Sorry if I miss anyone in here. The bike is his only mode of transportation, and he seems rather in love with the bike, he's not interested in buying another machine (no matter how I try and shift his focus to a better bike. I've tried guys. But to no avail)
Not entirely sure what is wrong with the rear end, he's had it tuned up several times and can't get it to shift reliably for more than a week, something seems to walk out of adjustment. The RD has some interesting play in it, kinda shakes side to side in places it shouldn't. (None of mine do this, seems odd to me)
The chain is part of his chain jump problems, it's stretched out enough to come a little over 1/2" off the big ring at the front. That needs replaced. I know that. He's complaining about it chunking (jumping) while he's riding it.
I'm hoping a new derailleur(altus has made my list), chain and shift mechanism will sharpen up his shifting, make it more reliable.
As for the tires, I think he's wanting the flat protection from a higher grade set up. Goat heads suck out here. I think there's another phoenix rider here in the forums, he can probably confirm that.
Oddly enough, his FD shifts rather well, at least seems so to me, goes into the commanded gear with no complaints. I'm currently working on adjusting the brakes on the bike, i think he needs a new barrel adjuster at the lever. Cable Keeps popping out.
Budget, he's trying to stay in the cheap and get things repair by repair while upgrading the running gear in the process.