BSA Owners' Club Forum

The BSA Workshop => Singles => Topic started by: AdrianS on 21 December, 2017, 17:39:08

Title: shimming brake shoes
Post by: AdrianS on 21 December, 2017, 17:39:08
I know this has been discussed before but there doesn't seem to be any "rules" about doing this.

The front brake lever is most effective at 90 degrees to the cable when operated. Sometimes it is difficult to compensate for wear by moving the operating lever to another position as the brake cam end is square shaped. Also the hub can also wear a little inside.
Oversize linings can be fitted but is it ok to fit shims over the ends of the shoes ( made out of tin cans ) to take up a bit of the space between the brake shoe and drum?
Title: Re: shimming brake shoes
Post by: Greybeard on 21 December, 2017, 18:46:29
Providing the shims are securely held in place there's no reason why not - just make sure that the shim is the same thickness either side of the cam so both shoes are adjusted by the same amount. My Matchless/AJS bikes are fitted with the means to install factory shims to account for wear. The shoe end bears on a mushroom shaped pad pinned into the end of the shoe and the shims are just washers that go underneath it so can't fall out.

Title: Re: shimming brake shoes
Post by: MALCOLM.JOHNSON on 21 December, 2017, 19:29:23
Be careful. The brake cams on BSA`s will impart a rubbing action, direct on your new "shims" and wear or displace very quickly if using tin cans as your shim source. If it jams it could pitch you off or at least damage the drum further.  The other thing that may be possible is to reverse the lever on its shaft as they usually are made offset to the square and may position your lever at a more advantageous angle. Alternatively, get some 5mm stainless sheet and custom make your own lever - if you have access to a vice, drill, hacksaw and square file - or if your lever has a square hole, make it an "8 pointer". Much easier than you might imagine. 
Title: Re: shimming brake shoes
Post by: JulianS on 21 December, 2017, 19:56:10
If your brake shoes are the floating type with removable pivot pads it is easy enough to shim betwen the pad and the shoe.