Improper PM calibration

Equipment
1

I run Quaq PMs on the two bikes that I run on the trainer, and I just realized I have been using the wrong calibration procedure at the start of my rides. Instead of having the drive side crank arm down, I have been putting the non-drive side down. Since I’ve been doing this consistently, I don’t think there’s too much of a problem. However, if the difference in the offset values is ~20-40, how much error and in what direction would it be–the numbers a re ~20-40 lower when it’s the drive side crank down.

I also would like to understand how much difference should I expect to see from immediately successive calibrations–presumably very little? I do tend to get very small differences (i.e. 2-4) when I do the unloading crank arm at 6pm technique. However, when using the backpedal technique I can tend to see some larger values. Further, does it matter if I am clipped in when I do the back pedal technique?

2

I would contact Quarq themselves as they’re probably the only ones who would really know.

3

https://quarq.zendesk.com/hc/en-us/articles/217176148-What-Is-A-Good-Zero-Offset-Number-

That number is a direct offset of the torque values, with 1 unit being 1/32 N-m. I wouldn’t worry too much about a 20-40 point difference.

4

-Zero’ing not calibrating
-Was told by a quarq rep that the zero value number should be between -500 and +500 and it should not deviate by more than 50 points between the beginning of the ride and the end of the ride.

I wouldn’t worry about crank arm position, I’d even argue that unless the conditions change a lot you don’t even need to reset the zero.

5

burn all data to the ground :wink:

Don’t over think it - retest FTP, start looking at the new numbers, remember this blip when looking at historical data