AeroPod, PowerPod and Newton

Hi John,

Could you check whether the power reading on my powerpod makes sense?

I did a ride recently after calibration and tested my power on a local short 2 KM climb with 5% grade. The 5 minute and 30-ish seconds effort were reading around the 398 watts and I personally think that is a bit too high because when I looked at Strava, people who put around this power range is at least around a minute faster.

Some useful information:
-My height is roughly around 173 cm, weight is 75 KG.
-My power pod is mounted on the combo mount ( hence aero factor of 1.6) and I ride fairly in an aero position ( bent elbow on hood ) on a regular road bike. The aero pod is fairly level.
-I used to have an FTP of around 260-270ish watts 2 years ago and I recently started training again by doing intervals and zwift. I used to have a direct force power meter but I sold it long time ago after not training for some time. I thought it might be a good idea to try the PowerPod since its fairly affordable and accurate in the right circumstances.

From your analysis, do you think the 5 minute reading on my ride is fairly realistic? Yes I did go hard by doing out of saddle climbs a couple of times during this segment but I still think that 400 watts is a bit too rich for me for a 5 minute effort.

Let me know if you find anything interesting or need any more info.

Attached is my profile and the ride.

In your particular ride you did a steep downhill, followed immediately with a steep uphill.

When riding downhill your body shifts its weight somewhat, towards the front of the bike. Believe it or not, PowerPod can detect your weight shift and it adjusts its sensors accordingly.

When you hit the bottom of the hill you immediately started climbing. This means that your weight shifted again (this time towards the back of the bike) so PowerPod once again began to adjust its sensors. However, depending on the magnitude of slope change this can take some time. You have a big change (-6% to +6%) so while the sensor adjustments were being made your readings were somewhat high.

This is an edge case that we see very rarely. But we want you to get great results no matter what your riding situation is, so we will see if we can change things some to improve the adjustment algorithms.

Hi John,

Wow that was certainly very interesting insight, thanks for your analysis.

I am reasonably happy with the power pod for the steady effort climb over ten minutes.. its quite accurate and I did compare the number with bike calculator and the wattage is very close.

As long the firmware keeps getting updated ( and getting more accurate for corner cases like this), I am happy.

One last question, is the out and back ride necessary to get more highly accurate readings? My impression is that if you get the 'assumption' right in the profiles, weight, aero, CdA, etcetra the readings should be close enough. How much of an improvement will it make if I perform an out and back ride?

Thanks,
Kenny

Your unit looks to be well calibrated. The O&B ride fine tunes the wind sensor. It won't hurt if you do it!