AeroPod, PowerPod and Newton

I just went to apply, post ride, a different profile based on a 10 km out and back ride I did today, to a ride I did on Saturday. This had the effect of reducing the average watts by ~20 W, from ~215 to ~195 W.

Prior to applying the new profile I extracted the original profile from the Saturday ride. After applying the new profile I thought I would reapply the original profile, but this had the affect of reducing the average power to 193 W.

I thought that weird so started from scratch. I deleted the original Saturday ride and profile, then I re-uploaded it, the ride showed an average watts of 215 W, as expected.

Then I extracted the ride Saturday profile and went to the option of applying a different profile post ride and selected the profile I had just extracted from this ride, which presumably shouldn't change anything, but it changed the average power to 193 W.

I don't get what is going on? I open a ride, extract the profile and then go to apply the same profile and the numbers change.

I am presumably being a bit dense, but does anyone have any ideas what is going on?

This is the orginal ride file in question.

I have attached some screenshots to this now.

1. this is the ride file (cant add this screenshot, too many images)
2. this is the edit profile screen with no profiles
3. this is the edit profile screen after extracting the ride file from the ride
4. this is the switch profile screen showing the Watts changing even though it is the same ride file.

I have just tried this on another ride and he same thing happened, applying the same ride file post ride changed the ride numbers, surely this isn't right?

PP does its computations "live", in firmware.

After the ride Isaac gets "readouts" of the PP data. Isaac algorithms try to recalculate the PP computations.

If Isaac algorithms are different (there are some differences; Isaac is not 100% "caught up" with our FW advances), or if the data downloaded is not exactly the same as the "live" data, then Isaac recomputations can be somewhat different.

Unless there are specific problems with your profile (in your case there are not) then I would tend to trust the direct download.

OK, that makes sense then, thanks.