Hi, I have a mid-80s Japanese steel frame that I'd like to build up with some older Dura Ace. I'd like to use:
-- downtube shifters (shifter will not be dura ace since I need to find a shifter that mounts via boss on center of downtube).
-- Takagi crank, replace the stock inner 40t with 36t if possible, so I have 36-52
-- RX100 freehub
- -7-spd hyperglide cassette (most likely 13-28).
I'm looking at the dura ace RD-7401 and RD-7402 rear derailleurs. If I end up getting a RD-7402, any issues using RD-7402 with 7spd cassette and shifter?
I'm guessing max 52-28 is too much for the RD-7402 spec, but I would never ride in that cross up.
** edit: if I'm reading sheldon brown correctly, the only way I can use pre-1997 dura ace RD is to mate it with dura ace shifters. so, I'll hunt up some 7-spd dura ace shifters and mount them ahead of the boss