oik01

So I recently upgraded parts on my bike, had some drive train issues and ended up crashing for the first time ever. Initial assessment I had thought i got away with minimal scratches but later noticed a rhythmic rubbing sound on my front brakes at the same frequency of the wheel rotation. I cleaned the wheel looking for an area of debris and found an area of dammage that I believe is the source of the problem. Changing brake calipers and realigning breaks and giving them a toe in didn't alleviate the noise. The dammaged break surface makes sense as the source because it would also explain the intermittancy and the ocurrence at the same frequency as wheel rotation.


What's your assessment? Is my wheelset useless now? If the breaks are maintaining stopping power can I continue to use it and hope they somehow smooth out the dammage over time? Is there a way to fix or replace the break surface?

Wheel is the front Oval 527 tubeless sitting on an old 9 speed trek 5000. I'm new to cycling and not sure how good those wheels are considered but I really liked the ride feel a they're lightweight so if there's a chance I keep them I'd rather go for that 😕

sch

Untreated the divots in the rim will wear out your pads much faster than normal. Since each divot has a slightly raised
rim on each side if you want to continue using the rim you need to get rid of the raised edges on each and every
divot in the rim. Remove the tire for best access, you can sand them down or what I would do is take a sharp edge
(knife/chisel etc) and carefully remove any elevated edge on each divot and lightly sand. Use your fingernail and
a magnifier to get every last bit of elevated edge. You will not be able to sand out the divots so the brake grab
will always be there but the pads will last longer, until you finally realize you really need a new rim.

Since most of the divots are closer to the tire perhaps you can lower the pads enough to clear the bigger divots?
This will reduce the grab more but it will never go away.

Bill in VA

Been there, fixed that using a fingernail emory board and carefully following the machining lines of the wheel. For the deeper dents, first use the emory board, then using a Dremel or other rotary tool, and a small polishing wheel and some polish LIGHTLY hit the sharp edges (only) of the divot. You want to smooth the sharp edge left by the gouge, but not polish the braking track, or it may be grabby or squeal. Then lightly use the emory board as in the first step following the machining groove to make is a bit rough.

The advantage of the emory board is the varying grits and it is slightly flexible. You can use a fine file for the first step to remove the higher ridges, but the board works as you can localize pressure.

Then clean suing alcohol to remove any grit and or contaminants.

Also lower the pad a tiny bit as recommended by sch above.

oik01

Will try that tomorrow. Did you manage to get rid of the noise by any chance or was it just a preserve brake pad longevity procedure?

dedhed

make sure there are no chunks stuck in your brake pads too.

tFUnK

Does your wheel also need to be trued?

Bill in VA

I did it to eliminate potential accelerated brake shoe wear and remove any potential stress risers from a sharp scratch in the alloy. Plus I could not abide by the look. Mine has a gouge like your where the raised piece could have rubbed or ripped the sidewall if the tire got a flat.

It quieted it down, but not to silence. But it kept getting quieter. Die to the smoothed edges of the scratches that side did not wear any more than the unscratched side.

satrain18

The new problem you now have is because you filed down an important structural part of the wheel–the brake track, you have now inadvertently decreased the life of your wheel and increased the likelihood of an tire blowout.

San Rensho 

Take tire off, Use a mill bastard file (yes officious monitors, I said the word, but its a term of art, probably something you can't comprehend) to file out the rim cuts, then I would take 60 grit paper and sand down the braking surfaces so the braking surfaces all have the same consistency.

ThermionicScott 

I have a couple rims gouged up like that from a freak crash when my wheels dropped into a pavement seam. I filed down what little high spots there were, and the rims have been fine to use since. You don't have to file and sand it until it's perfectly smooth... that will happen naturally as you continue to use the wheels.

oik01

Thanks guys. I did all steps. Filed off the raised edges, sand paper, repositioned brake pad. The process got rid of the noise successfully ( at least if there is still noise its not loud enough to be heard above my freewheel). Brake stopping power is preserved!