A bicycle chainring may have a plurality of first teeth that fit within the narrow link spaces in a drive chain, and a plurality of second teeth that fit within the wide link spaces in a drive chain. Each second tooth may have a first width that is greater than the its tip width at a location that is between about 40% and about 60% of the tooth height and a second width that is greater than the first width and is between the first plane and the root. A first transition portion may be on a first side of the second tooth and may extends between a first edge that is at the tip and extends in an edge direction that is substantially parallel to the central plane and a second edge that is disposed at the second plane and extends in the edge direction.

Chain-rings set, for a power transmission system, which includes a chain, a first chain-ring, a second chain-ring where the first chain-ring is formed by a support part of the teeth and a teeth part, where the second chain-ring is formed by segments each formed by a support part of the teeth and a teeth part, which includes axial displacement means of the segments, where an up-shift segment of the segments has a first tooth which is the first which is engaged with the chain in the rotation movement, and where the displacement means are configured for moving the up-shift segment to an engaging position such that the first tooth can engage with an engaging link of the up-shift section of the chain, when the chain is engaged in the small chain-ring, and without the support part of the up-shift segment reaching the same plane than the support part of the first chain-ring, and to successively displace the other independent segments to an engaging position with the chain without the support parts of the independent segments reaching the same plane than the support part of the first chain-ring.

A bicycle chainring may have a plurality of first teeth that fit within the narrow link spaces in a drive chain, and a plurality of second teeth that fit within the wide link spaces in a drive chain. Each second tooth may have a first width that is greater than the its tip width at a location that is between about 40% and about 60% of the tooth height and a second width that is greater than the first width and is between the first plane and the root. A first transition portion may be on a first side of the second tooth and may extends between a first edge that is at the tip and extends in an edge direction that is substantially parallel to the central plane and a second edge that is disposed at the second plane and extends in the edge direction.

A link connecting structure includes two outer link plates and two inner link plates. An inner side of each outer link plate is formed with a concave portion between two first coupling portions at two ends thereof. A connecting surface is connected between each first coupling portion and the concave portion. The connecting surface is gradually tapered inward from each first coupling portion toward the concave portion. An outer side of each inner link plate is provided with a pair of bent portions each extending from an outermost edge of each second coupling portion toward the connecting surface. A gap is defined between each bent portion and the connecting surface. The gap is less than the minimum thickness of a narrow tooth of a chainring, thereby preventing the tooth from being jammed in the gap.

A bicycle chain comprises a first inner link plate and a second inner link plate. The first inner link plate comprises a first inner-link end portion, a second inner-link end portion, and a first inner-link intermediate portion. The first inner-link end portion overlaps with a tooth of a sprocket when viewed in the axial direction to provide an overlapping area in a state where the bicycle chain is engaged with the sprocket. The overlapping area has a maximum circumferential length equal to or larger than 0.45 mm.

The present invention is directed to aqueous compositions with wax and graphene. These compositions offer surprising benefits in reducing bicycle or motorbike chain lengthening, particularly in off road environments with high dirt and water levels such as during mountain biking or off-road biking. The invention is further directed to a method of preparing such compositions and to the use of such compositions on bicycle or motorbike chains.

A belt drive system comprising a belt having a plurality of longitudinally spaced belt teeth, the belt further comprising a longitudinal groove extending in the endless direction of the belt through the belt teeth, a sprocket comprising a plurality of sprocket teeth on an outer circumference of the sprocket, each of the sprocket teeth extending parallel to the rotation axis, and each sprocket tooth configured to be received between adjacent belt teeth, and a first planar fin extending from at least one side of a sprocket tooth, the first planar fin configured to cooperatively engage the longitudinal groove, the first planar fin extending in a direction normal to a sprocket axis of rotation, the first planar fin having a width no greater than 20% of a sprocket groove width (W).

A bicycle chain comprises a first inner link plate and a second inner link plate. The first inner link plate comprises a first inner-link end portion, a second inner-link end portion, and a first inner-link intermediate portion. The second inner link plate comprises a third inner-link end portion, a fourth inner-link end portion, and a second inner-link intermediate portion. A first inner-link end edge has a first chamfer extending about the first inner-link center axis such that a part of the first chamfer is disposed in a first circumferential area defined from a first inner-link longitudinal centerline to a first reference line when viewed in an axial direction of the first inner-link center axis. The first circumferential area is smaller than 14 degrees.

The present invention relates to a bicycle driving device having increased torque, the device moving, to the front thereof, the center of a rotational track in a state in which an overall pedaling track (distance) does not increase, thereby removing the top dead center and enabling force to be strongly transmitted to a crankshaft during pedaling. According to the present invention, a rotational track of a pedal is moved to the front thereof such that when the pedal is in a forward position, the pedal is separated far away from the crankshaft so as to enable a strong force to be transmitted to the crankshaft by using the principle of the lever, and thus rotational torque can be increased.

A drive system comprises a frame, a first extension member, a second extension member, a crank shaft, a hub, a bearing, a cross shaft, a first arm assembly, a second arm assembly, a first chain assembly, a second chain assembly, a first rotatable pedal, a second rotatable pedal, and a steering column. The first arm assembly comprises a first frame arm, a first connecting arm, a first main arm, and a first crank arm. The second arm assembly comprises a second frame arm, a second connecting arm, a second main arm, and a second crank arm. The first arm assembly further comprises a first roller track assembly. The second arm assembly further comprises a second roller track assembly.