AeroPod, PowerPod and Newton

For a long time I've consistently obtained much lower numbers when using my iBike on my TT bike with RWS in contrast to on the road bike. On the TT bike, the iBike and RWS are all mounted on the aero bar - see photo (red elastic band to keep RWS plugged into iBike). RWS does not get in the way of my hands or arms.

Consistently, I get much lower numbers on my TT bike. EG, my FTP = 287, and on a recent very hard TT I managed a NP of 226 (yet I know I worked hard - I came 2nd in the State championships ). I've redone the calibation rides a number of times, and recent numbers are:
Aero: 0.197
wind scaling: 0.811
CdA: 0.243
Fric: 4.751
Tilt: -0.1
Crr: 0.0055
Cal weight: 163

I weigh 144lb, 5'11" tall.

Whilst riding, when going uphill, the power output on my TT bike seems more like what I'd anticipate .

After a major examination of the iBike and the RWS, I notice that the RWS seems to leak air when I blow into it. The plug into the iBike is different from an unused plug - see photo - new plug is the one on the left.

Could this be the problem?

I'd be grateful for any comments, or advice. Thanks !
STEVEN

It looks like your old plug has deformed.

You definitely want a good seal between plug and iBike. If the plug leaks then recorded wind speed would be low.

Thanks John. And I assume that with low recorded wind speed, the calculated power is lower, hence my low numbers?

I'll put on the new plug, recalibrate (which I can do on Tuesday morning), and hope for resolution!

STEVEN

Yup, artificially low wind speed results in artificially low watts...

New calibration ride, and new coast down rides, with plug that seals properly. Then did 2 x 20min TT intervals, using "old" profile (ie calculated with leaking plug) whilst riding. Changed to new profile at home --> NP increased from 207 to 243. Power variance much more stable. Rider much more happy. Thanks John!