Originally Posted by 67Carlton

Many thanks for the info jimijames, I had seen the 26.4 number in a few places, but was surprised to get a few larger measurement numbers with the caliper. Perhaps there is some slight ovalization of the seat tube? I think I'll start with trying to source a decent 26.4 and work my way up if I have slippage.

"Joy to ride" is exactly what I'm going for with this project, so I'm glad to hear of your experience with your '72. If it goes well, perhaps I'll work my way up to a 5-speed, just more parts to find along the way, though I'm finding that's half the fun. I'd also considered at 3-speed IGH if I can find one.