I'm planning out the upgrades already on my next bike (fat), working through the options for rear hubs. Was originally thinking Alfine, cake to service and reasonably tough. SRAMs imotion is out as I've already busted one of these. I know Shimano mention these are load shiftable, but they feel ugly when shifting under load. A rep was in the shop the other day and we got talking about the Nu Vinci - a fully sealed non-serviceable CVP, basically an infinite amount of ratios within the range.
I've done a LOT of 4x4ing in the dunes and on the beaches, the transmissions that excel in the sand are always the auto trannies, manuals always lose that bit of momentum on the gear change . My theory is that a cvp hub on a fat might shift better than a set ratio planetary hub (Alfine, Rohloff etc). Nu Vinci have their own forum, reading through the threads they seem to have many bases covered, with a lot of tech and online support.
Now, has anyone used one?
http://fallbrooktechnologies.com/08_Bicycle_home.asp