-=> Quoting Gary Henderson to All <=-
 GH> Hey All,
 GH> I have a Trek 2100, with Shimano STI 105's as the gear/component
 GH> package. It's from 1994, and is approaching over 4,000 miles.  Other
 GH> then greasing/degreasing the chain and gears, I have done nothing with
 GH> the bearings, hub, etc.
 GH> How often should the crankshaft bearings be replaced? Am I need of a
 GH> new chain? Do the sprockets on the rear wheel need to be replaced? 
 GH> What other maint should be done to keep the bike in tip-top shape?
 GH> I already have it planned for the shop to do an adjustment to the
 GH> gears and brakes and am wondering what else they should do at the same
 GH> time.. 
Your bottom bracket (i.e., cranckshaft bearings) shouldn't need to be
replaced for some time.  Two signs that it needs attention are (1) lubricant
leaking from the bottom bracket or (2) lateral movement when you pull the the
crank perpendicular to the plane of its usual rotation.
You probably need a new chain.  The shop will have a device to measure it,
which is probably cleaner than trying to do it yourself.
The sprockets on the rear wheel shouldn't need to be replaced for many years. 
I would almost guess that you are more likely to replace the bike with a
fancier model before you need to replace the sprockets.
Keep the bike clean.  Regularly clean the chain and put a good silicone chain
lubricant on it.  When you clean the chain, you also need to clean everything
the chain touches.  Some bicyclists recommend waxing the chain instead of
lubricating it.
    ===  ==== =   _@
    Ken Peck +  _ \<._
    =========  (_)/ (_)   Kenneth_Peck@clr.com
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