Mystery sound at brakes
 

I have Ultegra brakes and race lite wheels. Recently I noticed a soft clicking sound at the front brake/wheel. Really more of a whoosh than a click. It only happens when I brake. It's like there is something that comes around and rubs on every revolution when the brake is applied. I've cleaned the braking surface on the rim thoroughly, and checked the pads as well, but I can't see anything. This phenomenon just started. All I can think of is that I recently re-centered my brakes using the allen adjustment on the top of the brakes.

Does anyone know what could be causing this sound, and should I be concerned? I have a race this weekend.

Flash at the rim joint?

Rim out of true very slightly?

Look at your tires. There are often little "whiskers" sticking out of the sidewalls left over from the molding process. If one or more is brushing the caliper arm you can get the sound you are hearing.

I'll check that, hadn't occured to me, I've been so focused on the baking surface. I hope it's not that the wheel is out of true. The sound is a quick one, a regular cadence. If the wheel were out of true, wouldn't that cause a more gradual deformation and cause the brakes to rub over a greater distance (i.e.) more of the circumference of the tire? I'm not a wheel builder so I'm not sure. I use the trainer and a cyclops wheel block a lot, could I have somehow gotten my wheel out of true by rocking too much on the trainer?

I know it's easy for a mech to true the wheel. I just happen to be going out of town early tomorrow and might not have time to get to one.

If you pick up the front of the bike and spin the wheel, can you tell where the noise is commin from? Look for a tire rub or very slight wheel rub. These are just wild guesses but might help.