Brake pad fixing bolts - how tight?

Jamey
Jamey Posts: 2,152
edited May 2009 in Workshop
I've got V-brakes and when I'm tightening the bolt that holds the pad into the brake arm I usually get to the point where I have to apply reverse pressure to the pad itself to stop it from twisting as I tighten.

Is this too tight?

I toe my pads in to minimise brake squeal and I'm always worried that if I don't tighten that bolt enough then the pad will get pulled out of line by the forces exerted during braking, causing (at best) the toe-in to disappear or (at worst) the pad to revolve around completely and damage the tyre.

But tightening it that far makes it very difficult to perform fine adjustments like toeing-in and suchlike, because by the time I'm finished tightening (and exerting that reverse pressure to stop the pad twisting) the fine adjustments probably haven't survived the process.

Now I've read the Park Tool torque measurements page but I was hoping for more of a 'human' measurement of how tight you guys do it, especially fellow V-brake users or anyone who's used Vs in the past. I don't have a small torque wrench, only a large one and I tend to use ball-ended hex keys for brakes anyway.

Comments

  • whyamihere
    whyamihere Posts: 7,708
    They need to be tighter than the point where you're applying pressure to keep them straight, or they'll move.
    Here's how I do it: Adjust the pad position and put a small piece of card under the heel of the pad, about 1mm thick. This will provide the toe in. Then pull the brake on, HARD. Pull the lever absolutely as hard as you can. Then the friction between the pad and the rim will hold the pad in place so you can tighten it properly.
  • topdude
    topdude Posts: 1,557
    It is no good (dangerous) having the brake blocks moving during use. Using a normal Allen key i would do it up as tight as possible by hand while holding the block still as you describe.
    He is not the messiah, he is a very naughty boy !!