Cyclocross bikes with disc brakes. A few questions......

Plod

Good morning cyclists. I've read that the rules to cyclocross have changed and now permit disc brakes. Does this mean we are going to see a lot of new bikes with disc brakes and lots of new frames and forks with disc compatibility? Such a bike would appeal as a commuter and tourer and infact could do almost anything.

Also, could anyone tell me if disc brakes can be used with modern brake/ gear(sti?) levers? I think maybe mechanical disc are compatible but hydraulic ones aren't. Am I right? Next question is: what's the difference in weight and performance and how do they compare to calipers?

nicklouse

Focus have been making them for a while. The Mares cross.

yes to work with the STIs there is a Road cable disc brake.

there has been some development work on hydros but they are not mainstream.

sungod

mechanical disk brakes are compatible with 'standard' levers

even avid's entry-level bb5 is far superior on stopping power to high-end rim brakes like sram red, and doesn't suffer the same lag before braking in wet weather - i've used both of these, and others, correctly adjusted disks are just better than rim brakes, full stop

Monty Dog

I've had a crosser with discs for 5 years ago - I had to get it custom built because nobody made them back then. Brake performance is simply awesome - no rim brake is comparable and the big advantage is that they work regardless of conditions. Avid BB7s are a doddle to set-up and very reliable IME - they work with any road lever. However, with the UCI rule change, we can expect a whole range of new frames and hopefully some lighter, smaller brakes for 2011. My old frame is presently being converted to run SS as I have a Kuota Kross carbon frame which I use for racing - OK canti-braking is iffy but the weight and stiffness of the frame compensate- success in cross is dependant on handling, grip, being quick and staying off the brakes!.

andyp

I'm going to throw in a counter opinion - cable operated discs are very poor in my experience. Despite hours of attention I could never get them set up properly and they'd go out of adjustment as quickly as I got them set up. The weight penalty compared to cantilever brakes is high, I reckon around 1.5 kgs once you factor in the brake calipers, the discs and the hubs, and in my view isn't worth it.

I've just had my frame converted to take cantis, with a view that I might consider going back to discs when a road lever compatible hydraulic disc set up is available (and SRAM are saying 2012 for that).

Plod

Interesting. Many thanks.

nicklouse

andyp
what brakes were they as yes some are poor but the Avid BB7 are exceptionally good.

andyp

They were BB7s.

sungod

i had bb5, set up was fiddly to get right, but once done they stayed aligned for months, bb7 should be better as both pads move, rather than only one

there are differences in how the calipers are mounted to fork/frame, i think some need an intermediate bracket, might explain differences in ease/stability of set up

Plod

Does anyone ride a titanium bike with disc brakes?

ride_whenever

If you want hydro brakes it is certainly doable.

You can run split clamp flat bar levers as interrupters and have mechanically actuated hydraulic discs!

As for weight penalty, i think it is fairly marginal, particularly when you consider you can lose a lot of weight at the rim, and move it closer to the hub for snappier wheels!

Monty Dog

Yup, I have a custom titanium frame with discs and unlike andyp, my Avid BB7s have been trouble-free for 5 years. Funnily enough, just ordered a new pair of BB7s for another built - will be interesting to see how they compare. I had the frame built by Xi'an titanium (Xacd) and it's given me no trouble - the Van Nicholas Amazon is a similar off-the-peg option. If you want hydro-brakes, try the Tr!ckstuff Doppelmoppel - cable-operated master cylinder.