Abstract: A chain wheel for a chain drive with a chain wheel comprising a damping rim of elastically deformable material at at least one axial side of said chain wheel, said damping rim including circumferentially alternating elevations, each with a peak portion and indentations, of which said elevations are intended for a radial overlap contact with straps or side bars of a chain engaging into teeth and tooth spaces of a toothing comprising in each tooth space inlet and exit profiles and an intermediate roll bed, the peak portion of each elevation being arranged within a circumferentially limited portion of said chain wheel that is defined by a reference plane containing the chain wheel axis and the center of curvature of said roll bed and by the extension of said entry profile in the tooth space.

Abstract: In a sprocket buffer, in order to reduce a noise and a shake/vibration of the chain gearing mechanism, an elastic band is provided to be adhered in a bottom of the sprockets; a cylindric pin which is to be inserted into the coupling hole in the bottom of the sprockets is formed in a lower part of the elastic band, and a pressure portion having the same diameter as that of the coupling hole is formed integrally with the cylindrical pin at a lower portion of the outer peripheral surface of the pin, thereby improving a durability against a cut off of the pin head portion.

Abstract: A rotary polymeric torque transfer device such as a vehicle timing chain sprocket wherein the sprocket comprises a polymeric body having homogeneous teeth and torque is transferred to the body by a metal non-insert drive member which includes an inner portion defining a hub, a central portion for receiving fasteners for mounting the sprocket upon shaft support structure, and the drive member outer portion includes torque drive elements cooperating with shoulders defined on the polymeric body radially spaced from the body axis of rotation whereby the transfer of torque between the drive member and the polymeric body occurs adjacent the body periphery radially spaced from the rotation axis to increase the length of the moment arm and reduce the torque forces transmitted between the drive member and the polymeric body to prevent excessive stress and wear between these components.

Abstract: A pulley is provided which is capable of being used as an alternator pulley. The pulley has a central hub portion for connecting the pulley to a shaft and a belt engaging portion disposed radially outward from the central hub portion. The central hub portion and the belt engaging portion are injection molded from a thermoplastic polyphenylene sulfide polymer material. The pulley provides approximately a 75% weight reduction in comparison to conventional metal pulleys used in automotive applications. The pulley is injection molded having a sprue gate located substantially in a center of said central hub portion. A bushing is optionally provided in a center opening in said central hub portion.

Abstract: A component for a power transmission belt. The component is a fiber cord that is treated in a first step with at least one of a) an isocyanate compound and b) an epoxy compound such that after the first step the at least one of the isocyanate compound and epoxy compound is present in solid form in an amount equal to 0.5 to 2.0 weight %. The fiber cord is treated after the first step in a second step with an RFL liquid so that the percentage void in the cord, as determined by the following formula, is not greater than 1.5%:percentage void=100.times.A.sub.y /A.sub.x, where A.sub.x is the total surface area of the cord and A.sub.y is the void area.

Abstract: A nose sprocket for chain saws includes an inner peripheral surface defining a bearing race, and teeth disposed at an outer peripheral portion of the nose sprocket. Side surfaces of the nose sprocket are provided with a vapor-deposited low-friction coating, except that the inner peripheral surface and a portion of each side surface adjoining the inner peripheral surface are free of the coating.

Abstract: The invention relates to a divisible sprocket wheel manufactured from synthetic material and having a gear ring (1b) and a hub portion (1a), comprising two wheel halves (1) which are manufactured by means of injection molding and have their axial faces (1f) abutting against each other, and means (3, 4) for enabling fixing the wheel halves together, wherein each wheel half (1) is solid and consists of a first synthetic material forming at least one half of the hub portion of the sprocket wheel; a second synthetic material forming at least one half of the gear ring of the sprocket wheel and the two radial outer faces (1d, 1e) of the wheel half, and a third synthetic material forming the internal portion (1e) of the body of the wheel half.

Abstract: A ceramic drive system includes highly efficient, light weight, durable, and wear and abrasion resistant sliding and rotating components. In particular, the components of the ceramic drive system has center links, center rollers and sprockets arranged for sliding and rotating contact and each comprising high precision tetragonal zirconia polycrystal (TZP) ceramic or alternatively zirconia-alumina ceramic composite.

Abstract: A resin pulley was made of a resin material wherein an inorganic fiber such as glass fiber, an inorganic powder such as silica powder, an organic fiber such as cotton cloth fiber, and an elastomer are blended in a phenol resin.Each content of the inorganic fiber, inorganic powder, organic fiber and elastomer in the above resin material is within the following range.

Abstract: A pulley assembly for a driven shaft is disclosed. The pulley assembly includes a pulley to which a turning force is transferred from a driving unit; a sleeve fixedly mounted to a casing of the driven unit through which the driven shaft passes with a clearance between an outer periphery of the driven shaft and an inner periphery of the sleeve; a bearing structure for bearing the pulley rotatably about an axis of the driven shaft, the bearing structure being disposed between the pulley and the sleeve; and a torque transferring structure for transferring the turning force transferred to the pulley to the driven shaft, the torque transferring structure being interposed between the pulley and the driven shaft.

Abstract: A transmission with a fixed transmission ratio comprises a pliable endless member which is provided with a profile of mainly transversely oriented teeth, and at least two pulleys which are each provided, on their circumferential surface, with recesses which mate with the teeth. The pliable member is a flexible belt which is stiff in its longitudinal direction and which may be made of metal, for example.

Abstract: A belt pulley with a substantially cup-shaped profile that is delimited on one side, in at least the axial direction, by an integrally shaped-on rim flange is disclosed. The rim flange is configured as the hub ring of a torsional vibration damper, the hub ring being connected, by means of a damping ring made of elastomeric material, to an inertial ring.

Abstract: Vibrations of the camshaft or crankshaft of a combustion engine are damped between a composite pulley which receives torque from the engine and one or more sheaves which are driven by an endless flexible member and serve to transmit torque to a pump, a blower, a compressor, a steering wheel mechanism and/or an alternator. The endless flexible member exhibits a certain amount of elasticity and the composite pulley comprises a rotary input device which is driven by the engine and a hollow rotary wheel which has a circular radially inner portion in rolling contact with the periphery of the input device. The outer diameter of the input device is smaller than the inner diameter of the wheel. The latter performs pendulum movements in response to changes in the length of the elastic flexible member.

Abstract: A pulley formed of resin having improved strength. The pulley includes a central body formed from a synthetic resin material. The main body has a belt-retaining portion along the outer peripheral surface thereof. A boss made of a metallic cylindrical body is embedded in the axial center of the main body. The boss is adapted to be secured to a rotary shaft. A plate-shaped metallic insert extends from an outer periphery of the boss to the interior of the main body. A plurality of service holes are formed in the insert, as is at least one engaging hole. The engaging hole is filled with the same synthetic resin material as the central body is formed of.

Abstract: Noise produced by a chain drive mechanism is significantly reduced by providing rubber rings on the faces of a sprocket, with the rubber rings dimensioned so that they are not contacted by the chain as it comes into engagement with the sprocket. The rubber rings absorb sprocket vibration and are as effective in reducing noise as are conventional rubber rings which are contacted by link plates of a chain to alleviate the effects of collision shocks. Since the rings need not be contacted by the chain, it is possible to reduce their thicknesses so that the sprocket can be utilized in restricted spaces.

Abstract: The disclosure relates to a damper pulley that exhibits a good damping effect and has a preferable resonance ratio. An annular damper-mass member is joined to an annular surface of a plate portion of a pulley through a first resilient rubber member. Two fan-like concave portions are formed in the surface of the annular damper-mass member, which faces the annular surface of the plate portion, at symmetrical positions with respect to the center of rotation of the pulley. Two projections are formed on the annular surface of the plate portion so as to perpendicularly project into the fan-like concave portions. A second resilient rubber member is interposed between each concave portion and projection. When torsional vibrations are exerted, each second resilient rubber member produces compression deformation, thereby generating a large spring force, whereby the resonance frequency against the torsional vibrations sufficiently increases even when the inertia moment of the mass member is increased.

Abstract: A chain wheel having a basic element with a cylindrical outside surface and a chain pinion which projects beyond the outside surface in the radial direction. At least one shrink ring made of a polymer material is thermally shrunk onto the cylindrical outside surface of the basic element. The polymer material may consist of a block polymer which contains a polyolefin and an elastomer material.

Abstract: A plastic sprocket wheel includes a sprocket body having a series of circularly spaced recesses located around a body circumferential edge, there also being a body side face opening in at least one body side face which communicates with the recess edge openings so that replaceable tooth elements can be slidably inserted into an associated recess when tooth replacement such as required when one or more teeth of an operating sprocket break or are rendered unusable. The replacement mounting requires no separate fastening devices for holding replacement teeth securely to the sprocket body, friction fit being sufficient to that end. The sprocket body is of resilient material such as an acetal, a polyethylene, a polypropylene etc., and the tooth elements can be of metal or the same material as the sprocket body, or such can be a combination of materials, e.g., a strong metal tooth piece molded in a resilient or plastic material core.

Abstract: A sprocket assembly, particularly adapted for use in wastewater settling tanks, is provided, which assembly is adapted to be supported on a shaft having a longitudinal axis. The sprocket assembly includes a polymeric sleeve adapted to be mounted on the axially extending shaft, the sleeve including a low friction bearing surface formed of ultra high molecular weight polyethylene. The sprocket assembly further includes a sprocket wheel adapted to be mounted on the bearing surface of the sleeve for rotation relative to the sleeve about the longitudinal axis of the shaft. Seals are further provided to inhibit the introduction of grit between the sleeve and the sprocket wheel.

Abstract: A toothed sprocket with rim portion made of a first composite material of discontinuous fiber disposed in a plastic matrix and where the teeth of the rim portion are covered with an encircling layer of a second composite material that includes a fibrous material and an elastomeric matrix and fibers embedded in the matrix.

Abstract: A power transmission wheel of the gear wheel sprocket wheel and pulley wheel type has hub portion or rim portion formed of a composite material of discontinuous fiber disposed in a plastic matrix where teeth are formed in one of the portions so as to define flank surfaces and where lateral side portion of fiber follow the contour of the surface so as to minimize in portions of fiber at ends the flank surfaces. A method for manufacturing a power transmission wheel by winding a strip of uncured material having embedded discontinuous lengths of fiber, and winding the strip in a volute fashion to form a preform having oppositely facing sides, and pressing the preform on one side and shaping the preform, and heating the preform to define a power transmission wheel.

Abstract: A connection system is provided for mounting apertured components such as gears, pulleys, rollers and the like on shafts. In preferred form, the system of the invention provides connections that are releasable so that shaft-mounted components can be repositioned, removed, serviced and/or replaced. A component that is to be mounted on a shaft is provided with a mounting hole that has an inner diameter that loosely receives the outer diameter of a shaft onto which the component is to be mounted. A ring of elastomeric material is inserted into an annular space that is defined at a location between the inner diameter of the mounting hole and the outer diameter of the shaft; and, the elastomeric material is tightly clamped between a pair of relatively axially movable clamping members that extend into opposed end regions of the annular space.

Abstract: A sprocket assembly, particularly adapted for use in wastewater settling tanks, is provided, which assembly is adapted to be supported on a shaft having a longitudinal axis. The sprocket assembly includes a polymeric sleeve adapted to be mounted on the axially extending shaft, the sleeve including a low friction bearing surface formed of ultra high molecular weight polyethylene. The sprocket assembly further includes a sprocket wheel adapted to be mounted on the bearing surface of the sleeve for rotation relative to the sleeve about the longitudinal axis of the shaft. Seals are further provided to inhibit the introduction of grit between the sleeve and the sprocket wheel.

Abstract: A belt drive comprising a toothed belt and a toothed pulley. The belt is provided with a guide rib that extends in the longitudinal direction of the belt and traverses the teeth thereof. To provide lateral guidance of the belt on a toothed pulley, the guide rib engages an annular groove on the periphery of the pulley. Disposed on the base of the annular groove of the pulley is an insert that is made of a material that has a softer resilience than does the material of the belt. The radial height of the insert is such that when the toothed belt runs up onto the toothed pulley, the guide rib of the belt first contacts the soft-elastic insert, and only after radial compression of the insert do the belt teeth rest upon the corresponding surfaces of the toothed pulley.

Abstract: A composite rotary drive member such as a gear, pulley or the like is formed from thermoplastics material that is molded in situ about one or more metal inserts. A circumferentially extending drive formation of desired shape and size is defined by the molded plastics material, and is molded without a need for conventional measures to compensate for shrinkage. The drive member is formed by first forming a composite preform member that has injection molded thermoplastics material with peripheral portions extending about one or more metal inserts. A band-like ring of injection molded thermoplastics material is molded to extend contiguously and continuously about peripheral surface portions of the molded commposite preform member, with the plastics material of the band-like ring and of the composite preform member uniting to form a single plastics structure.

Abstract: A driving gear for a bicycle is provided which comprises a gear body provided with a large number of teeth and a support member supporting the gear body. Between the gear body and the support member there is provided a driving transmission for transmitting a driving force from one of the gear body and support member to the other. A gap is provided at the driving force transmission through which the gear body and support member are rotatable relative to each other by a predetermined angle. At a location shifted from the driving force transmission there is provided an elastic member which compensates the gap and is elastically deformed when the gear body and support member rotate relative to each other so as to absorb the gap, thereby enabling the driving force to be transmitted from the driving force transmission.

Abstract: A chain drive system is provided having a metallic chain and a metallic sprocket, both meshing with each other. The sprocket is constituted by a double ply or pair of members of the same radius, each having a number of teeth formed at the same pitch on the outer peripheries thereof. An elastic member is held between at least the tooth portions in the chain-mating portions of these ply members. A part of the elastic member projects radially outwardly from at least the bases of the root portions of the split-member defined sprocket to function as elastomeric buffers.The sprocket may include roller portions capable of making meshing contact with the sprocket teeth. A shaft portion supports each roller portion. Elastic rings member may be formed round the shaft portions so as to project radially outwards beyond the outer periphery of the roller portions.Portions of the elastic member may project transversely through sprocket wall openings and merge with buffer rims.

Abstract: An idler wheel assembly for a track-type vehicle has a hub member and a plurality of replaceable wear segments positioned around the circumference of the hub. A plurality of U-shaped grooves in the circumferential surface of the hub receive resilient means. The wear segments also fit within the grooves and hold the resilient means in place. A plurality of clamping members encircle the hub, overlap the wear segments, and clamp the resilient means between the wear segments and the grooves as they are secured to the hub. The wear segments are therefore resiliently isolated from the idler hub. Conventional idler wheels for track-type vehicles have exterior rims which contact the track and guide the track as the vehicle is operated. This contact between the wheel rims an the track produces objectionable noise and vibration. The subject idler wheel assembly generates low levels of noise and vibration by isolating the rims or wear segments from the wheel hub with resilient rings.

Abstract: The invention relates to a gear wheel consisting of plastic material or a similar material having a coefficient of thermal expansion higher than that of steel. The gear wheel further includes a helix of steel or another material having a coefficient of thermal expansion similar to or identical with that of steel embedded in the gear rim of the wheel radially inside the teeth, whereby the helix has such a strength and dimension that it determines the coefficient of thermal expansion of the gear rim.

Abstract: A drive sprocket assembly for driving an endless chain assembly for propelling a vehicle includes a support hub which is mountable to the power output portion of the vehicle and a plurality of replaceable teeth which are mountable to the hub. Each tooth is resiliently isolated from the support hub, and resilient to the chain assembly, by non-metallic materials to reduce noise generated by the sprocket teeth striking the endless chain assembly. Conventional drive sprocket assemblies use a one piece toothed sprocket, or segments having several teeth, bolted to a support member. These prior sprocket assemblies generate considerable noise from impacting of the sprocket teeth with an endless chain. The subject sprocket assembly produces low levels of noise by utilizing individual replaceable teeth which are isolation mounted to the sprocket support hub.

Abstract: A rotary drive member such as a gear or pulley has a hub portion that can be mounted on a shaft for rotation about the axis of the shaft, a rim portion that can be engaged by another drive member such as a gear, chain or belt as the rotary drive member rotates about the axis of the shaft, and a radially extending web that rigidly interconnects the hub and rim portions. The rotary drive member is formed by injection molding plastics material to provide a unitary, one-piece plastics member that envelops selected portions of a pair of inner and outer insert members that extend concentrically about the shaft rotation axis and that are formed from metal. The inner insert takes the form of an elongate, tubular metal sleeve that defines inner diameter portions of the hub portion of the rotary member. The outer insert takes the form of an annular metal disc that extends radially with respect to the shaft rotation axis to define portions of the radially extending web.

Abstract: A pulley comprising an outer rim provided with an outer running surface for a pulley belt and a hub concentric with the rim and a dampening element connected to the rim and hub in a non-rotating manner, the rim and hub being rigidly supported to one another in a radial and axial direction and the rim capable of moving at an angle to the hub in the circumferential direction, the rim and hub being made of a hard polymeric material and the dampening element being made of a softer polymeric material, the outer rim (3,15,22) and the hub (4,14,21) are connected to form an integral element by leaf spring-type ribs (6,16,23) having their least bending resistance moment around axes running parallel to the longitudinal axis of the pulley (1,13,20).

Abstract: A composite gearwheel structure for reciprocating the gripper-carrying straps in weaving looms, comprises a gearwheel body of synthetic plastic material. Its teeth are partially covered with sheet metal associated with the body and forming an integral part thereof.

Abstract: Gear for chain drives comprising a gear body of cast material having a hub section, a gear rim section with spur teeth, and a web section joining said hub and gear rim sections, and a ring plate of metal embedded in the web section, the outer edge of said plate being near the bottom of the areas between the spur teeth and having axial openings filled with casting material around its periphery, said ring plate having at its outer radial edge, radially outwardly directed projections, which are located in each case in a tooth, and which are embedded in the casting material of the gear body, said projections extending beyond the bottom of the spaces between adjacent spur teeth, and an axial opening formed in the ring plate adjacent each projection and radially below it.

Abstract: A multistage front chain gear for a bicycle is provided which includes a gear body which is formed of synthetic resin and having at least one larger diameter toothed body and at least one smaller diameter toothed body having different numbers of teeth. First and second contact plates are formed of material having a larger cutting resistance than the synthetic resin used for the gear body. The first contact plate is attached to the outside surface of the larger diameter toothed body, and the second contact plate is attached to the inside surface of the smaller diameter toothed body. As a result, each toothed body is protected from being cut by a driving chain.

Abstract: A sprocket assembly is disclosed for use as a drive or idler wheel for the endless tracks of a track type vehicle. Included is an inner rim rigidly and concentrically mounted to a hub and having a series of studs projecting radially outwardly therefrom at constant circumferential spacings. Each stud has fitted thereon a universal shock absorber having two or more concentric tubes of rigid material with a preloaded elastic member or members engaged therebetween. Disposed concentrically outwardly of the studded inner rim is an outer rim having a series of sprocket teeth formed on its circumference and defining an annular row of radial, inwardly open cavities to closely receive the respective shock absorbers on the studs of the inner rim. The shock absorbers damp the forces exerted between the inner and outer rims in all of the axial, radial, and rotational directions of the sprocket assembly.

Abstract: Crankshaft noise from an internal combustion engine is reduced by the known step of using a crankshaft damper pulley 10 on the front end of the crankshaft. This damper pulley has a damper ring 16 interposed between the hub and the rim of the pulley. Noise is further reduced by fitting a plug 20 to the front of the engine to cover the area within the ring 16 of the damper pulley. The plug 20 is preferably of neoprene rubber.

Abstract: A sprocket wheel assembly of a crawler vehicle which comprises a first inner tube mounted on a drive shaft, a second inner tube rotatably mounted on a final reduction gear casing and fixedly connected with the first inner tube, and an outer tube disposed so as to extend over the outer circumferences of the first and second inner tubes. A first elastic annular block unit is interposed between the first annular tube and one end section of the outer tube and a second elastic annular block unit is interposed between the second inner tube and the other end section of the outer tube. A sprocket wheel for driving a linked-together endless track is fixedly mounted to the outer tube.

Abstract: A composite plastic and metal pulley intended primarily for use with an endless drive belt for vehicle accessories, particularly an alternator. The pulley is formed by a hollow cylindrical-shaped molded plastic member having a series of outwardly opening V-shaped belt-receiving grooves on the outer surface thereof. A flat disc-shaped metal member is mounted within the central bore of the plastic member perpendicular to the longitudinal axis thereof. The outer edge of the metal disc is scalloped and is embedded firmly within the plastic to prevent rotation of the disc with respect to the plastic member. A central opening is formed in the disc for mounting the pulley on the extended end of the alternator shaft.

Abstract: A sprocket wheel for a tracked vehicle, the sprocket wheel being in the form of an annular body having teeth integrally moulded of elastomeric material, the teeth including metal inserts moulded therein and providing track engaging surfaces in the inter-tooth valleys about the sprocket wheel.

Abstract: A front gear for bicycles comprising a gear main body made of plastics and a metal core embedded in the gear main body. The metal core includes ribs embedded in support arms of the gear main body and a boss having a serrated bore for a crankshaft to fit in and embedded, at its outer peripheral portion other than the inner peripheral portion thereof, in an inner annular portion of the gear main body. One of the support arms has an opening in register with a positioning hole formed in one of the core ribs.

Abstract: A drive wheel and sprocket assembly for use in the power transmission of a conveyor device such as a roller conveyor comprises a drive wheel which is mounted on the hub of a sprocket assembly. The drive wheel mounts the hub with a modified spline connection in which a plurality of radially overhanging teeth on the drive wheel are resiliently interlocked with shoulders formed in the assembly hub. In a preferred embodiment, the drive wheel is molded of polyurethane.

Abstract: An improved sprocket wheel for substantially planar feeding of a strip of film in a photographic camera by applying a thrust to end edges of two parallel and spaced apart rows of perforations provided along the film strip includes two corresponding trains of film feeding teeth, each tooth having a curved film thrusting surface confronting the plane along which film is fed in the camera and comprising a base portion having a gentler slope with respect to the film feeding plane than an involute tooth profile and an upper portion having a steeper slope with respect to the film feeding plane than an involute tooth profile, and further having a ridge defined between the outer side surface and the film thrusting surface of each tooth to substantially conform to a rounded corner of each film performation and thereby facilitate smooth feeding of the film.

Abstract: A buffer device for reducing the impact and noise of the coupling of a roller chain and sprocket. A groove is provided adjacent the teeth of a sprocket which receives a buffer ring. The buffer ring includes an outer resiliently compressible ring and an inner spring-like ring which is not compressible, but which is capable of resilient deformation. The buffer ring is sized to very loosely fit in the groove to avoid wear concentration. The outside diameter of the buffer ring is larger than the inscribed circle of the link plates of the roller chain engaged with the sprocket.

Abstract: A sprocket wheel of an endless track-type vehicle has a hub and a plurality of sprocket teeth segments fixedly secured to the outermost of the hub to engage a plurality of bushings of an endless track for driving the same. The hub comprises a substantially annular-shaped radially inner part, a substantially annular-shaped radially outer part arranged movably with respect to the inner part by the interposition of a plurality of deformable resilient block segments tightly inserted into an annular space defined by and between the inner and outer parts, and a stopper mechanism for preventing the deformable resilient block segments from an excessive deformation thereof.

Abstract: A sprocket for a motorcycle in which noise due to chain-sprocket intermeshing is reduced. A pair of resilient vibration reducing members are provided, one on each side of a metal sprocket body. The circumferential edges of the vibration reducing members are either curved or tapered to maintain contact with the motorcycle drive chain over a wide range of load conditions.

Abstract: A sprocket-wheel, gear-wheel or like wheel, substantially manufactured of a synthetic material, comprising a hub which is divided along a plane which lies perpendicular to the center line of the hub-boring, said hub parts being provided with adjacent recesses for jointly accommodating a toothed ring member and being affixed to one another by bolts or the like to clamp the toothed ring member therebetween.

Abstract: A wheel (16) in a continuous track assembly (12) has a hub (18) and a rim (20) connected to the hub (18). First apparatus (29) engages a track (14) of the assembly (12) to drive an associated work vehicle (10). Second apparatus (42) mounts the rim (20) in a movable relationship to the hub (18). The first apparatus (29) in movable relationship to the rim (20) to substantially absorb and isolate noise created by engagement of the wheel (16) and track (14) to drive the vehicle (10). The rim (20) is movable relative to the hub (18) to substantially isolate impact forces exerted on the wheel (16) resulting from operation of the vehicle (10).

Abstract: A chain noise preventing device wherein a cushioning ring, having an outside diameter larger than that of a semicircular inscribed circle of chain formed when the chain meshes with a sprocket, is arranged on at least one side surface of the sprocket.

Abstract: A chain sprocket having guide plates comprising flanges of a frangible material located along opposite sides of the sprocket is disclosed teeth and projecting outwardly therefrom to prevent lateral disengagement of the chain under conditions of severe usage, particularly with use of the sprocket and chain assembly on a racing motorcycle. The guide plates are particularly useful in guiding the slack lower reach on of a motorcycle chain during acceleration of a motorcycle, and are also useful in guiding the slack upper reach of the chain during deceleration.