Carbon brake disks?

[wbks]

noticed on the gp bikes, as far back as 2000 from what I can see, they use carbon brake disks. I was just wondering if anyone here knows what the reason behind this is? Is it because it reduces the unsprung weight, disperses heat better or what? I was just thinking of how that would make some serious bling for a road bike:bleh:

[enigma51]

noticed on the gp bikes, as far back as 2000 from what I can see, they use carbon brake disks. I was just wondering if anyone here knows what the reason behind this is? Is it because it reduces the unsprung weight, disperses heat better or what? I was just thinking of how that would make some serious bling for a road bike:bleh:

You cant by them for a road bike due to the how to make being top secret. Also they need heat to work and average every day riding will not give them enough heat

They also provide greater stopping power than normal disks a quick google search will give you all the info you want

[naphazoline]

noticed on the gp bikes, as far back as 2000 from what I can see, they use carbon brake disks. I was just wondering if anyone here knows what the reason behind this is? Is it because it reduces the unsprung weight, disperses heat better or what? I was just thinking of how that would make some serious bling for a road bike:bleh:


i'm no expert by any means,but at a guess,i'd have to say that it would be a weight saving thing.

i can't imagine them lasting long,as carbon fibre might be good in impact situations,but when it comes to friction,it wears very fast. or at least in my experience.

[wbks]

Yea I figured they were too factory like to be sold. So if they weren't thrashed they would be pretty weak compared to the average steel floaters? I'll google

i can't imagine them lasting long,as carbon fibre might be good in impact situations,but when it comes to friction,it wears very fast. or at least in my experience. Yea well they must almost rebuild the engine completely every round so replacing disks probably wouldn't matter to most teams huh

[wbks]

From what I got, they can tollerate higher temps and have better performance because of that heat.
Although the braking performance is unrivalled, the use of carbon-fibre brakes requires a little time to get used to for a driver. Jarno Trulli explained: "In fact, during the first milliseconds after pressing the brake-pedal; it feels like nothing is happening. This delay is in fact the length of time required by the disk/caliper tandem to reach operating temperature, which increases by 100°C per tenth of a second for the first half-second of braking, after which it can reach up to 1200°C. After that short period, decelleration is immediate, and brutal". When at optimum operation temperature, the coëfficient of friction between the pads and the discs can reach as much as 0.6.

[xwhatsit]

Sounds like a similar story to ceramic brakes, which are probably old-hat now -- but they need to be pretty toasty hot before they work well, wear out very quickly, and need to be checked all the time (worries about fractures or something). So not suitable for the road.

It's funny, in car circles, they say the same thing about cross-drilled brake discs -- just track bling, no good on the road, they'll break up and wear out too quickly and screw your pads. Yet almost every modern bike has ventilated discs.

[naphazoline]

.....Yea well they must almost rebuild the engine completely every round so replacing disks probably wouldn't matter to most teams huh

oh wouldn't it be great to have that sort of money?

[wbks]

It probably would screw your pads and wear out fast on a car. I mean, they are pretty heavy. A bit more stressfull than on a 150kg bike. I noticed the carbo disks aren't crossdrilled. Maybe one day they will be developed enough to be suitable for road use. Any of you by chance ever seen a gp bike with red hot brake disks?

[johan]

Here are ceramic rotors. They don't have to be warmed up like carbon rotors but are still light and good:

http://www.motowheels.com/italian/myproducts.cfm?parentcategoryid=643|Brake%20Rotors&productID=3715&showDetail=1&categoryID=644|748-998%20Rotors&vendoridtodisplay=0&filterFor=&collection=4|Brakes

[k14]

They replace them after every race, don't last long at all. Also the fact that they take a while to warm up means you can't use them on the road. Brembo makes most of them for the GP teams, pretty sure you could buy some if you had the $$. They used to have them on 125's and 250's in the late 90's but they were banned cause they were so damn expensive.

[wbks]

It would take a little longer for sure but i read that they get to optimum temperature pretty much half a second after you apply the brakes. But then again you would have to brake late and hard into every corner just to be able to slow down, wouldn't you. Must be like riding with cold-wet rotors, otherwise. Those ceramics look niiice, too. Surprised I haven't seen many of them around. But then, racing in nz is pretty 'grass roots', isn't it

[JMemonic]

It probably would screw your pads and wear out fast on a car. I mean, they are pretty heavy. A bit more stressfull than on a 150kg bike. I noticed the carbo disks aren't crossdrilled. Maybe one day they will be developed enough to be suitable for road use. Any of you by chance ever seen a gp bike with red hot brake disks?

You can buy them for cars PBR make them, cross drilled and slotted, I wnt and had a wee look the nighbours sports car has them on not sure if standard but all wheels.

[wbks]

I always thought they just have those groves and a kind of gap between the disk on high performance car brakes. Kinda like two disks in one. I'm sure you're right though.

[TonyB]

As I understand it, they swap back to conventional discs (cast iron/steel) for wet races because they can't get enough heat into carbon ones to make them work. Thats what the commentators always say anyway. Or it could be because they have too much intial power and bite. Either way, there is no way they would be suitable for the road

[wbks]

That makes sense. Interesting...Wish they had better motogp coverage on tv1 and prime :( Just out of interest, are carbon disks legal for WSBK?

[Squiggles]

the 1098RR wets are steels/iron/whatever and the drys are carbon

[wbks]

Doesn't it usually run an iron/steel disk on the back all weather?

[racerhead]

Just read this in a magazine today and remembered this post.

Cost of carbon brakes(in £ sterling)

Single disc £2500
Set of pads £1000

So for just discs and pads alone its already up to £6000 plus the usual cost of caliper, master cylinder and hoses.

It didint say how long a set of pads or disc lasted but it did say they needed skilled maintenance.

[vifferman]

Doesn't it usually run an iron/steel disk on the back all weather?
They run carbon front disks in the dry, but steel in the wet, as the carbon ones cool down too much.
The carbon ones (apart from offering fiercer braking and less fade) are lighter so less rotating mass.

As for drilled disks, yes, it's mostly just a fashion for road bikes, as solid ones have a greater surface area and better performance. Same with stainless steel disks: the iron ones (a la Moto Guzzi and older Ducatis) have better friction, but rust more, so the Jap manufacturers use s/steel.
Apparently grooved ones are more effective for dissipation of surface water in the rain, but they're much more expensive to machine.