RoadBikeReview.com's Forum Archives - Cyclo-Cross


Archive Home >> Cyclo-Cross(1 2 3 )


newbie to Cross question - What Crank length should I use?(7 posts)

newbie to Cross question - What Crank length should I use?ss-nyc
Nov 26, 2003 2:16 PM
I was lucky to find a new-old-stock Surly Cross-Check in my size 52, in Bean Green which I really like, and one of the earlier greens that was Reynolds 631 tubing. Since I have never had/built a cross bike before I need some help with crank length.

My road geared has 170s
My road single-speed has 170s
My road fixed has 170s
My mountain geared had 175s (I got rid of it a few months ago)

What should I use on a cross bike and why?

Please give me your strongest opinions!
my newbie experiencePmbH
Nov 26, 2003 4:02 PM
So I used to ride 172.5 road and 175 mountain years ago. In the past 10 years, I stopped road biking, kept mountain biking, and got back into road biking. When I picked up road again, I went with 175s because that's what I was used to... All bikes had 175s till I picked up cross.

I picked up cross using an old touring bike. It has a low bottom bracket. I went with 170s to help with clearance under the pedals. Now that I've done some cross racing, I've discovered the following:

- 5mm doesn't make a hoot of difference in terms of clearance
- If I'm careless, I'll strike a pedal on the ground just as easy with 170s or 175s
- I can feel the difference between 170s and 175s, and I miss my 175s
- Time to get some new cranks on the cross bike

As of right now, my opinion is to use what's familiar to you.
on the other handlaffeaux
Nov 26, 2003 5:02 PM
On the other hand there are those of us who can't tell the difference between a 170mm and a 175mm crank while riding the bike. I'd guess that I have 175s on my bike, but I'd have to look to be sure.

Ride 170s if that is what you're used to. There is no right answer, it's what you prefer.
Best of both(all) worlds?haystack
Nov 26, 2003 7:02 PM
When I was initially looking for a road bike, the people at the LBS couldn't give me a definitive answer to the crank length question other than shorter cranks are better for spinning i.e. criteriums and longer cranks offer more leverage i.e. better for climbing. Well, since I was planning on both of those possibilities and everything in between, I asked about and settled on 172.5s. The jack-of-all-trades crank length, while master at none. I now ride 172.5s on my road and CX bikes and 175s on my MTB (thats what they came with) and things are just fine (though I haven't placed in any CX races yet).
It's jack of all trades only if everybody has 32" inseam (nm)shirt
Nov 27, 2003 10:46 PM
Match your road bike...skateparks
Nov 28, 2003 3:40 PM
Match your road bike...MShaw
Dec 1, 2003 11:28 AM
From what I've seen, 'cross ain't about torque its about horsepower! (at least here in San Diego!) For the most part, the hills that are steep enough to need the long cranks are faster running.

If you're used to running 170s, that's what I'd stick with.

Mike