I have a full suspension MTB, about 12 years old, in relatively good condition. The frame is a bit heavy, but it's something I've learned to live with.
The transmission is absolutely out of whack though, especially the rear derailleur and the rear sprockets - both worn out - as well as the chain. The front derailleur is fine and the sprockets too. My ultimate goal is to make my life a bit easier on the uphills since I can't afford to invest on a new bike yet.
My question is if it would make sense to buy new a rear derailleur, sprockets and a chain and install them on the bike? What should I pay attention to?
P.S. I'm fairly experienced with bicycle mechanics. The sprocket brands available here are sram and shimano.
If you want to attempt hills, don't do what I did.
I had my MTB 11-28 cassette replaced with a road 12-21 cassette. It's great on flats, lets me optimize my speed. But now that I've started going on hills... holy jesus it's killing my knees. Even had my granny gear changed from 24 to 22... helped a little... but not a lot. I think what I may end up doing is getting another cassette (maybe 11-34 or something) and swapping that out when I plan on doing long hilly rides.
mechBgon: The rear sprocket has 6 gears, and the number of teeth on the largest one is 28.
Mithrandir: Would you have to change the chain and the gear shifter when replacing the sprockets like that? I also have a road bike and I know exactly what you mean when going uphill. The transmission is just not made for that kind of thing. Changing the sprockets sounds like a good idea.
It's probably a good idea to replace the chain because the chain is probably sized for the smaller big-big combination, and would not fit when you put an even bigger gear on it. Though technically you shouldn't be cross-chaining anyway, but it's still proper to make sure the chain actually fits on all gears.