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Old 07-05-22, 11:44 AM
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ofajen
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Originally Posted by WhyFi
And what does your power meter, HR, and RPE tell you? I'm quite comfortable spinning at 120rpm, but my power and RPE start getting out of whack, once I get over 105 or so. After noticing this, I've made a conscious effort to check that I'm not settling in to a comfy, but inefficient, cadence.
Just a reminder that the internal power requirement of pedaling (just moving legs, feet and pedals in a circle but applying no external power to the pedals) is a sharply increasing function of pedal rate.

Formenti’s published data covers 50 rpm to 110 rpm and matches a cubic function quite nicely. It’s about 1.0 W/kg at 110 rpm. Assuming that the power remains a cubic function at higher rpm, it will be 3 W/kg at 160 rpm and 6W/kg at 200 rpm. That’s just the overhead of keeping feet in position to apply power.

The power you apply to bike and rider and that your meter measures is on top of that. By way of comparison, at 70 rpm it runs about 0.3 W/kg and at 90 rpm it runs about 0.6 W/kg.

Otto
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