no tension adjuster on caliper?

GordonFreeman
GordonFreeman Posts: 120
edited May 2012 in Workshop
Just adjusting my brakes. However, the left brake hits before the right.
I can#t see any tension adjuster in the sprin on this caliper so how am I supposed to align it?
Everytime I align it by centering it, when I brake, the left is back on the rim again touching.

It is a side pull with anchor bolt.
http://imageshack.us/photo/my-images/69/img4170d.jpg/

Actually, I just tried moving them by adusting both mounting nuts holding the caliper but the problem is when I pull the brakes, they don't seem to release very well and both pads stay just touching the rims. I have to pull the calipers apart a little to get room again.

Maybe they need serious cleaning or something. The only thing that seems to solve it is loosening the mounting nuts a bit, which presumably gives space to the spring? However, I thought everything was meant to be as tight as possible?

Comments

  • lpretro1
    lpretro1 Posts: 237
    Can't see from the picture, but there may be a bolt in the centre behind the spring which will take a flat spanner and you can just move the brake left or right to suit?
  • BillyMansell
    BillyMansell Posts: 817
    The bolt through the frame should be tight as it keeps the caliper in place.

    As you've discovered, by over-tightening the bolt the in front of the caliper locks up the caliper so loosen it again until the caliper arms move against the spring freely again but not so slack that the arms move fore and aft.

    On the back of the caliper there will be two flats, one either side of the spring, which allow you to adjust the position of the caliper left and right with the use of a cone/flat spanner.
  • GordonFreeman
    GordonFreeman Posts: 120
    BillyMansell wrote:
    The bolt through the frame should be tight as it keeps the caliper in place.

    As you've discovered, by over-tightening the bolt the in front of the caliper locks up the caliper so loosen it again until the caliper arms move against the spring freely again but not so slack that the arms move fore and aft.

    On the back of the caliper there will be two flats, one either side of the spring, which allow you to adjust the position of the caliper left and right with the use of a cone/flat spanner.

    Doesn't seem to be anything there.
    The vid I searched just said you move the entire caliper by moving both mounting nuts together - is that the correct way? Are these just old style calipers or something?

    http://imageshack.us/photo/my-images/37/img4171rl.jpg/
    http://imageshack.us/photo/my-images/259/img4169y.jpg/
    http://imageshack.us/photo/my-images/69/img4170d.jpg/
    http://imageshack.us/photo/my-images/59/img4172h.jpg/
  • BillyMansell
    BillyMansell Posts: 817
    GordonFreeman wrote:
    Doesn't seem to be anything there.
    The vid I searched just said you move the entire caliper by moving both mounting nuts together - is that the correct way? Are these just old style calipers or something?

    http://imageshack.us/photo/my-images/37/img4171rl.jpg/
    http://imageshack.us/photo/my-images/259/img4169y.jpg/
    http://imageshack.us/photo/my-images/69/img4170d.jpg/
    http://imageshack.us/photo/my-images/59/img4172h.jpg/
    There might be flats on the black carrier for the spring but it's hard to tell. Not to worry, you can still adjust it by hand it's just easier of you can get a spanner in there.

    To explain further, the spring carrier is fixed onto the bolt that runs all the way through the brake. As you firstly tighten the rear nut clockwise it will rotate the bolt, and therefore spring, clockwise so you need to counter this by somehow holding the spring in place. You can try with your hand to hold the caliper closed against the rim but the more you tighten the rear nut the more the central bolt will naturally want to rotate.

    The front nut is primarily for holding the caliper arms in place on the central bolt and isn't required when fitting the brake. Once you've tightened the rear nut then you can rotate both nuts together in the same direction to align the caliper.

    So the video is correct in that if you turn the nuts at the same time in the same direction then the whole brake assembly should move, but if you turn the nuts against each other, and particularly the front nut against the central bolt, then you'll lock up the caliper as you've found.
  • GordonFreeman
    GordonFreeman Posts: 120
    BillyMansell wrote:
    GordonFreeman wrote:
    Doesn't seem to be anything there.
    The vid I searched just said you move the entire caliper by moving both mounting nuts together - is that the correct way? Are these just old style calipers or something?

    http://imageshack.us/photo/my-images/37/img4171rl.jpg/
    http://imageshack.us/photo/my-images/259/img4169y.jpg/
    http://imageshack.us/photo/my-images/69/img4170d.jpg/
    http://imageshack.us/photo/my-images/59/img4172h.jpg/
    There might be flats on the black carrier for the spring but it's hard to tell. Not to worry, you can still adjust it by hand it's just easier of you can get a spanner in there.

    To explain further, the spring carrier is fixed onto the bolt that runs all the way through the brake. As you firstly tighten the rear nut clockwise it will rotate the bolt, and therefore spring, clockwise so you need to counter this by somehow holding the spring in place. You can try with your hand to hold the caliper closed against the rim but the more you tighten the rear nut the more the central bolt will naturally want to rotate.

    The front nut is primarily for holding the caliper arms in place on the central bolt and isn't required when fitting the brake. Once you've tightened the rear nut then you can rotate both nuts together in the same direction to align the caliper.

    So the video is correct in that if you turn the nuts at the same time in the same direction then the whole brake assembly should move, but if you turn the nuts against each other, and particularly the front nut against the central bolt, then you'll lock up the caliper as you've found.

    Surely turning the fornt nut tighter or the back nut tighter is the same thing isn't it as they are connected by the same bolt?
  • pdw
    pdw Posts: 315
    No, because there's stuff in the middle (the spring mount) that's fixed to the bolt. Tightening the front bolt clamps the caliper arms against that stuff. Tightening the rear bolt clamps the frame against that stuff.

    To adjust the alignment, loosen the rear bolt slightly, grab the brake and rotate it, then hold it steady whilst you re-tighten the bolt to stop it rotating. As others have said, there may be flats on the stuff in the middle that make holding it steady easier, but it's not essential.
  • g00se
    g00se Posts: 2,221
    if it's a CHEAP caliper, there's the 'quick' way of adjusting a one-sided one...

    Get a hammer and a blunt cold chisel or screwdriver and place it over the coil of the spring - on the side where the caliper arm is NOT moving away from the wheel rim.

    BANG

    It will now work better. If it's not moved enough - do it again. If it's moved too much, do it on the other side...

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