An electric drive system for a vehicle; said drive system including an electric motor at at least one wheel of said vehicle; said electric motor comprising an electric field source adapted to induce rotational torque in the brake disc associated with said wheel of said vehicle. In an alternative form there is provided a method of imparting a torque to a wheel of a vehicle; said wheel having a brake disc rotor mechanically associated with it; said method comprising utilising said rotor as a motor rotor whereby said rotor performs a dual function of a disc brake and a motor rotor.