Abstract:
A ridden motorized vehicle such as a motorized scooter, motorcycle, ATV, tricycle, snowmobile, or lawn tractor, having a driven rear wheel may be equipped with an enclosed chain or belt drive enclosure having a first end and a second end and an inner enclosure and an outer enclosure, such that the inner enclosure has the rear suspension member and the rear wheel mounted at the second end, and concentrically pivots at the first end on the motor assembly output shaft of a motor assembly fastened to or comprising part of the main vehicle frame, and the outer enclosure pivoted on another bearing co-linear with the motor assembly output shaft, but mounted on a removable section of, or attachment to, said frame.

Description:
RELATED APPLICATIONS 
     The present application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/582,814, filed on Jan. 3, 2012, which is incorporated herein by reference. 
    
    
     BACKGROUND AND SUMMARY 
     Presently disclosed is a rear suspension and drive enclosure for a ridden motorized vehicle. The presently disclosed rear suspension and drive enclosure may be used with any ridden motorized vehicle having a driven axle pivotally attached to the frame of the motorized vehicle, the driven axle operably connected to a motor power source. Such ridden motorized vehicles may include motor scooters, motorcycles, all-terrain-vehicles, tricycles, snowmobiles, and lawn tractors. 
     Ridden motorized vehicles, such as those disclosed herein, generally comprise a frame, a power system, and at least one drive wheel. The at least one wheel may provide traction with the ground directly, or may be part of a track system such as with a snowmobile. The power from the power system must be transferred to one of the wheels, usually the rear wheel, to propel to the vehicle. The power from the power system is usually transferred to the rear wheel through a swingarm, or drive enclosure, disposed between the frame of the motorized vehicle and the rear wheel. A swingarm is used to firmly hold the axle, of the driven wheel, a fixed distance laterally from the frame while allowing the rear axle to pivot upwardly and downwardly to allow the suspension to absorb bumps and vibrations from the ground. Also the drive linkage assembly, whether a drive shaft, chain, or belt is disposed along the swingarm, providing power to the rear wheel. 
     Use of an enclosed drive chain or belt between the motor assembly and the rear wheel is known for use with ridden vehicles such as motorized scooters, motorcycles, all-terrain-vehicles, and snowmobiles. In most cases this includes a fixed multi-piece chain and rear sprocket housing that is mounted to the rear suspension, an enclosure for the motor sprocket which is affixed to the motor, and flexible enclosure sections which connect the upper and lower sections of the two fixed enclosures. This type of system is costly, heavy, and complex to manufacture and maintain. In scooters it is also common to have a drive system wherein the motor is attached to the rear suspension and drives the rear wheel via a gear drive, a drive shaft, or a mixture of gears and chains. Such designs described, for example, by Japanese Patent Application Publication JP 2010-228627 are complex, and the motion of the motor with the suspension increases unsprung weight to the detriment of ride quality. 
     Unsprung weight is the mass of every component on a ridden vehicle not supported by the suspension. Such components may include the wheels, brake systems, axel, and suspension system. In systems such as those described by JP 2010-228627 this also includes the motor and the gear system. A ridden vehicle having a lighter unsprung weight will have unsprung components moving more readily with the road bumps and irregularities, maintaining the traction between the road and the wheel, and therefore, provide a more uniform grip and improved performance. A ridden vehicle having a heavier unsprung weight will have unsprung components which will absorb less of the bumps and irregularities in the road and, therefore, vibrations will be transmitted to the rest of the vehicle, the rider, and passengers. For the same reason road noise will increase with vehicles having a heavier unsprung weight as well. Therefore, there is presently a need for a ridden motorized vehicle, such as a motor scooter, motorcycle, ATV, tricycle, snowmobile, or lawn tractor, having a lightweight rear suspension and drive enclosure system. 
     Further, systems of the prior art include motor scooters and motorcycles having a swingarm type rear suspension system, pivoting on an axis shaft mounted to the frame behind the engine, such that the output shaft of the engine is not aligned with the pivot point of the drive enclosure or swingarm, and include a chain drive enclosure in the swingarm. These systems require at least two chains and a double intermediary sprocket on the swingarm pivot axis, providing a system which is complex and difficult to manufacture and service. The distance between the swingarm pivot point and the rear wheel axle remains constant during operation of the motor vehicle. A ridden vehicle having a swingarm or drive enclosure pivot point not aligned with the output shaft of the motor assembly is a vehicle having a rear wheel axle having a variable distance from the output shaft of the motor assembly while the rear wheel pivots upwardly and downwardly about the swingarm pivot point. A variable distance between the rear wheel axle and the motor assembly output shaft prevents a drive chain or belt having a fixed length to directly connect the rear wheel axle with the motor assembly output shaft. Some prior art systems have a sprocket on the output shaft of the motor assembly and a final sprocket mounted on the rear wheel concentric with the axle which allows for loosening and tightening of the chain during suspension movement, caused by the variation in distance between the engine and wheel sprockets as the suspension moves, and, in turn, causing noise, wear, and imprecise drive delivery. To overcome this problem other prior art systems have a double intermediary sprocket at the swingarm pivot point, and two chains or drive belts, one between the sprocket on the output shaft of the motor assembly and the double intermediary sprocket at the swingarm pivot point, and a second between the double intermediary sprocket at the swingarm pivot point and a sprocket on the rear wheel axle. Such prior art systems have many components comprised within the drive train of the motorized vehicles and are, therefore, complex to manufacture, install, and maintain. 
     There is presently a need for a drive system in ridden vehicles which provides both rear suspension with an enclosed drive transfer system, such as a drive shaft, belt, or chain, while reducing the unsprung weight of the system. Also, there is presently a need for a lightweight rear suspension and drive enclosure system for a ridden motorized vehicle which has fewer parts, to reduce the cost and complexity of manufacturing, installation and maintenance of such systems. Presently disclosed is a simple two piece enclosure wherein the drive transfer system is totally enclosed, has integrated chain tensioner, has one drive transfer system, such as a drive shaft, chain, or belt between a motor assembly output shaft and rear wheel axle, has lower unsprung weight, and provides easy service access to the drive transfer system. 
     Presently disclosed is a ridden motorized vehicle having a drive enclosure disposed between the frame and the rear wheel. The ridden vehicle having a frame, a motor assembly attached to the frame, and the motor assembly having an output shaft. Such a motor assembly may comprise any type of motor, for example, an electric motor or an internal combustion engine. The output shaft of the motor assembly may be adapted to directly or indirectly transfer the power from the drive assembly to a desired location at least one drive wheel. In some embodiments, the motor assembly may comprise a motor, as previously discussed, and together with a gear system or gear box operably connected to the motor, the gear system adapted to change the speed of the output shaft from the motor assembly. The motor and gear system may be arranged as desired. In some embodiments, the gear system may be aligned with the output shaft of the motor, such that the motor and gear system, included as part of the motor assembly, are positioned side-by-side widthwise in the vehicle. In other embodiments, the motor and gear system included as part of the motor assembly may be positioned lengthwise in the vehicle, such that the gear system is next to, either behind or in front of, the motor, and operably connected to the motor, the gear system having an output shaft, being the output shaft of the motor assembly. 
     The drive enclosure of the ridden vehicle has a first end and a second end. The drive enclosure adapted to allow the rear wheel to pivot upwardly and downwardly relative to the main chassis frame, with the first end pivotally attached to the frame, the attachment point aligned with the output shaft of the motor assembly, and the second end having a rear wheel attached. The ridden vehicle may have a sprocket attached to the output shaft of the motor assembly at the first end of the drive enclosure and a sprocket attached to the rear wheel axle at the second end of the drive enclosure, with a chain or belt disposed around and between the two sprockets providing drive from the motor assembly to the rear wheel. The ridden vehicle may have a shock absorber disposed between the drive enclosure and the main chassis frame providing shock resistance for the ridden vehicle, about the first end pivoting on the frame, while being ridden over uneven terrain. 
     In some embodiments, the drive enclosure may comprise an inner drive enclosure section and an outer drive enclosure section fixed to the inner drive enclosure section by fasteners to provide a monocoque structural drive enclosure capable of withstanding the torsional forces exerted by the weight and motion of the vehicle as it is ridden. The inner drive enclosure section being inward along the longitudinal axis of the motor vehicle, i.e. adjacent the rear wheel, the outer drive enclosure attached to the inner drive enclosure being outward along the longitudinal axis of the ridden motor vehicle relative to the inner drive enclosure, i.e. on the side of the inner drive enclosure opposite the rear wheel. Such a configuration forms a monocoque structure. The monocoque structure of embodiments of the drive enclosure provides a drive enclosure adapted to support the structural loads and torsions exerted by the ridden vehicle during operation, by using the drive enclosure&#39;s external skin, as opposed to an internal frame or truss. 
     Such a monocoque structural drive enclosure provides a drive enclosure with fewer parts compared to prior art drive enclosures. The presently disclosed monocoque structural drive enclosure provides for reduced cost of manufacture, installation and maintenance, as well as reduced complexity of manufacture, installation and maintenance. The presently disclosed monocoque structural drive enclosure also provides for reduced unsprung weight of the ridden vehicle, thereby improving ride quality and reducing road noise. Also, the presently disclosed ridden vehicle, having a drive enclosure with a pivot point aligned with the motor assembly output shaft, provides a vehicle providing a single drive chain or belt between the sprocket on the motor assembly output shaft and the sprocket on the rear wheel axle while maintaining the distance between the motor assembly output shaft and the rear wheel axle, as opposed to a dual drive chain or belt system of the prior art. Therefore, a ridden vehicle of the presently disclosed design provides for reduced complexity of manufacture, installation and maintenance, as well as reduced cost for all three phases. 
     In some embodiments, the ridden vehicle may be a motor scooter having a motor assembly disposed on the main chassis frame, while also providing a flat board, step-through construction. This embodiment provides a motor scooter with reduced unsprung weight while also providing the step-through convenience of traditional motor scooters, which traditionally have their motor assembly disposed on the rear wheel axle. This easily maintains the attraction of the motor scooter to both men and women alike, while greatly reducing unsprung weight with the motor assembly attached to the frame of the motor scooter instead of the rear wheel axle. The greatly reduced unsprung weight provides a motor scooter with an improved ride quality and reduced road noise. In some embodiments, the ridden vehicle may be an electric scooter or a hybrid scooter. 
     In some embodiments, the monocoque structural drive enclosure is disposed on one side of the motorized vehicle, such as a motor scooter, motorcycle, ATV, tricycle, snowmobile, or lawn tractor, providing for easy access and maintenance to the rear wheel, allowing the rear wheel to be removed without disassembling the drive enclosure. In other embodiments, the presently disclosed monocoque structural drive enclosure may be assembled on both sides of the vehicle, having a dual drive chain or belt, providing for increased power to be transmitted between the motor assembly and the rear wheel. Furthermore, the motor assembly, as discussed above, may have an integrated or attached gear system disposed between the motor shaft and the output sprocket at the first end of the drive enclosure, the output shaft for the gear system aligned with the pivot point of the drive enclosure at the first end of the drive enclosure. 
     Also disclosed is a ridden vehicle comprising a frame, at least one motor assembly attached to the frame, and a motor assembly having an output shaft. The motor assembly may be attached to a motor assembly mount portion, removable from the frame. Such a configuration provides for a more simple installation and manufacturing system for assembling the ridden vehicle. The ridden vehicle may also have a drive enclosure having a first end and a second end, the first end having a frame connection point aligned with the output shaft of the motor assembly, and the second end having a wheel connection point, the drive enclosure adapted to pivot about the frame connection point. The ridden vehicle further comprises a wheel connected to the wheel connection point at the second end of the drive enclosure and a linkage apparatus disposed between the output shaft of the motor assembly and the wheel connected at the second end of the drive enclosure, the linkage apparatus adapted to transfer power from the output shaft of the motor assembly to the drive wheel. The linkage apparatus between the output shaft of the motor and the wheel may be a drive shaft, a chain, or a belt. 
     The drive enclosure of the presently disclosed ridden vehicle may comprise a first part and a second part, the first part positioned inwardly of the vehicle, adjacent the rear wheel, the second part positioned outwardly and fastened to the first part. Such embodiments of the drive enclosure may provide a monocoque drive enclosure. 
     The motor assembly comprises a motor, or alternatively a motor and at least one gear. The motor may be an internal combustion engine or an electric motor or a combination thereof. The drive enclosure may further comprise a tensioner mounted in the drive enclosure and adapted to exert a tension force to the linkage apparatus. A shock absorber and/or spring, may be disposed between the drive enclosure and the frame, to provide shock absorption when the ridden vehicle is in operation. 
     The presently disclosed ridden vehicle may further comprise at least one first sprocket attached to the output shaft of the motor assembly, and at least one second sprocket attached to the rear wheel axle, the linkage apparatus disposed between the first sprocket and the second sprocket. 
     In some embodiments, the ridden vehicle may comprise the drive enclosure disposed between the frame and the rear wheel on a single side of a vehicle. In other embodiments, the ridden vehicle may further comprise at least two drive enclosures, each drive enclosure disposed on opposing sides of the vehicle, each drive enclosure having a first end and a second end, the first end of each drive enclosure having a frame connection point aligned with the output shaft of the motor assembly, and the second end of each drive enclosure having a wheel connection point, the at least two drive enclosures adapted to pivot about the frame connection point. In embodiments of the ridden vehicle having at least two drive enclosures, the frame connection point of each drive enclosure may be adapted to attach to the frame. Where each drive enclosure is attached to the frame on opposite sides of the frame, or alternatively, each drive enclosure is attached to the frame on the same side. 
     Also disclosed is a drive enclosure for a ridden vehicle, comprising an inner drive enclosure disposed between a vehicle frame and a rear wheel of a vehicle, the inner drive enclosure having a first end and a second end, the first end having a frame connection point, and the second end having a wheel connection point, the inner drive enclosure adapted to pivot about the frame connection point aligned with the output shaft of a vehicle motor assembly; and an outer drive enclosure fastened to the inner drive enclosure. In some embodiments the outer drive enclosure comprises a first end and a second end, the first end having a frame connection point, and the second end having a wheel connection point, the inner drive enclosure adapted to pivot about the frame connection point aligned with a ridden vehicle motor assembly output shaft. Additionally, or in the alternative, the inner drive enclosure and outer drive enclosure form a monocoque drive enclosure. 
     The scope and content of the presently disclosed ridden vehicle, as discussed above, may also be augmented by the following description of the drawings. The drawings depict a two-wheeled motor scooter but the invention herein described is applicable to all forms of ridden motorized vehicles including, but not limited to, motor cycles, motor scooters, all-terrain vehicle, snow mobiles, tricycles, or lawn tractors. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference is made to the accompanying drawings in which particular embodiments and further benefits of the invention are illustrated as described in more detail in the description below, in which: 
         FIG. 1  is a side-view of a motor scooter having the presently disclosed drive enclosure. 
         FIG. 2  is a side-rear perspective view of a motor scooter having the presently disclosed drive enclosure. 
         FIG. 3  is a schematic view of the rear end of a two-wheeled vehicle having a monocoque drive enclosure. 
         FIG. 4  is a schematic view of the frame end of the presently disclosed drive enclosure. 
         FIG. 5  is a schematic view of the wheel end of the presently disclosed drive enclosure. 
         FIG. 6  is a schematic view of the rear end of a two-wheeled vehicle having a draft shaft within a drive enclosure. 
         FIG. 7  is a schematic view of the rear end of a two-wheeled vehicle having a second drive enclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 and 2 , disclosed is a ridden motorized vehicle  1  having a monocoque drive enclosure  8 . The monocoque drive enclosure having a first end  9  and a second end  10  extending from the main chassis frame  2  of the motorized vehicle  1  to the rear wheel  6  of the motorized vehicle  1 . A rear shock absorber  7  may be attached to a shock absorber mount  31  at the second end  10  of the monocoque drive enclosure  8 , with the opposite end of the shock absorber mounted to the main chassis frame  2 . The shock absorber mount  31  may be integrated into the monocoque drive enclosure  8  or may be separate and attached to the monocoque drive enclosure  8 . The shock absorber  7  may be attached to the second end  10  of the drive enclosure  8 , as shown in the Figures. Alternatively, the shock absorber  7  may be attached to the drive enclosure  8  at the first end  9  or at some other position along the drive enclosure  8 . 
     In some embodiments, the shock absorber  7  may be attached to the rear wheel axle  26 . In any case, the rear shock absorber  7  may be combined with a rear spring to form a suspension system, such a spring may be a separate component or may be integrated with the shock absorber  7 . The first end  9  of the monocoque drive enclosure  8  may be pivotally attached to the main chassis frame  2  of the ridden motorized vehicle  1 . The rear wheel  6  of the ridden motorized vehicle  1  may be attached to the second end  10  of the monocoque drive enclosure  8 , and the monocoque drive enclosure  8  adapted to allow the rear wheel  6  to pivot upwardly and downwardly in relation to the main chassis frame  2 . The shock absorber  7  adapted to absorb upward and downward forces caused by irregularities in ground surface while the motorized vehicle  1  is being ridden. 
       FIG. 3  is a perspective schematic view of the rear end of a two wheeled ridden vehicle  1  having a monocoque drive enclosure  8 . The two-wheeled vehicle  1  has a main chassis frame  2 , a motor assembly  3  mounted rigidly to said frame  2 , a rear wheel  6 , and rear shock absorber  7 . The motor assembly  3  has an output shaft  4  adapted to transmit the power from the motor assembly. The motor assembly  3  may comprise any form of motor, for example, an electric motor, or an internal combustion engine. Further, the motor assembly  3  may form part of the structure of the frame  2 . In some embodiments, the motor assembly  3  may comprise a motor, as previously described, and a gear system or gear box. The gear system or gear box adapted to change the speed of the output shaft  4  of the motor assembly  3 . In some embodiments, the gear system or gear box may be disposed to be aligned with the output shaft of the motor, the motor and the gear system, included as part of the motor assembly  3 , positioned side-by-side, widthwise in the motorized vehicle, the motor assembly  3  having an output shaft  4  aligned with the pivot point of the drive enclosure  8 . In alternative embodiments, the motor and the gear system may be positioned lengthwise in the ridden motorized vehicle, the gear system in front or behind the motor, the motor and gear system included as part of the motor assembly  3  having an output shaft  4  aligned with the pivot point of the drive enclosure  8 . 
     The structural monocoque drive enclosure  8  comprises a structural inner drive enclosure  11  and a structural outer drive enclosure  18 . The structural inner drive enclosure  11  has a first end  9  and a second end  10 .  FIG. 4  is a schematic view of the first end  9  of the monocoque drive enclosure  8  attached to a two-wheel ridden vehicle  1 . Now referring to  FIGS. 3 and 4 , the first end  9  of the structural inner drive enclosure  11  is pivoted on a front inner pivot bearing  15  which has its outer race  16  pressed into the inner drive enclosure  11 , and has its inner race  17  riding on a boss  21  externally concentric to the motor assembly output shaft  4 . The boss  21  may be part of an engine or motor assembly housing or integral to a mount section  5  of the frame  2  to which the motor assembly  3  is attached. In some embodiments, as shown, the drive enclosure  8  may be disposed between the frame  2  and the rear wheel  6  on a single side of a ridden vehicle, such as a motor scooter, electric scooter or hybrid scooter, and adapted to secure the rear wheel  6  to the vehicle  2  and to house the front and rear sprockets  28 ,  27  and the drive chain or belt  29 , or linkage apparatus. 
       FIG. 5  is a perspective view of the second end  10  of the structural drive enclosure  8 . Referring now to  FIGS. 3 and 5 , the inner drive enclosure  11  also has a bearing  22  mounted in an integrated outer race housing boss  25  at the second end  10  of the structural inner drive enclosure  11 , and an axle shaft  26  to which rear wheel  6  is fastened. Rear wheel  6  rotates in the inner race  24  of the bearing  22 . The rear sprocket  27  is mounted to the rear wheel axle  26  on the opposite side of the inner enclosure  11  from the wheel  6 . The front sprocket  28  is mounted to the motor assembly output shaft  4 . The front sprocket  28  and the rear sprocket  27  are connected by a drive chain or belt  29 . An automatic or manual drive tension adjuster  30  may be mounted to the lower part of inner drive enclosure  11 . Rear shock absorber  7  may be attached to a mount  31  on inner enclosure  11 . In other embodiments, such as illustrated in  FIG. 6 , the motor assembly output shaft  4  may be connected to the rear axle  26  by a drive shaft  40  disposed within the monocoque drive enclosure  8 . Such a system may or may not comprise sprockets at the output shaft  4  of the motor assembly  3  and the rear wheel axle  26 . 
     The inner drive chain enclosure  11  may provide the structural support necessary to hold the rear wheel  6 , rear sprocket  27  and other elements in lateral relation with the main chassis frame  2 , and the structural support necessary for the shock absorber  7 , while allowing upward and downward pivoting of the rear wheel  6  relative to the main chassis frame  2 . 
     An outer enclosure  18  may be fixed to the structural inner drive enclosure  11  with fasteners  32  which attach the outer enclosure  18  and the inner enclosure  11  together. The attached outer enclosure  18  and inner enclosure  11  may be adapted to prevent ingress of water and other substances into the drive enclosure  8  and thereby reducing corrosion and wear on the drive chain or belt  29  and the sprockets  27  and  28 . The sealed drive enclosure  8  may also house a lubricant and preservative, such as an oil, to improve the longevity of the drive chain or belt  29  and sprockets  27  and  28 . The fasteners  32  adapted to attach the outer enclosure  18  to the inner enclosure  11  may be any type of fastener, for example bolts, screws, or clips, adapted to seal the outer enclosure  18  onto the inner enclosure  11 . The outer drive enclosure  18  may also provide structural support to the structural drive enclosure  8  similarly to the inner enclosure  11  and may be fixed to the inner enclosure  11  to form a monocoque structural assembly  8  adapted to carry drive, torsional and lateral rear wheel loads between the rear wheel  6  and the main frame  2  with reduced deflection. The outer enclosure  18  has a first end  19  and a second end  20 . The first end  19  of the outer enclosure  18  mounts to the outer race  34  of a pivot bearing  33  in an integrated housing  35 . An outer pivot axle  36  is provided to be positioned into the pivot bearing  33 . The outer pivot axle  36  is attached to, or integral with, an axle plate  37 , and is aligned with the motor assembly output shaft  4 . The axle plate  37  may be attached to main frame  2 . The second end  20  of the outer enclosure  18  comprises a wheel axle bearing  38  which captures the rear wheel axle  26 , the wheel axle bearing  38  aligned with bearing  22  of the inner enclosure  11 , when the outer enclosure  18  is mounted to the inner enclosure  11 . The outer enclosure  18  having a bearing  33  in the first end  19  and a bearing  38  in the second end  20  engaging with the frame pivot axle  36  and the rear wheel axle  26  permits the outer enclosure  18  to provide structural support to the monocoque structural drive enclosure  8 . 
     The axle plate  37  may be adapted to secure the first end  9  of the drive enclosure  8  to the frame  2 . In some embodiments, as shown, the axle plate  37  may be attached to the motor assembly mount section  5  which, in turn, is attached to the frame  2  of the ridden motorized vehicle  1 . Such configurations allow easy removal of the power section of the vehicle  2 , including the motor assembly  3 , the drive enclosure  8  and the rear wheel  6 . In some embodiments, the motor assembly may be attached to the motor assembly mount section  5 , which is removable from the frame with mounting pins  12  and fasteners  13 , as shown in  FIG. 4 . 
     In some embodiments, the inner enclosure  11  and the outer enclosure  18  may be formed of the same material, such as metal, high density plastic, or carbon fiber. Such metals may include titanium alloy, magnesium alloy, aluminum alloy, steel alloy, iron alloy and combinations or composites thereof. The inner enclosure  11  and outer enclosure  18  may be pressed from sheet material, forged or cast to form a monocoque structural member capable of providing support for the torsional stresses exerted by the rear wheel  6  and shock absorber  7  during operation of the vehicle  1 . 
     In other embodiments, the inner enclosure  11  may provide all of the structural support necessary for the drive enclosure  8  to perform its function. The outer drive enclosure  18  may be a non-structural cover, without having bearings at the first end  19  aligned with the output shaft  4  of the motor assembly  3 , and at the second end  20  aligned with the rear wheel axle shaft  26 . The non-structural outer drive enclosure  18  may be formed of a different material than the inner drive enclosure  11  or may be formed of the same material. 
     In some embodiments of the ridden vehicle  1 , a gear system or transmission may be disposed between the motor assembly  3  and the first end  9  of the drive enclosure  8 . The gear system may be in-line with the output shaft  4  of the motor assembly  3 , with the pivot point of the first end  9  of the drive enclosure  8  aligned with the output shaft of the gear system or transmission. In some embodiments of the vehicle  1 , the motor assembly  3  may further comprise a gear system or transmission disposed between the motor and the sprocket  28  at the first end  9  of the drive enclosure  8  with the gear system or transmission adjacent the motor within the motor assembly  3 , with a drive connection between the motor and the transmission. The output shaft of the motor assembly  3  may also be the output shaft of the gear system or transmission and connected to the sprocket  28  at the first end  9  of the drive enclosure  8 . The pivot point of the drive enclosure  8  at the first end  9  of the drive enclosure  8  may be aligned with the output shaft of the gear system or transmission. In some embodiments, the ridden vehicle  1  may comprise a transmission or gear system disposed in the monocoque structural drive enclosure  8 . Such a gear system or transmission may be disposed at the hub of the rear wheel  6  on the rear wheel axle  26 . Alternatively, the gear system or transmission may be disposed at another location along the drive enclosure  8 . 
     The ridden vehicle  1  may comprise of a single drive enclosure  8  as shown in the Figures, disposed on one side of the vehicle  1  providing for access for maintenance to the rear wheel  6  of the vehicle  1  without dismantling the drive enclosure  8 . Alternatively, the ridden vehicle  1  may comprise two inner drive enclosures  11 , and two outer drive enclosures  18 , disposed on opposite sides of the vehicle  1  as illustrated in  FIG. 3  (showing the left side) and  FIG. 7  (showing the second drive enclosure on the right side). The two drive inner enclosures  11  and outer drive enclosures  18  disposed on opposite sides of the vehicle  1  may be substantially similar in construction, housing sprockets at the first end at motor assembly output shafts  4  and at the rear wheel axle  26  and a drive chain or belt  29  disposed around and between the sprockets. Alternatively, one of the inner drive enclosures  11  may house the sprockets at the first end  9  at the motor assembly output shaft  4  and at the rear wheel axle  26 , the second of the inner drive enclosures  11  providing structural support for the rear wheel  6  and shock absorber  7  and/or suspension system, and disposed between the main chassis frame  2  and the rear wheel axle  26 . In each case, the pivot point for the inner drive enclosures  11  and outer drive enclosures  18  on both sides of the ridden vehicle  1  are aligned with the motor assembly output shaft  4 , or a gear system or transmission output shaft, thereby providing a vehicle  1  having a single drive chain or belt  29 , reducing the complexity of manufacture and maintenance of the ridden vehicle  1 . 
     The drive enclosure  8  may comprise a monocoque structure having an inner enclosure  11  and an outer enclosure  18 , comprising at least one motor assembly sprocket  28  and at least one wheel sprocket  27 , a drive belt or chain  29  disposed around and between the at least one motor assembly sprocket  28  and the at least one wheel sprocket  27 . Such a drive enclosure  8  may be adapted to be attached and removed from the ridden vehicle  1  as a single combined component, adapted to attach to the motor assembly output shaft  4  and the frame  2  at the first end  9  of the structural drive enclosure and attach to the rear wheel axle  26  at the second end  10  of the structural drive enclosure  8 . 
     The shock absorber or suspension system  7  may be disposed between a position along the length of structural drive enclosure  8  and the main chassis frame  2  of the vehicle  1 . The combined component drive enclosure  8  adapted to provide the structural support for the torsional forces exerted on the drive enclosure  8  from the rear wheel  6  and suspension system or shock absorber  7  while the ridden vehicle  1  is in operation. The combined component drive enclosure  8  may provide for a modular construction and maintenance system of the vehicle  1  reducing the cost and/or simplifying construction and maintenance of the vehicle  1 . The drive enclosure  8  may be adapted to have a liquid tight seal between the inner drive enclosure  11  and outer drive enclosure  18  so as to be capable of housing fluid and/or lubricant, such as oil, and, therefore, provide permanent lubrication and cooling for the drive chain or belt  29  and sprockets  27  and  28 , increasing the longevity of the drive chain or belt  29  and sprockets  27  and  28 , and increasing the time period between maintenance intervals for the drive chain or belt  29 . 
     The presently disclosed ridden vehicle  1  having a motor assembly  3  having an output shaft  4  attached the main chassis frame  2  and having a monocoque structural drive enclosure  8  having a pivot point aligned with the output shaft  4  of the motor assembly  3 , provides for a ridden motorized vehicle  1  having reduced unsprung weight, allowing the rear wheel  6 , drive enclosure  8 , and rear shock absorber  7  to react with the irregularities and undulations in the ground surface, absorbing the vibrations, such that the rider and/or passenger experience less vibration through the main chassis frame  2  of the vehicle  1 , giving improved ride quality and reduced road noise. Such a ridden vehicle  1  also having reduced complexity of manufacture and maintenance of the swingarm or drive enclosure  8 , which can provide for reduced costs of maintenance and manufacture of the vehicle  1 . Reduced weight of the vehicle  1  provides for improved fuel economy and performance compared to a ridden vehicle having a higher weight with a similar motor or motor assembly system. 
     Another embodiment of the presently disclosed ridden vehicle  1  may be a motor scooter having a motor assembly  3  disposed on the main chassis frame  2 , or comprising part of the main chassis frame  2 , while also having a flat foot board  39  (as shown in  FIG. 1 ), having a step-through construction. Therefore, such a ridden vehicle  1  provides a vehicle  1  having reduced unsprung weight while providing the step-through convenience of traditional motor scooters which have the motor assembly disposed on the rear wheel axle, thus maintaining the attraction of the motor scooter to both men and women alike, while providing improved performance and ride quality. Such a construction, having a greatly reduced unsprung weight allows the rear wheel  6  and suspension system  7  to move with the irregularities and undulations of the ground upon which the ridden vehicle  1  is being ridden. This allows the rear wheel to maintain traction with the ground while going over irregularities and undulations in the ground, and therefore provides a motor scooter with an improved ride quality, performance and reduced road noise. 
     This written description uses examples to disclose the invention and also to enable one of ordinary skill in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to one of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.