A rotor assembly for a cold planer is disclosed. The rotor assembly may include a rotor chamber that is configured to house a milling drum, and the milling drum may be configured to rotate within the rotor chamber. The rotor assembly may further include a plate movably coupled to the rotor chamber and an upper pulley wheel rotatably mounted to the plate. Furthermore, a lower pulley wheel may be rotatably mounted to the rotor chamber and the lower pulley wheel may be operably coupled to the milling drum such that the lower pulley wheel and the milling drum synchronously rotate. The rotor assembly may further include an actuating mechanism operably coupled to the plate, and the actuating mechanism may be configured to move the plate and the upper pulley wheel between an operation position and a transport position.