An axial flux electric machine has a rotatable shaft, a fixed stator core comprising a ferromagnetic material and defining an axis of rotation, and a rotor assembly comprising a plurality of permanent magnets. The rotor assembly is rotatable about the axis of rotation. An axial air gap is defined between the stator core and the rotor assembly. The rotor assembly is axially displaceable towards and away from the stator core. The rotor assembly has a first position wherein the axial gap is a predetermined width greater than zero, and a second position wherein the axial gap is zero, such that the rotor assembly and the stator core contact each other.