The present invention provides shift mechanisms and methods of controlling a transmission. According to one embodiment of the present invention, a shift mechanism for use with a transmission includes a central axle defining a central axis; a master cylinder configured to increase the pressure of a liquid; and an eccentric assembly comprising a support member provided about the central axle and an eccentric mount coupled with the support member, the eccentric mount defining an eccentric axis and being in fluid communication with the master cylinder and configured to provide radial adjustment of the eccentric axis relative to the central axis providing adjustment of the gear ratio of the transmission.