Bless Shimano for perfecting the freewheel, even after it became close to obsolete.
I was fixing up a dumpster bike for a customer. I literally plucked this bike out of the town dump, because it looked OK. Well, it wasn't, and it needed a ton of work. Live and learn, I guess.
It's a Windsor from about 1978. Ten speed drive train, with SunTour V-GT derailleur and long ratcheted stem shifters.
The chain made a lot of racket around the freewheel, so I replaced it. It looked worn anyway.
Hmm, the racket persisted. The rim wasn't as straight as I wanted, so I overhauled the hub to see what was the matter. Ick, the cones were pretty badly scored. Aha, so that's what was making the noise. Well, sometimes putting stuff back together and not really fixing things can make things better in a mysterious way, so I did that. The noise persisted. Oh well.
I replaced the entire rear wheel. I had a nice wheel with a Miche hub (really smooth) and a Wolber 58 rim. Ooh, nice classic stuff. Some really nice spokes, too. I knew it might come to this because the rim the bike came with was bent, and the truing I did on the wheel didn't produce very satisfying results anyway.
OK, so I replaced the wheel, and the darned noise still persisted! Hmm, new hub, new chain, the derailleur seems good. What could it be?
I put on a generic un-branded freewheel, an exact copy of a Shimano. Oh my God, the noise is gone. The teeth on the old freewheel (SunTour) didn't look worn, but who knows?
And Oh my God again, the shifting is now amazing. It's like indexed shifting! Those tooth profiles must be a brilliant innovation. I give a little credit to this classic of a derailleur, but really, this freewheel makes more of a difference than I ever would have thought.
I was tempted to put the old wheel back on, but I'm too honest to do that. I didn't like it.
I'll supply pictures later. It's too dark out now.