What cadence should I aim for?
I recently got a cyclocomputer that measures cadence and I'm not sure what a good speed is or what benefit I would get by altering my natural cadence. On good, level tarmac, I find myself doing about 75-80 RPM. I'll get North of 100 when sprinting away from a stoplight, and down in the 50-60 range when mounting a moderate incline.
I don't know what might impact cadence, but I'm 5'11 (180 centimeters), 150 pounds (68 kilograms, 10.7 stone). In addition to biking 30-40 miles a week, I do CrossFit, a combination of gymnastic and weightlifting exercises, so I've got quite a bit of raw strength.
Here's a pretty good article on cadence. http://www.beginnertriathlete.com/cms/article-detail.asp?articleid=433
For any given speed, you can either spin at a higher cadence in a lower gear, or a lower cadence in a higher gear. The high cadence + low gear combination should reduce the strain on your joints since you don't have to push as hard. You just have to do it more often.
I like to ride around 90rpm and sometimes drift up to 100-110 especially if I'm trying to catch up to or overtake someone. I'll drop down to 80 for long, steep climbs (seated -- no idea what my cadence is standing).
Lance Armstrong apparently maintains 110rpm for efficiency. It took me a while to get used to 90 so I'd suggest building up to it slowly. Let us know when you can do 110 comfortably!
Chris Carmichael, Lance A's coach, recommends higher cadences, and working to increase your overall cadence by about 10% per year. Some of his earlier books mentioned shooting for around 100 rpm on the flats, apparently there is some beneficial assist to circulation at that rate, which helps offload some of the work from your heart. While climbing he says you will usually need to drop down to around 70-75 rpm to be effective.
The problem with trying to copy Lance is that he's a physiological freak of nature. The reason he uses a high cadence is to shift stress away from his legs and onto his freak of nature cardiovascular system. The best thing you can do is measure your power output at different cadences. I find I can generate the most power at 90 rpm. YMMV
A big reason to have your cadence around 100 is that you are pressing down less for the same speed which in the long run will save your knees. Slow grinding pedaling will also grind out your knees. It is a bit tricky at first but when you get the hang of it over the course of a summer it will just feel natural.
@JohnDyer and the Darkcanuck: What difference is seen in our muscles during different cadence? I heard calves are used for high and quad for low cadence, am I correct?
@JohnLam You're saying that the most RPMs you can do without losing significant power is 90, correct? Stationary at 0 RPMs with the cranks horizontal should be the absolute maximum power one can achieve. Or am I misunderstanding? Maybe "power output" is measured per RPM?
@Freakyuser I'm no expert but that makes sense to me.To maintain a given speed, the torque required is inversely proportional to your cadence. Your quads are stronger than your calves, so for high torque (low cadence - high ratio) you'll need to use that.At high cadences you _could_ use your quads the same way, but because of how our bodies work, it's more tiresome.That's because it takes more oxygen to rotate your thighs a big distance than to rotate your feet a small distance, so you wind up using your calves as much as possible, and it works out fine because you don't need the extra torque.