A bike having an energy recovery device includes a driving wheel that is coupled to a rear wheel driving shaft pulley of the bike and rotates with the rear wheel of the bike. When a wire is pulled by the bike rider, an outer peripheral surface of a rotating wheel contacts an outer peripheral surface of the driving wheel and rotates together by means of friction with the driving wheel. When the wire pulling force is released, contact with the driving wheel is released. A piston moves in the forward/backward direction inside a cylinder of a compressor. During operation, air is compressed by the movement of the piston, exits through an exhaust opening formed on the rear portion of the cylinder, and is stored in an air tank through an air hose.