Abstract: A power transmission system used in connection with a vehicle power wheel of a bicycle or other vehicle which has a fixed axle and which utilizes a rotating chain sprocket engaging an endless chain receiving an input torque and transmitting an output torque. The system includes a transmission ratio varying apparatus that is operable connected to the wheel by the endless chain. The transition ration apparatus incorporates a drive collar fixedly secured to a sprocket and having one or more input and output drive rings. A drive body is displaceable with respect to the input and output drive rings and includes input and output pawls pivotally connected to the drive body and engageable with the input and output drive rings. A shifter housing is moveable with respect to the fixed axle cam to rotatable shift the drive body with respect to the drive ring and change the relationship between the input and output pawls and thereby vary the torque transmission ratio.

Abstract: A power transmission system used in connection with a vehicle power wheel of a bicycle or other vehicle which has a fixed axle and which utilizes a rotating chain sprocket engaging an endless chain for receiving an input torque and transmitting an output torque. The system includes a transmission cadence varying apparatus that is operably connected to the wheel by an endless chain. The transmission cadence apparatus incorporates a left crank arm fixedly secured to a spindle which is fixedly secured to a left drive plate which incorporates a radial slot for a cam post to travel. A post ring is eccentrically mounted relative to the spindle via ball bearing means on the post ring housing which is then fixedly secured to the bicycle bottom bracket frame. The post ring incorporates 2 cam posts that are rigidly mounted 180 degrees apart in which one of the cam post drives the left drive plate radial slot and the other cam post drives the right crank radial slot.