Top of v-brakes are loose

notnot
notnot Posts: 284
edited May 2013 in The workshop
The Shimano v-brakes on front of my bike have come lose. They still stop the bike reliably, but the mechanism moves from left to right far too easily (you can easily put the top of the mechanism from left to right with a fingertip). This means it often ends up with the pads rubbing the wheel.

If anyone knows how I can tighten these up so they stay in the same position, that would be great. Hope the description I've given makes sense, and sorry about the stupid question!

Comments

  • desweller
    desweller Posts: 5,175
    Sounds like the springs are not engaged. On most V-brakes you can release the spring tension to aid wheel removal/replacement and pad position setting.

    A photo would help diagnosis.
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  • notnot
    notnot Posts: 284
    Thanks for the reply. Camera's on the blink, but they look rather like these ones http://www.google.co.uk/imgres?imgurl=h ... AQ&dur=407

    The top of the brake - the bit on the picture with a plastic ridged cover over the cable - slides far too easily from left to right (or vice versa) on my bike: you can push it with a fingertip, and it easily gets knocked out of place.
  • desweller
    desweller Posts: 5,175
    So it's just the rubber boot that covers the end of the noodle?

    Don't worry about it. It just protects against dirt ingress, but I've never known one stay in place for very long.
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  • notnot
    notnot Posts: 284
    Sadly not - the whole top of the brake (the bit the rubber boot covers, and the metal to either side of the boot) slides from left to right, which moves the pads out of position.
  • desweller
    desweller Posts: 5,175
    OK, so the brake arm moves too? And then does not spring back into place?
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  • notnot
    notnot Posts: 284
    Yes - brake arms move and don't spring back into place, meaning that the pads can rub.
  • desweller
    desweller Posts: 5,175
    Could do with pictures. Like I say, sounds like your springs are not engaged.
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  • The Rookie
    The Rookie Posts: 27,812
    Or not adjusted correctly....
    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.
  • gbsahne001
    gbsahne001 Posts: 1,973
    on the back of the arm there's a spring, if that's slipped from it's locating lug, then this can happen.
  • notnot
    notnot Posts: 284
    Right, here's a first rubbish photo
  • notnot
    notnot Posts: 284
    And here's the second

    Any suggestions on what to try adjusting? Or I can take better pictures of particular bits in the daylight.
  • gbsahne001
    gbsahne001 Posts: 1,973
    Looks like the spring on the LH arm's either not in place properly or needs replacing, the guide for the brake cable also looks as though it needs replacing, as it's kinked and appears to be pinching the cable.
  • notnot
    notnot Posts: 284
    Thanks. If there's an idiot's guide to checking (and potentially replacing) brake arm springs, that would be great.

    (The cable looks kinked in the photo, but I think that's an effect of camera angle/shadow. It's a nice smooth curve when you see it in real life :) )
  • The Rookie
    The Rookie Posts: 27,812
    Remove cable, push arm so pad touches rim, let go, does it spring back, if yes the spring is fitted and working (load can be adjusted by the small screw near the base, caution the heads round out easily) if no the spring is either damaged or not located in the fork (3 holes, one should have the and of the spring wire poking thorugh it).

    the kinked noodle (the steel tube the cable tries to run through) will cause the brakes to stick on by not allowing the cable to retract.
    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.
  • notnot
    notnot Posts: 284
    Thanks! Adjusted springs and brakes, and I think I've fixed it :) Will go for a spin tomorrow to make sure - but looks much better here.