QUESTION: I’ve heard that it’s better for knees if you spin a lower gear on climbs rather than mash a big gear. Why is it harder on the knees to pedal at a slower rpm? What about pedaling slowly when out of the saddle? — Jim M.
RBR REPLIES: Good questions! The important element here isn’t the total time taken to climb the hill, but rather the total load on the knees during any given pedal stroke.
If you ride up the hill in three minutes at 80 rpm, you’ve divided the total work into 240 pieces (3 x 80). It takes the same amount of work to climb the hill in three minutes in a bigger gear at 60 rpm, but the work has been divided by only 180.
So, there’s more work being done on each pedal stroke when you have a lower cadence in a bigger gear. There’s more stress on the knee on each pedal revolution. Make sense?
Standing up definitely takes stress off most knee problems cyclists are likely to have. It’s a good choice when you’re climbing with someone who is slower and uses lower gears. It gives you a chance to stretch your legs and take weight off your rear end, and the pressure off your lower back.