Abstract: A drive mechanism for connecting a crank arm of a bicycle crankset or the like to a crankshaft, in a selected one of at least two modes. In one available mode, a crank arm is oriented to the crankshaft at a fixed angle about the axis of rotation of the crankshaft. In another available mode, a crank arm can be rotated freely about the crankshaft in a first direction but is connected drivingly to the crankshaft by a pawl so as to rotate the crankshaft in an opposite second direction. In a third available mode, the pedal crank arm is free to rotate in either direction with respect to the crankshaft through a limited angle of rotation beyond which a pawl in one member of the drive mechanism will engage another member and cause the crank arm to rotate the crankshaft.

Abstract: A method and apparatus for measuring and evaluating pedaling efficiency of a cyclist. Instantaneous measurements of torque exerted through crank pedal arms are correlated with crank pedal arm positions through one or more complete crank rotations. Average torque exertion on the crank arms is determined for specific sectors of the entire crank rotation and the resulting values are compared. For example, the average torque through the top half of a crank rotation is compared with the average torque for an entire crank rotation, with a comparison expressed, for example, as a ratio. A numerical result of certain comparisons is thus obtained as guidance for future training of the cyclist to improve performance.

Abstract: A crank mechanism useful on a bicycle or an exercise machine utilizing a pair of crank arms. A crank arm is attached to a crankshaft so that it can turn the crankshaft in either direction but is free to move through a defined angle about the crankshaft between positions of oppositely driving engagement with the crankshaft. The mechanism can be used in training athletes. In one embodiment the mechanism can be used to aid a bicyclist in maintaining an aerodynamic posture.

Abstract: An exercise machine and a method for its use in training selected muscle groups by controlled use of brakes to resist crank movement adjustably at specific and adjustable controlled positions in the rotation of a crank. A control system may be incorporated to cause brake mechanisms to apply varying amounts of resistance to a pair of pedal-driven cranks to simulate the efforts required to ride an actual bicycle over a course including various upslopes and down-slopes.

Abstract: A crank including a mechanism capable of connecting the crank arm to a shaft to drive the shaft in rotation in either a unidirectional drive mode or a bidirectionally driving mode, the mechanism being quickly adjustable between modes. A coupler in the mechanism may be slidable between a first position engaging the crank arm with a hub portion fixedly mounted on the shaft and a second position in which a unidirectional clutch can operate to allow rotation of the crank arm freely about the shaft in one direction but cause rotation of the shaft in the opposition direction. The coupler may be arranged to be coupled only when the shaft is in a selected angular position.

Abstract: A unidirectional power drive mechanism operated by a plurality of crank arms and associated one-way clutches connecting the crank arms independently to a crankshaft arranged to provide a unidirectional power output. The crank arms are able to rotate through full revolution to drive the crankshaft in a forward direction with either one of the crank arms separately applying torque to the crankshaft, or with both crank arms together applying torque in a forward direction, but each crank arm is free to rotate rearwardly with respect to the crankshaft. This arrangement of and inclusion of the various components substantially improves many aspects of energy throughput of human powered machines.