Patent Abstract:
An adapter ( 30 ) for a motorcycle frame ( 10 ) configured with a vertical suspension system, as in Harley-Davidson® Sportster®, Dyna®, FXR™ and Road King™ style motorcycles that widens the shock ( 16 ) upper attachment points in order to permit the installation of a wider rear wheel. The adapter ( 30 ) is configured to attach at the original shock frame attachment point, secured in place by a replacement shock attachment bolt ( 18 ′) that is longer than the original shock bolt ( 18 ). The structure of adapter ( 30 ) provides support against the increased torque of weight on the shock ( 16 ), due to the additional length of the bolt, and adapter ( 30 ) is correspondingly recessed to closely fit over the junction area (J) of the frame&#39;s ( 10 ) generally horizontal member ( 12 ) and riser ( 14 ), so as to resist rotational torques that may be applied to fender, selectably mountable on replacement struts ( 21 ).

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/764,711, filed Feb. 2, 2006. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of Invention  
         [0003]     This invention relates generally to kits and components thereof for retrofitting motorcycle factory frames with wide rear tires. Specifically, this invention relates to such kits and components for retrofitting such frames configured as in a Harley-Davidson® Sportster®, Dyna®, FXR™ and Road King™ style motorcycle to allow for safe, simplified and expedient mounting of a wide rear tire.  
         [0004]     2. Related Art  
         [0005]     It is known in the art that wider rear tires can be installed by modifying a rear swing arm for a motorcycle&#39;s rear wheel. Manufacturers typically use a swing arm structure that fits between the stock frames then spreads outward from that point back to accommodate the wider tire, which include tires in excess of 130 mm wide. The motorcycle manufacturer, Harley-Davidson®, has a number of motorcycle models where the rear tire suspension consist of a shock absorber attached on each side of the tire and frame, positioned generally upright, with one end anchored to the axle and the other end anchored to the frame. For the shocks to operate properly for an extended period of time, the shock attachment points must be in the same plane with the force of gravity on the mass of the motorcycle. Since the tire must fit between the shocks, the potential width of the tire that can be installed is therefore limited by the width of the shock attachment points. Stock tires may vary in size.  
         [0006]     The Soileau U.S. Pat. No. 6,230,837 patent discloses a single piece swing arm that compensates for a wider tire in order to achieve a true centerline configuration in a motorcycle configured like a Harley-Davidson® Sportster®. The disclosed swing arm spreads the shock attachment point at the axle in a manner that can be employed with the current invention, but the shock&#39;s frame attachment point is spread in that disclosure by cutting the spanner bar between the two sides of the frame, spreading the sides of the frame, and then installing an extension to the spanner.  
         [0007]     Another method of spreading the shock&#39;s frame attachment points includes welding a wider portion to each side of the frame at the shock&#39;s original frame attachment points, such wider portion has a new frame attachment point, as well as a new strut to support a wider fender, since the old strut would need to be cut off to get it out of the way of the new wider tire. This technique takes a substantial amount of time for a skilled welder to make sure the parts all fit properly and provide precise positioning of the new attachment points for the shocks and struts. Additionally, welded bonds are difficult to thoroughly inspect to ensure their sound integrity.  
         [0008]     It would therefore be a new and useful improvement over the prior art to have a frame adapter that fits to the frame at the shock&#39;s original frame attachment point, being secured by a longer shock bolt, which may provide for the mounting of a replacement strut, and displaces the shock&#39;s frame anchor point to a wider position that corresponds to a wider shock swing arm attachment point, while at the same time providing adequate support against the increased torque on the frame, adapter and shock anchor bolt, due to moving the shock anchor point further away from the center of the frame. It would be an improvement that the device may be assembled using a single shock bolt that can be properly torqued for a confirmed secure fit, and which avoids any drilling of the frame that may weaken the structure. It would be an improvement that the device permits a wide-tire conversion process to take place in a short amount of time, with a minimum of specialty equipment and skills. It would be an additional improvement to the field to provide a modification kit, including left-side and right-side frame adapters, and a suitably extended shock bolt. An additional kit could also include a pair of replacement struts that bolt to the adapter. An additional kit could also include a replacement rear swing arm having an increased width corresponding to the width increase provided by that particular kit&#39;s adapters.  
       BRIEF SUMMARY OF THE INVENTION  
       [0009]     My invention is an adapter for a motorcycle frame configured with a generally vertical suspension system, as in Harley-Davidson® Sportster®, Dyna®, FXR™ and Road King™ motorcycles. The adapter may be attached at the original shock frame attachment point, secured in place by a replacement shock attachment bolt that is longer than the original bolt. The structure of the adapter provides adequate interface with the original frame so as to prevent movement under loads, which may be applied to either or both the suspension system and rear struts during operation of the modified motorcycle.  
         [0010]     Accordingly, objects of my invention are to provide, inter alia, a motorcycle frame adapter, adapter kit and motorcycle wide-tire conversion process that; simplifies and shortens the time of the conversion process; supports a tire wider than a stock tire; and enables one with routine mechanical skills and equipment to perform the conversion. Other objects of my invention will become evident throughout the reading of this application. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a side view of a motorcycle having a rear wheel suspension system using a generally upright shock absorber of the prior art.  
         [0012]      FIG. 2  is a side view of an installed exemplary inventive adapter.  
         [0013]      FIG. 3A  is a side view of the upper frame junction area of the prior art frame shown in  FIG. 1 .  
         [0014]      FIG. 3B  is a perspective view of the upper frame junction area of an alternative embodiment of the prior art motorcycle frame.  
         [0015]      FIG. 4  is a perspective view of an exemplary inventive right-side adapter and replacement strut.  
         [0016]      FIG. 5  is an inside side view of an exemplary adapter.  
         [0017]      FIG. 6  is an inside side view of an alternate exemplary adapter for a differing motorcycle model.  
         [0018]      FIG. 7  is an outside side view of the exemplary adapter shown in  FIG. 5 .  
         [0019]      FIG. 8  is an outside side view of the exemplary adapter shown in  FIG. 6 .  
         [0020]      FIG. 9  is a generally front perspective view of an exemplary adapter.  
         [0021]      FIG. 10  is a generally front perspective view of an alternate exemplary adapter.  
         [0022]      FIG. 11  is a generally front perspective view of an additional alternate exemplary adapter.  
         [0023]      FIG. 12  is a generally rear and top perspective view of alternate exemplary adapters of differing widths and for differing motorcycle models. 
     
    
     DESCRIPTION OF THE INVENTION  
       [0024]     It should be understood that the following terms, as used herein, are defined as follows: “leading edge” or “front” means the part of the object that when integrated into the motorcycle would face the direction of forward travel of the motorcycle; “trailing edge” or “rear” means the part of the object that when integrated into the motorcycle would face away from the direction of forward travel of the motorcycle; “inside,” “outside,” “inner,” and “outer” used in reference to components, or parts thereof, as being toward the center of the motorcycle or away from the center of the motorcycle, respectively. The terms “upper,” “lower,” “top,” “bottom,” “left” and “right” are used from the viewpoint of a person positioned to operate the motorcycle and the motorcycle being in an upright position. A generally vertical suspension system is where a rear shock absorber has one attachment point that is higher than the other attachment point, and the linear shock absorber body is upwardly angled from the horizontal, as reference on a motorcycle that is in the upright, operating position.  
         [0025]     Referring to the drawings by numerals of reference,  FIGS. 1, 3A  and  3 B illustrate examples of the prior art motorcycle frame  10  upon which the current invention may be applied. Of particular concern is frame junction area J toward the rear or trailing end of the frame  10 , where a generally horizontal member  12  on each side of frame  10  joins with a respective frame riser  14  coming up from the bottom of frame  10  on both sides. The particular frame  10  shown in  FIG. 1  is to a Harley-Davidson® Sportster®, which means specific things to one skilled in the art. The current invention can be used with any frame that has the configuration of the generally horizontal member  12 , riser  14  and generally vertical shock  16  anchored in the junction area J of horizontal member  12  and riser  14 .  
         [0026]      FIG. 3B  illustrates an example of a frame known as a Dyna® series motorcycle frame. Since Sportster® frames, Dyna® frames, FXR™ frames, and Road King™ frames mean specific details to one skilled in the art, the specific designs of various year model frames as produced by Harley-Davidson®, including Sportster®, Dyna®, FXR™ and Road King™ frames, are hereby included by reference. Other motorcycle frames may be patterned after these frames, and may fall under the scope of this disclosure.  
         [0027]     For simplicity of discussion only the components on the one side of the motorcycle shown may be discussed, but unless expressly stated, mirror images of the components exist on the other side of frame  10 , as is readily understandable by one skilled in the field of art. A tire (not shown) may be attached to frame  10  with swing arm  23 , which in turn is pivotally attached to frame  10  with swing arm bolt  24 . Shock absorber or shock  16  is attached at the lower end to swing arm  23  and at the upper end with shock bolt  18  to a shock bolt hole  20  in junction area J. Junction area J is an important structural area of frame  10 , because the entire weight on the rear end of the motorcycle, passenger and any cargo rests on the rear shocks through these points.  
         [0028]      FIG. 2  shows an exemplary adapter  30  installed on a Sportster( frame  10  at junction area J. An additional bushing  28  has been inserted on replacement shock bolt  18 ′, in between the upper connection on shock  16  and adapter  30 . Bushing  28  provides additional displacement of shock&#39;s  16  anchor point without making adapter  30  excessively thick. Bushing  28  is of a large enough diameter cylinder to provide adequate torsional support between shock  16  and adapter  30  to prevent excessive lateral torque being applied to replacement shock bolt  18 ′. As compared to the prior art configuration of  FIG. 3A , shock  16  is still in the same general orientation. It is simply displaced outwardly away from the center of frame  10 . In both prior art and inventive embodiments the shock&#39;s  16  upper anchor point still aligns with shock bolt hole  20  injunction area J.  
         [0029]      FIG. 4  shows an adapter  30  adjacent to, but separate from a replacement strut  50 . Strut bolt holes  52  align, as well as shock bolt hole  20 . In the exemplary embodiment, strut bolts (not shown) are to pass through strut bolt holes  52  in strut  50  and seat in threaded strut bolt holes  52  in adapter  30 . Though this is the preferred method, other equivalent means of fixing replacement strut  50  to adapter  30  are encompassed by this invention, where strut bolt holes  52  may be other forms attachment points for securing the strut to the adapter.  
         [0030]      FIGS. 5 and 6  show the inside surfaces and  FIGS. 7 and 8  show the outside surfaces  38  of two exemplary adapter  30  for the right side of differing year models of Sportster® motorcycles.  FIGS. 5 and 6  show recess  36  that is formed to closely correspond to the shape of the junction area J on its particular motorcycle. Upper shoulder  40  is shaped to form a wrapping support around a horizontal member  12  of the motorcycle on which it would be installed. Similarly, lower shoulder  42  shaped to form a wrapping support around riser  14  of that motorcycle. Upper shoulder  40  and lower shoulder  42  diverge toward the leading edge  32  and converge toward the trailing edge  44  of adapter  30 . This corresponds to the angle at which the respective horizontal member  12  and riser  14  converge into junction are J.  
         [0031]     Adapter  30  may be secured in place by the installation of shock  16  with a suitably longer replacement shock bolt  18 ′ through shock bolt hole  20 . Replacement struts  50  may be attached to adapter  30  to support a new wider rear fender (not shown). Also referring to  FIG. 2 , in the exemplary embodiment strut bolts  54  are inserted through strut bolt holes  52  to seat in corresponding strut bolt holes  52  in adapter  30 . The firm fit of recess  36 , supported by upper shoulder  40  and lower shoulder  42  being biased against horizontal member  12  and riser  14 , respectively, secures adapter  30  in place sufficiently to safely withstand operational torque on shock bolt  18 ′, and torque that may be placed on replacement struts  50 .  
         [0032]     Referring to  FIGS. 9 through 12 , various widths a, b, and c adapters  30  may be used in order to attain the desired displacement of the upper attachment point of shock  16 . Adapter width is determined by the amount of desired displacement that is needed for the particular model of motorcycle.  FIG. 9  shows an exemplary left-side adapter  30  for an earlier year model Sportster® frame  10 . The appropriate right-side adapter  30  would be a mirror image of the shown adapter  30 .  FIG. 10  shows an exemplary wider left-side adapter  30  for the same year model Sportster® frame  10  as shown in  FIG. 9 . The comparative difference in width is shown in  FIG. 12  at widths a and c. The corresponding right-side adapter  30  for the adapter  30  shown in  FIG. 10 , shown on the center-right in  FIG. 12 , is a mirror image of the left-side adapter  30 , shown by itself in  FIG. 10  and on the center-left in  FIG. 12 .  FIG. 11  shows an exemplary left-side adapter  30  for a late year model Sportster® frame  10 . The appropriate right-side adapter  30  would be a mirror image of the shown adapter  30 . On the late year model Sportster® frame  10  the junction area J is more compact, so the overall size of the corresponding adapter  30  may be smaller. The comparative width of this embodiment of adapter  30  is shown in  FIG. 12 , at width b.  
         [0033]     Adapter  30  is designed to particularly match the junction area J of a particular model and type of motorcycle. Recess area  36  must appropriately compliment the particular junction area J, so that shoulders  40  and  42  properly bias against frame  10 . Referring to  FIGS. 9 through 12 , in a similar way the width a, b, and c of a particular adapter  30  must correspond to the length of the replacement shock bolt  18 ′ to be used, as well as the width of the replacement swing arm (not shown).  
         [0034]     Referring to  FIGS. 1 through 4 , to install adapter  30 , the project motorcycle (not shown) will be prepared for the conversion by removing items that will interfere with the task, such as the rear wheel and the brake caliper. The existing shocks  16  are removed from left and right junction areas J by removing shock bolts  18  from shock bold holes  20  in frame  10 . Existing struts  21  will be in the way of the new wider wheel, so both left and right struts  21  need to be removed just to the rear of junction area J, being careful to not damage the integrity of junction area J. This may be done be a variety of methods, including a metal saw or cutting torch. Install the appropriate left or right side adapter  30  to the each side of frame  10 , securing each with a longer replacement shock bolt  18 ′ , as the shock is reinstalled on both sides. Bushings  28  may be used to gain additional separation between shocks  16 , as well as ensure a precise fit of replacement shock bolt  18 ′ and shock  16  with each adapter  30 .  
         [0035]     All the essential components for this modification may be packaged in a kit, so that all the parts correctly correspond in size. This includes that the width of adapter  30 , the length of replacement shock bolt  18 ′ correspond to each other, and are intended for use with a specific width wheel and swing arm. Further items to complete the modification, such as components to widen the drive train, as described in U.S. Pat. No. 6,230,837, issued to Soileau, may also be included in a conversion kit. The disclosure of U.S. Pat. No. 6,230,837 is hereby expressly incorporated by reference into this disclosure.  
         [0036]     The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.

Technology Classification (CPC): 1