Abstract: The present disclosure relates to strain wave gears, vehicle drive systems (10) including such gears and methods of torque and cadence measurement. The vehicle drive system (10) comprises a first rotational input, a second rotational input and rotational output (6), wherein the first rotational input is transmitted through a strain wave gear (5) to a first rotational input one-way bearing (34), and wherein the second rotational input is transmitted through a second rotational input one-way bearing (32) to the rotational output (6), the first (32) and second (34) one-way bearings being affixed to a secondary axle (330, 42), the secondary axle (42) driving the rotational output (6), wherein the second rotational input is provided by a primary axle (26), the primary (26) and secondary (42) axles being coaxial, the secondary axle (42) surrounding the primary axle (26), and wherein a strain gauge (84) is provided to measure the torque applied to the primary axle (26).

Abstract: A one-way bearing, a bearing assembly, and a free-wheeling mechanism for a bicycle are disclosed herewith. The bearing assembly, in one aspect, includes a one-directional bearing having an inner and an outer race, the one-directional bearing including a sprag clutch mechanism. The bearing assembly, according to this aspect, further includes a first thrust bearing and a second thrust bearing, wherein the inner and outer races of the one-directional bearing are formed to retain one or both of the first or second thrust bearings, and a one-directional bearing mechanism located between the inner and outer races. In at least one aspect, the inner race has a flange extending in a radially outward direction, the sprag clutch mechanism abuts the flange on an inner axial side of the flange, and the flange abuts the first thrust bearing on an outer axial side of the flange.

Abstract: A gearing system comprises a first rotational input, a second rotational input and a rotational output. The first rotational input and second rotational input may transmit a rotation to the rotational output, wherein one of the first rotational input and second rotational input is connected to the rotational output through a one way clutch, and wherein the other of the first rotational input and second rotational input is connected to the rotational output through an overrunning clutch, wherein said one way clutch and said overrunning clutch are rotationally coupled. The gearing system may be used in electric bicycles, but may also be used in other dual propulsion vehicles such as hybrid cars.