Originally Posted by BarelyAWake
I'd say simply having a frame where the chainstays aren't an issue. While many have used the internal gear hubs with great success onroad - I dunno if it'd take the pounding offroad. There is also the need for as many low gears as reasonably possible, I'm particularly lookin' forward to my "granny gears" when I do manage to get a jack shaft.
As I see it, the biggest prob with the derailleur is smackin' it upside a rock. I've somehow managed to avoid that for now but it is inevitable. Luckily - I have a few spares
There is one internal gear hub meant for offroad, the Shimano Alfine, it has a triple clutch, unlike any other internal gear hubs. The SRAM i-motion has a version of this, but I think it still meant for on road use.