POWER READINGS DOWNLOAD INCORRECT

[JOHN WALKER]

TT RIDE ON OPEN AIR VELODROME.. DURING THE RIDE THE WATTS APPEARED CORRECT AND WERE CONSTANT FOR THE CADENCE AND SPEED. AS DISPLAYED ON iBike. DURING THE 5min ALL OUT EFFORT @ 14.8km THE AV WATTS REMAINED OVER 300W DURING THE RIDE.
DURING THE 20min T.T. @ 28.3KM THE AVE WATTS DURING THE RIDE WERE OVER 300w AND TOWARDS THE END OF THAT PERIOD DROP T0 UNDER 300W ( DUE TO FATIGUE ) WHICH IS TO BE EXPECTED. SO WOULD HAVE EXPECTED AN AVERAGE 280/300W FOR THE 20min TT.

HAVE DOWN LOAD THE RIDE AND SEE FOR THE 5min ALL OUT EFFORT - AV 200W
AND FOR THE 20 min TT AVE 202WATT LIKE A FLAT TYRE.

Watts gone wrong?

Will try and attach file.

Also have a new Garmin Edge 800. Heart and cadence are in sink and being displayed on the screen of the Edge.
However, the power is not being displayed. Have written to Garmin and followed their instructions, but still no go with watts being displayed on screen. I notice, e.g. for cadence there is an ID number, but for the watts no such ID. Have noticed with iBike - Edit Profile - Advance - that for Power the ID shown is 0. Is this correct?