AeroPod, PowerPod and Newton

Dear here,

on my TT-Bike I have no Powermeter and want to used the Aeropod in Profile 1 as Powermeter. My CDA is around 0,225 instaed of 0,285 estimated.
I have installed a Powertap rear wheel to the TT-Bike for calibration rides. Aeropod is now well connected to the Powertap.

Which procedure would you propose to set up the Aeropod in Profile 1, that I can install my disc rear afterwards and have best fit in TT-Position? Currently Aeropod shows in Profile 1 w/o PT-Hub Power-Output of 380W on my 10 miles Test-Course but unfortunattely thats not true )

Especially set up of Windscaling, Cm & Crr is not clear for me.

Any proposals?

quantus wrote: ↑Wed Aug 13, 2025 8:58 am Dear here,

on my TT-Bike I have no Powermeter and want to used the Aeropod in Profile 1 as Powermeter. My CDA is around 0,225 instaed of 0,285 estimated.
I have installed a Powertap rear wheel to the TT-Bike for calibration rides. Aeropod is now well connected to the Powertap.

Which procedure would you propose to set up the Aeropod in Profile 1, that I can install my disc rear afterwards and have best fit in TT-Position? Currently Aeropod shows in Profile 1 w/o PT-Hub Power-Output of 380W on my 10 miles Test-Course but unfortunattely thats not true )

Especially set up of Windscaling, Cm & Crr is not clear for me.

Any proposals?

Please post a .ibr ride file with both your AP and PT power data, and I will help you figure out things.

Oh great. I will send on friday.

Out and back TT ride

Hi, after a new calibration of an additional speedsensor garmin has shown me 2134 mm circumferance. That matches better to the 28mm conti gp 5000 tyre.

Here is the procedure I used with your profile 3 out-and-back ride file, using Velocomp Aero (VA)

1) I opened the file in VA, then used the command "File/Revert to Original Download..." to get the information as it was downloaded originally (it looks like there was an extra lap in the file you posted).

2) There are two laps shown: lap 1 is your O&B route. Note that in the Stats Window to the left of the graph, AP Power (Power) is 288W watts, while DFPM power is 321 watts. Note also that wind speed is lower than bike speed: when the wind sensor is calibrated, on an O&B route the "wind scaling balance" (WSB) should be 0.0, and wind speed should be very close to bike speed. The consequence of too-low wind speed and too-low default CdA is that AP is about 40W low, so we need to tweak the O&B for maximum accuracy, and likely update your default CdA value of 0.225
3) Click on lap 1 (your O&B lap); it turns solid blue. Note that in the lap 1 row, CdA is 0.234. This is the AP-measured CdA for the lap, not your default value of 0.225 4) Place the pointer over lap 1; the lettering turns solid white
5) Right-click on lap 1; two options appear
6) Place the pointer over the selection "check device calibration" and then click on the selection. A new window appears:
7) Below the pointer graph, in the window "CdA to use", type 0.234, the value from the lap 1 result, then click Accept in the bottom right corner
8) The corrected O&B result appears, and note that with CdA = 0.234 AP and DFPM watts now only about 0.5W apart!
9) The final step is to update your AP with your adjusted parameters. Select "Edit/Edit Profiles..." and click on "Extract from Ride file"... Your corrected profile will be highlighted at the top, with the CdA 0.234 and updated wind scaling. Connect your AP to VA and then click on "Send to Device".
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Something I note from your ride file is that your Crr (rolling resistance) is very low, about 0.0024. This is a Crr value found in a velodrome. If that is where you did your ride then fine; if not please let me know where you did your ride and I will show you how to adjust things.

Thx a lot for your guidance. I will check it out.

Crr is too low, i know. The street is very good tarmac. Conti GP5000 with latex inner tubes.
Cm: hot waxed chain and new premium steel ball bearings.

Would you recommend to repeat the run at lower wind conditions to come closer to windscaling 1.0?

Which Crr would you recommend based on the first run?
https://www.strava.com/activities/15545040813

Is there a way to check the Estimation Quality of Crr based on a trial run for a specific course?

Dear John,

here are my learnings from your guidance:

1.) Accept Windscale Calibration 2.) Accept Crr Estimation 3.) Adjust CDA to match the Power

Power Match
Should I repeat the run at lower wind speed with the found parameters?

Would you recommend Profile 3 or Profile 4 to do the test run?

quantus wrote: ↑Fri Aug 22, 2025 7:59 am Power Match
Power_Match.png


Should I repeat the run at lower wind speed with the found parameters?

I have no idea what you are posting here...

quantus wrote: ↑Fri Aug 22, 2025 8:01 am Would you recommend Profile 3 or Profile 4 to do the test run?

What are you trying to accomplish? Best calibration, or CdA test?

Best Calibration for my Aeropod to use it as Powermeter to use the Bike without DFPM.
Nevertheless the numbers for CDA and Crr should be reasonable at my specific Test Course.

But Thx, your guidance was helpful and I will use as proposed by you.