aeroworkbook
Loading data
For each run you load into the excel tool, a separate worksheet will be created named Run_X where X is the number of the run, starting at 1 for the first one you load. It will also create a Summary worksheet showing data for all runs, and two graphs showing the CdA and power variation to your baseline.File based system
- Change use cloud in basic settings to false.
- Click on Load FIT files.
- Select one or more FIT files from the file system.
Aeroportal based system
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- Change use cloud in basic settings to true.
- Click on Load FIT files. You will be prompted to log into your aeroportal account.
- Select one or more FIT file then click the Open
If you don’t have one, click here for instructions on how to create.
On windows files are saved to the following directory:
C:/Users/[UserName]/AppData\Roaming\AerosensorExcel
On Mac they are saved to the following directory: /Users/[UserName]/Library/Containers/com.microsoft.Excel/Data/Library/Application Support/AerosensorExcel
Run analysis
There are a few steps to getting the best accuracy from your data.
On the worksheet for each run you can edit any of the cells highlighted yellow.
Select valid runs
Aeroworkbook will automatically mark runs as valid based on the speed tolerance criteria by putting an X in the Valid column of the Lap summary table, highlighted in yellow.
A few tips on selecting laps:
- For Out-back runs, you need an even number of laps. You should be able to see the out and back pairs.
- Check the Distance column to make sure the lap looks correct.
- Check the Power column to check you aren’t on a warmup or cooldown lap.
- Look at the CdA column to make sure the CdA looks stable. Sometimes in the velodrome the first and last laps can be outliers because getting into or out of position on the bike.
Check if auto cal is appropriate.
Decide if using auto cal is appropriate or not. We will shortly be adding more guidance on this.
You can whether to use auto cal for this specific run by selecting true or false under Auto cal in row 5.
Check run parameters
The run parameters entered into the Garmin via the CIQ are shown under Run parameters in the column marked Setting in device and also copied to Used for calibration when first loaded.
If any of these were not correct, or for example you are not using auto cal and want to manually change the Aero Cal value then can change it here.
Recalculate
Either click Recalculate sheet to recalculate data for the active run sheet, or click Recalculate on the Control worksheet to recalculate all runs. The data is recalculated in the run sheets and also updated in the Summary sheet.
Interpreting data
In the summary sheet you see a list of all of your runs. The final, calibrated CdA is in the column under “CdA Final”.
In the very first column you can select your baseline. This is usually the first of a block of runs, and is the run you want to compare everything else to.
Under the section “Delta to baseline” you see the difference between each run and the baseline. This is the most important section.
- CdA shows the difference between each run and the baseline in terms of pure CdA.
- Watts shows this difference in terms of power. Since power is a function of speed, you need to select an appropriate speed to calculate the power at.
Aerodynamic power, the power expended purely on aerodynamic drag, can be calculated as follows. This assumes zero headwind.
p_{aero} = \frac{1}{2} \rho v^3
Where:
p_{aero} = Aerodynamic power (Watts)
\rho = Air density (kg/m3), typically around 1.2
v = Speed (m/sec)
Histograms
On each run sheet histograms of headwind and wind yaw angle are shown for all of the laps marked as valid.
For each headwind bucket it shows the percentage of time spent with that level of headwind.
If aero calibration is correct, it should be centred around zero.
For each yaw angle bucket it shows the percentage of time spent with that wind yaw angle.
This is Abs Yaw where negative values are treated as positive as generally we assume the aerodynamics are symmetric, so you just want to see what variation is.
Here, by bucket we mean a headwind or yaw angle range.
For example, each headwind bar is 2kph wide, so the bar at 4kph counts all of the datapoints where the headwind falls between 3 and 5kph.
