Bike Forums - View Single Post - Cadence, who needs it?

01-23-23, 07:45 AM

#41

ofajen

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Quote:

Originally Posted by 63rickert

Does anyone here do a warmup? You should, any sport, and emphatically in cycling. Do that warmup at 110 and 120rpm. Easiest way to do that is to have a group that does that. Used to be every cycling club everywhere did exactly that. Those clubs are gone. Doing it on your own is harder. It can be done. It can be done faster.

Force is not energy and the internal work of pedaling seems to follow a power law, not an exponent.

However, it is a sharply increasing function of cadence, so you make a great point that spinning is a good warmup.

From Formenti’s data, you can assume about 1.0 W/kg at 110 rpm. It appears to obey a cubic power law in the region (50-110 rpm) that he published.

If that power law continued above 110, you would spend 1.3W/kg at 120 and 1.65W/kg at 130. If it applies out to 150, that would be 2.5W/kg and if it still applies at 200, you are spending 6W/kg (I assume most of it from your rider/bike kinetic energy) to move your legs and the pedals.

Of course, it’s not all clear that we should assume that function continues at those higher cadences.

Otto

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