Abstract: A unitary monocoque frame is provided for a bicycle including a right half shell having a peripheral edge and a left half shell having a peripheral edge symmetrical with the peripheral edge of the right half shell. The right half shell includes an integrally formed head tube portion and an integrally formed seat tube collar. The left half shell includes a curved surface to join with the head tube portion and a cupped recess to receive the seat tube collar. A tongue extends along at least a portion of the peripheral edge of one of the right and left half shells. A groove extends along at least a corresponding portion of the peripheral edge of the other one of the right and left half shells. The tongue and groove are in mating engagement to join the right and left half shells forming the unitary monocoque frame.

Abstract: A unitary monocoque frame is provided for a bicycle including a right half shell having a peripheral edge and a left half shell having a peripheral edge symmetrical with the peripheral edge of the right half shell. The right half shell includes an integrally formed head tube portion and an integrally formed seat tube collar. The left half shell includes a curved surface to join with the head tube portion and a cupped recess to receive the seat tube collar. A tongue extends along at least a portion of the peripheral edge of one of the right and left half shells. A groove extends along at least a corresponding portion of the peripheral edge of the other one of the right and left half shells. The tongue and groove are in mating engagement to join the right and left half shells forming the unitary monocoque frame.

Abstract: A power assist module includes a battery powered motor mounted on a manually operated vehicle, such as a bicycle. The power assist module is fixedly mounted on the bicycle and can be easily removed without the need for tools, so that the bicycle can be manually operated in a conventional manner when so desired without carrying the extra weight of the power assist module. The power assist module includes a motor assembly which is operated through a gear reduction assembly to drive a crank drive gear mounted in conjunction with a crank arm of the bicycle.

Abstract: A power assist module includes a battery powered motor mounted on a manually operated vehicle, such as a bicycle. The power assist module is fixedly mounted on the bicycle and can be easily removed without the need for tools, so that the bicycle can be manually operated in a conventional manner when so desired without carrying the extra weight of the power assist module. The power assist module includes a motor assembly which is operated through a gear reduction assembly to drive a crank drive gear mounted in conjunction with a crank arm of the bicycle.