A bicycle, cycle or bike, is a pedal-driven human-powered vehicle with two wheels attached to a frame, one behind the other.

• 自行车，亦称脚踏车，台湾话另称孔明车或铁马，是一种通过蹬踩踏板驱动的人力交通工具。一个车架子带两轮子，分前后排列。