Just fitted my new XT rear brake to the Zesty using a Shimano 180mm post to IS adapter.

When I spin the wheel the disc rubs on the top of the calliper as if it were too big. I’ve spaced it out with a washer and it’s ok but obviously something is wrong with the set up. I’ve checked all the packaging and everything appears to be the right size and there are no parts like washers left over.

Any ideas?

Back to front?

Definitely a 180 rotor and not 183? I’ve seen it before.

Thanks for the ideas but…

Definately the right way up! That was the first thing I checked.

I’ve had 2 rotors in there now both marked as 180mm.

Sounds pretty normal to me. I’ve had to fit a few with washers so they fit nicely. Not a big issue.

Sounds pretty normal to me. I’ve had to fit a few with washers so they fit nicely. Not a big issue.

Interesting.

It works fine but it’s pretty poor engineering.