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Where are the Ceramic Brake Rotors?

The promise of ceramic brakes, including dramatically reduced weight, coupled with  increased stopping power and heat dissipation, has been around for more than a decade.  The reduction in rotating, unsprung mass (how about 4 pounds … 2 pounds per rotor in the front wheel) alone would make a dramatic improvement in handling and suspension performance.

The promise is still there, but ceramic rotors remain extremely expensive and unavailable on OEM machines.  Brake Tech, for example, offers these as an aftermarket replacement for OEM discs.

We call on the knowledgeable readers of MD to chime in here, including some of the engineers who read this site. What will it take for ceramic brake discs to become commonplace on production motorcycles?


  1. Grunbay says:

    I have felt the bliss of shedding rotating mass when I replaced the stock wheels on my Ducati 900SS with magnesium wheels. I would love to peel a few more pounds from the wheelsets, but one has to remember that the weight savings at the rim (where you save most of the weight when you upgrade your wheels) has a significantly greater effect than weight saved near the hub. For the money invested, and considering the radial location of the weight savings, I opted to stay with iron discs.

  2. Paul Simmons says:

    I don’t see the logic behind spending all this money on a brake rotor to reduce unsprung weight and rotating mass – at lease on street bike that has a rim and tire that weigh around 20 pounds. The moment of inertia (the quantity we want to reduce when we are talking about rotating mass, and the quantity the gives the feeling of gyroscopic stability and slows down turning) is the product of the mass elements multiplied by their distance from the centre of rotation, so weight lost at the wheel rim makes a much bigger distance than weight lost nearer the axle. If you had two 320-mm discs on your front wheel, reducing the brake discs’ mass by 75% would be the equivalent of eliminating ONE POUND from the rim or tire – a much, much cheaper option. Ceramic discs would only make sense if you already had carbon fiber wheels and a lightweight tire. If you got a carbon fibre rim and reduced your rim weight by 5 pounds, the effect on rotational inertia would be five times greater than reducing your brake disc weight by 3 pounds. You would need a lot of money to justify the expense of ceramic brake discs from the point of view of reducing rotating mass.

  3. donniedarko says:

    Someone on the R1 forum posted this about the build of CMC rotors albeit for the automotive build

  4. donniedarko says:

    I own the CMC offering from Braketech and their Ductile Iron Axis rotors as well. First off to the above comment of using steel rotors on GP bikes in the wet is due to the required temperture needed in pure Carbon/Carbon rotors and pads. CMC rotors ride exceptionally well in the wet IMHO as their optimal thermal temperture range is much lower.

    Initial bite is more aggressive but not bad aggressive. XRAC pads and a variable ratio master cylinder make it very streetable. Also there were iterations of the rotors. The first had issues but later ones are totally good. The company that made the rotors StarBlade [?] went the wayside with the economy as I understand.

    The rotors, yes, have to be with homologation rules in WSBK as I understand and since $3400 rotors dont come stock on any bikes to make them good. Also I believe a cost hold down, they aint cheap.

    Also taking the proverbial ‘dump’ before you ride is the same as riding with Magnesium or Carbon rotors/wheels et al isnt the same. Unfortunately the physics of MoI and rotating mass has little to do with healthy bowel movements… LOL One feels good the other handles good 🙂

    I run BST wheels too, and with the CMC’s its a riding experience that is unlike anything else any other mod can do. The rotating mass [MoI] diet is = 7 free hp. Add uber light tires like Michelin Pures and it gets silly. Handling gets distorted and the bike more nervous but its amazing. Adjustments to riding style and suspension and its a smile everyday riding my bike to work.

    A goal on my bike has been to reduce as much unsprung weight, so all unsprung load bearing hardware is in ti. A 520 chain kit and ultra light sprocket with ti cush drive pins [that alone cuts near 1/4 lb] of substantial rotating mass especially at speed. Lighter calipers, and caliper brackets.

    Some people go for engine work. My motor is bone stock sans deristriction and a optimized map.

    Chassis and brakes folks is where its at. Unfotunately the ti thing can become an addiction but riding moto’s is one already. I just go to another 12 step meeting for my ti problems 😉

    Apparently BrakeTech is working on another material but looks to be more expensive… well see.

    CMC’s are fantastic, pad use will differentiate bite and feel. If you have the dough and can get them by all means… for the record I ride an ‘old’ 2002 R1. Riding a full liter bike that weighs just over 380 lbs wet makes for 250cc handling and motard like handling in the tighter corners.

    Cool artlicle MD 🙂

  5. Reinhart says:

    I went to the swap meet at Vet’s Stadium and picked up a practically new rotor for 2 bucks. The old one had 55,000 miles on it and needed replacing. I doubt if I will ever be able to find the same deal with a ceramic rotor.

  6. Norm G. says:

    Q: “What will it take for ceramic brake discs to become commonplace on production motorcycles?”

    A: valuing consumers.

  7. Gary says:

    I seem to remember reading that ceramic rotors need to be very hot before the work properly. Great for a race machine; for a road bike, not so much. Then there is the cost …

  8. Steve says:

    FYI, BrakeTech hasn’t actually delivered any CMC brakes in quite some time now. It’s all well and fine saying you have a product, but they have none to ship.

  9. ziggy says:

    In times of economic crisis, proven technologies and homologation are preferred. Right now it is a risk / cost issue to adopt this technology. Sales overall in the business range from flat to falling due to less disposable income and demographic change. You might find a few leading-edge companies that will flirt with this technology, but until the macro picture changes decisively, expect products mades on iterative refinement as opposed to revolutionary technology.

  10. Superlight says:

    The carbon fiber analogy rings true also for ceramic brake rotors – if there were a process that enabled lower costs you would see these brakes in production at affordable prices.

  11. Stripler says:

    I’ve been trying to buy some of those CMC rotors from BrakeTech for the last year, and they still don’t have any for sale. They produced some for a while a few years ago, but I was told late last year that the aerospace supplier they got materials from went out of business so they were having to come up with a new formulation.

  12. craigj says:

    Probably the same reason as you don’t see carbon fibre wheels as OEM … cost. It’s one thing to have ceramic brakes as a $10,000 option on your Porche or Mercedes as you are already dealing with a 6-figure buy in. When the bike you are looking to buy is $15,000 do you reall need to spend several thou more on ceramic brakes?

  13. rg500gamma says:

    Sorry, but I don’t see the value in dropping a grand over steel disks for incremental improvement unless your next house payment depends on your track results. As it is today, I see entirely too many hogs on gixxers, looking like the Michelin Man. Don’t spend the $ on the disks, get your BMI below 25 and keep it there. As far as mass production goes, are you serious? That is purely cost driven. Never in a million years…

  14. Crashie says:

    To improve handling, there is no more noticeable area to knock off pounds than on the wheels. Rotating mass is the biggest hindrance to directional changes. Also, saving on unsprung weight allows the suspension to work a little easier.

  15. the bp says:

    this isn’t really about braking power…
    thee weight of rotating mass on the front wheel effects the bikes turn-in so much it is ridiculous. A 12oz savings is noticeable, so 4lbs would be crazy, and the faster you are going the more it matters!!!
    Also the front forks job is to stop the momentum caused by the weight of the front wheel bouncing off irregularities in the road, as well as to push it back. Like playing catch, so would you rather play catch with a beach ball or medicine ball?

    Obviously if we are talking about for DOT use, performance in the wet and longevity are serious issues, Does anyone KNOW if these have performance issues in the wet?
    Fragility is another good point… even on the track, does anybody KNOW if these can be broken in a minor spill or with a solid whack by debris… or a wrench?
    Of course if the braking power really is much more, I could see going to one rotor up front(talk about weight savings!!!)

  16. Ross says:

    Why bother? You can save more weight by skipping breakfast… is there a problem with the current brakes which needs fixing?

    • Agent55 says:

      Losing a few pounds of un-sprung weight is going to make a much bigger difference than skipping breakfast, lunch AND dinner.

  17. Patrick D says:

    I’m fairly sure that even MotoGP bikes revert to steel discs when it’s wet, so they must be a disadvantage in the wet.
    Whilst the technology might be out there, current braking technology is easily ahead of (road) tyre limitations, so where’s that extra stopping power going to benefit you? Hauling on the brakes on a modern superbike will not leave anyone wishing for more power there, and even make them apprehensive about using them in anger on a wet road.

    To save weight, anyone modifying their bike can save way more in the right place for going for trick (carbon, magnesium etc) wheels. You’ll save kilos rather than pounds.

    • Joe Bar says:

      This is rotating, unsprung weight. Much more important to handling and performance than weight in other areas.

    • Agent55 says:

      Cermaic and carbon discs used in MotoGP aren’t the same thing. Ceramic discs are available on a lot of high-end cars and are safe in wet conditions, I think it’s just a cost issue right now. The weight savings of ceramic discs is no joke, it would make noticeable difference in feel and lap times if you tried them back-to-back with steel.

    • Norm G. says:

      re: “so where’s that extra stopping power going to benefit you?”

      the snake portion of mulholland where so-cal riders wad themselves with reckless abandon into the gaurdrail.

    • donniedarko says:

      The carbon/carbon rotors in GP have to have high heat running through them to work. Why you will often see them run shrouds on them to keep heat in them. In the rain they disperse heat were they dont perform thus running ductile iron rotors

  18. betternow says:

    i agree that unsprung weight is important but if it were truly as dramatic as you say, i then wonder why have OEMs moved like a herd to upside-down forks which add to that very aspect of weight? Right-side-ups can be built with no flex and have the better weight ratio.

    • Dave says:

      USD forks have less unsprung (i.e., moving) weight as the piston weighs less than the housing. Also, the housing is larger in diameter – providing greater resistance to flex.

    • Norm G. says:

      re: “i then wonder why have OEMs moved like a herd to upside-down forks which add to that very aspect of weight?”

      wonder no further my good man… it’s because USD looks “cool” and cool moves product.

  19. soi cowboy says:

    How about one steel disc and one ceramic disc on the front wheel?

  20. Jeff says:

    There were issues with the early samples back in the late 90’s with grabby brakes at low speeds, and I have also heard that the brake-in procedure is more temperamental. I think they’ve basically sorted the low speed braking, but my guess is that steel brakes are a more forgiving option in terms of providing consistent and controllable stopping power for novices and experts alike, are easier to break-in, and won’t crack if a mechanic whacks it with a 17mm wrench. Ok so I’m making up that last point, but does anyone know if these things are susceptible to cracking?

    • donniedarko says:

      No bed in issue that I had. Less then the ductile iron rotors I have from Braketech. They work excellent at low speed they just are aggressive so you have to be more deft on brake modulation.Machanic whacking my rotors with a 17mm wrench? Any mech whacks anything on my bike he swallows teeth. They are less prone to cracking. Stainless steel is the most brittle, ductile iron is the softest, and CMC even more resilient. Ive had mine for over 10k and the wear is minimal if any. One thing that is exceptional about them is the light wear, and I also run track spec CP911 star pads. Im switching to the more streetable XRAC once I install my new calipers.

  21. Gutterslob says:

    Wasn’t there some rule that bikes had to have steel brakes to be considered legal for WSBK homologation, or something like that?