Abstract: A control unit for a chain shifter uses a reversible electric selector motor to position a cam selector within a pawl guide housing so that a traveling pawl will be directed as necessary for chain shifting. The motor rotates a low mass eccentric, the eccentric providing sufficient angular force to actuate a spring-loaded latch key, the key positioning the cam selector. As the eccentric accelerates, it gains sufficient force until it impacts and moves one of a pair of latch arms holding the key in a central position, allowing the latch key to rotate.

Abstract: A method and system for computer-controlled shifting of a bicycle is provided. In preferred embodiments, the present invention provides a computer system that detects speed, hub speed, and crank speed, determines the optimum bicycle gear selection to maintain a desired cadence, and shifts the bicycle to the optimum bicycle gear. The computer also inputs a shift up and shift down signals from the cyclist to override the computer-selected gear. When the cyclist indicates a shift up or down, the computer adjusts the desired cadence. The computer determines the gear selection to ensure a uniform transition from the current gear to the next gear. The computer ensures that when shifting from the current gear to the next gear, the bicycle does not transition through a gear that is not between the current and next gears.

Abstract: A bicycle transmission comprises a sprocket assembly rotatably coupled to the frame of a bicycle for receiving a chain, a front and rear sprocket selector for causing the sprocket assembly to shift the chain from one sprocket to another, a sliding bracket for retractably mounting the sprocket selector to the bicycle frame, adjustment brackets for finely adjusting the front and rear sprocket selectors to correspond to the path of the sprocket assembly, and a compensator for engaging and following the chain as it is shifted between sprockets to eliminate any free chain between the compensator and the sprocket and for reentraining the chain in the event of complete derailment. In addition, the bicycle transmission may include a sprocket assembly comprising a stationary sector, a swinging sector hingedly coupled to the stationary sector, and a plurality of load bearing surfaces extending radially outwardly of the stationary sector for taking the load from the swinging sector.

Abstract: A bicycle transmission comprises a sprocket assembly rotatably coupled to the frame of a bicycle, a chain entrained around a sprocket of the sprocket assembly, a sprocket selector for causing the sprocket assembly to shift the chain from one sprocket to another, a sliding bracket for retractably mounting the sprocket selector to the bicycle frame, an adjustment bracket for finely adjusting the sprocket selector to correspond to the path of the sprocket assembly, and a compensator for engaging and following the chain as it is shifted between sprockets to eliminate any free chain between the compensator and the sprocket. In addition, the bicycle transmission may include a sprocket assembly comprising a stationary sector, a swinging sector hingedly coupled to the stationary sector, and a plurality of load bearing surfaces extending radially outwardly of the stationary sector for taking the load from the swinging sector.