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Squeeling brakes

Discussion in 'Bicycle Mechanics and Repairs' started by ronaldalfred, 6 Aug 2007.

  1. ronaldalfred

    ronaldalfred New Member

    Location:
    llanelli
    Hi all ,newbie here.
    I have a GT Windstream and the front brakes squeel ,I have tried new blocks but no difference,I also cleaned the rims with lemon juice as reccommended by a local bike shop but no difference.Same brake blocks on the rear , no noise with them.
    No big deal really as I don't need to ring the bell when I come up behind someone,I just brake lol
    Any ideas ?
    Thanks
    Ron
     
  2. Mr Phoebus

    Mr Phoebus New Member

    Is the rim slightly out of true?
    I tried a few black blocks (harder rubber) without success, I've cured my brake squeal by fitting the softer red pads.

    I'd toed all the previous pads in, etc, but without completely curing the squeal.





    Squeeeeeal little pad!
     
  3. Squealing brakes are usually caused by the brakes not being "toed-in" correctly.

    The brakes should be set up so that there is a gap at the back of the brake block, so that the front of the block touches the rim first. I usually set mine up so that there is a gap of approximately 1mm at the back of the block when the front of the block is just in contact with the rim.

    If the toe-in is correct sometimes a small piece flint or something will get stuck in the block a cause the noise when it rubs on the rim.

    Hope this helps
     
  4. P.H

    P.H Über Member

    CTC technical guru Chris Juden gave a very clear explanation of what causes it, but I can't remember if it was in the mag or on the website. Basically the pads grab and release at a high frequency, if that matches something else you'll get the squeal. That’s why the same set up on the rear doesn't act the same. Apparently, more efficient modern brakes suffer more and are less likely to respond to toeing in, because they're less flexible. Brake boosters often work, cost about a fiver from Ebay. Apart from the noise, they should still be working fine, so it isn't critical that you find a solution.
    If all else fails, find someone with carbide rims to cycle with, I guarantee you won't be able to hear yours over that noise, it's like fingernails down a blackboard through an amplifier turned up to 11
     
  5. ronaldalfred

    ronaldalfred New Member

    Location:
    llanelli
    Thanks for the tips,I readjusted the blocks and the squeal is reduced to a much more acceptable level.
    Ron
     
  6. Mr Phoebus

    Mr Phoebus New Member

    Just remembered... another cause of squeal is a glazed rim.
    Gently rub the braking area with some fine wire wool or a fine kitchen scourer.
     
  7. wafflycat

    wafflycat New Member

    Location:
    middle of Norfolk
    It's important you keep your rim in a good clean condition...
     
  8. Mr Phoebus

    Mr Phoebus New Member

    Basil Brush, and Robgul, joined up with my local ride last Saturday.
    Basil had the most battered rim I've ever seen ;):ohmy::ohmy: spiders legs around all his nipples,:ohmy::ohmy::ohmy: a great big gaping hole :ohmy::ohmy::ohmy: and the largest crack I've ever seen :angry::ohmy::ohmy:
    how it never just collapsed I'll never know?
    He had to leave the group and ride to the nearest LBS, and leave his bike to get a new rim fitted,leaving him catching the bus home.
    I've heard of getting yer money's worth out of something. :angry:
     
  9. wafflycat

    wafflycat New Member

    Location:
    middle of Norfolk
    I see you examined his rim and crack very closely...
     
  10. Mr Phoebus

    Mr Phoebus New Member

    Yes! I got down on my hands and knees. (I kid ye not!)
     
  11. Mankymitts

    Mankymitts New Member

    Location:
    Glasgow
    I have given up adjusting brakes to stop them squealing as I find that they start squealing again within days. Makes the pedestrians jump out of the way.

    MM
     
  12. rustychisel

    rustychisel Well-Known Member

    Yeah, all very well, but IME squealing rims is one step away from severe 'grabbing', anf that is not very pleasant!!!!!!