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: 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: A motorcycle is described which has a frame and a rear wheel attached to a driven pulley. A drive pulley is rotatably mounted to a rigid bracket attached to the frame such that a relative orientation between the drive pulley and the driven pulley is maintained substantially constant. A drive belt is coupled to the drive pulley and the driven pulley such that a rotation of the drive pulley imparts a rotation of the driven pulley. A transmission output gear is attached to an output of a transmission, and a drive coupler is provided as an interface between the transmission output gear and the drive pulley.

Abstract: A rear axle for motorcycles comprises a torque or link bar and a fork that is elastically suspended to the frame and encloses a Cardan drive shaft in a first parallel arm thereof which is joined to a housing for the bevel gear pair driving the rear wheel. At both end portions of the torque bar there are provided a second pivot for connection to the frame above a first pivot of the fork, and a third pivot for connection to a floating member, respectively, in which the floating member is in turn supported within the housing for the bevel gear pair by a fourth pivot firmly joined to the hub of the wheel. The axis (F) of the third pivot is parallel to the axis of rotation (R) of the rear wheel.

Abstract: A motorcycle including a front wheel, a rear wheel, a frame, a seat and handlebars is disclosed. The motorcycle includes a linkage connecting a brake pedal with a caliper. The caliper is located within a body perimeter of the motorcycle. The caliper is adapted to engage a disk and the caliper can have a line of action. The direction of the line of action of the caliper can be different than the axis of rotation of the rear wheel. The linkage can also convert vertical motion into horizontal motion.

Abstract: An internal combustion engine includes a crankshaft, a mainshaft, a clutch and a countershaft. The mainshaft is for a transmission and holds a transmission gear train. The clutch is disposed on the extension of the mainshaft. Furthermore, the countershaft for the transmission holds a gear train to mesh with the transmission gear train. Accordingly, power is transmitted in order from the crankshaft to the clutch, the mainshaft, and the countershaft. This arrangement ensures better knee-grip when the internal combustion engine is mounted on a vehicle and improves in-vehicle mountability by reducing the width and the axial length of the internal combustion engine. A mainshaft is disposed about immediately below the crankshaft. At least a part of the mainshaft is provided at the same axial position as the crankshaft.

Abstract: A power steering device is provided which is capable of detecting an initial torque of torque detection means precisely in a short period of time in the initial setting therefor. In detecting the initial torque of the torque detection means, assist power generating means such as an electric motor for applying assist power to a handle shaft is used to rotate a steering handle within a minute rotational range in positive and negative-going directions from a neutral position in the steering direction. The rotation of the steering handle in this initial setting is performed so that the amplitude of the repetitive rotations in the positive and negative-going directions are decremented as time passes. Then, an output of the torque detection means is detected as the initial torque with the steering handle being held stationarily at the neutral position.

Abstract: A rear axle for motorcycles comprises a torque or link bar (40) and a fork (10) that is elastically suspended to the frame (100) and encloses a Cardan drive shaft (30) in an arm (17) thereof which is joined to a housing (14) for the bevel gear pair (22, 23) driving the rear wheel (50). At both end portions of the torque bar (40) there are provided a first pivot (43) for connection to the frame (100) above the attachment pivot of the fork (10), and a second pivot (45) for connection to a floating member (20), respectively, in which said floating member is in turn supported within said housing (14) for the bevel gear pair (22, 23) by a further pivot (27) firmly joined to the hub (52) of the wheel (50). The axis (F) of said second pivot (45) is parallel to the axis of rotation (R) of the rear wheel (50).

Abstract: To provide a power transmission mechanism into which a driven flange is assembled, the power transmission mechanism producing no metal contact noises. A driven flange is divided into an engine side flange and a wheel side flange. The engine side flange may be formed of a steel forging and the wheel side flange may be formed of an aluminum forging. The engine side flange is spline-fitted in a final gear integrally rotated with a bevel gear. Furthermore, openings are formed in the wheel side flange at equal intervals and blocks having a threaded hole therein are pressed into the openings. In addition, the engine side flange, the wheel side flange, and the blocks are integrally connected together with bolts.

Abstract: To provide a swing arm for a vehicle which can ensure the rigidity of a fastened portion of the swing arm to a final gear case with a simple configuration. A swing arm for a vehicle pivotably mounted on a body frame and having a swinging end fastened to a final gear case on which a rear wheel is mounted. A reinforcing plate is provided in the vicinity of the swinging end of the swing arm and fastened to the swing arm at two positions spaced apart from each other in the longitudinal direction of the vehicle.

Abstract: In a motorcycle in which an engine unit is mounted to a motorcycle body and a power transmission unit coupled to the engine unit is arranged to the motorcycle body to be swingable through a pivot shaft, a rear wheel suspension system is formed so as to include the power transmission unit, a pair of arm members disposed to lateral side portions of the motorcycle body in parallel to each other, and connection members connecting both end portions of the arm members. One of the arm members constitutes the power transmission unit which has an inner hollow portion in which a power transmission member is accommodated and has a structure dividable into lateral two parts forming an arm base section and a cover section.

Abstract: A power unit of the motorcycle is provided with an engine unit in which a counter shaft is pivoted to a rear portion in a casing of an engine body provided with a crankshaft disposed along a motorcycle body width direction and a bracket having a fitting hole extending rearward so as to pass through in the width direction is formed in a rear portion outside the casing, a transmission unit and a bevel unit which are pivoted in a manner to be independent from the engine unit. One side surface of a front portion of the transmission unit is fixed to one side surface of a rear portion of the casing in the engine unit so as to connect the counter shaft to the input shaft to be integrally rotatable, the same side surface of the rear portion in the transmission unit is fitted and fixed to one side surface of the bracket so as to fit and fix the bevel unit to another side surface of the bracket. Thus, the output shaft is connected to a bevel input shaft to be integrally rotatable.

Abstract: In a motorcycle power unit, a crank shaft (56) and a clutch shaft (57) disposed on the right side (in the figure) from a body center (127) and a cylinder head (129H) is disposed on the left side from the body center (127). Since the crank shaft, the clutch shaft and a transmission shaft are disposed on one of right and left sides with respect to the body center and the cylinder is disposed on the other side with respect to the body center, it becomes possible to make a favorable lateral balance of the power unit.

Abstract: To provide a power unit less affected by the length of the cylinder of an engine. A cam shaft drive mechanism is composed of a cam shaft drive pulley, a belt, a pair of cam shaft pulleys, and a tensioner disposed on the front surface of a power unit. Since the cylinder is disposed in the width direction of the vehicular body with its cylinder axis substantially in the horizontal direction (for example, a tilt angle .alpha. with respect to the ground is set at +10), the center of gravity of the vehicle is lowered and also the cylinder length can be set within the vehicular width. This increases the degree of design of the vehicle.

Abstract: A generally open, welded-up type of motorcycle frame wherein the pivot axis for the rear wheel suspension system is disposed forwardly of the rear end of the frame so as to provide a large degree of suspension travel with small angular movements and without necessitating a large wheel base. The construction also minimizes torsional bending and sheering forces on the frame members that support the rear wheel.

Abstract: A motorcycle shaft drive assembly which provides for easy removal of the rear wheel, drive shaft and final drive assembly is disclosed. The motorcycle has a rear frame section pivotally connected to a front frame section. A rear wheel and final drive assembly are removably connected to the rear frame section. A drive shaft extends from the output of an engine mounted on the front frame section to the final drive assembly. The drive shaft extends into a coupling member at the engine output. A support is provided for the drive shaft when the rear wheel, drive shaft and final drive assembly are being removed from or installed onto the remainder of the motorcycle.

Abstract: A motorcycle has a motor mounted on a frame, a drive shaft extending from the motor transversely to the direction of travel, a rear wheel axle and a shaft drive mechanism extending longitudinally from the drive shaft to the rear wheel axle for transmitting power from the drive shaft to the rear wheel axle. The drive mechanism has an elongate housing with a first end portion pivotably mounted about the drive shaft and a second end portion pivotably mounted about the rear wheel axle. A drive gear is located on the drive shaft for rotation thereby, and an axle gear is located on the rear axle for driving the rear axle. A pinion shaft is supported by the housing so as to be rotatable about its own longitudinal axis.

Abstract: A shaft driven motorcycle rear wheel suspension in which reactive energy in the gear housing is directed into the frame and away from the damping unit is provided by a four bar arrangement having the swing arm 28 connected to the gear housing 22 at a point 32 offset from the rear wheel axle 50, a link arm 38 above the swing arm and connected at the wheel axle, and bars 36, 40 interconnecting the swing arm and the link arm.

Abstract: The rotary axle of the support arm device is adapted to be maintained in position rigidly and in adjustable manner at the free end of the arm and the free end of the arm comprise plane and generally axial bearing surfaces adapted to contact corresponding bearing surfaces directed generally transversally and provided on two rings of a removable bracket piece in order to allow a rigid blocking of this bracket piece on the free end of the arm after adjusting the position and the device is applied when an easy adjusting of the chain tension is required, especially for a rear wheel of a motorcycle.

Abstract: Two embodiments of off the road motorcycles embodying low pressure balloon tires. In each embodiment, an improved final drive arrangement is provided that includes a ring gear that is disposed substantially inwardly of the outer periphery of the rear wheel to provide a relatively compact final drive housing to facilitate leaning of the motorcycle. In one embodiment, the ring gear is driven by a pinion gear that is directly affixed to one end of a drive shaft and which is driven at its other end from the engine by means of a chain drive. In the other embodiment, the ring gear is driven by a pair of transfer spur gears from a drive shaft that is articulated and which is driven directly from the engine output shaft.

Abstract: Oscillating supporting device for the driving wheel of a vehicle comprising an arm parallel to the median plane of the wheel and pivotally mounted on the vehicle chassis trough a transverse shaft disposed at one end of the arm, by means of two bearings disposed in such a way that the median plane of the wheel is substantially situated at mi-distance thereof, the wheel being mounted on a rotation axle carried by the arm at its other end, the connecting shaft and rotation axle being parallel to each other, wherein the rotation axle is supported by two other bearings disposed on either side of the wheel, the first of which is integral with the arm and the second of which is carried by a link pivotally mounted on the arm, the internal cage of the second bearing being crossed through by the end of the rotation axle and blocked thereon by a removable fixing nut.

Abstract: An improved drive and braking arrangement for an off the road single rider multi-wheeled vehicle. The drive arrangement includes a shaft drive and the brake includes a brake disk that is fixed for rotation with the drive shaft. The brake disk is contained within a housing for its protection and the housing is made up of two pieces, one of which is affixed to a tube that contains the drive shaft and is affixed to the engine and the other of which is affixed to a tube that forms a portion of the final drive.

Abstract: A rear wheel braking apparatus for a motorcycle wherein a rear fork with a rear wheel pivotally mounted on the rear end thereof is coupled to the frame of the motorcycle via a pivot shaft in a vertically swingable manner; a rear wheel drive device for coupling between the output shaft of an engine on the frame and the rear wheel is provided side by side with the rear fork; an anti-lock controlling unit for controlling the braking hydraulic pressure to be fed to the rear brake in response to the output from a built-in sensor is provided on the rear fork in the vicinity of the pivot shaft; and wherein the drive shaft of the sensor is coupled to the rear wheel drive device.

Abstract: A scooter having a low bed footboard, a rear cover rearwardly of said footboard and a front cover forwardly of said footboard. An engine is located beneath the forward portion of the footboard. A variable diameter pulley V-belt transmission is located beneath the rear cover and is pivotally mounted to provide a swing arm rear suspension. A drive shaft extends between the engine and the transmission beneath the footboard. A storage compartment is positioned within the rear cover beneath a seat. A fuel tank is located within the front cover generally above the engine.

Abstract: An improved drive arrangement for an off the road motorcycle having a rear wheel that has a width substantially equal to the width of the motorcycle frame. The rear wheel is supported by a trailing arm and is driven by a drive that includes an intermediate shaft that is rotatably journaled on the trailing arm. One end of the intermediate shaft is driven from the engine output shaft by a drive shaft and the other end of the intermediate shaft drives the rear wheel through a chain. The chain is positioned a substantially greater distance outwardly from the longitudinal center line of the motorcycle than is the drive shaft so as to afford a good rider position and relatively narrow width.

Abstract: An improved drive arrangement for an off the road motorcycle having a balloon tired rear wheel that has a width at least equal to the width of the vehicle frame. The rear wheel is driven from an engine output shaft by a drive shaft that is contained within a trailing arm that supports the rear wheel and which has an angularly disposed portion for transferring the drive from an inwardly placed engine output shaft to an outer location on the rear wheel.

Abstract: An embodiment of steering arrangement for motorcycles wherein the rear wheel is supported for steering movement and is mechanically coupled to the mechanism for steering the front wheel so that both wheels will be steered in unison. The rear wheel is driven by means of a shaft drive.

Abstract: An improved final drive arrangement for an off the road motorcycle embodying large low pressure tires wherein the rear wheel is driven from one end of an intermediate shaft that is rotatably supported on the rear wheel supporting trailing arm by means of a drive shaft.

Abstract: A motorcycle having an engine inclined to the symmetrical center plane of the motorcycle frame. A drive shaft employed with the engine is inclined relative to the center plane of the motorcycle frame so as to diverge outwardly from the center plane as it extends rearwardly from the engine.

Abstract: An oscillating supporting arm assembly for the driving wheel of a motorcycle, includes an arm mounted to oscillate angularly about a connecting shaft of the motorcycle and cooperating with a suspension assembly between the arm and motorcycle, the wheel being removably fixed to a supporting shaft on one side of the free end of the supporting arm, the supporting shaft extending through the arm on two bearings, a wheel driving pinion is fixed to the supporting shaft, on the side of the arm opposite to the wheel and is driven by a chain mechanically connected to the driving assembly of the motorcycle, the supporting arm having the configuration of a U with two legs between which the rim and the tire of the rear wheel are located, one of the legs having hinge connections which cooperate with the connecting shaft of the motorcycle, the wheel has its median plane extending at substantially equal distances from the two hinge connections of the supporting arm, the wheel is rigidly connected to a brake disc cooperating

Abstract: A power transmission mechanism for a motorcycle includes a change speed gear mechanism which includes a driven countershaft having one end projecting out through an opening in a transmission casing. The countershaft has a driving bevel gear formed integrally thereon and meshes with a driven bevel gear enclosed in a final gear case detachably connected to the transmission casing. Removal of the final gear case permits axial removal of the countershaft and its integral bevel gear through the opening, as well as removal of certain of the gear elements in the change speed gear mechanism, which also pass through the opening.

Abstract: A power transmission unit for a motorcycle is disclosed which includes a power unit case consisting of a crankcase and a transmission case both of which are integrally formed with one another. A bevel gear case incorporating therein a bevel gear assembly is detachably secured to the power unit case at a recessed section of the latter. The recessed section is located rearwardly of a generator which is disposed at the outermost part of the power unit case. The bevel gear assembly comprises a driving bevel gear connected with a countershaft in the power unit case, and a driven bevel gear connected with a final shaft which is in turn connected to a rear wheel.

Abstract: An improvement in a shaft drive apparatus which is an outer casing extending over and liquid-tightly enclosing a torque damper on a propeller shaft which interconnects the output shaft of an internal combustion engine to a bevel gear mechanism on the rear wheel of a motorized two-wheeled vehicle. The casing is attached to the propeller shaft to rotate therewith. An outer covering can cover a universal joint which interconnects the torque damper and the input shaft of the bevel gear mechanism. The outer cover extends over and liquid-tightly surrounds the universal joint and engages the outer casing and has its interior in communication with an interior of the outer casing. The interior of the bevel gear casing can also communicate with the interior of the outer casing.

Abstract: A rear wheel control unit for a two-wheeled vehicle with universal drive mechanism, such as a motorcycle, is disclosed. The rear wheel control unit comprises an axle housing for accommodating a drive unit of the universal drive mechanism of the two-wheeled vehicle in operative connection with the rear wheel of the vehicle. The axle housing has a connecting member for accommodating a shaft of the universal drive mechanism and is pivotably mounted to the frame of the two-wheeled vehicle by first and second wheel control arms arranged in a four-bar linkage. The first wheel control arm is formed as a one-armed oscillating lever articulated on the wheel side with the connecting member of the axle housing. The second wheel control arm serves as a moment support member.

Abstract: Power unit apparatus for a motorcycle driven by an internal combustion engine has a split power unit case. The crankshaft and the driving shaft of a reduction gear mechanism are clamped between the upper and lower sections of the power unit case. The driven shaft is located on the lower section. A guide shaft for shifter forks and a shift drum controlling operation of the shifter forks are both located on the upper section above the driving and driven shafts.

Abstract: A motor cycle includes a frame, a front and rear wheel, and an engine mounted to the frame which has at least two exhaust pipes. A muffler is mounted to the frame beneath the engine, and both exhaust pipes discharge into the muffler. At least one tailpipe exhausts from the muffler. The silencing volume of the muffler can enable a shorter-than-usual tailpipe to be used, which need not interfere with access to the rear wheel axle.

Abstract: A motorcycle power train arrangement is disclosed which comprises a liquid cooled engine block and a transmission case, substantially exposed and mounted symmetrically to the longitudinal median plane of the motorcycle, largely filling the space between the front wheel and the rear wheel, and including a liquid coolant radiator mounted in substantially vertical position transversely to the direction of travel, a plurality of parallel cylinders being arranged transversely and a crankshaft longitudinally to the direction of travel, the transmission case being located under and/or behind the engine block, and a valve chamber cover forming a symmetrical outer longitudinal limit of the power train; characterized in that the cylinders are located on one side of the engine block in a single line; in that the crankshaft is located on the other side of the engine block and is spaced from and parallel to the longitudinal median plane; and in that covers for the valve chamber and a crank space form on both sides symmetr

Abstract: A power transmission device of a motorcycle comprising a main transmission case formed integrally with an engine crank case and accommodating a main transmission, and a sub-transmission case provided at the rear side of the main mission case. The sub-transmission case accommodates a sub-transmission which is drivingly connected to the main transmission and also to a rear wheel of the motorcycle through a transmission mechanism. The transmission mechanism and the sub transmission are disposed at opposite sides of the rear wheel. The sub-transmission case is composed of a case body and a cover for covering an opening of the case body. The opening is formed at a lateral side of the gears of the sub-transmission so that the gears are accessible and replaceable by removing the cover from the opening.

Abstract: A Cardan drive for motorcycles in connection with which the housing, within which the ring gear connected with the rear wheel is contained and the pinion connected with the Cardan shaft is mounted is supported via an upwardly extending control arm operatively connected to a guide member pivoted to the frame at a point thereof lying above the swing arm of the rear wheel.

Abstract: A motorcycle has a front frame, and a rear arm pivotally mounted to the frame for mounting the rear wheel. The rear wheel is driven by a propeller shaft that has a universal joint intersected by the axis of a bearing structure which mounts the rear arm. The bearing structure which mounts the rear arm lies inboard of the propeller shaft, whereby to enable reduction of the widthwise dimension of the motorcycle, and to enable a lighter-weight assembly of this portion of the motorcycle to be utilized, because it is unnecessary to bifurcate the bearing structure or to place part of it laterally outside of the propeller shaft.

Abstract: A motorized two-wheeled vehicle comprising a frame having front and rear wheels and a vertical V-type engine mounted on the frame in a central region between the wheels. The engine comprises at least one pair of left and right cylinders arranged in the form of V and a pair of left and right carburetors are mounted rearwardly of the cylinders and are connected to the respective cylinders by intake pipes. A cylinder head of each cylinder is secured to a cylinder block such that the head is angulated to assume an angular position in which the axis of the cross-flow pattern is inclined inwardly and towards the rear with respect to the longitudinal axis of the engine to form an angle therewith.

Abstract: A motor cycle includes a frame, a front and rear wheel, and an engine mounted to the frame which has at least two exhaust pipes. A muffler is mounted to the frame beneath the engine, and both exhaust pipes discharge into the muffler. At least one tailpipe exhausts from the muffler. The silencing volume of the muffler can enable a shorter-than-usual tailpipe to be used, which need not interfere with access to the rear wheel axle.

Abstract: An oscillating supporting arm assembly for the driving wheel of a motorcycle, includes an arm mounted to oscillate angularly about a connecting shaft of the motorcycle and cooperating with a suspension assembly between the arm and motorcycle, the wheel being removably fixed to a supporting shaft on one side of the free end of the supporting arm, the supporting shaft extending through the arm on two bearings, a wheel driving pinion is fixed to the supporting shaft, on the side of the arm opposite to the wheel and is driven by a chain mechanically connected to the driving assembly of the motorcycle, the supporting arm having the configuration of a U with two legs between which the rim and the tire of the rear wheel are located, one of the legs having hinge connections which cooperate with the connecting shaft of the motorcycle, the wheel has its median plane extending at substantially equal distances from the two hinge connections of the supporting arm, the wheel is rigidly connected to a brake disc cooperating