I recently replaced the brake shoes on the rear of a bike because they’d worn out. During this exercise it became apparent that there is a misalignment in the brake calliper (photo attached, it’s not the clearest in the world but I struggled to get a good angle). On one side, the brake shoe lies flush with the wheel rim, but on the other side, there is a considerable misalignment, and the brake pad does not lie flush.
I’m confident that it’s not something I’ve introduced fitting the new brake shoes because on inspection the old ones had worn unevenly in a pattern which matched this misalignment.
I attempted a fix by grinding down one side of a spare washer but this failed as it couldn’t take up the misalignment.
Looking at the whole assembly more closely, I am moving towards the conclusion that something within the brake calliper such as the arm the shoe attaches to may be out of alignment or structurally deformed, but there is nothing obvious to me on inspection.
One possible solution is to replace the calliper, but I’m reluctant to do this without a bit more thought in case the problem isn’t with the calliper. With this in mind, I’d welcome any suggestions from UKC as to possible causes and fixes. I’m currently drawing a bit of a blank and struggling to find any possible solution on the internet (I could well be using the wrong terminology).
The caliper is a Shimano Sora caliper, in case such information is relevant.