Abstract:
Apparatus for substantially covering a motorcycle open belt primary drive system that improves the safety of the motorcycle riders as well as protects the drive system of the motorcycle. The apparatus is capable of being mounted to a conventional drive system and frame of a motorcycle having an open belt primary drive system. The apparatus includes a front pulley cover assembly, a rear pulley cover assembly, and a grill. Each pulley cover assembly includes a bearing housing that is attached to the drive system pulley of a motorcycle, a pulley cover, and a bearing that joins the bearing housing and the pulley cover into a single assembly. The bearing provides a reduced friction connection between the bearing housing and the pulley cover that allows the pulley cover to freely rotate or spin independent of the bearing housing.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to one or more covers for a motorcycle open belt primary drive. Specifically, the invention relates to a protective housing that can be removably attached to the motorcycle and includes at least one free-spinning pulley cover.  
       BACKGROUND OF THE INVENTION  
       [0002]     A motorcycle generally includes an engine, steering assembly, front and rear wheels, a transmission operably connected to the rear wheel, a drive system for transmitting power from the engine to the transmission, which is generally located directly behind the engine, and a frame. The drive system generally includes a pulley system called a primary drive. The engine transmits power or energy from the crankshaft to the clutch housing of the transmission through the primary drive, which is illustrated as a belt drive herein but is adaptable to a chain drive. Then the energy is transferred from the transmission to the rear wheel through a final drive, which can be a belt or chain, to propel the motorcycle.  
         [0003]     Due to the design of a motorcycle, the rotating or moving drive system is generally exposed, which can lead to dangerous conditions for the motorcyclist, as well as the motorcycle. A common problem among motorcyclists is getting shoelaces, baggy pants such as bellbottoms, or other loose materials caught in the drive system of a motorcycle while it is running, which can cause accidents, injuries, and death. Also, debris and other foreign matter from the road can also damage the drive system if the drive system is exposed to the outside environment.  
         [0004]     U.S. Patent Application Publication 2004/0118240 A1 (Young) discloses an adaptive drive system cover for motorcycles that encloses the entire chain or belt. This cover is unitary and heavy, and has no means for rotational movement.  
         [0005]     WO 2004/024468 A2 (Rivers et al.) discloses a free spinning rim for the wheels of a motorcycle. This rim provides ornamental appeal by revolving about the axle shaft at a different speed than the wheel, but does not provide the motorcyclist with any safety features.  
         [0006]     U.S. Design patents D273,947 (Johnson) and D294,131 (Stahel) disclose ornamental open motorcycle primary cover, but do not disclose any rotating elements.  
         [0007]     U.S. Patent Application Publication 2004/0259673 A1 (Bertrand et al) discloses pulley cover for snowmobiles that encloses the entire chain or belt. This cover is unitary and heavy, and has no means for rotational movement.  
         [0008]     It is therefore a need for a pulley cover that is lightweight and rotates to provide a safety function as well as an ornamental design.  
       BRIEF SUMMARY OF THE INVENTION  
       [0009]     The needs for the invention set forth above as well as further and other needs and advantages of the present invention are achieved by the embodiments of the invention described herein below.  
         [0010]     The present invention substantially covers a motorcycle open belt primary drive system to improve the safety of the motorcycle riders as well as protects the drive system of the motorcycle while not adding a significant amount of weight. The present invention is capable of being mounted to a conventional drive system and conventional belt tensioner plates having an open belt primary drive system. The present invention includes a front pulley cover assembly, a rear pulley cover assembly, and a grill. Each pulley cover assembly includes a bearing housing that is attached to the drive system pulley of a motorcycle, a pulley cover, and a bearing that joins the bearing housing and the pulley cover into a single assembly. The bearing provides a reduced friction connection between the bearing housing and the pulley cover that allows the pulley cover to freely rotate or spin independent of the bearing housing.  
         [0011]     In one embodiment of the present invention, a front pulley cover and a rear cover display a rotating ornamental design.  
         [0012]     In another embodiment of the present invention, the space between the front pulley cover and the rear cover houses a decorative grill.  
         [0013]     It is the object of the present invention to provide a pulley cover that protects the motorcyclist and prevents the clothing and apparel of the motorcyclist from coming in contact with the edges of an open primary drive belt and the exposed features of the pulley, such as edges, outer flange, bore cavity, and clutch plate and screws.  
         [0014]     It is another object of the present invention to provide a lightweight pulley cover assembly that is adaptable to an existing drive system of a motorcycle. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a perspective side view of an exemplary embodiment of the present invention attached to a motorcycle;  
         [0016]      FIG. 2  is a front view of the present invention of  FIG. 1 ;  
         [0017]      FIG. 3  is a pictorial view of the present invention of  FIG. 1 ;  
         [0018]      FIG. 4  is a pictorial view of a front pulley wheel of a motorcycle with the present invention removed;  
         [0019]      FIG. 5  is a pictorial view of a rear pulley wheel and clutch of a motorcycle with the present invention removed;  
         [0020]      FIG. 6A  is an exploded view of an exemplary embodiment of a front pulley cover assembly of the present invention of  FIG. 1 ;  
         [0021]      FIGS. 6B and 6C  illustrate an alternative embodiment of the present invention for joining the front pulley cover and the front cylindrical bearing support;  
         [0022]      FIG. 7A  is an exploded view of an exemplary embodiment of a rear pulley cover assembly of the present invention of  FIG. 1 ;  
         [0023]      FIGS. 7B and 7C  illustrate an alternative embodiment of the present invention for joining the rear pulley cover and the rear cylindrical bearing support;  
         [0024]      FIG. 8  is a front view of a grill of present invention of  FIG. 1 ; and  
         [0025]      FIG. 9  is a top view of a grill mount of the present invention of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0026]     The present invention substantially covers, for example, a conventional open belt primary drive of a motorcycle as shown in  FIG. 1  and is designated generally therein by the reference character  10 .  FIG. 1  illustrates the present invention  10  adapted to a motorcycle  2 . The motorcycle  2  includes a steering assembly  5 , a drive system having transmission  4  and engine  6  interconnected by primary belt  14 , and all being connected or otherwise attached to frame  8  of motorcycle  2 . Furthermore,  FIG. 2  shows an a pictorial front view of an exemplary embodiment of the present invention  10  including front pulley cover  12 , rear pulley cover  40 , and grill  60  oriented between covers  12  and  40 , whereby present invention  10  covers the entire length of primary belt  14  and belt cavity  11  formed therein ( FIG. 3 ). Returning to  FIG. 2 , the two-way arrows indicate that covers  12 ,  40  are capable of rotation in either the clockwise or counter-clockwise direction depending on the forces exerted on covers  12 ,  40 . Grill  60  is generally a static component.  
         [0027]     Now referring to  FIGS. 3, 4 , and  5 , during the operation of motorcycle  2  ( FIG. 1 ), engine  6  transmits torque or power through a crankshaft (not shown) that is transformed into a rotation velocity causing the crankshaft to rotate at a predetermined rotational speed. Front pulley wheel  18  ( FIGS. 3 and 4 ) is conventionally attached (e.g., bolted) to the crankshaft (not shown) at inner flange  19 , which results in front pulley wheel  18  rotating while the crankshaft is rotating. Primary belt  14  is mounted on front pulley wheel  18  and rear pulley wheel  20 , and transfers the engine power or energy from front pulley wheel  18  to rear pulley wheel  20  causing rear pulley wheel  20  to rotate. Rear pulley wheel  20  in turn is connected to rear clutch basket  21  ( FIG. 5 ), which is operably connected to transmission  4  and drives rear wheel  3  of the motorcycle  2  ( FIG. 1 ).  
         [0028]      FIG. 6A  illustrates an exploded side view of front pulley cover assembly  45 , which is generally identical to the rear pulley cover assembly  55  (described in detail below). Front pulley cover assembly  45  includes front bearing support  36 , front bearing housing (also referred to as front mounting plate)  22 , and front pulley cover  12 . Front pulley cover  12  includes front face  28  with an ornamental design  30  ( FIGS. 2 and 3 ) and cylindrical shaft  32  extending orthogonally outward from rear face  43 . Cylindrical shaft  32  includes first outer circumferential surface  34  and second outer circumferential surface  35 . Front bearing housing  22  includes inner cylindrical bearing bore  50  and outer cylindrical bearing bore  51 , which form first inner circumferential surface  53  and second inner circumferential surface  52 , respectively. Inner cylindrical bearing bore  50  and outer cylindrical bearing bore  51  are sized larger than the outer surface thickness or radial dimensions of outer circumferential surface  34  and second outer circumferential surface  35  such that cylindrical shaft  32  can be freely received therein without interference (discussed below in detail) into inner cylindrical bearing bore  50  and outer cylindrical bearing bore  51 .  
         [0029]     Front cylindrical bearing support  36  is joined to front bearing housing  22  and front pulley cover  12  by conventional joining means such as, for example, bolts/screws, adhesive, welding, brazing, complimentary threaded male/female members, and friction, press-fit or interference fit. For illustration purposes only, the friction, press-fit, or interference fit joining means will be disclosed, but such disclosure is not meant to limit the present invention to only the disclosed embodiment. Front cylindrical bearing support  36  includes cylindrical bearing bore  29  that forms inner circumferential surface  27 . Inner circumferential surface  27  has a slightly smaller diameter than the diameter or radial thickness of outer circumferential surface  34  of cylindrical shaft  32 . The difference in the diameter or radial dimensions is the interference fit dimension. To join front cylindrical bearing support  36  to front pulley cover  12 , the components must be press-fit together to overcome the frictional and the normal forces applied to the mating contact surfaces  27 ,  34  caused by larger diameter or radial thickness of cylindrical shaft  32  being inserted into the smaller diameter cylindrical bearing bore  29  of front cylindrical bearing support  36 . After the press-fit operation, front pulley cover  12  is connected to front cylindrical bearing support  36  by an interference fit that is sufficient to retain frictional load under normal operating conditions.  
         [0030]     Front cylindrical bearing support  36  is also connected to front bearing housing  22 , for example, by an interference fit sufficient to retain frictional load under normal operating conditions. Outer circumferential surface  33  of front cylindrical bearing support  36  has a slightly larger diameter or radial thickness than the diameter of first inner circumferential surface  53  of front bearing housing  22 . As described above, the difference in the diameter or radial dimensions is the interference fit dimension. To join front cylindrical bearing support  36  to front bearing housing  22 , the components must be press-fit together to overcome the frictional and the normal forces applied to the mating contact surfaces  33 ,  53  caused when the larger diameter or radial thickness of bearing support  36  is inserted into the smaller diameter of inner cylindrical bearing bore  50  of front bearing housing  22 . After the press-fit operation, front bearing housing  22  is connected to front cylindrical bearing support  36  by an interference fit that is sufficient to retain frictional load under normal operating conditions.  
         [0031]     Front bearing housing  22  mounts to outer flange  23  ( FIG. 4 ) of front pulley wheel  18 . Front bearing housing  22  includes countersunk screw holes  26  spaced substantially equidistant along the outer radial circumference  25  of front bearing housing  22 . Front pulley wheel  18  includes complimentary screw holes  9  that match the circular pattern of countersunk screw holes  26 . Screw holes  9  can be drilled/tapped into front pulley wheel  18  at the time of installation if not already available on conventional off-the-shelve front pulley wheels. A plurality of conventional screws  24  ( FIG. 6A ) threaded through countersunk screw holes  26  and screw holes  9  clamp front bearing housing  22  (and front pulley cover assembly  45 ) to front pulley wheel  18 . Countersunk screw holes  26  are accessible through opening in front face  28  of front pulley cover  12 , for example apertures  7  formed by ornamental design  30  of front pulley cover  12 .  
         [0032]     Ball bearings  31  ( FIG. 6A ) allow front pulley cover  12  to rotate freely and independently of front bearing housing  22 , front pulley wheel  18 , and primary belt  14 .  
         [0033]     In operation, front pulley cover  12  begins to rotate initially at substantially the same rotational speed as front pulley wheel  18  until frictional bearing loads are overcome. Front pulley cover  12  rotational speed is also a function of aerodynamic loads applied when the motorcycle  2  is in motion. The motorcycle may create airflow over the outer surfaces of the present invention as the motorcycle is moving. The airflow over front face  28  of front pulley cover  12  can created aerodynamic forces on the protrusions  73  of the ornamental design  30  ( FIGS. 2 and 3 ), which act like sails of the sailboat, that will cause front pulley cover  12  to rotate. Also, airflow over front face  28  can create a pressure differential along front face  28  that will also naturally cause front pulley cover  12  to rotate or spin even if there are no protrusions on front face  28 . When motorcycle  2  is at rest and engine  6  is turned off, front pulley cover  12  will continue to rotate or spin naturally until frictional bearing loads or bearing drag cause front pulley cover  12  to stop.  
         [0034]     Further, while motorcycle  2  is in motion or at rest and engine  6  is on or pulleys wheels  18 ,  20  or belt  14  are otherwise moving, any obstacle (for example, clothing, hands, feet, arms, legs, road debris, etc.) that comes in contact with front pulley cover  12  or rear pulley cover  40  will cause front pulley cover  12  or rear pulley cover  40  to immediately reduce rotation speed relative to the drive system and stop rotation when necessary to avoid further progress of the obstacle into the drive system, and further prevent damage or ham to the obstacle, in particular, the riders.  
         [0035]     Now returning to  FIG. 6A , front pulley cover  12  can include rim  13  extending horizontally outward towards front bearing housing  22  and substantially in parallel to cylindrical shaft  32 . Inner circumferential surface  15  of rim  13  has a radial dimension from the centerline of front pulley assembly  45  greater than the radial dimension of outer surface  54  of front bearing housing  22  such that front bearing housing  22  is freely received therein without interference into cavity  16  of front pulley cover  12  when the components of front pulley cover assembly  45  are joined together (described above). The longitudinal length of rim  13  or depth of cavity  16  is sufficient such that outer surface  54  of front bearing housing  22  is substantially encased or isolated by front pulley cover  12 , but the longitudinal length of rim  13  is not long enough to interfere with the operation of belt  14  when attached to front pulley wheel  18 . Thereby, any obstacle that extends beyond front face  28  of front pulley cover  12  towards the drive system will not be drawn into the drive system by the rotational and aerodynamic effects of front bearing housing  22  and belt  14 .  
         [0036]     Further, rim outer surface  17  of rim  13  can be extended to a radial dimension from the centerline of front pulley cover assembly  45  greater than the radial dimension of belt  14  ( FIGS. 3 and 4 ), thereby further preventing an obstacle from being drawn into the drive system due to aerodynamics or drafting effects of belt  14 .  
         [0037]      FIGS. 6B and 6C  illustrate an alternative embodiment of the present invention that includes a snap ring groove  102  formed in shaft  32  of front pulley cover  12  and snap ring  101 . In addition to or in place of the interference fit disclosed above to join front pulley cover  12  and front cylindrical bearing support  36 , snap ring  101  is inserted into cooperating snap ring groove  102  once the components of front pulley cover assembly  45  have been fully assembled. The reference numbers of the other features of front pulley cover  12 , front cylindrical bearing support  36 , and front bearing housing  22  remain the same as disclosed in  FIG. 6A .  
         [0038]      FIG. 7A  illustrates an exploded side view of rear pulley cover assembly  55 , which is generally identical to the front pulley cover assembly  45 . Rear pulley cover assembly  55  includes rear bearing support  37 , rear bearing housing (also referred to as rear mounting plate)  38 , and rear pulley cover  40 . Rear pulley cover  40  includes front face  41  with an ornamental design  42  ( FIGS. 2 and 3 ) and cylindrical shaft  44  extending orthogonally outward from rear face  79 . Cylindrical shaft  44  having first outer circumferential surface  46  and second outer circumferential surface  47 . Rear bearing housing  38  includes inner cylindrical bearing bore  48  and outer cylindrical bearing bore  49 , which form first inner circumferential surface  56  and second inner circumferential surface  58 , respectively. Inner cylindrical bearing bore  48  and outer cylindrical bearing bore  49  are sized larger than the outer surface thickness or radial dimensions of first outer circumferential surface  46  and second outer circumferential surface  47  such that cylindrical shaft  44  can be freely received therein without interference (as discussed above and further discussed below in detail) into inner cylindrical bearing bore  48  and outer cylindrical bearing bore  49 .  
         [0039]     Rear cylindrical bearing support  37  is joined to rear bearing housing  38  and rear pulley cover  40  by conventional joining means such as, for example, bolts/screws, adhesive, welding, brazing, complimentary threaded male/female members, and friction, press-fit or interference fit. For illustration purposes only, the friction, press-fit, or interference fit joining means will be disclosed, but such disclosure is not meant to limit the present invention to only the disclosed embodiment. Rear cylindrical bearing support  37  includes cylindrical bearing bore  81  that forms inner circumferential surface  68 . Inner circumferential surface  68  has a slightly smaller diameter than the diameter or radial thickness of outer circumferential surface  46  of cylindrical shaft  44 . The difference in the diameter or radial dimensions is the interference fit dimension. To join rear cylindrical bearing support  37  to rear pulley cover  40 , the components must be press-fit together to overcome the frictional and the normal forces applied to the mating contact surfaces  46 ,  68  caused by larger diameter or radial thickness of cylindrical shaft  44  being inserted into the smaller diameter cylindrical bearing bore  81  of rear cylindrical bearing support  37 . After the press-fit operation, rear pulley cover  40  is connected to rear cylindrical bearing support  37  by an interference fit that is sufficient to retain frictional load under normal operating conditions.  
         [0040]     Rear cylindrical bearing support  37  is also connected to rear bearing housing  38 , for example, by an interference fit sufficient to retain frictional load under normal operating conditions. Outer circumferential surface  39  of rear cylindrical bearing support  37  has a slightly larger diameter or radial thickness than the diameter of first inner circumferential surface  56  of rear bearing housing  38 . As described above, the difference in the diameter or radial dimensions is the interference fit dimension. To join rear cylindrical bearing support  37  to rear bearing housing  38 , the components must be press-fit together to overcome the frictional and the normal forces applied to the mating contact surfaces  39 ,  56  caused when the larger diameter or radial thickness of rear cylindrical bearing support  37  being inserted into the smaller diameter inner cylindrical bearing bore  48  of rear bearing housing  38 . After the press-fit operation, rear bearing housing  38  is connected to rear cylindrical bearing support  37  by an interference fit that is sufficient to retain frictional load under normal operating conditions.  
         [0041]     Rear bearing housing  38  mounts to outer flange  57  ( FIG. 5 ) of rear pulley wheel  20 . Rear bearing housing  38  includes countersunk screw holes  61  ( FIG. 7A ) spaced substantially equidistant along the outer radial circumference  62  of rear bearing housing  38 . Rear pulley wheel  20  includes complimentary screw holes  83  ( FIG. 5 ) that match the circular pattern of countersunk screw holes  61 . Screw holes  83  can be drilled/tapped into rear pulley wheel  20  at the time of installation if not already available on conventional off-the-shelve rear pulley wheels. A plurality of conventional screws  59  ( FIG. 7A ) threaded through countersunk screw holes  61  and screw holes  83  clamp rear bearing housing  38  (and rear pulley cover assembly  55 ) to rear pulley wheel  20 . Countersunk screw holes  61  are accessible through opening in front face  41  of rear pulley cover  40 , for example apertures  85  ( FIG. 2 ) formed by ornamental design  42  of rear pulley cover  40 .  
         [0042]     Ball bearings  63  ( FIG. 7A ) allow rear pulley cover  40  to rotate freely and independently of rear bearing housing  38 , rear pulley wheel  20 , and primary belt  14 .  
         [0043]      FIGS. 7B and 7C  illustrate an alternative embodiment of the present invention that includes a snap ring groove  104  formed in shaft  44  of rear pulley cover  40  and snap ring  103 . In addition to or in place of the interference fit disclosed above to join rear pulley cover  40  and rear cylindrical bearing support  37 , snap ring  103  is inserted into cooperating snap ring groove  104  once the components of rear pulley cover assembly  55  have been fully assembled. The reference numbers of the other features of rear pulley cover  40 , rear cylindrical bearing support  37 , and rear bearing housing  38  remain the same as disclosed in  FIG. 7A .  
         [0044]     In operation, rear pulley cover  40  begins to substantially rotate initially at the same rotational speed as rear pulley wheel  20  until frictional bearing loads are overcome. Rear pulley cover  40  rotational speed is also a function of aerodynamic loads applied when the motorcycle  2  is in motion. The motorcycle may create airflow over the outer surfaces of the present invention as the motorcycle is moving. The airflow over front face  41  of rear pulley cover  40  can created aerodynamic forces on the protrusions  75  ( FIGS. 2 and 3 ) of the ornamental design  42 , which act like sails of the sailboat, that will cause rear pulley cover  40  to rotate. Also, airflow over front face  41  can naturally create a pressure differential along front face  41  that will also cause rear pulley cover  40  to rotate or spin even if there are no protrusions on face  41 . When motorcycle  2  is at rest and engine  6  is turned off, rear pulley cover  40  will continue to rotate or spin naturally until frictional bearing loads or bearing drag cause rear pulley cover  40  to stop.  
         [0045]     Further, while motorcycle  2  is in motion or at rest and engine  6  is on or pulley wheels  18 ,  20  or belt  14  are otherwise moving, any obstacle (for example, clothing, hands, feet, limbs, road debris, etc.) that comes in contact with front pulley cover  12  or rear pulley cover  40  will cause front pulley cover  12  or rear pulley cover  40  to immediately reduce rotation speed relative to the drive system and stop rotation when necessary to avoid further progress of the obstacle into the drive system, and further prevent damage or harm to the obstacle, in particular, the riders.  
         [0046]     Now returning to  FIG. 7A , rear pulley cover  40  can include rim  64  extending horizontally outward towards rear bearing housing  38  and substantially parallel to cylindrical shaft  44 . Inner circumferential surface  65  of rim  64  has a radial dimension from the centerline of rear pulley assembly  55  greater than the radial dimension of outer surface  66  of rear bearing housing  38  such that rear bearing housing  38  is freely received therein without interference into cavity  67  of rear pulley cover  40  when the components of rear pulley cover assembly  55  are joined together (described above). The longitudinal length of rim  64  or depth of cavity  67  is sufficient such that outer surface  66  of rear bearing housing  38  is substantially encased or isolated by rear pulley cover  40 , but the longitudinal length of rim  64  is not long enough to interfere with the operation of belt  14  when rear bearing housing  38  (and rear pulley cover assembly  55 ) is attached to rear pulley wheel  20 . Thereby, any obstacle that extends beyond front face  41  of rear pulley cover  40  towards the drive system will not be drawn into the drive system by the rotational and aerodynamic effects of rear bearing housing  38  and belt  14 .  
         [0047]     Further, rim outer surface  65  of rim  64  can be extended to a radial dimension from the centerline of rear pulley cover assembly  55  greater than the radial dimension of belt  14 , thereby further preventing an obstacle from being drawn into the drive system due to aerodynamics or drafting effects of belt  14 .  
         [0048]     Now returning to  FIGS. 6A and 7A , outer diameters of rim  17 ,  64  of front pulley cover  12  and rear pulley cover  40 , respectively, are larger than front pulley wheel  18  and rear pulley wheel  20 , respectively (as described above). In an exemplary embodiment, the outer diameter of front cover  12  is approximately ⅓ smaller than the outer diameter of rear pulley cover  40  based on the characteristics of the motorcycle drive system, particularly pulley wheels  18 ,  20 , as illustrated herein. Actual dimensions of pulley covers, bearings, and bearing housings are dependent on the particular make and model of the motorcycle and are not to be limited to the illustrations contained herein.  
         [0049]     Referring to  FIGS. 8 and 9 , an alternative embodiment of the present embodiment includes grill  60  that completes the ornamental design and protects the entire drive system from any obstacles contacting or interfering with belt  14 , front pulley wheel  18 , and rear pulley wheel  20 . Grill  60  is located between front cover  12  and rear cover  40  as shown in  FIGS. 1-3  and attached to frame  8  of motorcycle  2 .  
         [0050]     Grill  60  can include a front plate  69  and a longitudinal structural member or grill mount  77  orthogonally attached to the rear side (not shown) of front plate  69  forming a generally T-shaped configuration. Front plate  69  and grill mount  77  can be a unitary component or multiple of attachably removable separate components. The unitary component is formed by front plate  69  and grill mount  77  being permanently connected by conventional attachment means including, but not limited, to welding, brazing, adhering, or other joining processes. The following description of grill  69  and grill mount  77  illustrate a two component configuration, but it is not intended to limit the present invention to only the disclosed configuration. Further, there could be more than two components depending on the mounting requirements to the frame  8  of a particular motorcycle  2 .  
         [0051]     Front plate  69  is generally trapezoidal in shape and of sufficient length L to span the distance between pulley covers  12 ,  40  and of sufficient width w to cover belt cavity  11 . Front plate  69  can include sides  82  having semi-circular cutouts  84 . Cutouts  84  have slightly larger radii r 1 , r 2  than radii r 3 , r 4 , respectively, of the adjacent pulley covers  12 ,  40  ( FIG. 2 ). Upper side  86  and lower side  88  are tapered outward from front pulley cover  12  to rear pulley cover  40  to create a smooth transient between front plate  69  and pulley covers  12 ,  40 , thereby minimizing open spaces between the assembled components in the present invention for obstacles, debris and/or other foreign matter to enter the drive system. In an exemplary embodiment, the tampered sides are substantially tangent to the outer diameter circumference of the pulley covers  12 ,  40 . Front plate  69  can include outer grill holes  70  for mounting front plate  69  with conventional bolts or screws to outer grill mount holes  72  in outer face  78  of grill mount  77  ( FIG. 9  and discussed in detail below). Front plate  69  can also include an ornamental design  90 .  
         [0052]     Grill mount  77  can be a longitudinal structural member being generally a rectangular frame  92  of length L longer than the width of belt  14  and, particularly, being of sufficient length to connect front plate  69  to frame  8  of motorcycle  2  without interference with the operation of belt  14 . Inner face  74  of grill mount  77  includes inner grill holes  71  for mounting with conventional bolts or screws to belt tensioner plates (not shown) of motorcycle  2  having complimentary holes (not shown). The belt tensioner plates are adjustably attached to engine  6  and transmission  4 . The width w of grill mount  77  is of sufficient length to accommodate the bolt pattern of inner grill mount holes  71  and outer grill mount holes  72 . The thickness ( FIG. 9  in plane) of grill mount  77  is dependent on the size of grill mount holes  71 ,  72 . The thickness of grill mount  77  must further be sufficient to structurally support front plate  69 . Grill mount  77  may further include one or more support members  94  interconnecting sides  96  of frame  92  for additional structural support. One or more support members  94  can interconnect sides  96  in any arrangement suitable to meet the structural requirements of grill  60  and is not to be limited to illustrations contained herein.  
         [0053]     Any metal, polymer, or composite materials that are capably of withstanding the operating and environment conditions experienced by motorcycle  2  are suitable for the components of the present invention. For example, billet 6061 aluminum, a typical alloy used in aircrafts, can be used for front pulley cover  12  and rear pulley cover  40 .  
         [0054]     As described above, the front bearing housing  22  and rear bearing housing  38  initially rotate at a speed consistent with that of pulley wheels  18 ,  20 . Front and rear pulley covers  12 ,  40  are however free-spinning and thus will stop spinning if there is adequate resistance, a safety feature to prevent clothes or other materials from getting caught in the other pulley covers, or exposed pulley wheels or belt. Once the front and rear pulley covers  12 ,  40  are put into motion by the rotation of the front and rear bearing housings  22 ,  38 , covers  12 ,  40  will continue to spin, driven by the pressure differential and the force of the wind on the exterior surfaces of the pulley covers when the motorcycle is in motion or moving.  
         [0055]     The ornamental designs shown herein are for illustrations purposes only and not intended to limit the present invention. Any ornamental design that complies with the structural integrity of the pulley covers and grill are contemplate within the scope of this patent application.  
         [0056]     The present invention is illustrated by the previous examples. However, it should be understood that the invention is not limited to the specific details of these examples. It will now be apparent to those skilled in the art that other embodiments, improvements, details, and uses can be made that are consistent with the letter and spirit of the foregoing disclosure and within the scope of this patent application, the appended claims and their legal equivalent.