Patent ID: 7537229

Claim:
A unicycle, comprising an n-shaped fork with two lower open ends and an upper closed end, a wheel rotatably mounted between the open ends of the fork via a drive axle centrally extending through the wheel and the open ends of the fork, the drive axle having two opposite ends each having a crank mounted thereon, a pedal mounted to a free end of each of the cranks for a user to step thereon and drive the wheel via the drive axle, a seat post longitudinally securely mounted on the closed end of the fork, a seat attached to a free end of the seat post for the user to sit thereon when riding the unicycle, a curved sleeve connected to the seat post from the rear of the unicycle, the curved sleeve being concentric relative to the wheel, a quick-release device disposed on a free end of the curved sleeve, a connecting post telescopically received in the curved sleeve, the connecting post being curved and concentrically corresponding to the wheel such that the connecting post is adapted to move relative to the curved sleeve when the quick-release device is released, the connecting post having a free end with two opposite sides each having an L-shaped linkage mounted thereon, and two auxiliary wheels each rotatably mounted on a free end of each of the linkages.