Rear brake squeal
 

I know this one has been posted a gazillion times, and I've researched it, but nonetheless, I still have problems with the rear cantis squealing like crazy. The rims are clean, I took off the pads and sanded them to an even finish. They are toed in, but yet they still sqeal really loud. The front are no problem. The front rim is a higher quality Sun Ringle double wall while the rear is an off the rack wheel from PB that has a wear indicator groove (which also deforms the brake pads as they wear). The only other difference is that the front canties get 'pulled' since they are in front of the fork, while the rear ones get 'pushed' being behind the seat stays. I guess the next step is to take some steel wool to the rear rim and try to scruff it up a bit.
Do higher quality rims have less tendency to squeal?
Thanks!
Jon

Newly installed shoes with fresh surfaces will have a tendency to squeal, the same way new chalks screeches on a chalkboard. You can fool with the toe-in, but if you just live with it a short while it'll resolve itself most of the time.

We were just talking about this yesterday at work. We all agreed that new and clean made the tendencies to squeal worse (along with moisture and oils/lubes on the rims).

I mentioned my technique of placing a bit of garden mulch (as in bark) between the rim and pad then riding around the parking lot to help silence the offensive brake. Andy.

What brake is it? Some brakes arm will just squeal. Avid Shorty 4s come to mind but there are others.

Another cause may be the frame. If the frame is too light in the brake area, the seat stay can twist which causes the toe of the brake to lift off the rim and chatter. This is a fairly rare problem, however, compared to the caliper itself.

They are the Shimano CX-50's and have maybe 500 miles on them. I stopped by the lbs on the way home tonight and he made some adjustments and tightened up the spring by moving it to the top hole in the canti boss mounts. He pretty much got the squeal out. He mentioned that the long arms can contribute to the squeal. The brakes comes with 3 different barrels that determine the distance between the brake pad and the mount on the bosses. I went with the longest ones because that is what the yoke seemed to fit. If I went with one of the shorter options, I think I would lose mechanical advantage or possibly need a new yoke.