I'm looking to get a bike and set it up for cyclocross, but on a budget. I'm seeing a fair number of late model (late 90's to '02 or so) Cannondale road bikes for not too bad of a price. I know there are some differences in geometry, but how much of a problem would it be? The BB heigth seems to be less than 1' difference, so I'm not super worried about clearence there. I know the standover heigth will be less for the road bike, but what does that really matter? The parts I'm a little leary of are the size of tires/wheels I'll be able to run on a road frame, and the frames strength. I've been told the stays can be spread to accomidate a larger wheel, but I don't want to do that. Will the road frames take a large enough wheel? The strength I have less knowledge of than the rest combined. Will the road frames hold up to use as a 'cross bike for a few years? I know C'dale's mtb frames from a few years ago are known for being bomb proof, are the older road frames signifigantly stronger than the newer ones? BTW, the bikes I'm seeing mostly are R500, R600, and around those lines, mostly in triple. Thanks for your time.
You are going to be very limited on on tire selection since its a road frame & the ones that will work/fit you will need to air up so much, the ride will be VERY harsh, especially on an old C-dale. I had some Specialized Tri Cross's on an old steel road bike once & it was a very bumpy, on the verge of "out of control" ride.
Also, unless you are planning on racing only in dry conditions on fast grassy courses, you wont have much room for clearance (mud) in the brake dept. I would look a little harder for a good deal on a cross frame, you'll be better off. You should be able to find something in the price range you are looking. Good Luck!
The biggest issue when trying to cnovert a road bike for cross is squeezing the tires in under the brakes and the rear triangle. And no, you can NOT spread the rear triangle of an aluminum bike (unless you want to break it!). If you are giong to buy a bike for cross, do yourself a favor and avoid the headaches of trying to convert one - just buy a cross bike.
Just this past cross season I converted my trek road bike into cross... installed a cross fork with canti breaks and put the smallest width nobby tires on. Bearly squeaked by with clearance. My 1st race went well. No problems. 2nd race, there was stretch of mud that left mud hard packed in my rear road break and where the chain stays meet at the seat tube. Following the muddy streatch was a bit of an up hill. It was as if I was in the big chain ring, 12 on the back trying to climb this hill with the mud packed in. I tried one other race, and the mud conditions were even worse.. except this time I rigged up a mud deflector so the mud would deflect around my rear break. That mud found a way in and it cram packed itself in and made my race 5 times harder than it should have been. I have decied to spend the approx. $800 on a cross frame. Sold the old trek frame that I attempted to make a cross bike. The mud clearance is what you want. You cannot get it on a road bike. I at least learned that I really want to invest the money in a cross frame! Good luck.
A very cheap way to have a cyclocross capable bike is simply find an old 70's- 80's steel roadbike with the old centerpull brakes- mafac, universal and the like. These usually have a good bit of tire clearance in the back (don't get a high-end racer, get a sport or other mid-market level). Plus the centerpull brakes have excellent mud clearance, great stopping power and you don't need to worry about canti braze-ons. Keep the 42t chainwheel, take off the 52t for a single ring up front, keep the front derailleur on to prevent chain- drop, install a bar-end shifter, put on some cross tires and you're good to go. I raced an old Schwinn my first season like that, 35c tires and lots of extra clearance, could even install fenders under the brakes when it later became my commuter. Not a lightweight, but still lighter that some of the mtbs in the C races and faster too. You can also find hybrid frames that will work too. But add up the costs- if you really want to race cross, you'll eventually want a real cross bike. But the makeshift can be done with little money, you can see if you like mud, and it makes a great commuter/utility bike later on.