Originally Posted by
TandemGeek
I'm a bit confused... Were you using an Avid caliper w/Avid adapter with your fork (below)...
... or was it some type of an aftermarket adapter?
Wrong style mount, the one in the photo is post mount fork or frame style perch to the Avid post bolt mounts.
The one he should be using will have two threaded holes that are lateral when installed (capscrew heads outboard), and then the brake caliper capscrews, with the cup alignment washers installed with heads aft and threads forward.
For grins I had the box of perches nearby and measured a few. The new style Avids all came in at 11.0+-. A Shimano measured <10.0mm, The old style Avid is difficult to measure, but could be close to 10.0mm.
PK