I've got a pair of late model shimano dual pivots that I'm trying on my '80 Le Mans today. As far as fitment from 700c to 27", all I'm having to do is grind out about 1/64" of material at the bottom the slot. It will be different for every application I'm sure, but I'll post which worked better on mine at the end of the week. All the vintage guys will lynch me for this, but I can say the clean design of the dual pivots looks a whole lot better.