I've been commuting by bike for the past year and a half and have logged nearly 3,000 miles. Unfortunately my enthusiasm for riding has outstripped my mechanical knowledge. I haven't done much in the way of maintenance on the bike and now that i compare it to a friend's (mostly ignored) bike it seems like everything needs replacing.
chain - original to the bike! 1.0 on the chain wear tool.
freewheel - worn since i've never replaced the chain
bottom bracket - isn't smooth, there is a fair amount of friction
crank set - the chain wheels seem to wobble a bit, also probably worn from the chain
all cabling and housing - no a big deal but probably should be done
brake pads - easy, but my brakes are frustrating me lately, maybe because i need to true my wheels?
stem - might as well, i'd like a more aggressive riding posture
...and once i've figured that out, i wonder, "do i have the proper size frame?"
In all, I'm feeling pretty overwhelmed. Have you guys been through this? Where do I go next? I know plenty of people would just walk into a shop but I'd rather understand the machine. When it comes down to it, I'd just like some reassurance that i'm doing the right thing.