After servicing my front hub which I posted in Sturmey Archer XL-FDD Service, the drum brake started to stick again. It was getting to the point where I would have to roll the bike backwards to release the brake at red lights, not particularly ideal!
So straight into it, I tore the brake down into bits. Nothing unusual to report from last time though.
As the pivots were already lubricated last time, I figured maybe it had to do with the shape of the cam. I went to file more of a radius onto it, I thought it may be due to a flat spot which might have stopped the shoes from retracting.
The shoes have little metal caps which slide on the cam, you can see they have a slight ridge on them, which I flipped around so they would only rub on new material.
Back together again. So far the sticking has disappeared, and after a few weeks it's still not back. Fingers crossed!
This has happened about once a year or so with my X-FDD. So far I've been able to get away with just filing the braking surface slightly, sometimes I use a plastic scouring pad on the drum as well (I tried sandpaper once, but that causes a fair amount of noise while braking). It would be nice to hear from someone that could put their finger on the real problem: a weak spring, pad material, or something else. I especially liked your last XL-FDD post, now I know what the little flanged nuts are called in the U.S.: push nuts.
ReplyDeletePerhaps someday my '63 Humber Sports will die a similarly slow death, but I'm not looking forward to it, it really is a great bike.