What is the 2mm Allen Key for on side pull brakes?

Manc33
Manc33 Posts: 2,157
edited December 2013 in Workshop
On my BT'win side pull brakes, although cheap, they have a 2mm allen key bolt kinda on the top of the caliper. What does this adjust?

I noticed there's no "toe in" on my brake pads. I put some new brakes pads on and noticed after a few rides, one pad isn't totally flat, its only worn at the bottom of the pad. Maybe I just need to brake more to get them flat on, because like I said you cannot toe them in, there are no cone washers etc.

I know that 2mm adjuster can't be for the overall tension because you can do that on the brake lever.

I guess it just moves one arm in or out?

Can't really find anything on Sheldon Brown or Google. I am sure cheap Shimano side pull brakes don't even have this and it only starts with 105 upwards? Where the screw is I can't really see what it adjusts.

Comments

  • wishitwasallflat
    wishitwasallflat Posts: 2,927
    Manc33 wrote:
    On my BT'win side pull brakes, although cheap, they have a 2mm allen key bolt kinda on the top of the caliper. What does this adjust?

    I noticed there's no "toe in" on my brake pads. I put some new brakes pads on and noticed after a few rides, one pad isn't totally flat, its only worn at the bottom of the pad. Maybe I just need to brake more to get them flat on, because like I said you cannot toe them in, there are no cone washers etc.

    I know that 2mm adjuster can't be for the overall tension because you can do that on the brake lever.

    I guess it just moves one arm in or out?

    Can't really find anything on Sheldon Brown or Google. I am sure cheap Shimano side pull brakes don't even have this and it only starts with 105 upwards? Where the srew is I can't really see what it adjusts.

    Its for fine adjustment of centering - to centre caliper brakes with the fixing nut loose put the brakes on so they centre and tighten up the nut - if the pads are still unequal distances from rim and/or hit the rim at different times (watch if the rim deflects when the brakes go on) adjusting that little grub screw on top will fine tune the centering.
  • Manc33
    Manc33 Posts: 2,157
    OK cheers, so it does only do the tension?

    I forgot, I have flat bars and MTB shifters with a tension adjuster there, on my road STi levers I never had that at the lever.

    I really need to get some Ultegra's on it.
  • wishitwasallflat
    wishitwasallflat Posts: 2,927
    Manc33 wrote:
    OK cheers, so it does only do the tension?

    Yes I suppose you could say that because it adjusts the spring to centre the pads and lets you set them so they touch the rim at the same time when you pull the brakes.

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