Cyclocross - Any REAL differences between cyclocross crank and road crank?

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Tony O
08-05-07, 12:55 PM
Hey guys and gals,

I was perusing the Nashbar site and came across two items that look pretty identical to me, Truvativ cranks on sale:

http://www.nashbar.com/profile.cfm?category=600081&subcategory=60001034&brand=&sku=19118&storetype=estore&estoreid=997&pagename=Estore%20by%20Subcat%3A%20Component%20Liquidation%20Sale%2DRoad%20Cranks

http://www.nashbar.com/profile.cfm?category=600081&subcategory=60001034&brand=&sku=19047&storetype=estore&estoreid=997&pagename=Estore%20by%20Subcat%3A%20Component%20Liquidation%20Sale%2DRoad%20Cranks

I tried to find exact specs on Truvativ website to no avail. To me for all intents and purposes they look exactly the same except one is $30 cheaper. These same cranks came on my JTS so I'm thinking of picking up another set for my Nashbar build.

any thoughts on differences or advantages of one over the other?
thanks
Tony O

cslone
08-05-07, 01:13 PM
Pretty much just looks like the road one has 53/39 rings while the cross one has 46/38 rings.
acorn_user
08-05-07, 04:46 PM
Most road cranks have a Bolt Circle Diameter (BCD) or 130mm or 135mm. Cross cranks and compact doubles have a bcd of 110mm. 110 is good news, because it gives you a lot of flexibility, up and down. The lowest chainring you can get on 130 is 38t (39t on 135). If you search for compact, you'll get more hits. Recommend the Sugino XD.

cslone
08-05-07, 06:01 PM
Most road cranks have a Bolt Circle Diameter (BCD) or 130mm or 135mm. Cross cranks and compact doubles have a bcd of 110mm. 110 is good news, because it gives you a lot of flexibility, up and down. The lowest chainring you can get on 130 is 38t (39t on 135). If you search for compact, you'll get more hits. Recommend the Sugino XD.

Those are both 130 bcd.
cachehiker
08-06-07, 12:57 PM
I just converted my old Ultegra 6500 Double to cross duty by installing 38/48 chainrings.
same time
08-06-07, 01:30 PM
Look the same to me, except the chainrings. It uses the same length bb spindle, etc.

Wow, 50 bucks is pretty cheap. Of course, if you had to buy smaller chainrings, there would go the savings. I would hold out for 110 bcd cranks, but I like small gears. I think my cross bike has 32/42 on it.
Tony O
08-09-07, 12:58 AM
thanks for the feedback guys. With both the advice I've recieved on this forum and also with a bit of web research, I've decided that I'd like to go with a compact crank of some sort, maybe the Truvativ one in my original link or something similar (for my Nashbar build) The JTS I have came with a 53/39 chainring and an 11-34T bracket and though I'm certainly not a competitive cyclist by any stretch of the imagination, I don't find the 53 too big for roads around and I rarely ride on the smaller chainring so I'm a bit confused on what might be the best combo for me. I think maybe my bet is whatever I choose up front, to stick with 11-34T in the back to give me a bit more oomph on the flats.

Now I just need to start spending a bit more time on ebay as I'm realizing all too quickly what most of you already know...building up a bike from scratch (especially with new parts) can be a very expensive lesson
and really doesn't make much economic sense (better off buying complete bike!).

live and learn...
-Tony O