My history with bicycles goes back to about 1954, beginning with a Schwinn pedal-brake one-speed, fat-tired bomber. My next iteration, a few years after that, was a road bike with the amazing Sturmey-Archer 3-speed shifter, which sat right up on the handlebars. That was indeed revolutionary: I distinctly remember the satisfying click the shifter made as I moved effortlessly between all three (count them!) gears.
Bicycles do accumulate, as they are hard to part with. I believe I have seven (excluding the little ones for visiting grandchildren). My inventory includes a Moser, a Bianchi, and a beautiful carbon-fiber Trek from my friend Dave. Recently I pulled out an old Nishiki 12-speed from the back shed, to clean it up and put it on an indoor bike trainer for winter exercise. In the process of going over the Nishiki, I was struck by its lovely derailleur, a Shimano 600, which I had never really paid any attention to before.
Started by the 26-year old Shozaburo Shimano in Japan in 1921, the Shimano company celebrates its hundredth anniversary in 2021. Shimano started off producing bicycle freewheels, the sprocket that delivers power to the rear wheel but which also allows you to stop pedalling without being instantly launched off your bike.
The modern bicycle derailleur—a fancy term for a gear shifter–is a paragon of mechanical ingenuity. It has to move forwards and backwards, inwards and outwards, all the while maintaining the appropriate tension on a continuously moving bicycle drive chain. When downshifting, the derailleur must adroitly deliver the chain from the smallest sprocket to the next bigger one. Depending on the number of speeds your bike has, it must do this same delivery five, six or seven times, and then back down again when you upshift.
My Shimano 600 is probably the final state of the art of the “find and grind” style of derailleur, which was soon overtaken by SIS, the index shifting revolution, which Shimano introduced in the 1980s. SIS shifting automatically centers the chain over the appropriate sprocket.
The delicate filigrees on my 600 suggests that Shimano may have been influenced by their Italian competitor Campagnolo, who built high-end derailleurs that were not only perfectly functional, but elegant as well. What a wonderful notion, to incorporate a bit of art into one of the most relentlessly mechanical devices we humans have ever invented.
One thought on “Derailleuring”
You know someone is a writer when they can describe bicycle gears in a way that is interesting to someone who doesn’t even really know what they are talking about. I’d put a smiley face here if I could. Good one Don.