I'm in the middle of plotting and planning a mixed vintage/modern build… I wanted an old school steel frame and wound up with the frame and fork of what I think is a 531 Jeunet (yes, French). Started reading through some interesting threads here and elsewhere and am leaning strongly in the direction of trying to be true to the spirit of the thing while still allowing myself some modern conveniences.
The 9-speed years seem to be the last time things were bright and shiny and I figure I need to stop at square spindles, what with the French threading. I've been looking mostly at Ultegra (or maybe Centaur), probably 9-speed, for derailleurs and hubs.
Can I run a T.A. Cyclotouriste crankset with a 9-speed chain without coming to grief? I was thinking about running it as a 54/40 double. Anything else I should be aware of or thinking about?
Since I'm in over my head I'm guessing there will be more questions down the road.