Abstract: A wheel of a unicycle has two beams disposed in parallel in a rim. A bolt is extended between the beams. The head of the bolt is disposed away from the geometric center of the wheel and the bolt extends through the geometric center of the wheel. Two plates which are connected together by a nut are slidably disposed between the beams. The bolt is engaged with the nut. An axle is extended outward from each plate. A rotation of the head of the bolt causes the axles to move either away or toward the geometric center of the wheel.

Abstract: A bicycle with an eccentric rear wheel including a inner rim with two plates set in parallel with each other across a diameter of the inner rim and an outer rim. A sleeve with a seat formed on it is provided around a hub of the eccentric wheel and serves to receive a shaft head extending from one end of a threaded shaft. The threaded shaft has a pinion on an end thereof opposite to said shaft head. Toothed blocks are slidably mounted on each seat stay to be engageable with the toothed pinion so as to cause the wheel to rotate more or less eccentrically about the hub.