so, mr. bike, mr. trek 4500 alpha, you appear to need surgery. your front break needs to be rebuilt, you front sproket is bent, and gear cables all out of wack. they'll need to be replaced. that should clear up the problem with the rear gears, however, we need to replace your chain, so we might as well replace that two.
and seeing as we're going to do all that, we might as well give you shocks the once over.
in otherwords, we're going to crack you open and tinker with your ticker.