Abstract: A continuously variable power transmission comprising rotatable input shaft attachable to rotating power means; rotatable output shaft providing driving axle means; and planetary power transmission train interconnecting said input shaft and said output shaft, said planetary power transmission train including a drive input assembly, a variable pulley assembly and a power control mechanism interconnected in such a manner as to permit alteration of the direction and speed of rotation of said output shaft by varying the drive ratio of the pulleys and the driving-driven relationship of the pulleys.