[Closed] BB7 caliper alignment off - any ideas?

With the bolts undone, Ive used spark plug gauges between pads and disc as spacers.

Apply brake, then tighten the bolts.

Gets the alignment spot on.

Just use a thin shim under the spacers on the tri alignment spacers.

I have a Salsa fork that causes the same problem.

Ah, different direction of alignment.

I this case, the caliper is about 2-3mm too close to the axle.

avid 185mm rotor, avid 185mm adapter...

???

cheers stu, missed yours.

Just push the caliper further out with some spacers then?

Yep.

I used some old Hope shims.

TBH I wouldnt be overly worried about that. Its only about 1mm unworn at the outside of the disc.

You'd be bothered about it if it was juddery and fluttery and annoying when the rotor spokes hit the brake pads. Which it is.

Agreed, it would be annoying.
Most of the discs on my bikes have a similar wear pattern to yours (mine are hydro rather than cable admittedly) and I don't get that juddering, tbh the rotor spokes would quickly shave off any pad material anyway.
It might be worth gently sanding the braking surface with some fine grade wet and dry paper and also check the pads aren't glazed.

tbh the rotor spokes would quickly shave off any pad material anyway.

maybe they might, but they haven't. 600 miles haven't really affected the judder, and the judder is definitely in time with the rotor spokes hitting the pads. Only at medium pressure though, feathering and really hard braking don't create same result.

If I had a dremel, I could grind away the part of the pads that overlap the bottom of the rotor (pretty obvious, as the pad wear is different) but spacers will be quicker and easier.

Just realised as I was typing that this problem is only an issue because one of the pads is stationary, so as the moving pad comes into contact with the rotor and pushes it towards the stationary pad, the outside of the rotor moves further than the inside, and the bottom of the moving pad is exposed to the angled rotor spokes.

Your hydros will have both pads moving into a stationary rotor (i.e. it's not being moved away from the plane) so the spokes aren't hitting the pads in the same way.

Thanks! I wouldn't have realised that without you mentioning the hydros. It doesn't really affect what I'm going to do about it, but it's nice to understand the problem a bit better.

Yes that makes sense. Perhaps you could run the fixed pad closer to the disc? Or perhaps re-centre the caliper so that its slightly closer to the fixed pad than the mocing pad, so the disc isnt being pushed off centre so much. i.e. when the brakes are applied the disc is central, whereas at the moment when the brakes are on the disc is pushed off centre?

The judders caused by the set up as you've realised.

That wear pattern is fine on Avids - all mine look like that - and I don't have judder.

Do you have the set up manual for the brakes? If you don't then you should be able to find it on Sram.com. The non moving pad does need to be nearer the rotor than the moving pad.

To flatten the pads just rub them on a brick. Although if they have been worn significantly uneven then you'd be better off ffitting a new set and then setting up the brakes.

Yup, all good ideas. I can ease the problem by closer alignment, but not solve it. And I need a bit of clearance because the brakes rub anyway from the forks flexing when I'm honking on the bars out of the saddle.

It might be worth checking that the mount is a 185mm front mount and not a 203mm rear mount too.

Cheers, done, right mount. I even checked it was the right way round!