I recently acquired a 80's era Serotta with a full Shimano 600 set-up. I was thinking of upgrading this bike from 6 speed to 8 speed. I am usually Campy guy so my knowledge here is limited.
What components need to be upgraded? I want to keep the shifting to downtube shifters and run them as friction.
What I think I need: an 8 speed rear hub, cassette, and new chain?
Will the existing deraileurs work with an 8 speed upgrade?
One more thing, where can I find a headset wrench for that crazy starfish nut?
Surly Cross-Check, '85 Giant road bike (unrecogizable fixed-gear conversion
I tried converting 6 speed Shimano Exage to 8 speed and it didn't work. That's when I started getting into fixed gear.
But the good news is that 8 speed derailleurs are really cheap. The shifters should work just fine if they're friction.
You will need a new rear hub. Just go out and get a new cassette wheel. You have tons of choices.
With 8 speed, you won't have many choices for gearing in the back. Pretty much anything but 12-26 is hard to find. But a SRAM 8 speed cassette is about $30 and the chain will set you back about $20. Yes, you will need an 8 speed chain.
You will need to get your frame re-spaced (widened) if you want to do it right, although you can just pull the rear triangle apart and squeeze the new hub in.
Also, a 9 or 10 speed rear derailleur will work fine. Including campy.