watch this space (CX disk brakes)

spasypaddy

fair enough, i would just worry about the fork shearing above and below the bolts

mudcovered

spasypaddy wrote:

fair enough, i would just worry about the fork shearing above and below the bolts

As would I. Some of the very early carbon fork designs have failed exactly as you describe. I think the ones that are around now are okay.

Mike

Roastie

mudcovered wrote:

Roastie wrote:

The BB7 has a lot of excess that could be shaved ... Bring on SRAM red BB disc calipers .

I still get a moment of terror when pulling on the brake lever of a rim braked bike in the wet and get the initial 0 response.

Mike

Yeah, riding the proto in a downpour last week was such fun - the clamps seem to work just as well wet (tho' I'm sure there must be some loss of performance) and respond just as well. I had to mentally reprogram myself not to compensate for braking by pulling the lever early...

Yeah - can't wait for decent disc cross forks.

Roastie

spasypaddy wrote:

would a carbon fork work with a disc brake or would it sheer off?

My proto runs a carbon disc fork (Kinesis) - though I suspect it is alu with a structural carbon wrap.

Wrath Rob

When discussing weight, don't forget the wheels. Disc brake specific wheels have different hubs for mounting the discs and don't have the same rims as you don't need the braking surface. Just to add to the complexity!

Roastie

On that point, Wrath, developments for 29ers have done us a lot of good for developing lightweight, disc specific 700c rims - which can be made lighter if they don't need to account for a braking surface. Hopefully there will also be some nice CX specific stuff coming in.

As for hubs, a lot of what has been developed for XC MTBs is a straight carry over - with the benefit of generally very good seals - though I suspect some really nice, lighter, CX specfic hubs will trickle in.

Kiblams

You know that the BB7 has a 'road' versions right? Not sure what the difference is other than the MTB version being black and the road being grey though...

Roastie

Kiblams wrote:

You know that the BB7 has a 'road' versions right? Not sure what the difference is other than the MTB version being black and the road being grey though...

Different cable pull ratios. I run BB7 Road. They are nice, but could be lighter.

ride_whenever

Stop getting hung up on weight of cables vs hydraulics.

The advantage comes from dual piston setups. AFAIK, all cable brakes have a static piston and a moving one. Hence in a really cruddy race you will need to adjust the fixed pad, which involves getting off. Hydros are self adjusting and have much much better modulation and lever feel. The TINY weight difference is insignificant given the UCI minimum weight.

The main reason hydros are hugely unlikely is the need for the shifter integration... It can be done, but i seriously doubt that it will be as it'd take a massive amount of R&D for shimano for what is a very niche market, they're only likely to be seen once they're allowed for road racing, where again, they'd be a handy way to improve performance whilst adding weight.

The alternative answer for enterprising cx fans is to mount the hydro levers in place of interrupters, then have cable actuation to the hydro lever, with a bit of luck it'd work really well.

andrewgturnbull

Hi folks.

Great news! I had just ordered a disc brake for my cross bike last week anyway!

What happened was that I managed to snap the fork on my cross bike, basically through going over the bars because of a lack of modulation on the cantis I had... I had to stop in a hurry and there was no response from the brakes, no response, no response... maximum response... f*** over the bars... fork and steerer parted company. Ok, so my canti had probably goen out of adjustment with brake pad wear, but it was enough for me to say stuff it.

In my local (Scottish) cx races, mtb have always been welcome, the only previso that you couldn't take a championship medal riding one. i've never cracked the top ten so I didn't really care about that and decided to get a disc fitted anyway while I was replacing the fork.

What I went for was this:

Kinesis DC19 fork
Avid BB07 road actuation cable disc
Shimano XT 6-bolt hub built onto a 32h open pro

Should be built up in time for a family holiday in Aviemore next week - let's see if I can keep up with the kids on their mtbs now!

Cheers, Andy

georgee

A couple of links for you all...

Canyons project 68:
http://www.canyon.com/_en/technology/project68.html

Edge/Tune sub 943 gram wheelset (the rims are so good the 26in version have won the worlds)
http://fairwheelbikes.com/cycling-blog/ ... elset.html

Orbea disc road bike (note the Shimano disc brakes, not avid)
http://www.bikeradar.com/gear/category/ ... c-08-28049

I had heard that no one had ever asked the UCI to consider changing this despite the idea being fairly obvious. I'd expect an article from someone like Leonard Kinn on Velonews giving us a decent insight shortly.

G

Roastie

ride_whenever wrote:

The main reason hydros are hugely unlikely is the need for the shifter integration... It can be done, but i seriously doubt that it will be as it'd take a massive amount of R&D for shimano for what is a very niche market, they're only likely to be seen once they're allowed for road racing, where again, they'd be a handy way to improve performance whilst adding weight.

The alternative answer for enterprising cx fans is to mount the hydro levers in place of interrupters, then have cable actuation to the hydro lever, with a bit of luck it'd work really well.

There is a Taiwanese company, I think it may be Token, who are working on an integrated stem/master cylinder setup - so brake cables run to the stem, then hoses run from the master cylinders to the calipers. Seems nice, but I do wonder about the weight.

I'm usually not too fussed about weight, but I do find that after 55 minutes of riding in the crud and lifting & carrying the bike a good few times a lap, every gram starts to feel like a kg (but then again, the bike is so caked in mud I'm sure it weighs a good kg more anyways).

Roastie

andrewgturnbull wrote:

What I went for was this:

Kinesis DC19 fork
Avid BB07 road actuation cable disc
Shimano XT 6-bolt hub built onto a 32h open pro

Very similar to the set-up I'm running on my Such - except I opted for XT Centre-lock and Halo Aerotrack (V-section rims shed mud better and are available in colours and no machined brake surface ). You'll love them, the BB7s are wonderful in competition.

ride_whenever

the token idea is interesting, there use to be an adaptor to mount hopes via a steerer spacer giving a boss for the cable and removing the levers. Worked rather well based on my browsing.