marin1

I ride with a 175mm crank arm on my training bike and race with a 172.5 mm crank arm on my race bike. I was wondering if there are any benefits or disadvantages to this. Any thoughts would be helpful or at the very least interesting.

voltman

Did you try the search?

531Aussie

not much difference. A 2.5mm change is more about a slight difference in feel, rather than anything else.

On 175:

There's a slightly different feel pedaling a 5mm bigger circle.
When seat height is adjusted, your knees come up 5mm closer to your chest.
This makes things a teeny bit harder on your knees.

Some claim it's harder to rev up 175s in a all-out sprint or sudden accelerations, but I disagree that 2.5mm affects this

fogrider

I think that for faster spins, go with shorter cranks. 2.5mm is very small and you can barely tell by looking at it, but for a full circle, its a 5mm diameter and at 100 rpm, your knees might feel the difference. just my opinion.

aprilia4life

It depends on your height, it's all relative. A 175 crank might be too long for some, but not all. Fat lot of good a 172.5 is if you are too tall for it and you are losing power.

ac29593

The only thing I regret about my new bike is not knowing anything about crank arm lenghts when I bought it. I loved the cranks on my old bike, and now Im not sure how long they are. I have 172.5 on my new bike and cant stand them....not sure if I had 170's on the other bike or 167.5's.

It was a 52cm 2003 Felt F65 if anyone has the specs, I would really appreciate it.


Edit: Now that I am checking out the Shimano Cranksets, I think they might have been 165's. No wonder I can tell a difference.

simplify

Here's a great thread--four pages worth. Excellent analyses of all the factors.

https://www.bikeforums.net/road-cycling/128549-here-s-list-pro-crank-lengths-you-tekkies.html