I've just noticed that replacing the brake pads was overdue. The metal of the brake shoe started scratching the rim already some time probably (sorry, I know it hurts to read that...).

How to decide if the rim has been damaged permanently?

Edit: Judging with naked eye, I'd say rims are clearly concave. But not only for the rear wheel, also on the front wheel. That means I have to replace them?

  • 2
    It's a question of how badly the rim's been scored. If only some very light scoring (and the rim isn't badly worn otherwise) then a quick pass with some fine emery paper to remove any burrs should result in safe, usable rim. Do note that most newer rims have several grooves in them, functionally similar to the wear indicators on auto tires. If the rim is worn (or gouged by the pad bracket) past the depth of the wear indicators, you should get new rims. Mar 20, 2016 at 14:48
  • If you have doubts (and it sounds like you do) take the bike to your LBS for an expert opinion based on eyeballs.
    – Criggie
    Mar 23, 2016 at 1:11

2 Answers 2


One way to check is placing a straight edge, for example a ruler, against the braking surface. If the surface is worn enough to be concave, there will be a visible gap in the middle.

Small scratches are not a problem, as already mentioned in a comment, many rims have pre-machined grooves to serve as wear indicators and even these do not cause any structural problems.


Mainly it depends on the depth of the scratch. If only a slight friction or scratch should be no problem, if there is more than 3mm scratch you should always pay attention to will result in permanent damage to the rim.

  • 3mm deep? Most rims aren't that tick. Can you please revise to add more details.
    – Móż
    Mar 23, 2016 at 7:46

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