I'm thinking about some offroad touring on an MTB with front suspension and disc brakes, and I'm wondering what weight I could put on a rear rack. I've seen some racks which attach to bosses some way up the seat-stays (as opposed to mounts at the dropout), and I've seen some which fit on a widened skewer in the hub itself. I've not seen any which attach to rack-specific holes in the dropout, and I don't know if that's possible because of the space required by the brake.
If you've done this, what kind of rack did you choose, and roughly how much weight could it support?
And... given the short chainstays on most MTBs, what was the handling like when you loaded up the back?
I have done one 200 mile trip with my front suspension/disc equipped mtb. I used an Axiom Journey Disc model rack and Nashbar mountain panniers. The rack worked well, and I had minimal issues with mounting it on my bike. My total load was 30 lbs. or so. The rack is rated by the manufacturer for more than that, but I haven't tried loading it to capacity. Didn't notice any handling issues, but most of the miles were on the road.