Abstract: A multi-sprocket arrangement for a rear wheel hub of a bicycle may have improved gearshift characteristics, reduced vibrations during skewed running, and improved wear characteristics. The multi-sprocket arrangement includes a multiplicity of sprockets of different diameters, wherein at least one of the sprockets has a multiplicity of teeth. Also on the circumference of said sprocket, as viewed in a circumferential direction, at least one sequence of teeth is provided in which, with regard to their material thickness, a thin tooth is followed by a thick tooth which is followed in turn by another thin tooth.

Abstract: The present disclosure relates to a chain ring having teeth positioned in one of three lateral positions. At least one tooth may be placed in each lateral position. At least half the teeth may be positioned in a middle lateral position. The teeth in the first and third lateral positions may apply opposing lateral forces to a bicycle drive chain.

Abstract: A bicycle sprocket assembly comprises a first sprocket and a second sprocket. The first sprocket includes a plurality of first sprocket teeth, a first sprocket inward surface, a first sprocket outward surface, and an axial space. The second sprocket includes a plurality of second sprocket teeth, a second sprocket inward surface, and a second sprocket outward surface. The axial space is defined between the first sprocket outward surface and an axially inward outer link plate in the axial direction while the second sprocket outward surface contacts an axially outward inner link plate in an engagement state where the one of the plurality of the second sprocket teeth is positioned between an axially inward inner link plate and the axially outward inner link plate in the axial direction. The axial space is larger than mm and equal to or smaller than 0.15 mm.

Abstract: A bicycle sprocket comprises sprocket teeth. The sprocket teeth include at least one first tooth and at least one second tooth. The at least one first tooth has a first radial-tooth height. The at least one first tooth has a first chain-engaging axial width which is smaller than a first distance defined between opposed outer link plates of a bicycle chain and which is larger than a second distance defined between opposed inner link plates of the bicycle chain. The at least one second tooth is adjacent to the first tooth and is disposed on a downstream side in a rotational driving direction of the bicycle sprocket. The at least one second tooth is configured to engage with inner link plates of the bicycle chain. The at least one second tooth has a second radial-tooth height. The first radial-tooth height is greater than the second radial-tooth height.

Abstract: A sprocket for engagement with a drive chain has a first and a second group of teeth, wherein the teeth of the first group and the second group are alternately arranged and each tooth of the second group is wider than each tooth of the first group. The profile of each tooth of the second group has a first protrusion in the front half of the tooth on a first lateral surface and a second protrusion in the rear half of the tooth on a second, opposite lateral surface of the tooth. In particular, the portion of each tooth of the second group engaging the chain may have a center plane that is rotated or twisted during forming about the radial center line of the tooth with respect to the central plane of the sprocket.

Abstract: A chainring is disclosed. The chainring includes a plurality of teeth about the outer perimeter of the chainring; and a chain retention feature at a root of one or more of the plurality of teeth and traversing at least a portion of a circumference of the chainring, the chain retention feature to align with at least a portion of a roller chain and assist in a retention of the roller chain on the chainring.

Abstract: 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.

Abstract: The present disclosure relates to a chain ring having teeth positioned in one of three lateral positions. At least one tooth may be placed in each lateral position. At least half the teeth may be positioned in a middle lateral position. The teeth in the first and third lateral positions may apply opposing lateral forces to a bicycle drive chain.

Abstract: A drive system for a vehicle includes a chain ring and a drive chain. The chain ring has a plurality of teeth serially arranged and joined to one another. A first subset of teeth has a first outer face that applies a lateral pressure to a link of a drive chain in a first direction. A second subset of teeth has a second outer face that applies a lateral pressure to another link of a drive chain in a second direction. The teeth all have substantially the same width. The top surfaces of the teeth are offset from the centerline of the drive chain. The centerlines of the top surfaces of the teeth are arranged asymmetrically on one side of the centerline of the drive chain.

Abstract: 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.

Abstract: A bicycle sprocket includes a sprocket body, a tooth ring, and at least one non-threaded fastener. The sprocket body is made of a first material and has a rotational center axis. A central portion of the sprocket body has a central opening through which the rotational center axis passes. The sprocket body further includes a plurality of arm portions that extend radially outward from the central portion with respect to the rotational center axis. Each arm portion includes a sprocket body attachment portion. The tooth ring is made of a second material different from the first material and includes an annular portion. The annular portion includes a plurality of tooth ring attachment portions and a plurality of chain-driving teeth extending radially outward from the annular portion. The non-threaded fastener fixedly connects a sprocket body attachment portion and to a corresponding tooth ring attachment portion.

Abstract: A multi-sprocket arrangement for a rear wheel hub of a bicycle may have improved gearshift characteristics, reduced vibrations during skewed running, and improved wear characteristics. The multi-sprocket arrangement includes a multiplicity of sprockets of different diameters, wherein at least one of the sprockets has a multiplicity of teeth. Also on the circumference of said sprocket, as viewed in a circumferential direction, at least one sequence of teeth is provided in which, with regard to their material thickness, a thin tooth is followed by a thick tooth which is followed in turn by another thin tooth.

Abstract: Solitary chainring for a bicycle front crank and drive chain, including a plurality of teeth formed thereabout. The plurality of teeth includes a first group of teeth and a second group of teeth alternating with the first group of teeth. Each tooth includes an outer face and an inner face which is opposite the outer face, and each tooth of the first group of teeth includes at least one first protrusion on the outer face or the inner face, and each tooth of the second group of teeth is formed without a first protrusion. The first protrusion is formed by a material deformation on one face of the teeth of the first group of teeth, wherein the material deformation is achieved from the inner face or the outer face, or it is formed by an application of material on one face of the teeth of the first group of teeth.

Abstract: A laminated sprocket assembly is provided formed of a plurality of layers that are connected together. Each of the layers is a stamped sheet metal layer having a plurality of spaced apart teeth located around a periphery thereof. The teeth in the plurality of connected layers are aligned. At least one of voids, channels, openings, or recesses are located in or between at least some of the layers for receiving and holding lubricating oil. This reduces noise and wear.

Abstract: A bicycle sprocket includes a first sprocket body and a plurality of first sprocket teeth. The first sprocket teeth include a plurality of tooth tip portions and a plurality of tooth bottom portions. The tooth bottom portions include at least one first tooth bottom portion and at least one second tooth bottom portion. The at least one first tooth bottom portion has a first tooth bottom shape. The at least one second tooth bottom portion has a second tooth bottom shape. The first tooth bottom shape is different from the second tooth bottom shape.

Abstract: A bicycle sprocket comprises a sprocket body and chain-driving teeth. The chain-driving teeth comprises at least one first tooth and at least one second tooth. The at least one first tooth has a first circumferential tooth-length defined in a circumferential direction at a radial location defined in vicinity of a reference line. The at least one second tooth has a second circumferential tooth-length defined in the circumferential direction at the radial location. The first circumferential tooth-length is larger than the second circumferential tooth-length. A dimensional difference between the first circumferential tooth-length and the second circumferential tooth-length is equal to or smaller than 1 mm.

Abstract: A method for generating a tooth space profile between two teeth of a wheel engaging with a roller pinion in a reference plane perpendicular to a central axis (X1) whose intersection with the reference plane defines a centre (C). The method comprises defining a nominal tooth space with symmetrical first and second profiles so that the space is suitable for receiving a roller which comes into contact, without clearance, with the facing active portions of the first and second profiles at the level of a primitive diameter. The method further comprises the steps of deforming the bottom portion of the first profile so that the bottom point is brought nearer to the centre by an amount equal to a given radial clearance, and moving the first profile angularly through a given angular half-clearance around the centre to shift it away from the radial axis.

Abstract: The present disclosure relates to a chain ring having teeth positioned in one of three lateral positions. At least one tooth may be placed in each lateral position. At least half the teeth may be positioned in a middle lateral position. The teeth in the first and third lateral positions may apply opposing lateral forces to a bicycle drive chain.

Abstract: Roller chain outer plate links including a cable support portion are disclosed. Example roller chain outer plate links include a link portion, a cable support portion oriented projecting from an outer face of the link portion, and a joint at one of the lead/tail ends of the link portion. The link portion, joint, and cable support portions each comprise portions integral with remaining portions of the outer plate link. Cable support portions of the roller chain outer plate links support a cable extending between components of an apparatus.

Abstract: A bicycle crank assembly comprises a crank arm, a first sprocket, and a second sprocket. One of the first sprocket and the second sprocket comprises a first shifting facilitation area to facilitate a first shifting operation in which a bicycle chain is shifted from the second sprocket toward the first sprocket in a first chain-phase state in which a reference tooth of a plurality of second sprocket teeth is received in an outer link space, and a second shifting facilitation area to facilitate a second shifting operation in which the bicycle chain is shifted from the second sprocket toward the first sprocket in a second chain-phase state in which the reference tooth of the plurality of second sprocket teeth is received in an inner link space.

Abstract: Disclosed is a rotation transmission mechanism including: an internal rotation member inserted by a crankshaft of a bicycle; and an external rotation member configured on the internal rotation member. The internal rotation member includes: an internal rotation member body. The external rotation member includes: a circular ring part configured at an outer side of the outer circumferential convex parts; and inner circumferential convex parts protruding to an inner circumferential side of the circular ring part and configured alternately with the outer circumferential convex parts. Elastic deformation parts are configured between the outer circumferential convex parts and the inner circumferential convex parts on a rotation direction side of the advancing outer circumferential convex parts. The outer circumferential convex parts are formed in such a manner that a surface on the rotation direction side is greater than a surface on an opposite side of the rotation direction.

Abstract: A drive system for a vehicle includes a chain ring and a drive chain. The chain ring has a plurality of teeth serially arranged and joined to one another. A first subset of teeth has a first outer face that applies a lateral pressure to a link of a drive chain in a first direction. A second subset of teeth has a second outer face that applies a lateral pressure to another link of a drive chain in a second direction. The teeth all have substantially the same width. The top surfaces of the teeth are offset from the centerline of the drive chain. The centerlines of the top surfaces of the teeth are arranged asymmetrically on one side of the centerline of the drive chain.

Abstract: A bicycle sprocket comprises a sprocket body and sprocket teeth. The sprocket teeth include at least one first tooth and at least one second tooth. The at least one first tooth has a driving surface, a non-driving surface, a first maximum chain-engaging width, a first tooth center plane, and a first chain-facing surface. The first tooth center plane is defined to bisect the first maximum chain-engaging width in the axial direction. The first chain-facing surface is provided between the driving surface and the non-driving surface in a circumferential direction and is inclined with respect to the first tooth center plane in the circumferential direction. The at least one second tooth has a second maximum chain-engaging width defined in in the axial direction. The first maximum chain-engaging width is larger than the second maximum chain-engaging width.

Abstract: A bicycle sprocket comprises a sprocket body and a plurality of chain-driving teeth. The plurality of chain-driving teeth comprises a first tooth and a second tooth. The first tooth has a first radial length radially defined from a reference line to a first radially outermost end. The second tooth has a second radial length radially defined from the reference line to a second radially outermost end. The second radial length is in a range of 1.5 mm to 2.9 mm. A shortest distance is defined between the downstream circumferential surface and a first intersection point of the circumferential center plane and an additional reference line. The shortest distance is equal to or larger than 2.0 mm. The additional reference line is defined at a reference position radially outward spaced apart from the reference line by 1.5 mm.

Abstract: A bicycle sprocket comprises a sprocket body, sprocket teeth, and at least one shifting facilitation area. The sprocket teeth include at least one first tooth and at least one second tooth. The at least one first tooth includes a first tooth center plane defined to bisect a first maximum axial width. The at least one second tooth includes a second tooth center plane defined to bisect a second maximum axial width. The second tooth center plane is offset from the first tooth center plane in an axial direction. The at least one shifting facilitation area is configured to facilitate a shifting operation of the bicycle chain.

Abstract: The device comprises a shaft 4, a notched mobile member—for example a wheel 1—and at least three arms 2.1, 2.2, 2.3 that together transmit movement between the shaft 4 and the mobile member. Each arm is hinged to two eccentric bearings 3, 3? that hold same parallel to said arm, regardless of the rotational angle of the shaft 4 with which they rotate synchronously. Each arm engages with the notches of the wheel 1 during at least a portion of the cyclic motion of same, by means of at least one tooth 7 of the arm, in such a way as to ensure mutual displacement. The bearings 3, 3? are arranged such that at least one of the arms engages with the mobile member, regardless of the rotational angle of the shaft 4. Said device can be used for producing low-clearance speed reducers.

Abstract: A bicycle sprocket comprises a sprocket body and chain-driving teeth. The chain-driving teeth each have a first axial surface, a second axial surface, a driving surface, and a non-driving surface. The chain-driving teeth comprises at least one first tooth and at least one second tooth. The at least one first tooth has a first maximum chain-engaging width defined in the axial direction. The at least one second tooth has a second maximum chain-engaging width defined in the axial direction. The first maximum chain-engaging width is larger than the second maximum chain-engaging width. The at least one second tooth includes a first chamfer provided between the first axial surface of the at least one second tooth and the driving surface of the at least one second tooth.

Abstract: A computer implemented method has operations including receiving a 3D computer aided design (CAD) file that contains a 3D model of a product and product management information (PMI) data, at an enterprise resource planning (ERP) hardware system having an executing integrated inspection application, the PMI data including data describing a characteristic of the product and a tolerance value for the characteristic, converting the 3D CAD file into a neutral 3D file preserving the PMI data, parsing the PMI data via the executing integrated inspection application to obtain lower and upper values of the characteristic of the product as a function of the tolerance value, storing the neutral 3D file, linking the neutral 3D file to the part in the ERP system, creating an inspection plan including an inspection characteristic linked to the part, transferring the PMI data to the inspection characteristic, and providing a view of the inspection characteristic showing the lower and upper values.

Abstract: A bicycle sprocket comprises a sprocket body and a plurality of chain-driving teeth. The plurality of chain-driving teeth comprises a first tooth and a second tooth. The first tooth has a first maximum chain-engaging width defined in an axial direction parallel to the rotational center axis. The second tooth has a second maximum chain-engaging width defined in the axial direction. The first tooth has a first width defined in the axial direction. The first width is defined at a reference position radially outward spaced apart from a center point of a reference line by 1.5 mm. The reference line is defined to connect centers of neighboring pins of the bicycle chain engaged with the plurality of chain-driving teeth when viewed from the axial direction. The first width is 70% or more of the first maximum chain-engaging width.

Abstract: A bicycle sprocket comprises sprocket teeth. The sprocket teeth include at least one first tooth and at least one second tooth. The at least one first tooth has a first radial-tooth height. The at least one first tooth has a first chain-engaging axial width which is smaller than a first distance defined between opposed outer link plates of a bicycle chain and which is larger than a second distance defined between opposed inner link plates of the bicycle chain. The at least one second tooth is adjacent to the first tooth and is disposed on a downstream side in a rotational driving direction of the bicycle sprocket. The at least one second tooth is configured to engage with inner link plates of the bicycle chain. The at least one second tooth has a second radial-tooth height. The first radial-tooth height is greater than the second radial-tooth height.

Abstract: A bicycle sprocket comprises a sprocket body and a plurality of chain-driving teeth. The sprocket body includes a radially outer periphery and an axial center plane. The plurality of chain-driving teeth include at least one noise-reduction tooth. The at least one noise-reduction tooth comprises a downstream circumferential surface, an upstream circumferential surface, and a first axial surface. The first axial surface is provided between the downstream circumferential surface and the upstream circumferential surface to face in an axial direction parallel to a rotational center axis. The first axial surface includes an inclined surface inclined relative to an axial center plane so that an axial width of the at least one noise-reduction tooth decreases from one of the upstream circumferential surface and the downstream circumferential surface to the other of the upstream circumferential surface and the downstream circumferential surface.

Abstract: A multi-sprocket arrangement for a rear wheel hub of a bicycle may have improved gearshift characteristics, reduced vibrations during skewed running, and improved wear characteristics. The multi-sprocket arrangement includes a multiplicity of sprockets of different diameters, wherein at least one of the sprockets has a multiplicity of teeth. Also on the circumference of said sprocket, as viewed in a circumferential direction, at least one sequence of teeth is provided in which, with regard to their material thickness, a thin tooth is followed by a thick tooth which is followed in turn by another thin tooth. The sprocket has an impression and/or a passage recess which form at least one gearshift path and permit a shift between two adjacent sprockets.

Abstract: A laminated sprocket assembly is provided formed of a plurality of layers that are connected together. Each of the layers is a stamped sheet metal layer having a plurality of spaced apart teeth located around a periphery thereof. The teeth in the plurality of connected layers are aligned. At least one of voids, channels, openings, or recesses are located in or between at least some of the layers for receiving and holding lubricating oil. This reduces noise and wear.

Abstract: Solitary chainring for a bicycle front crank and drive chain, including a plurality of teeth formed thereabout. The plurality of teeth includes a first group of teeth and a second group of teeth alternating with the first group of teeth. Each tooth includes an outer face and an inner face which is opposite the outer face, and each tooth of the first group of teeth includes at least one first protrusion on the outer face or the inner face, and each tooth of the second group of teeth is formed without a first protrusion. The first protrusion is formed by a material deformation on one face of the teeth of the first group of teeth, wherein the material deformation is achieved from the inner face or the outer face, or it is formed by an application of material on one face of the teeth of the first group of teeth.

Abstract: The present disclosure relates to a chain ring having teeth positioned in one of three lateral positions. At least one tooth may be placed in each lateral position. At least half the teeth may be positioned in a middle lateral position. The teeth in the first and third lateral positions may apply opposing lateral forces to a bicycle drive chain.

Abstract: A bicycle sprocket comprises a sprocket body and a chain engagement structure. The chain engagement structure includes a plurality of sprocket teeth. The plurality of sprocket teeth include at least one first tooth and at least one second tooth. The at least one first tooth has a first tooth top extending non-parallel to a sprocket-plane perpendicular to a rotational center axis when viewed from a radial direction of the bicycle sprocket. The at least one first tooth has a first axial chain-engagement width that is larger than an inner link space defined between a pair of inner link plates of a bicycle chain and smaller than an outer link space defined between a pair of outer link plates of the bicycle chain. The at least one second tooth has a second axial chain-engagement width that is smaller than the inner link space.

Abstract: A sprocket includes a first body with a plurality of teeth radially projecting therefrom, and second bodies on and limited to alternating teeth of the plurality of teeth, with the second bodies increasing an overall axial width of the alternating teeth of the plurality of teeth.

Abstract: A sprocket includes first teeth having a first maximum width, and second teeth having a second maximum width greater than the first maximum width alternately arranged with the first teeth. The second teeth have a leading surface relative to a drive direction of the sprocket, a lateral surface at the second maximum width, and a relief between the leading surface and the lateral surface, with a midline of the lateral surface being offset relative to a plane extended radially through a center of a respective tooth.

Abstract: A sprocket includes a first body with teeth radially projecting therefrom, and second bodies on alternating ones of the teeth, with the second bodies being asymmetrical about a plane extended radially from a rotational axis of the sprocket through a root center and a tip center of the alternating ones of the teeth, and the second bodies increasing an overall width of the alternating ones of the teeth.

Abstract: A sprocket includes first teeth having a first maximum width, and second teeth having a second maximum width greater than the first maximum width alternately arranged with the first teeth. The second teeth have a leading surface relative to a drive direction of the sprocket, a lateral surface at the second maximum width, and a relief between the leading surface and the lateral surface, with a midline of the lateral surface being offset relative to a plane extended radially through a center of a respective tooth.

Abstract: A bicycle sprocket comprises a sprocket body and a chain engagement structure. The sprocket body has a rotational center axis, a first side and a second side opposite to the first side in an axial direction parallel to the rotational center axis. The chain engagement structure includes a plurality of sprocket teeth. The plurality of sprocket teeth include a plurality of first teeth and a plurality of second teeth. The plurality of first teeth each include an outer-link supporting surface, an opposite surface, and a first radially outermost tooth-tip. The opposite surface is spaced part from the second outer link plate in a state where the chain engagement structure engages with the bicycle chain. The plurality of second teeth each include a second radially outermost tooth-tip that is offset from the first radially outermost tooth-tip of each of the plurality of first teeth in the axial direction.

Abstract: The present invention provides a chain wheel assembly and chain wheel device using it, wherein the chain wheel device includes a driver, a switching sleeve, plural chain wheels with different diameter sizes, plural connectors, and a fastener. Therein, the driver is connected to a wheel hub of a back wheel of a bicycle for transmitting a torque. One end of the switching sleeve is screwed to the driver. The chain wheels, axially stacked from the largest one to the smallest one, are disposed in a direction from the driver toward the switching sleeve, with sprockets disposed on the periphery of each chain wheel, respectively, for optionally engaging chain. The ring-shaped connectors are coupled between each two of the chain wheels, respectively. The fastener is screwed to the other end of the switching sleeve for axially fixing the switching sleeve.

Abstract: A bicycle sprocket comprises sprocket teeth. The sprocket teeth include a first tooth and a second tooth. The first tooth has a chain-engaging axial width which is larger than a first distance defined between opposed inner link plates of a bicycle chain and which is smaller than a second distance defined between opposed outer link plates of the bicycle chain. The second tooth has a chain-engaging axial width which is larger than the first distance and which is smaller than the second distance. The first tooth and the second tooth are spaced apart from each other in a circumferential direction of the bicycle sprocket to define a space which is free of a tooth configured to engage with the bicycle chain.

Abstract: A V-pulley includes a pulley body having a through hole provided at the center. Wheels are connected on the pulley body. An outer wheel is provided at each of two ends of the pulley body. Coaxial annular gears and annular inner wheels are alternately arranged between the two outer wheels. The diameter of a gear is less than that of an inner wheel. The outer wheels, the gears, and the inner wheels are fixedly connected through a connecting structure. The outer circumferential surfaces of the gears have meshing teeth disposed at an interval in a convex-concave manner. Two adjacent wheels and a gear between them form a V-belt groove. The opposite end surfaces of the two adjacent wheels form friction transmission belt groove side surfaces. The gear between the two adjacent wheels forms a mesh transmission gear. The belt groove side surfaces are inclined smooth surfaces.

Abstract: There is provided a wear-resistant chain having a high durability even in severe use environments such as those of a timing chain of an engine even though it is highly efficient and productive. A miniaturizing agent containing silicon is doped in a vanadium cementation process of a base material of steel. Vanadium carbide forming a surface-hardened layer contains a secondary phase composed of an amorphous structure containing silicon within crystal grains and a crystal grain size of the vanadium carbide is miniaturized to 1 ?m or less.

Abstract: A sprocket comprises a set of standard sprocket teeth, each having a first face width and capable of entry between the inner link plates of a transmission chain and engaging sprocket tooth-engaging driving elements of the chain while restricting side slip of the chain by contact with the inner link plates of the chain. The sprocket also comprises a set of narrow sprocket teeth also capable of engaging driving elements of the chain. Each of the narrow sprocket teeth is narrower than the standard sprocket teeth, and can engage driving elements without contacting the inner link plates of the chain. Contact resistance between the sprocket teeth and the chain is reduced and periodic sounds are reduced, while a stable running path of the chain is maintained.

Abstract: The present invention relates to a sprocket for use with a bicycle, the sprocket for use with a multi-sprocket assembly and chain, wherein the sprocket is made from a light but comparatively soft material and does not have shifting aids in the form of recesses and notches on the sprocket teeth where the chain rollers are in contact with the load flanks of the teeth.

Abstract: Embodiments provide various components of a chain saw, including saw chain elements, sprockets, and other fixtures, that may facilitate sharpening of cutter links during operation. In various embodiments, the components may increase stability during sharpening, provide nose mounted sharpening fixtures, and/or facilitate the resizing and/or reshaping of a sharpening element.

Abstract: The invention provides a chain transmission mechanism capable of alleviating impact and impact noise caused when a chain engages and contacts with a sprocket, of not increasing the impact and impact noise even if the chain transmission mechanism is driven in heavy load and in high speed, of reducing vibrations, breakage, wear and others of the chain and the sprocket and of improving its durability. Tooth bottoms of the sprocket are formed so as not contact any pin, bush or drive roller when the chain is wound around the sprocket as guide rollers rotatably supported coaxially with a pin of the chain rolls on a track along the guide rail provided on the side of teeth of the sprocket. The invention provides a guide rail around the sprocket to engage the chain and lighten its impact with the sprocket as the mechanism operates.

Abstract: A solitary chainring of a bicycle front crankset for engaging a drive chain, including a plurality of teeth formed about a periphery of the chainring, the plurality of teeth consisting of an even number. The plurality of teeth includes a first group of teeth and a second group of teeth arranged alternatingly between the first group of teeth. The first group of teeth and the second group of teeth are equal in number. Each of the first and second group of teeth include an outboard side and an inboard side opposite the outboard side and each tooth of the first group of teeth includes at least a first protrusion on the outboard side thereof and each tooth of the second group of teeth are free of the first protrusions on the outboard side and the inboard side.