Abstract: A self-stabilizing vehicle includes a mass gyroscope which is fixed at an occupant compartment chassis corresponding to a portion where occupants sit. The occupant compartment portion may tilt outwards in response to the centrifugal force. If the vehicle has three or more wheels, the load is evenly distributed on the left wheel and the right wheel which move oppositely up and down about an effectively centrally-mounted shaft pin. Further, the present disclosure proposes a method for operating the self-stabilizing vehicle. According to the self-stabilizing vehicle and the operating method thereof, a vehicle having a narrow body may be used. When the vehicle undergoes external forces such as the centrifugal force and the crosswind, the occupant compartment can maintain the vertical stability even though the wheels may slide sideways.

Abstract: A straddle vehicle comprises an axle; an external member which is externally fittable to the axle; and a fastening member fastened to the axle to prevent disengagement of the external member. The axle includes an outer tube member to which the external member is externally fittable, and an inner shaft member which is inserted into the outer tube member and is longer in an axial direction of the axle than the outer tube member. The inner shaft member includes a shaft part which is internally fittable to the outer tube member, a male thread part formed in an outer peripheral surface of a first end portion of the shaft part, and a retaining part protruding radially outward from a second end portion of the shaft part, the retaining part being configured to retain an axial tension of the inner shaft member generated by fastening the fastening member to the axle.

Abstract: The rear of a motorcycle with cardan suspension comprising a rear frame, a fork, hinged to said frame about a hinging axis, the fork rotatably supporting the rotation pin of a rear wheel of the motorcycle around a rotation axis, the fork supporting a cardan-shaft transmission comprising at least one first transmission shaft, suitable to be connected to a power take-off of an associable engine, at least one final shaft provided with a pinion rotatably connected to said rear wheel, wherein between the first transmission shaft and the final shape is interposed a first cardan joint, a floating arm that supports said pinion of the final shaft, the arm being floating around said rotation axis of the rear wheel. The floating arm comprises a cup portion arranged coaxially to the rotation pin and having at least an inner end that houses and supports said pinion.

Abstract: A braking force control apparatus for a saddle ride vehicle includes a transmission controller which reduces driving force of an engine by a predetermined speed reduction ratio and transmits the driving force to a drive wheel, a clutch device which connects—disconnects the driving force between the engine and the transmission, a brake device which generates braking force on the drive wheel, and a sensor which detects a state of the transmission. The transmission switches between a neutral state and an in-gear state, and when the sensor detects that the transmission is switching from the neutral state to the in-gear state, the controller causes the brake device to generate braking force on the drive wheel, and then releases the braking force upon completion of the switching to the in-gear state.

Abstract: The aim of the invention is to improve the stability of bicycles fitted with at least one seat for transporting children, by re-centering and lowering the centre of gravity of the child via a specific frame structure, optionally in combination with a choice of reduced wheel diameters and/or an increase in the spacing of the pedals. The location for the feet (31) of the child is inside the supporting structure (9, 10?) of the bicycle linking the seat tube (4?) to the rear wheel axle (14).

Abstract: A high performance motorcycle having a frame, engine suspension, and rear wheel drive system that enables rider foot positioning close to the longitudinal centerline of the motorcycle and an overall aerodynamic profile. The engine suspension, centering and damping system allows for lateral movement while damping vibration and unwanted oscillations. The rear wheel drive includes a driven pulley axially disposed on a rear wheel axle, a drive pulley configured to receive motive output from the motorcycle engine, an idler pulley disposed above a line between the axes of rotation of the drive pulley and the rear wheel axle, and a belt or chain disposed around and operatively connecting the drive pulley, the driven pulley and the idler pulley, wherein the idler pulley and the drive pulley configured so as to provide substantially constant tension to a belt or chain over the range of travel of the rear suspension.

Abstract: In an engine unit, a drive unit case includes a crank shaft disposed in a left-right direction of a vehicle, a drive shaft and a second main shaft. A transmission shaft is parallel or substantially parallel to the drive shaft and transmits rotational power, which has been transmitted via a middle gear, to a propeller shaft. A second clutch, which transmits rotational power from the crank shaft to the second main shaft, is freely detachably connected to an end of one side of the second main shaft which protrudes from a drive unit case more than the end of one side of the drive shaft, at a position that overlaps with at least one section of the middle gear on the side of the shaft direction of the drive shaft.

Abstract: An electrically-operated two wheeled vehicle provided with a swing unit which pivotally supports a drive wheel WR. The swing unit includes: a first rotary electric machine having a first rotor; a second rotary electric machine having a second rotor; and a planetary gear mechanism which combines a rotational drive force of the first and second rotors to each other and transmits a product of rotational drive forces to a drive wheel WR in a state where a rotational speed is increased. The first and second rotary electric machines are arranged parallel to each other in the longitudinal direction of a vehicle such that an axis Ax2 of the second rotor is positioned in front of an axis Ax1 of the first rotor along the vehicle body. This arrangement prevents a height position of a lower surface of a swing unit from becoming excessively low.

Abstract: A shaft drive type motorcycle includes a drive shaft for permitting a reduction in the vehicle weight. The shaft drive type motorcycle includes a gear box provided at a rear part of a swing arm with a bearing provided between the gear box and a rear wheel axle. The bearing includes an outer race and balls and an inner race operative provided to rotatably support the rear wheel axle. A presser flange is provided between the rear wheel axle and a rear wheel that includes a hollow cylindrical part pressing the inner race in the axial direction of the rear wheel axle. A flange part is provided as part of the presser flange to which a brake disc is mounted. A labyrinth structure is provided for making it difficult for oil from leaking out of the gear box.

Abstract: An electric vehicle includes a vehicle body frame; an electric motor; a swing arm pivotally supporting a rear wheel at a rear end thereof; a drive shaft for transmitting the driving force of the electric motor to the wheel; and a suspension connecting the vehicle body frame and the swing arm together. The electric motor is set in a longitudinal layout in which a rotating drive shaft is disposed in a front-rear direction of the vehicle; and is offset from a center to either of left and right sides in a vehicle width direction. The suspension is disposed under the electric motor and the drive shaft, and on the inner sides of the electric motor and the drive shaft in the vehicle width direction, and overlapping the positions of the electric motor and the drive shaft in the front-rear direction.

Abstract: A brake control system that is received in a waterproof case and can be easily assembled even when a plurality of electric wires or hydraulic pipes is connected thereto is provided. A brake control system for a vehicle is connected to hydraulic brakes through a plurality of brake pipes 116a through 116e and controls hydraulic pressure of the hydraulic brakes, wherein the brake control system is received in a case 100 having a waterproof property, a pipe supporting member 101, which enables the plurality of the brake pipes 116a through 116e to be arranged from an external side of the case 100 into the case 100, is formed on the case 100, and the pipe supporting member 101 and the case 100 are detachably attached to each other through a seal member 102.

Abstract: A motorcycle includes a rear fork with a first and the second extending portions, and a cross portion, the cross section linking the first and the second extending portions together. The first extending portion extends toward a first side of a rear wheel, the second extending portion extends toward a second side of the rear wheel. The first extending portion, which has an open cross sectional structure and through which a drive shaft is passed, is made to have larger outer diameter than the second extending portion, which has a closed cross sectional structure. Nonetheless, the rigidity of the first extending portion and the second extending portion are approximately the same. The drive shaft extends rearwardly and passes through the opening on the inside of the first extending portion.

Abstract: In a motorcycle in which a rear fork is swingably provided on a vehicle body frame with a power unit, a rear wheel is provided at a rear end of the rear fork, a drive shaft is provided between a gear case on a lateral side of the rear wheel and an output shaft of the power unit, and output power of the power unit is transmitted to the rear wheel through the drive shaft and the gear case. The rear fork extends along a lateral side of the rear wheel and has an arm through which the drive shaft passes. The arm has a tubular base part with a closed cross section, and a rear part with an open cross section through which the drive shaft passes. The base part has a thick-walled area at the rear end of the base part.

Abstract: A two-wheeled motor vehicle provided with a drive shaft (32) rotatably supported by a swing arm (28) rockable on a pivot shaft (27). The longitudinal center axis (32J) of the drive shaft (32) is located below a line (28C) interconnecting the pivot shaft (27) and an axle (40). The drive shaft (32) is surrounded by the swing arm (28).

Abstract: A motorcycle includes a vehicle body frame, an engine, a pivot shaft, a swing arm, a rear wheel, a gear case, a drive shaft section, and a bearing section. The drive shaft section includes a first drive shaft connected to an output power shaft of the engine through a first universal coupling and a second drive shaft disposed coaxially with the first drive shaft and connected to the first drive shaft through a spline portion to be movable in an axial direction with respect to the first drive shaft. The bearing section restrains relative movement of the first drive shaft and the second drive shaft along a diametrical direction. The bearing section is interposed between an inner circumferential face of one of the first drive shaft and the second drive shaft and an outer circumferential face of another of the first drive shaft and the second drive shaft.

Abstract: A motorcycle includes a swing arm, a rear wheel mounted on a leading end of the swing arm, a drive shaft disposed in the swing arm, and a final gear transmission mechanism interposed between the drive shaft and the rear wheel. The final gear transmission mechanism includes a gear case mounted on the leading end of the swing arm for supporting a rear axle; a first end bearing and a second end bearing for supporting a first end and a second end of the rear axle, respectively, a ring gear mounted on the rear axle for transmitting the rotary drive force of an engine to the rear axle; a holding portion for holding the first end of the rear axle in the axial direction of the rear axle; and a fastening member for fastening the second end bearing to the second end of the rear axle.

Abstract: A shaft drive type motorcycle includes a drive shaft, a constant-velocity universal joint interposed in the drive shaft, and the pinion gear provided at one end of the drive shaft and meshed with a final gear. A shaft part may be extended from a cup of the constant-velocity universal joint, the shaft part is provided with male splines, and a tubular part extends from the pinion gear. The tubular part is provided with female splines in which to fit the male splines, and the male splines and the female splines are coupled with each other.

Abstract: A power unit for a vehicle including a clutch capable of making and breaking the transmission of power to a drive wheel. The clutch is interposed in the course of a power transmission path, along which rotational power of a crankshaft is transmitted to the drive wheel. The clutch is rotatably borne on a crankcase, and its axis is set along the front-rear direction of the vehicle. A clutch actuator is provided for controlling the connection and disconnection of the clutch. The clutch actuator mounted to an engine body including the crankcase. This arrangement of the clutch actuator eliminates a need to increase the front-to-rear length of the engine and the vehicle body.

Abstract: An exhaust system for a motorcycle includes a bracket which includes a joint portion, an engine support portion, and a swing-arm support portion. The joint portion is configured to be connected to a vehicle-body frame. The engine support portion is configured to support an engine. The swing-arm support portion is provided separately from the joint portion and configured to support a swing arm which is swingable with respect to the vehicle-body frame and at a rear end of which a rear wheel is provided. An exhaust pipe extends rearwards from the engine. A muffler is connected to a rear end of the exhaust pipe and disposed along the swing arm. A muffler is connected to a rear end of the muffler support stay and a front end of which is connected to the bracket separately from the joint portion.

Abstract: A rear wheel drive mechanism acting as a drive force transmission mechanism provided in a vehicle is provided with a spline section provided on an outer periphery of one end of a first drive shaft acting as an output shaft, a spline hole provided on an inner periphery of a tubular engaging section of a universal joint and engaging with the spline section, and a circular clip disposed spanning the inner periphery and the outer periphery. An operating section of the clip faces a notched section provided on the tubular engaging section. The notched section is provided on a tip of the tubular engaging section and opens with respect to an axial dimension of the first drive shaft. The drive mechanism so configured simplifies the operation of mounting or removing a universal joint onto an output shaft of a vehicle.

Abstract: A two-wheeled motor vehicle provided with a drive shaft (32) rotatably supported by a swing arm (28) rockable on a pivot shaft (27). The longitudinal center axis (32J) of the drive shaft (32) is located below a line (28C) interconnecting the pivot shaft (27) and an axle (40). The drive shaft (32) is surrounded by the swing arm (28).

Abstract: A motorcycle includes a swing arm, which is swingably supported on a vehicle body frame by a support member. A suspension link member is connected between a lower portion of the vehicle body frame and the swing arm, and a rear shock absorber is disposed extending between the suspension link member and an upper portion of the vehicle body frame. A rear wheel of the motorcycle is rotatably supported on a rear end of the swing arm, and the wheel is driven by a drive shaft extending through a hollow bore formed in the swing arm. The suspension link member is connected between a portion of the swing arm and a lower portion of the vehicle body frame, such that the portion of the swing arm which houses the drive shaft is positioned above the support member for the vehicle body frame.

Abstract: A shaft of a pinion gear is engaged with a ring gear extends toward the front side in a final gear case that is provided in a power transmission system between a power unit and a wheel. Splines are provided on each of an outer circumference of the shaft, and on an inner circumference of a cylindrical portion of a pinion joint that forms a receiving portion of a joint provided at the rear end of a drive shaft for transmitting power from the power unit to the pinion gear. The two splines are engaged with each other. The pinion joint is fixed to the pinion gear by a bolt that is threadedly engaged with a threaded portion formed at the lower portion of a hole in the pinion gear shaft. A flexible portion of the bolt is formed between a head portion and the threaded portion of the bolt.

Abstract: A swing arm structure, in a shaft-driven vehicle, is configured and arranged compactly to minimize the size and weight thereof. A drive shaft of the vehicle is housed in a right arm portion of a swing arm. A front end of the drive shaft is connected to a powertrain output shaft via a universal joint. A pivot sleeve is disposed such that a central axis thereof is disposed downwardly and rearwardly of a central portion of the universal joint, and a front-end opening protrudes forwardly of the pivot sleeve. The central portion of the universal joint, having the largest diameter, is disposed forwardly of the center of a pivot shaft. This helps to keep the opening diameter small at the front of the right arm portion.

Abstract: A motorcycle includes a vehicle body frame, an engine, a pivot shaft, a swing arm, a rear wheel, a gear case, a drive shaft section, and a bearing section. The drive shaft section includes a first drive shaft connected to an output power shaft of the engine through a first universal coupling and a second drive shaft disposed coaxially with the first drive shaft and connected to the first drive shaft through a spline portion to be movable in an axial direction with respect to the first drive shaft. The bearing section restrains relative movement of the first drive shaft and the second drive shaft along a diametrical direction. The bearing section is interposed between an inner circumferential face of one of the first drive shaft and the second drive shaft and an outer circumferential face of another of the first drive shaft and the second drive shaft.

Abstract: A brake device for a motorcycle which includes a brake caliper for parking and which favorably ensures the followability of the swing arm in response to the fluctuation of a road surface. A brake caliper for braking and a brake caliper for parking are respectively arranged separately in the vertical direction with respect to the swing arm and, at the same time, are arranged in front of the rear axle. Here, the brake caliper for parking is arranged below the swing arm and the brake caliper for braking is arranged above the swing arm.

Abstract: To provide a rear swing arm installation structure that does not require large tightening force and upsizing and can avoid backlash of a rear swing arm. In a rear swing arm installation structure, a cylindrical spacer into which a pivot shaft is inserted is screwed into the pivot bearing holes of a pair of vehicle body frames. The spacer includes a head section of a large diameter and a screw section having a smaller diameter than the head section. The head section touches an end face of the pivot bearing hole of the vehicle body frame and the tip of the screw section touches an end face of a rear swing arm.

Abstract: A motorcycle is provided with a rear fork attached to a body frame so as to swing up and down freely. A rear wheel is attached to the rear end portion of the rear fork, a gear case is attached to a side of the rear wheel, and a drive shaft is provided between the gear case and an output shaft of a power unit. The output of the power unit is transmitted to the rear wheel via the drive shaft and the gear case. In the motorcycle, the gear case is supported by a rear-wheel axle provided in the rear end portion of the rear fork. A torque rod, which links an outer periphery portion of the gear case with the rear fork, serves as a stopper for rotation of the gear case. The resulting configuration provides a shaft-drive system that reduces the assembling time of the torque rod, and improves the productivity of the main line.

Abstract: To provide a rear wheel structure which can easily perform the mounting and dismounting of a rear wheel without causing a fluctuation in a banking angle. In the rear wheel structure which includes a pair of left and right swing arms which are arranged to sandwich a rear wheel, a driving force transmission device is provided for transmitting a driving force to the rear wheel along one swing arm, and a spacer which is arranged on an axle of the rear wheel. A muffler is arranged outside the swing arm on a side opposite to the driving force transmission device. The spacer is arranged between the swing arm on the driving-force-transmission-device-side and the rear wheel for mounting the rear wheel relative to the one swing arm.

Abstract: An elongate spike configuration of air filter for an automotive vehicle includes a cowl arranged to extend parallel to the ram air flow about the vehicle and resulting from movement of the vehicle at speed. The cowl is rotational and is power driven in rotation during operation of the vehicle such as to smooth ram air flow, reducing turbulence and excessive ram air pressure so as to improve running smoothness of the vehicle engine.

Abstract: A shaft type motorcycle includes a drive shaft for permitting a reduction in the vehicle weight. The shaft drive type motorcycle includes a gear box provided at a rear part of a swing arm with a bearing provided between the gear box and a rear wheel axle. The bearing includes an outer race and balls and an inner race operative provided to rotatably support the rear wheel axle. A presser flange is provided between the rear wheel axle and a rear wheel that includes a hollow cylindrical part pressing the inner race in the axial direction of the rear wheel axle. A flange part is provided as part of the presser flange to which a brake disc is mounted. A labyrinth structure is provided for making it difficult for oil from leaking out of the gear box.

Abstract: A tubular case into which a drive shaft configured to transmit a driving force from a transmission T of an engine to a rear wheel of a motorcycle is accommodated, the case including a case body which has an opening portion extending in an axial direction of the drive shaft and is configured to accommodate the drive shaft therein through the opening portion, and a cover removably attached to the case body so as to close the opening portion.

Abstract: A wheel suspension system having under powered acceleration a stable squat magnitude response.

Abstract: A motorcycle includes a vehicle body frame, a rear swing arm which is mounted on a vehicle body frame in a rockable manner by way of a pivot shaft, and a rear wheel which is pivotally supported on a rear portion of the rear swing arm and is rotated by a driving force of a drive shaft. The pivot shaft which constitutes a support portion and an axis of the rear wheel axle are arranged at the substantially same height. The drive shaft is arranged at a position upwardly spaced-apart from the drive shaft, that is, above the pivot shaft. The drive shaft includes a shaft-length variable mechanism which can change a length of the shaft. The resulting configuration provides a motorcycle having reduce weight while maintaining support rigidity of the rear swing arm.

Abstract: A motorcycle includes a rear swing arm which has upper and lower arms and an arm body. The upper and lower arms are vertically swingably attached to either a body frame or an engine via pivot shafts that are disposed in vertically spaced relation to each other and extend parallel to each other toward a rear wheel. The arm body is swingably connected to a rear end of the upper and lower arms via support shafts for supporting the rear wheel.

Abstract: An auxiliary power drive system is incorporated into a bicycle either as a retrofit or in initial construction. The power for the drive system is derived either from an electric motor or an internal combustion engine. The power developed by said motor or engine is delivered to the rear wheel of the bicycle by a flexible drive shaft which either drives a friction wheel operating on the tire of the rear wheel or to worm gear affixed to the rear wheel. The flexible drive shaft includes a friction clutch which discontinues the power of the drive shaft from driving the rear wheel when normal pedaling is resumed. The flexible drive shaft also includes a telescoping coupling to compensate any change in lengths of the drive shaft due to impacts on the rear wheel caused by the terrain the bicycle is riding on.

Abstract: A motorcycle includes a head pipe that is disposed at a front portion of a vehicle body and makes front forks pivot, and a pair of left and right down tubes that extend downward from the head pipe and extend to the rear side of an engine under the engine, wherein connecting members for connecting brake hoses that are formed of elastic members to respective brake pipes that are formed of metal pipes are disposed behind the head pipe, and the brake hoses that extend from the connecting members to a brake for a front wheel extend frontward after passing between the pair of the left and right down tubes.

Abstract: A torque shock or vibrations caused by the rotary inertia of a hydrostatic continuously variable transmission is reduced to improve ride quality of a vehicle when excessive torque occurs in a torque transmission path between a crankshaft and a drive wheel. A motorcycle includes a hydrostatic continuously variable transmission rotatably driven by torque of a crankshaft of an internal combustion engine. A rear wheel is rotatably driven by torque from the transmission. A torque damper absorbs excessive torque occurring in a torque transmission path from the crankshaft to the rear wheel. The torque dampers include an input side torque damper disposed in an input side torque transmission path between the crank shaft and the transmission and an output side torque damper disposed in an output side torque transmission path between the transmission and the rear wheel.

Abstract: An auxiliary power drive system is incorporated into a bicycle either as a retrofit or in initial construction. The power for the drive system is derived either from an electric motor or an internal combustion engine. The power developed by said motor or engine is delivered to the rear wheel of the bicycle by a flexible drive shaft which either drives a friction wheel operating on the tire of the rear wheel or to worm gear affixed to the rear wheel. The flexible drive shaft includes a friction clutch which discontinues the power of the drive shaft from driving the rear wheel when normal pedaling is resumed. The flexible drive shaft also includes a telescoping coupling to compensate any change in lengths of the drive shaft due to impacts on the rear wheel caused by the terrain the bicycle is riding on.

Abstract: In a motorcycle or a three-wheeled vehicle which tiltably supports a proximal end portion of a swing arm which pivotally supports a wheel on a vehicle body frame by way of a pivot shaft, the swing arm pivot structure is inexpensive and can be easily assembled without particularly using relatively expensive bearings such as taper bearings. At the same time, the preload adjustment is no longer necessary thus facilitating the assembling operation and the maintenance operation. A proximal portion of the pivot shaft is connected to the swing arm in a state wherein the proximal portion is non-rotatable relative to the swing arm. At the same time, a distal portion of the pivot shaft is fitted in and held by the vehicle body frame in a state wherein the distal portion is rotatable relative to the vehicle body frame.

Abstract: The assembly (10) for admitting combustion air to the engine of a motorcycle comprises: an air filter (12); a housing (11) for mounting at the top portion of the motorcycle and forming a support for the air filter (12); an air inlet module (13) fitted to the housing and including at least one movable shutter (131, 131?); control means for controlling the movements of the shutter (131, 131?); and assembly means (17, 171-174) for assembling the assembly at the top portion (21) of the motorcycle. The air filter (12) is generally annular and subdivides the inside volume of the housing (11) into a radially inner chamber and a radially outer chamber. The radially inner chamber is fed with air through the air inlet module (13), while the radially outer chamber forms, around the air filter (12), a chamber for stabilizing the flow of air downstream from the filter.

Abstract: A power transmission mechanism of a motorcycle includes a drive case which is disposed at the rear end of and outside of a rear swing arm, and which surrounds the axle of a rear wheel and incorporates a transmission device. In addition, the power transmission mechanism includes a drive shaft extending from an output shaft of an engine for transmitting power of the drive shaft to the rear wheel. The transmission device converts the direction of a driving force of the drive shaft and transmits it to the rear wheel. The drive shaft constituting part of the power transmission mechanism is disposed below the rear swing arm and the pivot shaft. The result is a motorcycle configuration that suppresses the vehicle width without expanding the rear swing arm.

Abstract: A motorcycle includes a swing arm, which is swingably supported on a vehicle body frame by a support member. A suspension link member is connected between a lower portion of the vehicle body frame and the swing arm, and a rear shock absorber is disposed extending between the suspension link member and an upper portion of the vehicle body frame. A rear wheel of the motorcycle is rotatably supported on a rear end of the swing arm, and the wheel is driven by a drive shaft extending through a hollow bore formed in the swing arm. The suspension link member is connected between a portion of the swing arm and a lower portion of the vehicle body frame, such that the portion of the swing arm which houses the drive shaft is positioned above the support member for the vehicle body frame.

Abstract: A two-wheel drive motorcycle having a drive train that supplies power to the front wheel and includes a series of rigid shafts or other internalized drive systems. The front wheel drive consists of components located on the axis of steering within the head tube and positioned symmetrically in a counterbalancing fashion within the front fork in order to counteract the torque reactions from the rotating front wheel drive while providing a full range of steering. The front wheel drive lengthens and shortens in parallel with the shock-absorbing front fork. An engagement clutch, a one-way hub, and torque limiting clutch operatively engaged with the front wheel drive are also disclosed.

Abstract: An air cleaner device for a motorcycle including a cylindrical filter element disposed in a box of an air cleaner, wherein air purified by the element is sent to an air-intake system. Further, a rectifying member is disposed around the outer periphery of the cylindrical filter element at a predetermined distance apart therefrom and the rectifying member is formed into a cylindrical shape so as to cover the entire outer periphery of the element.

Abstract: In a motorcycle, a pivot plate on a drive shaft side is arranged closer to a vehicle body center axis side than the drive shaft and, at the same time, a swing arm mounting portion of the pivot plate in the vicinity of the drive shaft is flattened. Further, a lower cross pipe is extended between the left and right pivot plates in a state that the lower cross pipe projects from the pivot plate on the drive shaft side, a down tube is lowered from a head pipe, a lower pipe is extended rearwardly in the longitudinal direction of a vehicle body frame from a lower end of the down tube, and a rear end of the lower pipe is connected to a projecting portion of the lower cross pipe thus offsetting the pivot plate arranged closer to the drive shaft side than the lower pipe to the vehicle body center axis side.

Abstract: A motorcycle includes a rear fork with a first and the second extending portions, and a cross portion, the cross section linking the first and the second extending portions together. The first extending portion extends toward a first side of a rear wheel, the second extending portion extends toward a second side of the rear wheel. The first extending portion, which has an open cross sectional structure and through which a drive shaft is passed, is made to have larger outer diameter than the second extending portion, which has a closed cross sectional structure. Nonetheless, the rigidity of the first extending portion and the second extending portion are approximately the same. The drive shaft extends rearwardly and passes through the opening on the inside of the first extending portion.

Abstract: A motorcycle having a frame, front and rear wheel assemblies and a motor and transmission assembly. The motor and transmission assembly attaches to the frame through a front mounting assembly and a rear mounting assembly such that the motor is selectively movable horizontally with respect to the frame. The front and rear mounting assemblies are preferably isolation mounted to dampen vibrations from the motor to the frame. In an embodiment a countershaft is mounted to the frame, the countershaft having a drive sprocket on one side, and a driven sprocket on the opposite side. Therefore, the transmission power take-off engages the countershaft through a chain on one side of the motorcycle, and the rear wheel assembly engages the countershaft through a chain on the other side of the motorcycle. Because the horizontal position of the motor is adjustable, the transmission chain can be adjusted independently of the rear wheel chain.

Abstract: A two-wheel drive motorcycle having a drive train that supplies power to the front wheel and includes a series of rigid shafts or other internalized drive systems. The front wheel drive consists of components located on the axis of steering within the head tube and positioned symmetrically in a counterbalancing fashion within the front fork in order to counteract the torque reactions from the rotating front wheel drive while providing a full range of steering. The front wheel drive lengthens and shortens in parallel with the shock-absorbing front fork. An engagement clutch, a one-way hub, and torque limiting clutch operatively engaged with the front wheel drive are also disclosed.

Abstract: In a rear wheel support structure for a motorcycle or a three-wheeled vehicle in which a proximal end portion of a swing arm is vertically tiltably supported on a vehicle body frame by way of a tilting support shaft, a rear wheel is rotatably supported on the swing arm by way of a rear axle, and a rear shock absorber is interposed between the swing arm and the vehicle body frame. The comfort of the ride is enhanced by ensuring a sufficiently long effective stroke of the rear shock absorber with respect to a stroke of the rear wheel. A tilting support shaft of a swing arm is arranged behind a rear axle in the longitudinal direction of the vehicle.