Originally Posted by
byrd48
So I popped into the local co op and picked up a 1997 Trek 700 Multitrack for $65. I might have overpaid a tad, the cassette was letting the sprockets move in both directions. We took it apart, oiled it up and got it working again. Looks like the wheels are not original but everything else seems to be. It has grip shifters, which I don't mind, but the shifting mechanism seems to get confused between gears in places, probably needs tuning. The running gear is Shimano Altus. Weighs in at 30 pounds. In keeping under my $200 budget, I might look at upgrading the rear cassette and derailleur, but I think I can outfit it with a rear rack and maybe fenders.
Upgrading anything that works is a slippery slope and can quickly blow your budget. There's a pretty big dividing line between 7 speeds and 8+ speeds due to difference in the rear hubs. Jumping to 8-speed gets you into the world of higher end parts but can quickly burn a hole in your wallet as a lot of things need to change together. The shifting problem you describe could be as simple as dialing in the cable tension. If that doesn't work, the rear cogs might just be too worn. If it does OK at one extreme or the other but gets progressively worse as you move to the other extreme, it's probably cable tension. It could require new cables, which will usually do more to improve your shifting than a derailleur upgrade. Grit in the cable housing really mucks with indexed shifting. If it shifts OK at the top and bottom ends of the range but has trouble in the middle, it's almost certainly the cogs. Happily, 7-speed freewheels are pretty cheap. If that's the problem, replace the chain too. There is a slight chance that something has gone wonky in the shifter, but usually if it works at all it's not the source of the trouble.
Congrats on the new bike.