29 May 2011
"Sufficiently advanced technology is indistinguishable from magic." I demonstrated Arthur Clarke's Third Law—a couple of years before he posited it in 1973—when I first saw a derailleur-guided bicycle chain hop from one sprocket up onto the next bigger one, and back down again. Shock. Disbelief. Delight. Tell me that @!%# chain didn't just jump back and forth. In my case, magic was old technology cast before a sufficiently naïve observer. You'd think two or three years at a fine engineering school would have prepared me better, but I was, after all, a math major.
Although modern medicine has saved my sorry butt more than once, and computers have enabled me to live fat, dumb, and happy (at least until I blundered into the dot-com bubble), it's this unassuming nineteenth-century technology that seizes my heart. I'll bike with a Huret derailleur any day. I think it's no coincidence that a German invented the linotype machine, an infernal Rube Goldberg behemoth that can't possibly work, and a Frenchman invented the derailleur, a simple, elegant little machine that can't possibly work.
In this new century derailleurs are no longer rare and novel; you can avoid them only on low end and the smallest of kids' bikes. One afternoon my grandson clamored to shed his training wheels and try his new, bigger, derailleur-equipped bike. I girded my loins, fully expecting to jog behind him, keeping the bike vertical, trying to shield him from the unnaturally intense gravitational pull that trees, telephone poles, and pavement exert on fledgling riders. I rehearsed my pep-talk for persuading the owner of newly-skinned knees to remount and try again. I dearly hoped I could take credit for teaching him to ride a bike, but that's not what happened.
That day one after another three fully-formed cyclists sprang forth from my forehead. I shifted the bike into granny gear. I held it so my grandson could climb on. He pedaled like crazy. I took only three steps before he pulled out of my grasp. He weaved all the way around the house, twice, finally slowing down and toppling onto the lawn, laughing maniacally. Thinking it premature, I hadn't bothered to teach him the controlled dismount, but he learned that by himself in a day or so. After a couple more tries he didn't even need the grandfather-assisted takeoff. Both of us were astonished. The derailleur changed everything: at that cadence, he was going fast enough that he didn't have to think about balancing, slow enough that he could avoid hitting things, and he didn't need to strain to propel fat tires through soft clinging grass.
Then his two younger sisters did the same thing. I was a little peeved that a clever inanimate object had deprived me of a teaching gig the most benign grandfather would kill for, but I'm over it now. It's not every day you get two low-grade epiphanies for the price of one, forty years apart.