I've got this very unusual screech in my rear avid arch rival 5's which developed almost overnight.

Toe in is set up properly, brakes are square to the rim and I've checked the pads for any grime.

Any ideas ??

claude

If your toe-in is set right, the only thing I can think of is that something in the brake mechanism might be loose causing the pads to shift as they hit the rim.

Hope this helps.

Bubba

I agree with Bubba. Another thing that can cause it is dirty rims. Hot saopy water or rubbing alchohol will clean them up good. Also if the pads are glazed menaing a shiny surface to them. Take some medium grit sandpaper or a non metal nail file and shave that stuff off.

Be carefull when applying lube to your chain,don't let it drip on your rims sidewalls......

solved... problem was one of the pads was not vertically square with the rim, but was hitting it at an angle - I guess the difference in friction between the left and right pads, and the fact that arch rivals are linked with that integrated brake booster horseshoe thing, was causing the whole mechanism to sqeal.

thanks for the feedback :)

claude