Cyclocross - Crank arm length question

This is my first forray into cross bikes. I will be racing cx for the first time this year. I ordered a 54cm Fuji Cross through our team deal, which comes with 172.5 cranks. I am a Campy guy, so all the Shimano parts will be ebayed and replaced. The 54cm comes with 172.5 cranks, where my road bikes are 56cm with 175mm cranks. While I am replacing parts, should I replace the cranks with something I am used to, i.e. the 175's, or is there a reason to run shorter cranks in cx?

Thanks!

hmmm... I wouldn't spend the dough on replacing cranks for 2.5mm difference. its a tiiny diffeence tha t you probably wont even notice. dont sweat it.

~Steve

well since he said he's replacing all the parts anyway - you can go either way with the cranks, the shorter ones will give you just a tad more clearance for the all-terrain-ness of cross. My 'cross bike has 175s and i've never had a problem with pedal strikes really. So if you want to while you're getting your campy fix, go for it - it wont hurt anything.

Okay, so it doesn't really matter? :D

Thanks guys. I just wanted to make sure there wasn't a specific reason to stay or change.

If it were up to me, I would swap it...

While you may not really notice the difference, you'll know that there is one...and that sort of knowledge sucks while suffering on a 'cross course.

Anyways, I think a longer crankarm is actually a better then shorter (think TT vs. a crit) and you need lots of torque to get out of some of the muck...but that's just me.

I run 175's on my road bikes, but last season I had 172.5 on my 'cross bike...this year I replaced them with 175's...