I've posted on this on the past, so if you've heard this before sorry.
I've now broken 9 freehubsover the span of owning my bike, which has been 3 years. Five of them have been Deore, 3 XT, 1 Hope. My bike is a Trek Liquid, which has the Carbon flexstays. I'm fat, but have never broken a freehub on another bike, and don't really ride mtn bikes that much, or that hard. I usually break them on a rough uphill climbs while in my 22x34 gear. I'll hit a root or rock and then hear a shearing type sound, usually the freehub gets jammed and sometimes it will fail to engage.
I read that sideloads are the number one reason why freehubs break, and I think that is why they are breaking with this bike. Under power the main pivot flexes the the bike bows out a bit. The main pivot on this bike is offcenter and the bike has long flexy linkages which I belive aggravates the problem.
I asked trek about it and they said they didn't think a frame could cause freehubs to break, but to take it to my local dealer. I bought the frame used though and I don't think I'll be able to get any help.
I'm thinking about getting something else. I like the ride of the liquid even though it seems a bit stiff unless at speed, and would like to find something similar with around 4-6 inches of rear travel. Many of the local riders like the Heckler but I I've had trouble finding one, they seem to be hot items. I've been been also thinking about a giant trance or reign. Any suggestions for a fat mans medium travel bike.
Gunnar Crosshairs, Giant Trance, Felt Breed, Marin SS MTB, Felt Pyre BMX bike, oldschool GT trials bike
if you want a new bike the yeti 575 is freakin sexy and then for a bit cheaper the giant trance x is an awesome bike.
if it was me though, i would have your lbs build you up a nice set of chris king wheels which have the most bombproof freehub ive seen. our shop has sold more sets of king wheels than i can count and ive never seen one fail personally. I doubt your frame is causing the freehubs to die.