pstock

I have had trouble finding a suitably sized complete cyclocross bike and so, having come across an appropriately sized frame for sale locally, my thinking has shifted to building one up.

Question: outside of the frame (and the cantilever brakes), are there any component/part differences between road bikes and cyclocross?

I ask because I have a rather large (that's understatement) stock of road bike parts (Campy, Shimano,old-style, modern) and wheels (clincher, tubulars) that I would prefer to use UP rather than buying new bits.

I could imagine for instance that CC might require more robust wheels.

Peter

cs1

If you have all the parts try them first. It's a lot cheaper that way. Then upgrade IF they break. Good luck

darrencope

The main difference would be the gearing. As long as you can get low enough gearing, standard road stuff should work fine!

marqueemoon

Low on the gearing, but not too low if you're racing it. Stick with a short cage rd. That will give you enough capacity for a 27 or 28 which is plenty for racing. Remember, cross is on a circuit and what goes up must come down. You are not going to be climbing forever.

No need for a compact crank, but for racing if you're using a standard double and racing you'll probably want a smaller big ring. 44 or 46. Otherwise you won't use it much.

Most modern wheels will be plenty stout enough. If you just want to get your feet wet clinchers will be fine, but if you can swing nice tubular cross tires you already have the wheels.

Don't skimp on the brakes and tires if you can help it.

GrayJay

Re-using old box-section tubular wheelsets can work great for CX. While CX courses can be bumpy, CX speeds are also considerably lower than road riding and you will usually shift your weight slightly off the seat (self-suspension) for big bumps. I am just under 200 lbs and am having no trouble with riding old 350gr, 32 spoke box-section tubular rims. The squishy CX tubulars also help to preserve the rim compared to narrow 100+ psi road tires. A set of 36 spoke GP4's would be nearly bulletproof.

In the interest of re-using obsolete road parts for CX, I have also been racing with 7-speed freewheels rather than modern casettes. I feel like there is much less need to have a bunch of closely spaced gear options for CX as compared to road riding where you need to cover a wider range of speeds and keep a fast cadence while matching speed of a pack.

marqueemoon

[QUOTE=GrayJay;14810764In the interest of re-using obsolete road parts for CX, I have also been racing with 7-speed freewheels rather than modern casettes. I feel like there is much less need to have a bunch of closely spaced gear options for CX as compared to road riding where you need to cover a wider range of speeds and keep a fast cadence while matching speed of a pack.[/QUOTE]

The only downside is neutral support probably won't be able to help you much.

That said I have 2 bikes with 7 speed Shimano (600 and XT). That stuff is awesome.

jbrow1

I run an 8 speed cassette and compact crank. I have a 36/46 geared crankset but I prefer the compact for two reasons:
1. I ride it alot on the road and in groups this time of year so the 50 is nice.
2. I also ride alot of mnt bike singletrack and the 34 feels better with my 28 big cog than a 36 does. Plus I have legs that resemble toothpicks, so I'm better at spinning than mashing.

I have double walled aluminum wheels off the shelf from the LBS for hundo out the door for both, beat the snot out of them, and no problems.

obrentharris 

If, among your collection of road bike parts, you have more than one set of bars you might want to try the ones with the smaller amount of drop first. Also forget about the road pedals: Go with MTB pedals.
Brent