Incorrect Wheel Circumference Entered

One for the mathematicians:

Yesterday I did a workout on my Kickr Snap (wheel on) trainer. I used a different bike with a 2050mm wheel circumference. But the circumference in settings was in the previous wheel’s setting of 2150mm. So 10cm/10mm/4’ difference (less) depending on your measurement flavour.

What was my percentage difference in effort over a 45 minute ‘Birch’ endurance workout? And does that percentage denote I worked harder or made life easier?

Presumably you did not do a calibration on the trainer for the most recent effort?

2150mm is about 700x32
2050 is about 26x2" or 700x17
Difference is about 5% right?

But none of that might matter depending on how the Kickr calculates wattage.
If the calculation is done based on stuff inside the resistance unit there should be no difference.
If, however, the calculation is done based on your wheel’s RPM then I imagine there would be a small difference.

Also, what Chad said.

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I did do a calibration beforehand. I simply forgot to change the size.

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Thank you. So no cardinal sin was committed and I can sleep easy.

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Perfect. Since you got the calibration, your power is good. :smiley:

The only difference would be in the “speed” and “distance” reported to Strava, Garmin Connect, etc. and that is hardly a problem.

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Fantastic! Thank you as always @mcneese.chad

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