While I'm wrestling with this funky freewheel, I had a crazy thought. I have a set of Shimano 600 Arabesque derailleurs not otherwise occupied and they would be great for this build. Since I don't like the reverse V-Comp anyway, and the Suntour rear is nothing special, why shouldn't I use them? Enter the crazy thought... The front derailleur is only a 2-speed, but since the crankset is 52/47/28, and I need a 52t chainring like another appendix, why don't I set up the Shimano to run the 47/28 as a wide double and grind the teeth off the 52 for a chain guard? Sacrilege? Heresy?

The 600 rear is a long cage and I would be able to use my Tourney 14-34t 7-speed freewheel. Not exactly vintage, but practical. Gear inches would run like this with 650B x 42mm tires: