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Howling mtb disc brakes

Discussion in 'Bicycle Mechanics and Repairs' started by LOGAN 5, 11 Dec 2007.

  1. LOGAN 5

    LOGAN 5 New Member

    Can anybody tell me how to get rid of 2 really horrible squealing - no howling disc brakes? They're on a Specialized Stumpy Expert so are not cheap end gear.

    The LBS have had the discs out and cleaned them rubbed the pads down but this hasn't worked.

    Motorbike discs don't squal any more (some might sometimes) so why are bike discs still susceptible to this awful screaching? They even start to screach when dry though not nearly as badly.

    Any advice gratefully received.

    Ultimate solution to change discs and pads perhaps.
     
  2. dangerousjules

    dangerousjules New Member

    i think you should change the pads since they are contaminated, then clean the disc with white spirit or nail polish remover
     
  3. davidwalton

    davidwalton New Member

    A little Copper Grease on the back of the pads. This stops squeals due to movement of pads.

    This is a standard fix for Motorbike and car brakes that squeal due to pad movement.
     
  4. To clean the pads put them in boiling water.

    The disks just wash them as you would do washing up. You can pay loads for cleaners for them but this works fine.
     
  5. barq

    barq Senior Member

    Location:
    Birmingham, UK
    Are you using sintered pads? They last longer but can make more noise. The other thing to consider is whether the disc brake mounts need to be faced by the bike shop. How old are the disc rotors? Are they worn? I know some rotors start squealing as they become slightly concave.

    Isn't it meths you should use rather than white spirit? I'm sure WS leaves an oily residue.

    I'm also not absolutely sure about using copper grease. I know people who've found it helped, but most of the manufacturers advise against because it can so easily contaminate the pads (more easily than with a motorbike).
     
  6. LOGAN 5

    LOGAN 5 New Member

    Thanks for your comments. The discs (as we speak) are being soaked in some - liquid- from the LBS, they are going to be re-united with the bike as some future point - soon i hope - otherwise it will be a new set.

    Found out today that new(ish) - that means 4 months of use - Stumpy Expert needs a new shock - courtesy of a warranty job thank god. Apparently there's a problem with the shocks and negative/positive air (bike shop speak!) and the seals going. so it's back to the mantufactuer to reconfigure the shock.

    I can feel a difficult cusomer comming on.......! Hope they can get it right this time.
     
  7. i dont know about your LBS but spech are good at looking after there cusomer base.
     
  8. barq

    barq Senior Member

    Location:
    Birmingham, UK
    A friend of mine demo'd one of those and had the same shock problem. Hope you get it all sorted out.
     
  9. ransos

    ransos Legendary Member

    Location:
    Bristol
    A thin smear of coppaslip on the back of the pads worked for me. If that doesn't work, the mounts probably need facing as Barq said.
     
  10. jay clock

    jay clock Massive member

    Location:
    Hampshire UK
    I had the same problem, and solved it by this method....

    Have a look at the pads and see how they are spaced either side of the disk. If not perfectly spaced, remove the bit that holds the pads (held on with 2 allen bolts and put washer(s) in to move it across. Or you may need to remove washers. You can buy special thin washers for this purpose, but i got some from a pot of washers I keep. Worked a treat
     
  11. LOGAN 5

    LOGAN 5 New Member

    Thanks for your comments. Not got the bike back yet so don't know if all has been fixed.