A bicycle-chain outer link plate comprises a first outer-link end portion, a second outer-link end portion, and a first outer-link intermediate portion. The first outer-link end portion comprises a first outer surface, a first inner surface, a first outer-link opening, and a first outer-link end outermost edge. The first outer-link intermediate portion comprises a first intermediate outer surface, a first intermediate inner surface, a first outer-link intermediate outermost edge, a first additional outer-link intermediate outermost edge, and a first intermediate chamfer. The first intermediate chamfer has a first minimum distance defined between the first outer-link intermediate outermost edge and the first inner edge along a reference line. A distance defined between the first outer-link intermediate outermost edge and the first additional outer-link intermediate outermost edge on the reference line is minimum in the first outer-link intermediate portion. The first minimum distance is equal to or larger than 1 mm.

A drive arrangement for a bicycle includes a crank having a crank mounting portion, a front sprocket having a front sprocket mounting portion attached to the crank mounting portion and a front chain engaging portion, an axle assembly, a plurality of rear sprockets located about an axis of the axle assembly, a chain configured to engage with the front chain engaging portion of the front sprocket and the plurality of rear sprockets, a gear changer having a gear changer mounting unit located about the axis of the axle assembly and having a first mounting portion spaced apart from a second portion mounting portion. The gear changer is configured to move the chain between an axially innermost rear sprocket and an axially outermost rear sprocket and a control unit is configured to control movement of the gear changer.

A bicycle chain lubricant that may be applied as a coating on a bicycle chain is a crystalline solid at ambient temperatures, yet when the chain is in motion the forces around internal components locally transforms the coating to a lubricous fluid. This increases chain efficiency in the drive train and reduces ware by limiting water and dirt access to chain internal components.

A vehicle may have a seat and front wheel similar to those of a bicycle. However, the vehicle may have two rear wheels. The position of the two rear wheels may be adjustable. When the two rear wheels touch each other, the vehicle may function as a bicycle. When they are moved apart, the vehicle may function as a tricycle. In tricycle mode, the vehicle may travel autonomously without a human rider. In bicycle mode, a human may ride the vehicle like a bicycle. To transition between bicycle and tricycle modes, each rear wheel may rotate about a horizontal axis that is parallel to a longitudinal axis of the vehicle. In some cases, a bike chain is connected to only one of the rear wheels. In bicycle mode, motion imparted by the chain to one rear wheel may be transferred to the other by friction.

A vehicle may have a seat and front wheel similar to those of a bicycle. However, the vehicle may have two rear wheels. The position of the two rear wheels may be adjustable. When the two rear wheels touch each other, the vehicle may function as a bicycle. When they are moved apart, the vehicle may function as a tricycle. In tricycle mode, the vehicle may travel autonomously without a human rider. In bicycle mode, a human may ride the vehicle like a bicycle. To transition between bicycle and tricycle modes, each rear wheel may rotate about a horizontal axis that is parallel to a longitudinal axis of the vehicle. In some cases, a bike chain is connected to only one of the rear wheels. In bicycle mode, motion imparted by the chain to one rear wheel may be transferred to the other by friction.

A power transmission chain (2) for use with a drive member (4) having a plurality of teeth (6), and wherein: (i) the power transmission chain (2) comprises a plurality of chain links (8) which are pivotally connected together by connecting members (9) and pivot arrangements (10) so that the power transmission chain (2) can pass around the drive member (4) in use; (ii) each one of the pivot arrangements (10) comprises first and second pivots (12, 14) which extend towards each other from opposite sides (16, 18) of the chain links (8); (iii) the first and second pivots (12, 14) have adjacent ends (20, 22) which face each other and which are spaced apart; (iv) the power transmission chain (2) comprises a plurality of engaging formations (24) for enabling engagement with the drive member (4); (v) the engaging formations (24) are positioned between the adjacent ends (20, 22) of the first and second pivots (12, 14); and the engaging formations (24) and the spacing apart of the adjacent ends (20, 22) of the first and second pivots (12, 14) cause the power transmission chain (2) in use always to be positioned on the drive member (4) for maximum efficiency of drive transfer between the drive member (4) and the power transmission chain (2), and irrespective of the diameter of the drive member (4).

An exercise measurement device comprises a housing for attaching to a frame of a bicycle, a generator, an annular rotational input member for rotationally driving the generator, the rotational input member being rotatably mounted on the housing and positioned around a crank axis line, a connecting member connecting the rotational input member to the crankshaft or the crank arm in a torque transmitting relationship, a sensor for detecting at least one of electric current of the generator, a rotational speed of the generator or the crank arm, a torque of the crank arm, a position of the crank arm, a strain in the crank arm, and a pressure on the pedal, a measurement computing unit for computing at least one of power and a pedaling force from an output of the sensor, and a display unit for displaying a computed value of the measurement computing unit.

An exercise measurement device comprises a housing for attaching to a frame of a bicycle, a generator, an annular rotational input member for rotationally driving the generator, the rotational input member being rotatably mounted on the housing and positioned around a crank axis line, a connecting member connecting the rotational input member to the crankshaft or the crank arm in a torque transmitting relationship, a sensor for detecting at least one of electric current of the generator, a rotational speed of the generator or the crank arm, a torque of the crank arm, a position of the crank arm, a strain in the crank arm, and a pressure on the pedal, a measurement computing unit for computing at least one of power and a pedaling force from an output of the sensor, and a display unit for displaying a computed value of the measurement computing unit.

A bicycle sprocket comprises a sprocket body and sprocket teeth. The sprocket teeth include at least one first tooth. The at least one first tooth has a first maximum chain-engaging width, a first tooth center plane, a first projection, and a second projection. The first maximum chain-engaging width is defined in an axial direction parallel to a rotational center axis. The first tooth center plane is defined to bisect the first maximum chain-engaging width in the axial direction. The first projection has a first maximum axial length defined from the first tooth center plane in the axial direction. The second projection has a second maximum axial length defined from the first tooth center plane in the axial direction. The second maximum axial length is different from the first maximum axial length.

A bicycle sprocket comprises a sprocket body and sprocket teeth. The sprocket teeth include at least one first tooth. The at least one first tooth has a first maximum chain-engaging width, a first tooth center plane, a first projection, and a second projection. The first maximum chain-engaging width is defined in an axial direction parallel to a rotational center axis. The first tooth center plane is defined to bisect the first maximum chain-engaging width in the axial direction. The first projection has a first maximum axial length defined from the first tooth center plane in the axial direction. The second projection has a second maximum axial length defined from the first tooth center plane in the axial direction. The second maximum axial length is different from the first maximum axial length.