It discloses about the bicycle. Apparatus of the present invention includes a sensor that users sit on the saddle when the sound generating device and a user that is installed in the switch, and a bicycle, which is installed on the saddle so that the work by the pressure approaches the bike recognize the user, the user by a sensor receiving the signal from the lamp, the switch that turns on when recognizing when the current If peat bicycle time longer than the shot time the bicycle previously controlled so that only the sound is generated in the sound generating device, a signal is input from the sensor control to the lamp is lit, and that the microprocessor is provided with features. According to the present invention, the quantity of exercise using a bicycle can be measured it is motivated, is particularly useful for the children can enjoy a play by the flashing of the lamp and sound generation. Bicycle, a switch, acoustic, light, a sensor, a microprocessor