Question about my downtube shifters
Just purely out of curiousity and nothing else. With my downtube shifters, if I were to ever decide to bump up my speeds from 6 to something higher...can those same downtube shifters be used to be recalibrated for the increase in shifting? Or do they make downtube shifters specifically for different speeds? IE 7, 8, 9 , 10 ETC?