Repairing a scratched rim?

[Colin Campbell]

I took a spill on December 21. Luckily, I was close to home, and was
able to ride. However, I noticed that there was a noise when I applied
the rear brake.

When I got home and examined the wheel, I didn't see anything wrong.
But when I checked more closely yesterday, I noticed that I had
scratched the rim on the braking surface (on the drive side of the rim).
It isn't a very deep scratch, and it is only about 3/4 inch long.

I'm wondering whether I might be able to sand the scratch down, so that
it doesn't tear up the brake pad. Or, could I just use it, and maybe
have the brake pad smooth out the scratch, at the cost of having to
replace the pad a couple of time. Or, must I replace the rim?

What are your opinions / suggestions?

The bike is a Trek 5200 with Bontrager Race Lite wheels. I replaced the
Shimano Ultegra components with Campy Record, and Trek traded the
Shimano hub wheels for Campy compatible ones at no cost.

 

[Leo Lichtman]

"Colin Campbell" wrote: (clip)I'm wondering whether I might be able to sand
the scratch down, so that it doesn't tear up the brake pad. (clip)
^^^^^^^^^^^^^^^
I would use a flat sanding block, so you remove only the raised metal. You
don't want to create a valley there, or you will probably feel it when
braking. If it continues to wear the pad on that side excessively, the next
step would be to fill it with Bondo, Liquid Steel or epoxy.

 

[amakyonin]

Colin Campbell wrote:
> When I got home and examined the wheel, I didn't see anything wrong.
> But when I checked more closely yesterday, I noticed that I had
> scratched the rim on the braking surface (on the drive side of the rim).
> It isn't a very deep scratch, and it is only about 3/4 inch long.

My solution is to use a needle file to remove any burr on the scratch.
This offers more control and is quicker than sanding. You don't want to
remove the scratch completely. Just take off the high spots so the pad
will slide smoothly on the rim again.

 

[jim beam]

Colin Campbell wrote:
> I took a spill on December 21. Luckily, I was close to home, and was
> able to ride. However, I noticed that there was a noise when I applied
> the rear brake.
>
> When I got home and examined the wheel, I didn't see anything wrong. But
> when I checked more closely yesterday, I noticed that I had scratched
> the rim on the braking surface (on the drive side of the rim). It isn't
> a very deep scratch, and it is only about 3/4 inch long.
>
> I'm wondering whether I might be able to sand the scratch down, so that
> it doesn't tear up the brake pad. Or, could I just use it, and maybe
> have the brake pad smooth out the scratch, at the cost of having to
> replace the pad a couple of time. Or, must I replace the rim?

as stated by others, remove the high spots only. a file is best since
you don't want to cut below the machined face of the rim as a general
abrasive would do. then ride. the rim will wear out through use
eventually anyway, so replace it then, not now.

>
> What are your opinions / suggestions?
>
> The bike is a Trek 5200 with Bontrager Race Lite wheels. I replaced the
> Shimano Ultegra components with Campy Record, and Trek traded the
> Shimano hub wheels for Campy compatible ones at no cost.

 

[catzz66]

Leo Lichtman wrote:
> "Colin Campbell" wrote: (clip)I'm wondering whether I might be able to sand
> the scratch down, so that it doesn't tear up the brake pad. (clip)
> ^^^^^^^^^^^^^^^
> I would use a flat sanding block, so you remove only the raised metal. You
> don't want to create a valley there, or you will probably feel it when
> braking. If it continues to wear the pad on that side excessively, the next
> step would be to fill it with Bondo, Liquid Steel or epoxy.
>
>

I was advised to use steel wool on a scratch where a sliver of metal had
gotten fixed into a brake pad of mine. Now I use steel wool sparingly
for situations like that. I sure would not take down any more metal
than I had to, whatever I did. There's a lot of construction where I
have to ride, so getting debris in and on my brake pads is a pretty
common thing for me.