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Creaking/screeching when braking(not brakes!)

chrisstevenschrisstevens Posts: 17
edited March 2009 in MTB workshop & tech
Hi Guys,

I have recently bought a genesis core 10 however whenever we apply the front brake we have a horrendous screeching/creaking noise which seem to amplify up the forks and through the handlebars.
I originally thought they may need bedding in but we are still having the issue. We have also purchased a new front brake system and that is exactly the same.
The headset and all other component appear to be as tight as they should be?

Any other ideas of what this problem could be would be appreciated!
At the minute I am trying to return this to the store that I bought it from as it is un-rideable in the state it is in since purchased.

TIA
Chris

Posts

  • nicklousenicklouse Posts: 81,520 Lives Here
    well that type of noise does sound like the brakes.

    and soulutions can be found in the FAQ´s

    but as it is new it is not something you should be fixing the shop should.
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  • dave_hilldave_hill Posts: 3,877
    Any other ideas of what this problem could be would be appreciated!

    At risk of appearing slightly sceptical, you say it only happens when braking, but it isn't the brakes?? Sure about that?

    Check that everything is securely fastened - wheel q/r, brake disc rotor mounting screws/lockring, brake caliper.

    Next, get some Isopropyl Alcohol (IPA), methylated spirit or specialist bike brake cleaning spray (NOT the type for cars/motorbikes, it's too harsh) and give the disc a good clean up with it and a clean rag or kitchen paper.

    Take the pads out of the caliper and lightly abrade the braking surface (put a piece of medium wet-and-dry or emery cloth on a flat surface and rub the pads up and down on it a few times). Before you replace them, put a VERY light smear of copper grease on the backs of the pads (NOT the braking surface obviously... :roll: ) - some people will now jump all over me for saying that because they think its dangerous, but what works for motorbike and car brakes also works on bicycle brakes.
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  • The only eason I say its not the brakes is because I have tried two complete sets of brakes and I recive the exact same result. Thats everything from the rotor through to the lever
  • dave_hill wrote:
    Any other ideas of what this problem could be would be appreciated!
    Before you replace them, put a VERY light smear of copper grease on the backs of the pads (NOT the braking surface obviously... :roll: ) - some people will now jump all over me for saying that because they think its dangerous, but what works for motorbike and car brakes also works on bicycle brakes.

    Why do some people think its dangerous?
  • nicklousenicklouse Posts: 81,520 Lives Here
    so MTB brake makers say do not use any grease or anything on the backs of their pads.

    and the main reason is there are holes in the metal backing and the heat of the brakes pulls the grease into the friction material rendering the brakes as useful as a chocolate teapot.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • you may find that the mount on the fork needs to be faced, paint in this area may be uneven and not allowing the calliper to seat correctly hence the resonance/noise generated. A lot of boardman hybrids seem to suffer this on the rear brakes due to poor finishing of the frame..
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  • stumpyjonstumpyjon Posts: 4,069
    You'll just need to check everything is tight (rotor bolts as well as caliper botls etc.) and that the calipers are aligned properly. Are you bedding the pads in properly as well?
    It's easier to ask for forgiveness than for permission.

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  • Is there any chance this fault could be anything else but the brakes?
    I'm at abit of a loss at this point.
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