A powered unicycle device for use upon a riding surface. The unicycle device includes a single wheel rotatably coupled to an axle, the wheel extending substantially in a fore-aft direction. A motor for driving the wheel is provided and electronic equipment, in communication with the motor, is configured to maintain fore-aft balance of the unicycle device while being ridden. An elongated curved rail, defining a curved path, is coupled to a support frame of the unicycle device and extends laterally in a side-to-side direction substantially transverse to the fore-aft direction. A seat is disposed above the wheel and is movably coupled to the rail such that the seat is capable of moving laterally along the curved path of the rail, in the side-to-side direction substantially transverse to the fore-aft direction, while the unicycle device is being ridden.