Calibration for tailwind/headwind consistency

[Bugsbunny]

Hi John

I've noticed on a number of rides now (on a relatively flat out and back loop), that the power readings appear to vary by an inconsistently large amount for headwind versus tailwind power readings when applying the same perceived power to my pedalling. More specifically, when going into a headwind the power readings seem to be far too low. Conversely, with a tail wind it seems to indicate it to be a bit high.

For example, when riding INTO the headwind PP is showing around 90 watts (after waiting for dynamic smoothing to "settle") where my perceived effort is around 140-160W. (My fellow riding buddy next to me who is 5kg heavier than me/same bike charactertics/same speed, showed 160w on his Garmin Vectors).

I have Dynamic power smoothing on and Garmin set to 0 second power smoothing.
I use an out front mount with no wind blockage.
I have CDA hard set at 1.7.

Is there any tips on how to calibrate or set up the PP to get greater consistency here? Or is there something you can point me to where I might have screwed up the settings... and I can verify.


Many thanks

Bugs

[Velocomp]

Please post a .ibr ride file illustrating the issue.

[Bugsbunny]

Hi John

Here is a the ride file I placed in my Dropbox. Sorry I don't know how to upload it directly to this site.
https://dl.dropboxusercontent.com/u/196 ... _Miles.ibr

And here is the out and back ride I did immediately after the above ride trying to see if would help correct it.
https://dl.dropboxusercontent.com/u/196 ... _Miles.ibr
I have since "accepted" the suggested changes.
The anomaly I can find is that the FTP says 80.8W - I'm not sure if that was input by me - but appears much too low.

Bugs

[Velocomp]

I've corrected your profile for windspeed, using the Analyze/Check Calibration command.

The corrected profile is attached. Please load into your device.

I also corrected the ride file with the updated profile. Wind speed looks much more normal.

the 80.8FTP is factory default. You can correct this in your profile.