I challenged a poster on another thread who regularly disparages XT M770 hubs at their mere mention (8 times and counting) to provide some evidence of the "XT problem". I'm still waiting. To my knowledge, this poster as well as most of the respondents on this thread has never, ya know, actually used M770 hubs.

Where's the problem? Shouldn't we expect to see more than "2 separate reports" of hub failures if there's an epidemic out there, especially since Shimano has sold boatloads of these hubs over the last five years? Why aren't Surly owners up in arms? The LHT "complete", one of the most popular touring bikes of recent years, has been equipped with M770 hubs for four model years (2008-2011). Why aren't the trekking (aka touring) bike owners in Europe with these hubs complaining? They're not and the M770 hub remains part of Shimano's premier trekking group sold there (no, it's not just an mtb hub).

Second, if an M770 hub fails, why is it automatically assumed that the cause was its aluminum axle and smaller bearings? Correlation does not imply causation. Since when did aluminum become a no-no material for a bike part? Have you taken a look at your bike lately and counted how many load-bearing components are made of aluminum? And it's not like aluminum-axled XT hubs are anything new. I have a 15 year old HB-M738 hub with (gasp!) an aluminum axle that still rolls as nicely as the day it left the factory.

It is far more likely that if an XT hub breaks it is for the same reason that all cup-and-cone hubs fail: improper maintenance. Cup-and-cone hubs need periodic cleaning and re-greasing and their bearings need to be properly adjusted or they will fail. If the owner accepts this maintenance obligation, he will be rewarded with virtually drag-less performance and easy field serviceability out in the Middle of Nowhere™.

I'd like to see some real data points regarding this alleged "XT problem" and not the "concern"-mongering, "Some say.."-ing, and internet folklore regurgitating that seems to accompany this topic whenever it's raised.