I happened to do a rack install on an FX today. Use long rack struts
and put about a 45° bend in them, far enough ahead of the rack that they're coming down to the frame's riv-nuts from above
the brake, instead of trying to go right through it.
Secondary option: you could get a seat collar with rack mounts built into it
. If you decide to get one of these, your LBS can get them from J&B Importers for you. This puts the rack mounts up high enough that you won't have clearance problems with the brakes. You still might need long extenders to reach the mounts and still have the rack sit back far enough to keep your bags away from your heels.
Last edited by mechBgon; 06-14-08 at 10:58 PM.