im 165-170 i just gained a few pounds thats why im trying to lose some weight by biking. my quarter just ended and i did horrible in school so i am having second thoughts on building up a bike. i still have a deal for some used parts though... xt wheelset and lx or xt derailleurs and xt cassette, some lighter stem and handlebar and hopefully better brakes/levers. the brakes suck hard when doing downhill, hurts my fingers.. they are cantilevers, would v brakes be a worthy upgrade?