Squealing brakes

[Kalidurga]

I know this has been discussed here before, but I'm at work and don't have time to search at the moment, so I'm going to very quickly start a new thread...

The stock canti brakes that came on my 2006 Specialized Tri-Cross squealed terribly on my first singletrack ride a month or so ago, and continued squealing afterwards. I cleaned my rims with rubbing alchohol, scuffed up the brake pads with sandpaper, and attempted to adjust them so they'd be toe'd in. Didn't help.

So, I had a pair of Kool Stop's installed. They squealed on the first ride. I went back and had them adjusted. They were fine at the beginning of the next ride, but were squealing again by the end. On the singeltrack ride I did yesterday, they were horrendous. The front brake was fine, but I was hesitant to use the rear brake because it was so loud. Made for a less-than-secure feeling even on an easy trail.

I'm going to take the bike back to the shop, but I'm curious what you ladies think the problem might be. My suspicion is that it's either one of the brake arms (I noticed a teeny bit of play in one of the rear brake arms yesterday when I was again attempting to toe in the new pads), or the rims. Any ideas or recommendations before I hit the LBS?

[7rider]

No recommendation other than what you've already tried (but hey! It's a good excuse to upgrade the wheels, right?)...

With squealing brakes....At least we always knew where you were! :cool:

[singletrackmind]

Sounds like you've got it covered to me. Vibration = squealing and can be caused by contamination on the rim or brake pads or any other thing that might allow vibration. How about if your rims are slick smooth, that could also cause vibration. I wonder (and have never done it) about using an extremely mild abrasive on the rim to break up the surface that allows for the noise?

[DebW]

See if you can tighten the brake on the canti post to eliminate that source of vibration. Otherwise, I'd say you've tried all the usual things. The only other thing I can tell you is that some brakes just squeal, even when you've done everything right. Anyone remember Mafac brakes from French bikes of the 70s? Those things squealed like heck no matter what you did to them. Sometimes you just have to embrace the squeal, be grateful that you have a built-in horn to alert pedestrians who step out in front of you, and that you can ride a paceline and never have to yell "braking!".

[ridebikeme]

Well it does indeed sound as though you have done everything right! CAn you tell me what type of rims you have? Are they silver? Are they a painted black?

[Kalidurga]

Well it does indeed sound as though you have done everything right! CAn you tell me what type of rims you have? Are they silver? Are they a painted black?

These are my rims: Alex Rims: Ace19 (http://www.alexrims.com/product_detail.asp?btn=4&cat=4&id=97). Black along the spokes, silver on the sides where the brakes hit.