DCwom

We finally did some reasonable hills for the first time this weekend so we used a lot of brake. Since getting the bike (new) the front breaks have always made an ugly kind of gritty sound, as if the rims had dirt/grit on them. I've cleaned the rims/pads, played with the angles, etc all to no avail. I figured maybe things just need to wear in so I've been ignoring the noise (stopping isn't compromised), but after the hills nothing has worn in, and they still sound awlful; kind of embarassing too when you roll up next to another rider.

This is not a vibration/squeal kind of noise, I'm pretty sure of that, and it seems to mainly be on the front wheel. I've cleaned the rim several times, and the noise appears to be less after the cleaning, after this weekend's hills there is a fare amount of black brake "stuff" (I hesitate to call it simply rubber) on the rim, I wonder if maybe I just have a set of bad pads that are fouling the rim and making it "rough & gritty"? I hav'nt had a chance to clean the rim again to see if the gitty noise is reduced.

Wheels are all true, shoes are aligned, etc. I'm stumped.

Any ideas?

Onegun

At the very least we'd need to know what rims and brake blox we're talking about before anyone could venture a guess.

jnbrown

Is the rim worn?
I had a set of wheels with a lot of use on them and the rim surface was scored producing the noise you describe.
You could try a different and perhaps softer brake pad like Kool Stop Salmon.

TandemGeek

If those are the original brake blocks that came on the Burley Tam way back when it was new they probably needed to be replaced when you first took delivery, noting that you mentioned they've always made a 'gritty' sound.

Brake blocks simply don't last forever and as they age they become less pliable and lose their grip even if the tandem sits unused. There's no set time table for how long brake blocks stay 'fresh' since there are so many different variables such as humidty, UV exposure, temperature, etc...

My guess is, if you replace the blocks you'll solve your problem, OEM replacements or otherwise. You'll want to clean your rims with a 3M scuff pad or similar and some solvents once more when you install the pads just to make sure you give the new brakes a fresh, clean brake track for the wearing-in process. It will take your new pads and clean rim a little while to get seasoned but there should be a pretty dramatic change even on the first ride.

DCwom

Wow TandemGeek, you've got a good memory, I think I've only mentioned once that we have a Burley Tamburello.

The Tamberello is actual brand new this Spring, that is the frame is brand new with brand new components. This is a hybrid that Mel @ TandemsEast made up using the Burley stock he bought up when Burley exited the tandem business. Given the Tamberdello was a road bike with drop bars, etc. I'd say most of the components are not stock Tamberdello parts (I never thought to ask Mel that question). The rims are Mavic A719, with Shimano XTR brakes.

TandemGeek

I'm still betting on the brake pad material being the root cause for the noise. If the brake blocks are fresh it could just be the XTR brake block compound.

DCwom

I finally got around to installinig new shoes and the gritty sound is gone, now I've got a nice squeal; at least this is a "normal" sound. For giggles I put the old pads on my single bike and they sound gritty there too, so it must be the pad material.

DCwom

Opps double post