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Fingers on discs

dflashdflash Posts: 32
edited June 2012 in MTB general
Hi, today I went mtbiking on a xc trail with my specialized hardrock sport disc. We were heading down very fast and I did a lot of breaking with both brakes I mean normal braking for that kind of road and then the front disc brake made a strange noise like it didn't want to brake, the pads were like sliding on the disc. Then I stoped and I touched the disc, it was heated ( I touched it with a clean finger and I burned my finger a little ). Now I'm afraid that I did something to the brake, because later then when I was heading home the pad from the front disc was touching the disc ,I mean it was touching it before but not that much. So is there some thing wrong with my bike or not is that normal or not?
I bought the specialized like a week ago, it has tektro draco brakes

Posts

  • cooldadcooldad Posts: 32,601
    Are they working ok now? If not you've possibly boiled the fluid, or more likely you've glazed the pads from dragging the brakes.
    Take the pads out and have a look.
    Then if they are OK centre them properly.

    Rotors do get hot - don't touch them.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    Any slight warp in a rotor will get exaggerated when they're really hot, so if the disc rubs slightly, it will rub quite a bit more for a while, until it cools down again.
  • RoostoidsRoostoids Posts: 128
    Love squirting water on hot brake rotors, never gets boring :|
    Specialised Camber Comp 2011
    Boardman Comp Road 2011
  • steelie600steelie600 Posts: 519
    Roostoids wrote:
    Love squirting water on hot brake rotors, never gets boring :|

    Can also knacker your discs!
    Idiot ^^^^^^^^^

    Ralph
  • cooldadcooldad Posts: 32,601
    steelie600 wrote:
    Roostoids wrote:
    Love squirting water on hot brake rotors, never gets boring :|

    Can also knacker your discs!
    Bollocks. Half the time you're riding through cold water and mud anyway.

    It is however pointless.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • steelie600steelie600 Posts: 519
    cooldad wrote:
    Bollocks. Half the time you're riding through cold water and mud anyway.

    It is however pointless.

    I see your bollocks and raise you this

    Granted its not brakes but the theory is the same

    Never a good idea to fully quench brake discs when red hot!
    Idiot ^^^^^^^^^

    Ralph
  • cooldadcooldad Posts: 32,601
    Next time your rotors are red hot I'll take your advice.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • cooldadcooldad Posts: 32,601
    And now that I have clicked on your link, I'll remember to check your sig first next time.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • YeehaaMcgeeYeehaaMcgee Posts: 5,740
    steelie600 wrote:
    Never a good idea to fully quench brake discs when red hot!
    And how often does that happen?
  • GiraffotoGiraffoto Posts: 2,078
    dflash wrote:
    today I went mtbiking on a xc trail with my specialized hardrock sport disc . . .the front disc brake made a strange noise . . .
    Do you have the original Avid BB5s on there, and was it a sort of squealing/grinding/rumbling combination of noises? If it's Yes to both, this sort of noise appears to be a standard feature of the brakes, but they'll still work. It wasn't the noise or the braking performance that led me to swap mine out, but the need to adjust them almost every ride.
    Specialized Roubaix Elite 2015
    XM-057 rigid 29er
  • Matt-r8Matt-r8 Posts: 298
    Sounds like you've boiled the fluid and glazed your pads. Pads are salvageable if you take them out, and lay a piece of abrasive paper on a flat surface and gently rub the pad over it. Not to coarse an abrasive paper, or you'll have no pad left. The most probable reason for the brakes binding after is that you have air in the system and it expanded due to heat build up, perfectly normal and everything should return to normal once cooled down to normal operating temperature. If it does persist, get a bleed kit or let your lbs do it for you.
    All this is assuming you have hydraulic brakes rather than cable operated.
    Finally: wath your fingers when rubbing down the pads and don't touch hot brake disks.

    Hope this helps.
    Matt.
  • GiraffotoGiraffoto Posts: 2,078
    Matt-r8 wrote:
    Sounds like you've boiled the fluid . . .

    I don't have any experience of boiled fluid, but unless the OP is on a 2012 model (or has swapped his brakes out) the Hardrock Sport Disk has cable brakes.
    Specialized Roubaix Elite 2015
    XM-057 rigid 29er
  • Matt-r8Matt-r8 Posts: 298
    I took a giant XTC zero carbon hard tail with Magyar brakes with165mm rotors. Not only did I boil the fluid and glaze the pads, and have the brakes binding, I blued the disks as well looked pretty cool lol.
  • njee20njee20 Posts: 9,613
    From the OP:
    I bought the specialized like a week ago, it has tektro draco brakes

    So they're hydraulics. To be honest I doubt you've boiled the fluid, people talk casually as if that's easy to do, but it really isn't. Could be anything, a rubbing disc isn't necessarily indicative of any damage, as Yeeha says it can be due to the hotter disc.

    Did things improve once they'd cooled down? Ie are the brakes ok now?
  • jairajjairaj Posts: 3,009
    Giraffoto wrote:
    but unless the OP is on a 2012 model (or has swapped his brakes out) the Hardrock Sport Disk has cable brakes.
    dflash wrote:
    it has tektro draco brakes

    These are hydraulic brakes.
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