Visual confirmation of auto-calibration

tl;dr: some visual confirmation that auto-calibration occurred would be nice

After reading some threads from frustrated users bemoaning the inaccuracy of their Zwift hub, I thought to put my outdoor bike with its quarq PM on the trainer and run some of my own experiments. Long story short, the Zwift Hub and crank-based PM are pretty much spot on across a broad range of effort levels: within 0.5%. (And I have done some real-world testing with conditions as controlled as possible to determine to the best of my ability that the quarq PM is highly accurate and precise. And to the brigade of posters who inevitably ride in whenever there is a discrepancy to point out drivetrain losses affect different measurement points differently: guess it’s not so hard for the trainer firmware to multiply by 1.02 after all.) So chalk this up as a success story — I hope users searching for “zwift hub reads low” stumble across this post and discover it’s not always the case.

However, in the course of this testing, I did discover that the auto-calibration is very necessary. I did the same fartlek workout twice in a row, but the first time I jumped straight in without ten minutes of pedaling followed by some coasting. And in the first workout, the two power meters were off by about 10 watts (didn’t seem to matter what the effort level was). Only in the second workout, which took place after an assumed spindown/auto-calibration, were the two PMs well aligned.

Hence, it would be nice to be able to know the calibration took place the next time I’m warming the thing up for a workout or race.

Yes please! I ride ERG mode 99% of the time (sometimes I continue for a bit after an ERG workout, but that’s rare). So doing a free ride to trigger the automatic calibration is a very specific effort/event for me. I would really like to know that it was successful if I do this. In fact I have no idea if the unit I have has calibrated ever at all.

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