HillRider, I have a 1985 Trek 660 with a Helicomatic rear hub that I've been thinking of simply replacing rather than scrapping the whole wheel. I haven't checked dimensions but had been assuming I'd need new spokes. Sounds like there's a chance of dropping in a Shimano rear hub. If so that might finally get me to move on doing something with that bike that's been hanging in the garage for over a year now.