iAero and PT+ Power rate of display

[LouisB]

I paired my PT+ to my iAero without any problem (I got the firmware 3.03) and there is some observations:

- The PT+ CPU and the iAero record about the same data, both at 1 sec. interval. That very good. (Better than the Edge 705 ?!)

- The PT+ CPU and iAero display about the same numbers. The iAero is maybe 1 sec off, and the numbers sometime differs by few watts (1-3w). But the numbers are changing so rapidely, it's hard to say.

- Both PT+ CPU and iAero have big fluctuation in the power numbers displayed. For example, let's say that i'm averaging 215w, both will display numbers between 195W and 235w within seconds, it's anoying. Here some pictures from 10 min on my KK. The power graph match very well what you see on the display. For comparison purpuse I add the power graph calculated from the KK equation in trainer mode:

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My PT+ CPU dont have the "Rate of display" option since I bought an Elite+ hub, but I know that the previous PT hub and others PT+ hubs offer this option to minimize this fluctuation.

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It would be great to have this option too on the iAero, even without DFPM. Something like a rolling average of 3, 5 or 10 sec for the display only. For recording pupuse I would prefer the numbers without filtering.

Louis

[djconnel]

Since the PT reports average power over a fixed time interval, not (like the Quarq or SRM) over integral numbers of pedal strokes, sometimes intervals contain a more or less favorable sampling of the relatively higher torque segments of the pedal stroke. For example, I might hit a sweet spot with my right leg, then a dead zone, then a sweet spot for my left leg. Or I might have two dead zones and one sweet spot. This results in inherent fluctuations in Powertap power. It's slightly worse, even, with the 1-second reporting interval with ANT+ Sport than it was with the old 1.26 second interval. So smoothing of displayed power with the Powertap data is really necessary to get meaningful feedback at a glance. I really support your timely suggestion (timely that I was myself considering pairing an iBike aero with my presently computerless powertap wheel).