Pigeons coming home to roost

[vitiris]

Well I bit the bullet and I am now choking on it! Saw what was an absolute bargain on e-bay for an unused Powertap Pro Zipp wheel, nobody bid and I negotiated a good price. I even went to pick it up and all looked fine. Anyway I went to fit it today and everything seemed ok except the power (the most important aspect) is all over the shop . Mileage, speed, cadence, heart rate are all reading correctly or very close according to my other computer (HAC4) but the power is crazy. I have tried to (or think I have) zero the torque, it says that 'watts' should disappear when in torque mode but mine just seems to flash. The chart of my 8 mile test ride is attached.

Any advice or help will be warmly appreciated

Sean

 

[jws]

Power will fluctuate continuosly because of changing resistive forces, e.g., hills and wind, and because your power input varies. I can't tell if your power readings are right from the graph(the smoothing is set too high), but it doesn't look abnormal.
You really need to look at average power over different durations to assess your abilities. I would suggest getting Cycling Peaks software to get the most from your PT.
The "watts" label should flash when in torque mode; this changed with firmware version 2.00 or so.
Here are some good links for power training:

http://www.cyclingpeakssoftware.com/

look at all the power links, especially "Power 411".

http://www.midweekclub.com/articles/

look at the FAQ and guides by Coggan and Howe

http://www.cyclecoach.com/

Ric Stern knows his stuff

Well I bit the bullet and I am now choking on it! Saw what was an absolute bargain on e-bay for an unused Powertap Pro Zipp wheel, nobody bid and I negotiated a good price. I even went to pick it up and all looked fine. Anyway I went to fit it today and everything seemed ok except the power (the most important aspect) is all over the shop . Mileage, speed, cadence, heart rate are all reading correctly or very close according to my other computer (HAC4) but the power is crazy. I have tried to (or think I have) zero the torque, it says that 'watts' should disappear when in torque mode but mine just seems to flash. The chart of my 8 mile test ride is attached.

Any advice or help will be warmly appreciated

Sean