the back brake is squealing and also vibrating that it can be felt through the frame. they were ok for 30 odd miles bit I just can't stop it happening now, it only appears to be affecting the rear, cheers

As far as i understand this is a fairly common problem with all brake types, I have Juicy 3s, M760, Mono Mini's and M4s ans all have done it at some time, admittily the Juicys seem to do it the most regularly. I run sintered pads on all. If it is perticularly bad try taking the pads out and flatten / rough them up wityh a metal file (keep file flat on surface), also try swapping pads front to rear. Also check caliper alignment and disk surface for smoothness.

If a disk has got very hot it is possible to pick up small amounts of metal and wipe it across the surface.

And finally for squeeling make sure the spring that keeps the pads separated is not bent and running the wrong side of the disc. The four fingers of the spring should sit evenly either side of the disc

have hope discs on my other bikes never had this issue with those intact I've never had to touch them apart from pad changes. justfound this re elixirs interesting…

http://www.bikerumor.com/2010/02/15/sram-issues-technical-bulletin-regarding-elixir-disc-brake-issues/

As mentioned, I would deffo check caliper aligment, but also check for sticky pistons.

Pads out, get a bit of brake fluid around the pistons, and carefully work them in and out (squeeze brakes, lube, clean, retract, repeat), cleaning and lubricating (with relevant brake fluid) as you go.

Bob's your uncle. 😀

Kev

cheers will give it a go

No experience of Avid Elixir 5's but experienced the squealing with Shimano and Hope set ups, simple solution to perhaps try first is to smear a little copperslip grease (anti-seize) compound on the back of the pads – that is, between the pad and the piston. It doesn't need much and often works. Of course the set up needs to be cleaned with a cleaner – either isopropyl alcohol or disk brake cleaner to make sure it's not just a contaminated rotor.

The four fingers of the spring should sit evenly either side of the disc pad

fixed it for you 😉