Swaping out Discs for cantilevers
 

I'm loking at buying a X bike with disc brakes primarily for commuting purposes however, I'd like to have the option to try X racing. I hear discs aren't allowed in races and have heard it's simply a matter of swapping the brake types.

How involved is it to switch the two types of brakes? if it's a lot of work I might forgo the dics. Though I'd really like to have them for commuting...

well its sort of involved. Discs require special hubs with the mount for the disc rotor itself. You can use a disc ready hub with rim brakes but you cant use a regular hub with disc brakes. If your fork/frame has the studs for the brake arms then your okay but the primary concern i have is that you would have to change the cables/housing each time you wanted to change the brake setup you have.

The frame has studs for sidepull brakes so does that mean the hub won't be an issue? The cable issue is exactly what Iwas concerned about.

Disc brakes are not legal in UCI events but many local races allow them. Check with some of your local clubs that hold cross races to find out. To swap out you I would guess the frame and fork have cati bosses? If so you will need new brake housing and cable. Plus on the front you will need a cable hanger that clamps onto the stem to hold the housing. In the rear the frame should have a built in cable stop but if not you can get one that connects to the seat collar. If you are going to swap out often get some in-line cable adjusters and and install them on the ends on the canti housing lengths then just ad on housing to make it down to the discs. That way you don't have to change the bar tape every time plus it makes adjusting the discs a little easier. Try -
http://www.bikemannetwork.com/biking/c/CX
for some parts. I think I got my 1 1/8 clamp on hanger from
http://aebike.com/site/page.cfm?Page...gory=27&type=C

What about rims? Don't know much about discs but do know there are disc-specific rims......I suppose they don't have good braking surfaces.

I don't see why v-brakes won't do just fine for commuting? I've been commuting on my bikes for 20 years. Heck, I just recently upgraded the front brake on my mountain bike TO v-brakes! You really don't see many road bikes with discs...............

stick with the discs - while I'm not from the US as I understand it unless you're an elite racer in state/national UCI sactioned events then there's no compulsion to use anything else. There's also a rumor floating around that the UCI suits will review the DB option sooner rather than later.

yes, rims can be different. Chances are a wheel made up with a disc compatible hub will not have a rim suitable for canti/V's.

The best bet would probably be to have two sets of wheels; one with discs, one without. (Obviously assuming that the original poster wants to swap out for racing purposes.)

You can just get disc ready hubs and rim brake rims, have cable all layed out and ready for different applications and your set