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  1. #101
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    Quote Originally Posted by ruscle View Post
    I emailed them about the compatibility with the 2 piece rotor and the V2 calliper's and Aaron said it will all fit fine and there isn't an issue. The rivet on the 2 piece does look very small and quite far into the actual structure of the rotor, so should prove not to clash with the calliper of the V2. I think I will be backing them for a pair of 180mm 2 piece rotors.

    Quite excited now and will be saving over 200g in weight. Main thing is gaining more modulation and power (Like I need that with Hope V2's!!)
    Thanks for that. That was one of my sticking points. Will be talking to them this week about an order.

  2. #102
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    Quote Originally Posted by Deerhill View Post
    Ps, I need jet brakes on my bicycle too
    Well, that's a bit more complicated, as those in question here, are not quite the same.


    Magura

  3. #103
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    Re:

    [QUOTE=gotfish8;9860433]check these out rotors out, I wonder if they reduce the "turkey worbble" noise? doesnt look like they have hit the market yet.



    Wonder what the pads will be made from?

  4. #104
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    [QUOTE=shehateme;9920141]
    Quote Originally Posted by gotfish8 View Post
    check these out rotors out, I wonder if they reduce the "turkey worbble" noise? doesnt look like they have hit the market yet.



    Wonder what the pads will be made from?
    Try reading more than the first !!

  5. #105
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    Quote Originally Posted by Mr.Magura View Post
    Well, that's a bit more complicated, as those in question here, are not quite the same.


    Magura
    I figured these were from something really neat like jet, of maybe space shuttle.. Now that I actually read the thread, these mounted to a single crown fork?

  6. #106
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    Quote Originally Posted by Deerhill View Post
    I figured these were from something really neat like jet, of maybe space shuttle.. Now that I actually read the thread, these mounted to a single crown fork?
    Why not?

    Magura

  7. #107
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    Quote Originally Posted by Mr.Magura View Post
    Why not?

    Magura
    More power and modulation always a nice upgrade, just wondering what fork you have there

  8. #108
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    Quote Originally Posted by Deerhill View Post
    More power and modulation always a nice upgrade, just wondering what fork you have there
    It's a modded Domain 318.

    I didn't like the Motion Control much, so built up a speed sensitive system for it.


    Magura

  9. #109
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    Quote Originally Posted by Mr.Magura View Post
    It's a modded Domain 318.

    I didn't like the Motion Control much, so built up a speed sensitive system for it.


    Magura
    I finally got lucky with rock solid csu, been through 3-4 uppers this year so been holding off the harder riding/braking and that is no fun!

  10. #110
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    Quote Originally Posted by Deerhill View Post
    I finally got lucky with rock solid csu, been through 3-4 uppers this year so been holding off the harder riding/braking and that is no fun!
    Try a Domain then. The Motion Control stinks, but the fork is rock solid, at a small weight penalty though.

    I've treated mine pretty bad (hefty carbon brake tests), and to be honest, I worry more about snapping a head tube than the Domain.

    On the plus side as well, is that it's super smooth, with a minimum of static friction.


    Magura

  11. #111
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    Quote Originally Posted by Mr.Magura View Post
    I've treated mine pretty bad (hefty carbon brake tests), and to be honest, I worry more about snapping a head tube than the Domain.

    On the plus side as well, is that it's super smooth, with a minimum of static friction.


    Magura
    That is good to know...I was hoping it was a Vengeance coil getting the brake test beating (been thinking about 27.5 clearance : )

  12. #112
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    Have the Kettle SiCCC rotors been tested by any of the magazine guys, or the independent test guys that chime in on these forums yet?
    I think the concept is overdue for introduction to the market, but I thought it would be a lot more expensive. I don't really see how they can be doing these for under a $100. If they are successful, I hope they or somebody else following up on their technology for making inexpensive carbon ceramic rotors applies this to some aftermarket brakes for sports cars. If it can transfer over, they could end up being price competitive with aftermarket upgraded iron disc systems
    .
    Mr.Magura: Do you know where they found a way to make them that cheap, and do you know if it may be practical for larger applications.

  13. #113
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    Why does everyone keep saying these composite rotors dissipate heat better.

    Custom Carbon Ceramic Disc Rotors From Kettle Cycles - COOL! | 29er.. »Cafe

    I thought the opposite was true: They are better able to manage the heat, but not by dissipating it, but by resisting heat buildup, and performing well at any temperature up until they are glowing hot.

  14. #114
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    Quote Originally Posted by autodoctor911 View Post
    Why does everyone keep saying these composite rotors dissipate heat better.

    Custom Carbon Ceramic Disc Rotors From Kettle Cycles - COOL! | 29er.. »Cafe

    I thought the opposite was true: They are better able to manage the heat, but not by dissipating it, but by resisting heat buildup, and performing well at any temperature up until they are glowing hot.
    Because they do dissipate more heat as temperature increases.
    The same holds true for steel rotors, but they just start fading at some point.

    Look up heat dissipation. It is not a linear function of temperature, but a rather steep curve.

    Magura

  15. #115
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    Quote Originally Posted by autodoctor911 View Post
    Have the Kettle SiCCC rotors been tested by any of the magazine guys, or the independent test guys that chime in on these forums yet?
    I think the concept is overdue for introduction to the market, but I thought it would be a lot more expensive. I don't really see how they can be doing these for under a $100. If they are successful, I hope they or somebody else following up on their technology for making inexpensive carbon ceramic rotors applies this to some aftermarket brakes for sports cars. If it can transfer over, they could end up being price competitive with aftermarket upgraded iron disc systems
    .
    Mr.Magura: Do you know where they found a way to make them that cheap, and do you know if it may be practical for larger applications.
    They claim to have one with my name on it, but let's see.


    Keep in mind how little material there is in a 2mm rotor, compared to that of cars.
    That's where you see most of the big cost difference.

    When I made mine, I started out with a rotor from a F16, that's why mine turned out a bit pricey.


    Magura

  16. #116
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    Ok, so they dissipate more or less heat than Iron at any given temperature?
    It has been a while, but I did pass Thermodynamics and Diff.Eq, and I know how heat is transferred, and what the rates are, and could probably even figure out how much longer it would take a carbon rotor to cool off than an iron one from a given temperature, or inversely, how long it would take to heat it up.
    What temps are they each running at in a drive cycle test for extreme mountain bike use?
    Would the Iron rotors in the same dynomometer test not dissipate heat more quickly?
    The advantage of the carbon rotor is that it functions just fine at very high temperatures, at which any material can dissipate heat quicker than at low temperatures.
    I have no doubt that the carbon rotors will work better in most conditions, while also saving quite a bit of rotating weight, and lasting much longer.
    the only reason heat dissipation could be an issue is that the pads also get hot, and most of their cooling is done by transferring that heat to an Iron rotor that dissipates heat much more quickly than carbon at a given temperature(you don't see many carbon heat sinks do you?).
    This could certainly be worked out with cooling fins(heat sink) on the backs of the pads, or a different pad compund that is able to handle the same temperatures as the rotors.
    Of course, if the amount of heat generated in the first place is not enough to even affect the pads, then it is not an issue even with current pads, as it seems Kettle has stated, but I think from reading their info, pad wear may be slightly more with the carbon rotors.

    As far as the cost being related to the base material cost, I think the most expensive part is forming it together, since you obviously can't just use normal epoxy or ester resins. The carbon fiber, ceramics and silicon carbide shouldn't be that expensive in raw form.

    No disrespect on the thermodynamics stuff, just trying to figure out what you mean by dissipates heat better.

  17. #117
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    Quote Originally Posted by autodoctor911 View Post
    Ok, so they dissipate more or less heat than Iron at any given temperature?
    It has been a while, but I did pass Thermodynamics and Diff.Eq, and I know how heat is transferred, and what the rates are, and could probably even figure out how much longer it would take a carbon rotor to cool off than an iron one from a given temperature, or inversely, how long it would take to heat it up.
    What temps are they each running at in a drive cycle test for extreme mountain bike use?
    Would the Iron rotors in the same dynomometer test not dissipate heat more quickly?
    The advantage of the carbon rotor is that it functions just fine at very high temperatures, at which any material can dissipate heat quicker than at low temperatures.
    I have no doubt that the carbon rotors will work better in most conditions, while also saving quite a bit of rotating weight, and lasting much longer.
    the only reason heat dissipation could be an issue is that the pads also get hot, and most of their cooling is done by transferring that heat to an Iron rotor that dissipates heat much more quickly than carbon at a given temperature(you don't see many carbon heat sinks do you?).
    This could certainly be worked out with cooling fins(heat sink) on the backs of the pads, or a different pad compund that is able to handle the same temperatures as the rotors.
    Of course, if the amount of heat generated in the first place is not enough to even affect the pads, then it is not an issue even with current pads, as it seems Kettle has stated, but I think from reading their info, pad wear may be slightly more with the carbon rotors.

    As far as the cost being related to the base material cost, I think the most expensive part is forming it together, since you obviously can't just use normal epoxy or ester resins. The carbon fiber, ceramics and silicon carbide shouldn't be that expensive in raw form.

    No disrespect on the thermodynamics stuff, just trying to figure out what you mean by dissipates heat better.
    No offense taken, we are just having a discussion

    I can't recall the exact number, but the heat dissipation factor for the carbon, is higher by itself than of polished steel.
    I measured that back then, by thermographic imaging.
    The biggest difference is as you pointed out yourself, that once they get up in temperature, they keep on working, and under those conditions, they offer pretty high dissipation. This could also have been offered to some extend by a steel rotor, but fading and failing will kick in before that happens.

    Actually carbon heat sinks exists. This is one of the ways to get a material that has different heat transfer characteristics, depending which direction it goes in the material.
    It works rather well, but is super expensive. Some of that effect can be found in certain types of carbon SIC rotors. I utilized that back when building my class A amplifiers, to distribute heat.

    Part of the reason the raw material is costly, is the treatment it needs to work.
    The other reason things gets expensive, is the amount of time and energy that goes into this stuff.

    The pic below shows my carbon SIC brake and the pads.
    I made the pads of carbon SIC with directional heat transfer, and threw in some fins for good measure.


    Magura

  18. #118
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    Ah, so they do make carbon heat sinks, you got me there. My point was that generally metals are better at getting rid of heat. Maybe the heat dissipation constant that you found to be higher for carbon was for radiant heat transfer? I think brake rotors cool mainly by conducting heat directly to air, so the radiant heat dissipation is less useful.
    I like your SIC pads, with built in heat sink. I didn't even notice them in the picture the first time I looked at it. You were able to machine the rotors and pads from existing aircraft parts?
    That setup should have very long life, I would presume. Is the friction coefficient very good cold after they are worn to smooth polished finish on pads and rotor? Or does the material retain a rough texture throughout it's wear?
    I worked on a formula SAE car back in 1994, and We tested some of the first carbon/carbon rotors designed for good cold bite. They were made with a rough finish to help initial bite. It worked well, and we actually never wore them smooth from the initial pattern, but we didn't put them to that much use either. The car completed competition that year, and wasn't driven again afterwards. We tore it down to make a much more crude car the next year. We stripped the motor and suspension from a carbon tub car with composite pullrods and single interconected(L&R) front and rear springs to build a steel tube frame car with more conventional 3 spring front and rear. The judges penalized anything exotic and high priced, so we went low tech the next time, including switching back to iron rotors. It was not a well developed car though, and we fared worse the next year, despite fewer cost penalties.

  19. #119
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    From experience....carbon rotors (and carbon compound break pads as well) on motorcycles work great on the racetrack AFTER they are fully up to operating temperature and kept there. However when not heated to temps they suck and are downright dangerous.
    Monte
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  20. #120
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    I read through all 5 pages and saw no mention of this and was curious if carbon SIC is a brittle material, or if there are significant concerns of damage or failure over conventional steel rotors in the event of a crash? If they deflect and retain there shape that would be better than bent rotors.

  21. #121
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    ^^^^^^
    What he said

  22. #122
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    I envision crash failure ... But I'm just making an educated guess, based on what I have seen happen to other composites.

    Done right ... This can work well.

  23. #123
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    Quote Originally Posted by bikeabuser View Post
    Done right ... This can work well.
    This would be the most educated that's been said about this so far


    Impact that would cause significant damage to a well made composite rotor, would kill a steel rotor as well for sure.
    Minor impacts that would make a steel rotor drag like crazy, would cause no damage to a composite rotor.
    Mine has seen impact a few times, with no significant damage.



    Magura

  24. #124
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    I am so bummed I did not pull the trigger on the these a month ago.

    If anyone in the Vancouver / Squamish / Whistler area is getting a set I would love to check them out on your bike (for a case of beer of course)

  25. #125
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    Quote Originally Posted by Mr.Magura View Post
    This would be the most educated that's been said about this so far


    Impact that would cause significant damage to a well made composite rotor, would kill a steel rotor as well for sure.
    Minor impacts that would make a steel rotor drag like crazy, would cause no damage to a composite rotor.
    Mine has seen impact a few times, with no significant damage.



    Magura
    I thought this might interest you - yet2.com - Tech of the Week Detail

    Waiting for it to catch on in the LED lighting market.

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