ever get this problem, calipers?

supafly1982
supafly1982 Posts: 631
edited April 2011 in MTB workshop & tech
when realigning calipers, do you ever have the problem that you tighten them and hold the break lever, run the wheel and all is fine but you need to nip them up tight, when you do this it drags the caliper towards the wheel pulling it out of line and then the pads rub the rotor.

i cant seem to stop this happening on one of my bikes :?

also the same bike the QR skewer is stuck solid in the hope front hub, any ideas there?

cheers
scott

Comments

  • nicklouse
    nicklouse Posts: 50,675
    what brakes? you may be just trying to over tighten the bolts.


    big hammer.
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  • cooldad
    cooldad Posts: 32,599
    1 - hold the brake while you tighten them - the caliper shouldn't move.
    2 - Nick got there first.
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  • The Rookie
    The Rookie Posts: 27,812
    As CD has said, keep hold of the brake lever while gradually nipping up the bolts, you'll find that one of the 2 is worse for twisting the calliper, so as you do it up in stages do the less troublesom first of each step.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • supafly1982
    supafly1982 Posts: 631
    yes guys, i am holding the lever and alternating between both bolts as i tighten so not to drag caliper out of alignment, the bike is a second hand zaskar i bought with hope breaks, the bolts are very tight to wind in and out, old locktight and oxydisation possebley, i think i could be pulling out of alignment because the bolts are hard to put in, even when they arent wound in tight and flush....... no they arent cross threaded ;) , looks like im going to have to source some bolts, they are very long, i will get a pic up tomorrow
  • stu8975
    stu8975 Posts: 1,334
    Are they I.S. or P.M. calipers? if I.S. then you will need to shim them.
    ANTHEM X
    Youth
  • The Rookie
    The Rookie Posts: 27,812
    Its friction between bolt and calliper that will twist it, not friction between bolt and whatever your bolting into!

    Have you got the washers under the bolt heads? Also a tiny drop of oil between that washer and the underside of the bolt head may help.

    Simon
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • kevolution
    kevolution Posts: 70
    I'd use grease on the bolts as it has less potential to migrate into the brake system in use.
    But some brakes do move the caliper when tightening the CPS bolts.
    Try shimming the mount soit sits further in and the CPS slots are not near thend of their adjustment.
    I've found they move less this way.
    And I work on 100s of brakes every weekend at a trail centre workshop.
  • nicklouse
    nicklouse Posts: 50,675
    I just do up the other one first.

    but with a washer in place there should be no probs.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • kevolution
    kevolution Posts: 70
    Hays CPS bolts have fixed washers. And they are some of the worst for this kind of behaviour IME. Npping the bolts down gently and making small adjustments as you go is usually successful.
  • supafly1982
    supafly1982 Posts: 631
    ive tried the small adjustments, will try a littly grease on washers, they are PM ,cheers for imput guys

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