Abstract: A shift mechanism for a bicycle and the like wherein a chain is shifted from sprocket to sprocket by an operator controlling a lever to position a camming surface to direct a guide pawl to tilt a segment of one sprocket whereby the tilted segment aligns with a nontilted sprocket during chain shifting.

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.

Abstract: A control unit for a chain shifter using 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.

Abstract: A two speed sprocket and chain shift assembly with one sprocket having a small pivoted sprocket segment and means for shifting the chain from one sprocket to another upon pivoting of the sprocket segment and with the chain being entrained on one sprocket when an operating means is activated and entrained on the other sprocket when the operating means is released.

Abstract: A sprocket shift assembly wherein sprockets of different diameters are arranged as a cluster on a common shaft and are coupled with a chain between driving and driven members. The chain is movable as the sprockets rotate from one of the sprockets to another by realignment of portions of the sprocket such that the chain is at all times in a positive driving relationship with the cluster.