Originally Posted by
RChung
I have long wondered whether people who have a specific idea about appropriateness for cadence also had a specific idea about appropriate crank torque or appropriate power. If so, I wondered what that would be; if not, I wondered why cadence takes precedence over crank torque or power. You appear to have specific ideas about appropriate cadence so I thought I'd ask you. I am not trying to imply anything. I'm asking a pretty simple question (though if you don't have a specific idea about appropriate crank torque I guess the follow-up question could be a little less simple).
This is a very thought-provoking question.
When I think about it, I would say that actually the recommendation to decrease strain on knees should be to minimize crank torque, which I know from my own data is pretty closely correlated with power output. So you could say, "protect your knees, decrease torque or power". Since your bike computer displays both power and cadence (at least for people with power meters), the more direct advice would be "decrease power".
Cadence on the other hand is less directly related to power output, I know that I can produce the same power output at a wide range of cadence. I can for sure produce high power with high cadence, so telling people to pedal with high cadence is not necessarily going to be an instruction that results in less strain on the knees. You'd have to tell people to pedal with high velocity and low force. But people could accomplish the same protective effect by pedaling at low velocity and low force.
When I look at my climbing data, I pedal at low cadence (60-75 rpm) and both high & low force. But I rarely pedal at high velocity and high force when going up a hill. It looks like all the high velocity- high force pedaling for me happens on the flats.