Pointless, existing MTB brake systems work fine. Your tyre will skid before you exhaust the power of existing discs.

Carbon tends to shatter and wear quicker.

If they work, then they make more sense on road bikes where the weight reduction adds more value, especially when discs are seen as adding weight. I'm certainly interested to see where these lead.

I agree, pointless, i think even in MotoGP they stick on steel rotors when its wet because the rotors can't get up to temperature to offer decent performance. with all the road disc trend i can't see people choosing marginal-at-best weight savings over consistent braking.

@gilesjuk

Keep in mind there's a lot more going on with these rotors than stopping power. The rotors are lighter and the company claims they handle significantly more heat. We'll be testing whether or not they live up to those claims—as well as their durability—in the near future.

We have tested and put on hundreds of miles on a development version of our own flavor in the Oregon hills. Carbon rotors can offer significant gains if done correctly and I look forward to trying these ones out in the near future on my XC ride.

Makes sense to me that you'd want to give the tech a shot, but it's really the heat dissipation that I'm interested in. If it's no better than steel, then I don't feel it's good enough, especially if you want to re-purpose for road disk or touring (a situation where I've boiled the hydraulic fluid and had to dump the bike a couple of times)

@gilesjuk - Clearly they don't always work and this was the impetus for developing these discs. Besides, there was a time when people thought discs on MTBs was overkill because apparently V-brakes were more than enough. Anyone still believe that now?

For every 100 dumb ideas that come out, there is often a genuine innovation that we may look back at in five years time and wonder how we lived without it.

interesting but the article reads like a cut and paste of a press release.

Why not develop Anti-lock Braking System for bikes? I think it would be more useful. But I think every development needs a chance to be tested. For now all I can say is this carbon rotor looks good.

I'd like to see more science, not just a statement “We can clobber them with science”

I want to know how the rotors are made.

The performance claims can hold true for the powered vehicle carbon reinforced carbon composite rotors where the material is not held together by a resin, but by graphite crystals - a product of pyrolisis and not related to how carbon fiber composite products, for example frames, are made.

If they are using a resin system, then the discs will fail given enough heat stress. While carbon fibers themselves are excellent heat conductors, and can radiate it well due to them effectively being black bodies, the resin is a heat insulator, and unstable above its Tg (glass transition temperature).

Another notable property of resins is that they are very heat reactive ie. they contract and expand depending on temperature, while Kettle Cycles claims less thermal expansion than steel.

Thus, the rotors sound like they are a c-c composite, but I'd like them to confirm this. However if they are a c-c composite that is not exactly exotic anymore...

I was ready to dismiss these as a load of nonsense but the fact that you can use standard sintered pads rather than expensive proprietary pads changed that. If they really are strong enough to take a knock and more importantly don't wear out faster than steel discs using sintered pads in Peak District grit then I can see the advantage of them over standard rotors even though they are a bit more expensive. If they do generate a lot more friction then you can use smaller rotors which further reduces weight and the likelihood of them taking a knock.

Also MotoGP bikes are totally different as they use carbon-carbon brakes which require huge heat to generate high friction, in the wet they use metal discs as they can't generate enough heat with carbon-carbon and as weight is less of an issue for motorbikes they can use thicker bigger discs to manage the heat produced.

How many people suffer with heat problems? It does exist, but is quite rare - at least in the UK, we don't have the opportunity to drag our brakes down 6000ft descents. A light weight solution will obviously benefit some, (and lightweight in general), but I think it will be a limited market.

They likely will remain true, unlike metal rotors...

Come on gilesjuk, do your six speed friction shifter work just fine too?

I wan't them to keep develping things to make my bike better. My new bike is a 'little' better than my first dirt rig in '87!

While you can't compare "apples to apples" with others, F1 cars, Moto GP/Superbike, snowmobiles, and M1A1 tanks use carbon brake rotors so developing a rotor to work well on a bike shouldn't be a problem. I've been waiting for one of the companies to develop a wider rotor brake system (5mm). Carbon rotors may allow them to do that.

@gilesjuk

You're wrong on all counts. Engage brain before operating a keyboard !

Surely the disc is only a small part of the real issue here, Its claimed this was inspired by brakes that failed -How? and why will just changing to an exotic rota help

TEMPERATURE is a problem, a sintered pad will work at higher temp but with such small amounts of compound before the backing plate there will be a piont where the thermo effiency of the compound will fail, but compounds that work at high temp dont work at low - look at the afore mention formula1 example, how hard they work brakes to maintain operating temp and we are talking maybe some of the same tech, thus can I have a pit wall for my bnext ride! just incase I am not perminantly at race pace :)

FLUID is part of the problem, cycle brakes have little if any effective resevoir thus once over temp there is no effective way of cooling the hydrualics, let alone a method of regulating temp as the system runs. The majority of motorsport retirement are due to hydrualics problems

CONTAMINATION- city use disc's regularly glaze giving little performance. It does not take much to affect the performance of the brake in this regard,

WE all push our cycles beyound limits - whether for some thats genuinely a performance limit or for others a maintanence or service piont. the loads and enrgies that are put through a cycle can be massive, that lucky moment when you did'nt crash that unexpected heavy landing - that mucky grinding ride. How many actually check all their components and torque settings before putting the bike away for the next ride - From the sounds and looks of some others machines on the trails its no suprise of failure and everyones quick to blame equipment

.

55g for a 160mm disc is substantially heavier than the steel Jetblack discs I currently use. Also I can stop my 200kg motorcycle with one finger and steel discs so my 12kg mtb shouldn't really be an issue.