So is there any gain in strength and durability in the higher end parts? Or is it only weight savings? I can already see durability is going to be a major issue for me, these things just don't seem to be built for my tonnage and leg strength. My rear sprockets were shifting all by themselves on a uphill today and making some very nasty noises doing it. The lbs already replaced my rear cassette under warranty with a supposedly stronger one after my first three rides.
Also when I raise the back wheel and turn the crank by hand to lube the chain it doen't exactly feel all that smoothe, I can definitely feel a lot of roughness in the bearings in the bb.