A high torque sprocket includes a body formed of a castable polymer material defining an outer periphery and a recessed hub section defining an inner surface for engaging a bushing having a smooth circular outer surface and at least one threaded port for securing with the high torque sprocket. A continuous toothed structure is disposed on the outer periphery of the body, which has a circular pitch. A textile reinforcement may be embedded in the body adjacent the inner surface of the hub section. The hub section inner surface is of a tapered shape and adapted to engage a conventional QD bushing or a taper-lock bushing. The continuous toothed structure may have a plurality of S-shaped grooves for engaging a belt and having a groove width, and the ratio of the groove width to the circular pitch may be 0.65 or less, or even a value selected from the range of 0.50 to 0.65.

A high torque sprocket includes a body formed of a castable polymer material defining an outer periphery and a recessed hub section defining an inner surface for engaging a bushing having a smooth circular outer surface and at least one threaded port for securing with the high torque sprocket. A continuous toothed structure is disposed on the outer periphery of the body, which has a circular pitch. A textile reinforcement may be embedded in the body adjacent the inner surface of the hub section. The hub section inner surface is of a tapered shape and adapted to engage a conventional QD bushing or a taper-lock bushing. The continuous toothed structure may have a plurality of S-shaped grooves for engaging a belt and having a groove width, and the ratio of the groove width to the circular pitch may be 0.65 or less, or even a value selected from the range of 0.50 to 0.65.