Ride by wire [Resources_Hand On]

Build a pushbutton-controlled electronic bicycle shifter on the cheap. When I was a teenager, I went from a bicycle with a 3-speed gear hub to a 10-speed with front and rear derailleurs. The wider range of gearing was empowering, but the derailleur shifting was sometimes a bit finicky, something that\´s still the case even as I\´ve gotten better bikes over the years. My road bike (a 1980s-era 12-speed) always seems to need its shifter friction tweaked. And my 21-speed mountain bike—which I converted to a human-electric hybrid a few years ago [see "The Hybrid E-Bike," IEEE Spectrum, September 2009]— has always had trouble with the indexed shifter for its rear derailleur, perhaps a consequence of the time it spent rusting on an outdoor scrap heap before I rescued it. · One solution would be to buy better mechanical components, of course. But instead I decided to experiment with electronic shifting. Bicycle designers have been dabbling with electronic shifting for more than two decades, and in 2009 the Japanese company Shimano started selling its Ultegra Di2 electronic system. Problem is, a Di2 shifting kit costs nearly US $1900. Ouch.