I am trying to upgrade the shifters on an old Nishiki I picked up. It's currently a five-speed setup, but I would love to put 7 speeds onto it. I'm used to downtube shifters, but this particular International frame doesn't have braze-ons. I'm not really interested in the Sora shift/brake levers; I like having my shifters and brakes separate. Is there any sort of adaptor that would let me mount braze-on shifters onto my braze-on-less downtube? I've done some looking, and found nada.
Unless of course someone wants to sell me some 7-speed bar-end shifters
Am I screwed, or is this possible?