Crank arm length? - Page 4

Increase? I am not looking for an increase, I am looking for a decrease. Again, after putting a fair amount of thought in to it and getting professionally fitted, I ordered my bike with 172.5 cranks in 2004. Then while cleaning the crankset not long ago, I measured the crank arms and discovered the bike shop sold the bike to me with 175mm cranks even though I ordered 172.5 mm cranks.

I am under 5'9" and feel that these 175mm cranks are not only a little hard on the knees, but also slightly inefficient for me with too big a circle. Heck, you are 6 feet and riding a smaller crank than I am most of the time-- 172.5s. Most of my climbs are not hills; they are very long mountain climbs with a lot of time in the saddle. If I was sitting and then standing or powering up over short rolling hills, maybe I would appreciate the "leverage" of 175s, but as it is, sitting on the saddle for mile after mile, I suspect I am gaining inefficiency (and possible knee damage) with the 175mm rather than anything positive. JMO.

The truth of the matter is what is best for you are the cranks with the length that feels best for you. While "in general" longer cranks mean better leverage, that generality is only valid when the only variable being changed is crank length. As such, it's not always valid with riders because changes in crank length can result in changes in efficiency, power output, and most importantly perception. If your perception is that your cranks aren't the right length, then it's likely you won't pedal as well as you can.

FWIW, I pedaled on 172.5's for a while, but I started to notice that I felt "confined" in my pedal stroke. Somethin' just felt a bit off. So I changed to 175's, and that was the key move. With the 175's, I felt better seated on climbs, AND my cadence went up. The point is that the bike/rider system is more complicated than generalities about the effects of varying crank lengths would let on. So, as Confucius said:
If it feels good, do it.

ooops, I misread. That farkin sucks that the dude put you on 175s

Maybe even 170s are worth considering, but I know it's expensive to keep changing

What's your 'latest' inseam with the clipboard jammed up your duff?