买一辆新的电动自行车,原有的自行车就不怎么使用了,这实在有些浪费。美国一个大学生研究小组发明了“绿轮”(Green Wheel),可以把普通自行车改装成电动自行车。普通自行车骑起来有些费劲,电动自行车总是有些笨重。“绿轮”中集成了发电机、电动机和电池,使得“绿轮”电动自行车快速、节能而且轻便。 Buy a new electric bike, the original bike is not how to use, and this is really a waste. A team of undergraduates in the United States invented the “Green Wheel,” which converts ordinary bicycles into electric bicycles. Ordinary bicycle ride some effort, electric bikes are always a bit cumbersome. “Green Wheel ” integrated generator, motor and battery, making “Green Wheel ” electric bicycle fast, energy-saving and lightweight.