I have done several rides and have found the comparison between my Power Tap DFPM and the Newton to be very close. I am seeing on solo rides about 1-2 % variation on average watts but 5-7% on maximum watts. I have found that by adjusting the Crr I can get the average watts perfect, but the maximum is still out somewhere around 5%. For a solo ride, the Crr adjustment seems to makes sense as qualitatively, the road conditions pretty closely mimic my adjusted values.
First, am I on the right track by using Crr as a calibration variable for non-drafting solo rides? And second, what is the best method to get the max power reading a little closer without affecting my tweaked average power? The max power reading took place in a sprint at around 30mph, so are aerodynamics the place to start with adjusting the max power number? I can only count on the road conditions to be fairly consistent, but cda, I am not so sure. Maybe I can't have it all?
Newton Calibration
Re: Newton Calibration
IMO both those are good and I wouldn't go adjusting anything arbitrarily.
If your iBike is reading 2% high, that is perfect because it calculates crank power, while the PT measures at the hub.
Which one had the highest sprinting watts? Your CdA in a sprint will likely be different than when riding normally, so not much you can do about that.
If you list your tires and tubes, road quality, position, etc... I can see if your Crr and CdA numbers are sensible.
If your iBike is reading 2% high, that is perfect because it calculates crank power, while the PT measures at the hub.
Which one had the highest sprinting watts? Your CdA in a sprint will likely be different than when riding normally, so not much you can do about that.
If you list your tires and tubes, road quality, position, etc... I can see if your Crr and CdA numbers are sensible.