Disk brakes rubbing

sato1212
sato1212 Posts: 26
edited April 2011 in MTB workshop & tech
Hey,

Ive just bought a new GT Aggressor XC2 from Halfords.

http://www.halfords.com/webapp/wcs/stor ... 65499#dtab

The problem is that when i spin the front wheel (i have yet to ride it yet), it makes a scratching noise as the disk from the hydraulic brake rubs against something (I think the actual brake), is this normal? if it is not how can i fix it?

Many thanks,
Ben

Comments

  • supersonic
    supersonic Posts: 82,708
    It needs to bed in, just ride it.
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  • saltyman
    saltyman Posts: 472
    some brakes even when bedded in will have pads that sit very close, infact slightly touching the disc, perfectly normal.
    roberts dogs bolx
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  • saltyman
    saltyman Posts: 472
    supersonic wrote:
    It needs to bed in, just ride it.

    yeah, they will soon free up.
    roberts dogs bolx
    cannondale hooligan 1
    cannondale badboy
  • sato1212
    sato1212 Posts: 26
    Thanks a lot for the quick advice :)
  • ThePriory1978
    ThePriory1978 Posts: 563
    I have a brake rubbing problem.

    I am in the process of upgrading my hydarulic disc brake set-up.

    I have basic Shimano Deore hydraulic brakes but i am replacing the rotors to new 203 and 180 floating Hope rotors and i have the appropriate new brackets and new pads.

    I have fully bled the system and I have checked the discs and they are super/perfectly/amazingly true, however the discs still wobble by about 1mm when fitted (i know its not a lot) but this means that the pads catch the discs quite heavily on each rotation on both the front and backs brakes.
    The brakes auto adjust and there is no individual adjustment to the clearance on individual pads.

    I have done ALL the usual adjustments loosing off the calipers, holding the brakes and then re-tightening bolts etc but my problem is the slight 1mm movement in the disc.

    Why would my perfectly true disc not spin true. Could my hub mounts be very slightly wonky?

    I'm a bit of a perfectionist and anything rubbing squeeling creaking wonky etc literally drives me nuts.

    Many thanks
    Snot green Canyon Nerve AM 8.0x
  • nicklouse
    nicklouse Posts: 50,675
    Have you reset the pistons? have you let them bed in again?

    floaters are more prone to some rubbing.
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  • ThePriory1978
    ThePriory1978 Posts: 563
    When you say reset the pistons?!... i don't know what you mean, but i have removed the calipers removed the pads from them cleaned them up and gently pushed the pistons back into the caliper as far as they would before refitting new pads, if this is one and the same thing.

    Bedding i havent done but shirley they should be able to be installed without binding in in the first place, if not i'm gunna have to ride with music blasting so i cant hear them :-(
    Snot green Canyon Nerve AM 8.0x
  • tsenior
    tsenior Posts: 664
    yah push the pistons back as far as possible. Check the disk is central in the caliper as well, my (old) hopes needed the shims moving aroud a bit

    when i first got disk brakes i did my nut trying to prevent slight rubbing before taking the bike out: wase of time: find a very steep hill, get up to speed and stop as quickly as possible using only on brake, repeat several times, your brakes should get very hot. this will accelerate the bedding process.

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