got over 500 solid miles on the stockers... not a problem... but they are heavy... and i'm 300#
IMHO a clyd looking for an XC bike can't go wrong with a d440... the stock componets are BEEFY... weakest thing on there is the non sealed head set (not realy a big issue IMHO... just replace it when it's worn) and the seat rails...
the 34t was also an issue for me... for some a 32t fits the bill... for me a 22t granny is what I needed for the trail... I use the bike mostly on the road these days so I tossed on an old LX ('95 model) front D, and crankset that I had laying around on the bike... friend gave me a front shifter (actualy gave me the set but the rear is 9spd and has a broken housing)... did buy some old sram 7.0 grip shifters for $10 so if I ever decide I don't like the triggers.
the other weak link IMHO for a clyd are the stoppers... they will do the trick... but it's nice to have a bit more power... a mechanical disc up front does wonders (thats how I run my "main" xc rig... 180mm bb7 up front and V in the rear (mullet)
so in recap...
- good strong frame and parts for a fatty pulling XC duties
- gearing change may be in order for you
- stopper upgrade is a good idea the faster you get