I read an article yesterday about biking in Beijing. As car ownership has surged over recent years, the population went from 4 out of 5 Beijingers commuting by bicycle to just 1 out of 5. Automobile traffic and congestion have consequently become a problem, and so there is now a counter surge in the popularity of electric bicycles.
At a certain point, these bikes simply become motorcycles, and so Beijingers are debating how to regulate these speedy and silent bikes—or if they should at all.
I don't think I've ever seen an electric bike, but I did see this homebrew moped parked outside the library one day.
I'm not sure what kind of motor he had rigged to that rack, but it looked like one off a dirty old weedwacker. Something where you have to mix the gas and the oil together. The engine spins the cam that rests atop the wheel, propelling the vehicle forward.
It didn't go too fast. But there was sure no danger of the rider ever sneaking up on anybody. You could hear him coming from around the block!