"
1-1/8 fork steerer, slightly shorter head tube, 406mm wheels with plenty of clearance for fat tires and fenders, 135mm spaced rear, disc or canti bosses, 68mm BB shell and replaceable RD hanger, updated bosses for racks and fenders and kick stand mount."

Then you'd have, almost to a tee, the steel Dahon Speed D7, apart from the disks and the Rd hanger. It is remarkable how the R20 has hung on as desirable, they turn up in my recycling centre frequently, and used to moulder there, but now are snapped up by dealers and flippers.