Abstract: An exercise bicycle has a main body, a sprocket wheel disposed in the main body, a chain surrounding the main body, a main shaft passing through the sprocket wheel, a fixed crank connected to the main shaft, an adjustable crank connected to the main shaft, a first pedal disposed on the adjustable crank, a second pedal disposed on the fixed crank, a seat post disposed on the main body, a seat disposed on the seat post, a head tube disposed on the main body, a front support rod supporting a front bottom of the main body, and a rear support rod supporting a rear bottom of the main body.