Originally Posted by
KC007
I found a beautiful NOS Regina Freewheel Extra America 6 speed 13-14-15-16-17[color=#111820]-18 * ISO Thread, do you think that will be compatible with my Campagnolo Nuovo Record Rear Hub?
I could not find any words on my hubs, except Campagnolo (but I know the hubs are either are from 70's or 80's Era)
As long as both the hub and freewheel have the same thread spec, it will work. English is 1.37" x 24tpi, 60° thread angle. ISO is 1.375" x 24tpi, 60° thread angle. Italian is 35mm x 24tpi, 55° thread angle. French is 35mm x 1mm, 60° thread angle. English/ISO and Italian are close enough to be compatible, but once you mount a mismatched part, best practice is not to go back and forth between and mismatched, as this reworks the thread angle each time and increases the chance of eventual failure.
Thread spec is marked on both the hub and freewheel, albeit sometimes in an arcane manner: