3

I have recently found out, that my rim brakes were slightly misaligned and the pads had developed an edge over some time and had worn a bit of paint outside the normal brake zone (see photos). It seems like a minor damage (I would say just cosmetics really). I was riding in wet conditions and the rims were very dirty, I suppose the dirt acted as an abrasive. It often happens to me that after riding a couple of hundreds of kms the brakes are not centered absolutely perfectly.

My question is, do you think that a similar situation (pads "overlapping the rim") in future might damage the rims significantly in terms of strength?

Thanks.

enter image description here

1
  • 1
    Welcome to the Bicycles SE. I added some text to the title to hopefully clarify your intent. If you feel this doesn’t help the question, you can revert the edit.
    – Weiwen Ng
    Feb 16 at 18:37

2 Answers 2

2

The answer to your question is yes, but before it becomes of concern, the brake track will already have worn to the point that the rim needs to be replaced anyway.

You should be aware that if the brake track becomes too thin, the pressure of the tyre will eventually blow it out and the tyre/tube will explode.

If you put a straight edge across te brake track, you should have a maximum of 1mm concave in the brake track, for safety. If it gets deeper, you will need a new rim. I say this because your rim looks quite worn but it's impossible to say how much without a reference point

1
  • It seems like there is not much concavity yet, so I suppose they have some kms left in them.
    – Sherwood
    Mar 13 at 11:00
5

Eventually, yes. Hard to say when that would happen here. You are correct that rain and road grit can act as a grinding paste. Some people who ride a lot in rainy conditions need to replace their rims fairly frequently because the brake track itself can wear out.

3
  • I see. I am not worrying about the brake track though, but the part of the rim outside the brake track. Can the rim fail or bend when some minor wear happens there?
    – Sherwood
    Feb 16 at 15:23
  • 1
    I understand, my point is that even the brake track can wear through in harsh conditions, and it's designed to be worn down. Minor wear is probably not a concern. Wear will not allow it to bend—the spokes give the rim its shape. But it could fail with severe wear. In general I'd be more worried about stress around the eyelets, which is a more common point of failure. Keep an eye out for cracking or deformation.
    – Adam Rice
    Feb 16 at 17:12
  • 1
    The brake track is, on most wheels, part of the structure. So yes, over time it can wear down to the point where the integrity of the wheel is compromised. I had this happen on an MTB that I regularly used on a trail that was always muddy. On inspection I saw that part of the brake track was pushed in from being too thin to support the pressure from the brake pads.
    – jwh20
    Feb 16 at 17:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.