Originally Posted by
smasha
thanks all - that's what i was suspecting, about being right on the border of big problem (drive train) and little problem (just the chain).
as much as i don't really have the money, i'm tempted to upgrade the bike to:[*]Shimano XT Cassette 9 Speed M770 (11-34)
Unless you are a competitive racer, weigh about two pounds per inch of height (140 pounds for 5'10) which suggests you have the body morphology for a great power to weight ratio and climbing ability, and are racing off the front in the mountains to an up-hill finish cassette upgrades don't buy you anything.
Where you are a 140 pound racer atop a bike just shy of the 15 pound UCI minimum saving 100g by getting titanium cogs results in a 0.1% speed increase that makes a five second per hour difference in your separation from the chasing peleton. The effects are essentially non-existent on flat ground and proportionally lower for bigger people atop heavier bikes.
I generally buy the least expensive cassettes with nickel-chrome plated cogs I can.
Spending more won't make them last longer (titanium cogs wear faster if you spend enough to get them)
In your case that'd be an HG50 that can be had for $25 not $100.
[*]Shimano XT Chainset 9 Speed M771 (26-36-48)
Once you have pins and ramps on your chain rings they're going to shift good and spending more won't make it better.The same caveat on weight applies. Chain rings last a very long time (several cassettes each of which lasts through several chains). Spending more won't get longer life.
[*]Shimano XT Rear Mech Shadow 9sp M772 (SGS)
Once you have a floating top pulley "better" rear derailleurs don't improve performance - they just look prettier. Spending more won't get longer life.
Rear derailleurs last a very long time. I got about 15 years out of my rear derailleur before it developed unacceptable slop in the pivots.
[*]Shimano XT Front Mech Conventional 9sp M771 (Unisize - Dual Pull)
Nearly all your front shifting performance comes from the pins and ramps and the remainder happens with a shaped cage that happens at much lower levels. Spending more won't get longer life (might get less; aluminum front derailleur forks show more wear than steel although it takes a long time).
Front derailleurs seem to last forever.
that's about $400-500(US) - half of which is the crankset. not cheap, but for the same money i could get a bus-pass for 4-5 months. i'd rather put the money into my bike! i didn't realize i've been riding it for a year and half!
If you want to spend money on a bike you might save your money for a raod bike with rack eyelets and fender clearance.