AeroPod, PowerPod and Newton

Hi,

I'm struggling to get to grips with my new aeropod.
I have done only 2 rides with the aeropod:

1:I've done a calibration ride (done on the hoods)
2: I've done a 'test' ride to see impacts of different positions.

on the test ride, i rode for a couple of km to a point where i could do two loops of approx 9.5km. The first loop was done on the hoods and the second was done on clip on aerobars.
I maintained (as far as practicable) consistent positions on each.
The second loop showed a time saving gain of 63s over the first.
I'd expect this to be about right, as its a cervelo R2 with a bike fit for touring rather than racing.
However, what i can't understand is the massive deviations in CdA when riding in a constant position.
During loop 1 (on the hoods) the CdA ranged from about 0.29 to 0.6.
During loop 2 (clip on aerobars) the CdA ranged a similar amount buy was 'normally' lower than loop 1.
it appears that when going downhill the CdA drops and when uphill it rises.


I am using Assioma single pedal power meter

Is there something amis?

I attach the test ride

David

Please post photos showing your AP is attached to your bike.

I actually think your data is OK.

I agree with you that, during descents, CdA drops significantly. But if you look you'll see that your power drops way off, too--for example, between minute 27 and 28, where average power is only 60W. It is difficult to get accurate CdA readings when the applied power is so low.

Between minute 13 and 27, where you are on the hoods, your CdA is about .402. CdA does vary some as you ride, but this is normal, particularly given the fact that you're on rolling hills and your power levels are varying significantly.

Between minute 37 and 49, on the same section of the course, you are on your TT bars and your CdA is about 0.313. For what it's worth, your numbers are very similar to mine!