tool to convert FIT files directly into CSV files for import into excel or other software.

Trackside Lap Logger

Aerosensor lap logger

View and log lap data trackside on a Windows computer.

Updated 8th January 2024.

ANT+ dongle driver

Windows driver for ANT+ USB dongle.

Firmware Updater

Aerosensor Updater for Windows

Update your aerosensor and aerodrome firmware to the latest version using a Windows laptop or desktop computer.

  • Install .msi file
  • Run ‘AerosensorUpdater’
  • Plug in Aerosensor device via USB-C and click update.

Updated 28th March 2024 to V1.4

Aerosensor Updater for macOS

Update your aerosensor and aerodrome firmware to the latest version using an Apple Mac laptop or desktop computer.

 

Updated 11th April 2024 to V1.12

WKO Charts

WKO CHART

Chart layout for viewing Aerosensor data in WKO V4 or V5.

(01.11.23 Update)

Note that WKO does not show the lap or session data, only the record data, which is the time history.

CAD Files

The CAD files are provided for free use; however, users assume all associated risks. Aerosensor disclaims any responsibility for loss or injury resulting from the use of these files.

Current Aerosensor stay

Includes stay and fairing, plus assembly.

Updated Aerosensor stay

One-piece stay released February 2024.