A pulley assembly (120) for engaging an endless member (118) includes a first pulley (124), a second pulley (126) and at least one transition segment set (128, 130) comprising one or more transition segments (152, 162a, 162b) that are independently movable between an engaged region and a disengaged region to transition the endless member (118) between the first pulley (124) and the second pulley (126). An actuator system (122) includes a support structure (220), an actuator subassembly (222, 226) secured to the support structure (220) and a stator (224, 228). The actuator subassembly (222, 226) includes a follower (250) and a sled (248), which is movable in a circumferential direction between an advanced position and a retreated position, in response to an electromotive force generated on the sled (248) by the stator (224, 228). The follower engages the cam surface (262) of the sled (248) to move in an axial direction between an extended position and a retracted position as the sled (248) moves between the advanced and retreated positions.