I’ve built my old Soul up as a singlespeed and I love it other than the vibration screaming back brake. I’ve changed the rotor and the pads, refitted the whole thing and still get a horrendous vibration noise. Is there a way to damp the frame or isolate the brake more? Brakes are Magura MT6s..these are fine on other bikes in the family.

no idea. if not the brakes, is it the frame or the hub?

Hmm. I switched out the wheels so probably not them but I hadn’t considered a cracked frame. I really hope not as this is the only frame I’ve kept hold of since new.

Is the IS mount correctly aligned and paint free? I had a frame that had a noisy rear brake. This was caused by a missing “chunk” of paint on the mount causing the caliper to be slightly miss aligned.

I have a Mk1 Soul and never had this after 3 different rear brakes in 17 years?

The mount is a good shout. I’ll definitely have a close look at that. It’s only been an issue for this latest build and so could quite possibly be something like chipped paint or rust. Thanks

Never had that issue on my Mk1 Soul either.
Think that had Formula Oro back when new, and now has XT 8000’s on there and the brakes are as silent as one could ever imagine. Both with a stock IS to 180mm adaptery thing.

Brake squeal comes from the pad disc interface. Some frames can amplify it but its not the cause. Id be looking at contaminated pads

My Soul snapped on the drive side chainstay at the kink. Have a good look there – but it’s probably pads.

If you’ve already done pads and disc, and it squeals straight away, it’s not likely to be contamination, or leakage (or it’d be a noticeable rate of leakage).

I’d be looking at frame or caliper mount alignment myself.

When I built up Mrs Fruitbat’s Mk4 Soul the rear brake screamed (weirdly, my identical bike didn’t). It was fixed by changing from resin to sintered pads.

I recently had this, but from the front wheel – turns out the hub was cracked…