Every car sold in America these days, along with an increasing number of motorcycles
, uses "by-wire" technology. Basically, sensors and computers are connected by wires which carry the electrical signals to and fro, eliminating the mechanical connection between the operator and the machine. There are many reasons to make this change, some of which have to do with the complex emissions systems employed by our automobiles. Also, a computer is sometimes able to determine what the operator wants even better than the human controlling things.
Shimano, by far the world's leading manufacturer of bicycle components, has begun making the transition from cables to wires on human-powered bicycles. The company's new Di2 comes complete with two brake/shift levers, two spring-less derailleurs equipped with servo-motors, a 7.4-volt lithium ion battery pack along with a wiring harness. Claimed improvements include accurate shifts every time and reduced weight. That's right -- the new electronic shifter weighs less than the company's high-end manual equipment.