Originally Posted by
achoo
Where's the evidence supporting that assertion?
Just because it's off by 10% (or was it the PowerTap that was off? Gee, we don't know...), that does not make it inconsistent.
Just to reach back in time and address this statement: I test my PT with 38 lbs of postal-scale-measured weights hanging off a pedal. I know how far off it is, and it's consistent.
There is no way to zero out a PowerCal. It will be all over the place, and is worth no more than a novelty as far as power is concerned. Even just normal HR drift will show a power increase that isn't there once you start getting dehydrated and hot.