An axial-flux generator for fluid turbines has a continuously variable generator that is constructed of a pair of rotors that move radially across a stator resulting in varying torque and varying power output. In one embodiment the rotors are normally held proximal to the center of a stator by spring tension. The stator is larger than the normally held position of the rotors. As the angular velocity of the rotors increases, the rotors move radially toward the perimeter of the stator, thus encountering a greater stator surface area providing increased torque, increased power generation and a higher-rated output speed when used with a fluid turbine.