Hi, first time poster here, I hope you folks can help me out. I recently got a 1997 Gary Fisher Big Sur frame for $20. It's in great shape and I'm figuring it'll be my new bike. I have a '91 trek 7000 but it's never really fit me right, it's pretty heavy, I'm just kind of tired of it. I have thumbshifters on it though, because I love thumbshifters, and I was thinking of just swapping over the drivetrain (7 speed) to the Fisher because that's how much I love thumbshifters. But if I do that I have pretty much 1 choice for a derailluer, a NOS Deore DX (the lx on it is wore out), and then my trek is dead in the water. I've tried to find some old 7 speed hubs/cassettes, but I haven't found anything.
So searching around various places I've thought of putting an 8 speed drivetrain on the Fisher and use my deore thumbshifters and hope the "extra click" works or just use 7 of the gears. But 8 speed stuff seems hard to find and I just can't figure out all the different compatabilities. A crankset has to be specifically for 8 or 9 speed apparently? Same with derailleurs? 8 and 9 speed hubs are the same but the cassettes are different, but 8 and 9 speed derailleurs are different and one won't work with the other?
Did I mention I don't have much dough?
See, I've found various cheap components around- xt hubs for $30 and 8 speed xt cassettes for $30, but no 8 speed derailleurs besides a deore that's 8 or 9. So I guess my question boils down to- what should/can I do if I want an 8 speed drivetrain for reasonable $$? Can a 9 speed derailleur work with an 8 speed cassette? Can I get at least 7 clicks out of my deore thumbshifters on an 8 speed derailluer or are they completely incompatable now? I don't even understand what makes a derailleur 8 or 9 speeds, I mean, it covers the same area, right?
Besides eBay, any recommendations on places that have NOS shimano stuff? Like 8 speed derailleurs or, heck, 7 speed hubs and cassettes? Sorry if this is a bit rambling, I just don't know where to start. One thing I do know- I don't want a freakin' 9 speed drivetrain if I can help it. Thanks.