Originally Posted by
Joe F
Interesting discussion. I had considered going from 175 to 165 after the earlier thread, but thought the difference in length to be so small it wouldn't make enough difference to be worth the investment. Might have to find someone around here with a 165 and give it a spin. My knees have taken a lot of abuse over the years between sports injuries and motorcycle wrecks, not to mention the occasional crash out on the mountain bike trails. Not in need of replacements yet or anything, but I can tell they aren't what they once were in mobility and strength.
The effect is 2X.
You raise the seat another 10mm, when in the 6 o'clock because of the shorter crank.
When at 12 o'clock, the pedal is another 10mm closer to the ground then it was before.
Therefore, you sit 20mm higher then the top of the pedal stroke.
Late Edit-
I also tried some 160mm cranks, but they were too short for me. I couldn't really improve the cadence and it was "less comfortable" trying. It was like the acceleration/deceleration occurred too rapidly for my ratty, chubby knees to follow "smoothly". Like being on a kids trike.