Abstract: A rotor for a disc brake assembly includes a centrally disposed hub and at least one friction surface disposed annularly about the hub, the friction surface including a single continuous spiral groove disposed between the hub and an outer radial edge of the rotor, the single continuous spiral groove including a first portion wherein the groove is disposed radially side-by-side relative to itself and concentrically about the hub with each adjacent segment of the first portion of the groove being spaced from itself by a first predetermined distance, the single continuous spiral groove also including a second portion wherein the groove is disposed radially in side-by-side relation relative to itself and concentrically about the hub with each adjacent segment of the second portion of the groove being spaced from itself by a second predetermined distance which is different from the first predetermined distance to improve braking of the rotor.