True center wide drive for motorcycles

A motorcycle modification kit, primarily for Harley Davidson frames, having an oversized wide swing arm for pivotal mounting to a motorcycle frame for supporting a rear wheel having a wide series rear tire. The invention uses offset spacers for the transmission pulley and brake rotor such that the tire remains aligned along the center line of the motorcycle.

BACKGROUND OF THE INVENTION
 1. Field of Invention
 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 with true center wide drives and rear tires.
 2. Related Art
 It is known in the art of motorcycle maintenance that wider rear tires can
 be installed by modifying the rear swing arm for the motorcycle's rear
 wheel. However, these shop modifications are often done to inexact
 specifications, posing safety hazards. Further, these modifications to the
 swing arm only do not compensate for misalignment of the rear wheel and
 tire caused by inherent offset. For example, the Desrosiers 5,996,718
 patent discloses a swing arm for customizing the rear wheel of a
 motorcycle using a triangular shaped swing arm typical to Harley-Davidson
 Softail.TM. motorcycles. However, the Desrosiers '718 patent does not
 compensate for the inherent offset orientation oblique to the motorcycle
 centerline. This causes the front and rear tires to be aligned on
 different center lines, resulting in poor stability and balance. It would
 therefore be a new and useful improvement over prior art for an
 after-market modification kit to include both a wider rear swing arm for
 the rear wheel and an offset transmission pullet to move the drive
 belt/chain outward t allow even swing arm spacing on both sides of the
 rear tire.

DESCRIPTION OF THE INVENTION
 The True Center Wide Drive for Motorcycles is shown generally in FIG. 1 as
 10. The Drive 10 comprises a wide swing arm 20, offset pulley 30, strut
 spacer 60, and offset brake rotor spacer 50.
 The wide swing arm 20 is shown in FIGS. 1, 2, and 3. Wide swing arm 20
 comprises two legs 22 joined by a leg connecting member 24. Preferably,
 leg connecting member 24 is of uniform thickness. Importantly, leg
 connecting member 24 is wider than the corresponding piece in factory made
 frames. The wider length enables wider rear tire 21 to be placed inside of
 the wide wing arm 20. Of course, a wider swing arm 20 will require a
 longer rear axle 150.
 Offset pulley 30 is shown in FIGS. 1, 3, and 4. Offset pulley 30 includes
 an inner surface 31, an outer surface 32, an offset 33, a main drive gear
 hole 34, and a transmission sprocket surface 35. Offset pulley 30 is
 generally cylindrical in shape. Pulley inner surface 31, once installed,
 is adjacent to the motorcycle's transmission 29 so that pulley outer
 surface 32 is proximate the exterior of motorcycle 74. Adjacent the pulley
 inner surface 31 is the offset 33. Intermediate the offset 33 and the
 pulley outer surface 32 is the transmission sprocket surface 35. The main
 drive gear hole 34 is located through the pulley inner surface 31 and the
 offset 33.
 In typical pulleys, the corresponding pulley inner surface is flush with
 the inner side 36 of the transmission sprocket surface 35. Offset pulley
 30 includes offset 33 which provides an additional spacing 37 between the
 inner side 36 and the pulley inner surface 31. Thus, typical pulleys do
 not include the offset 33 or the additional spacing 37.
 Offset pulley 30 may also be adjustable so that offset 33 can be moved in
 relation to pulley inner surface 31 thereby changing the additional
 spacing 37. In this embodiment, offset 33, including pulley inner surface
 31, can be removed and are separate from the remainder of offset pulley
 30. The offset 33 is locked into place to the remainder of the offset
 pulley 30, thereby also defining a specific spacing 37, by releasable
 locking means which may comprise set screws, splined, threads, or key
 ways.
 Offset brake rotor spacer 50 is shown in FIGS. 1, 3, 5, and 7. Rotor spacer
 50 is annular in shape and includes an inner surface 51 and an outer
 surface 52 that also defines a spacing 58. Rotor spacer 50 also includes a
 plurality of countersunk wheel holes 53, a plurality of adapter rotor
 holes 54, and a lip 55. When attached, rotor spacer inner surface 51 is
 adjacent to the wider motorcycle tire. A plurality of first bolts 56 are
 inserted through the countersunk wheel holes 53 and into the original
 brake rotor bolt holes on rear wheel 28. Thus, the brake rotor spacer 50
 is attached to the tire. It is important that the wheel holes 53 be
 countersunk so that rotor spacer outer surface 52 can fit flush with the
 rotor. Lip 55 extends outwardly from the rotor spacer outer surface 52 and
 provides center alignment to the rotor as the tire rotates. The rotor fits
 flush with rotor spacer outer surface 52. A plurality of bolts 57 are
 inserted through the original rotor holes and into the plurality of
 adapter rotor holes 54. Thus, the rotor is attached to the offset brake
 rotor spacer 50.
 It is noted that rotor spacer 50 in FIGS. 1 and 3 includes five holes and
 that it includes ten holes are included in FIG. 5. For the embodiment of
 FIGS. 1 and 3, it is understood that holes 54 and holes 53 may comprise
 the same holes and that bolts 57 and bolts 56 may comprise the same bolts
 so that such bolts are inserted through the rotor through the rotor spacer
 and into rear wheel 28. Countersinking is not necessary in this
 embodiment. FIG. 5 illustrates the embodiment including different holes,
 53 and 54, and bolts, 56 and 57.
 Strut spacer 60 is shown in FIGS. 5, 6A, 6B and 9. Strut spacer 60 is
 attached to frame cross-member 59 of the motorcycle. Strut spacer 60
 includes an inner cylindrical element 61, and two opposing
 semi-cylindrical outer elements 62. The two outer elements 62 are
 identical to each other, and each includes a hole 63 proximate each of its
 two ends. Inner element 61 and outer elements 62 are sized and constructed
 so that the inner element 61 can snugly fit within the outer elements 62.
 In other words, the two outer elements 62 together form a generally
 cylindrical shape that completely surrounds the inner element 61. When
 surrounded, the inner element outer surface 64 should abut the inner
 surface 65 of each outer element 62. The inner element 61 should be
 shorter in length so that, when the inner element 61 is surrounded by the
 two outer elements 62, the inner element 61 is located intermediate the
 holes 63 and does not obstruct such holes 63. In addition, when the inner
 element 61 is surrounded by the two outer elements 62, the holes 63 on
 corresponding ends of the two outer elements 62 should align. Once
 aligned, bolts 66 should be inserted through the holes 63 and should be
 tightened with nuts 67. Upon tightening, the inner element 61 will be
 securely held in place within the outer elements 62.
 Inner element 61 includes a length 100. Length 100 is the additional width
 that is necessary to enable the reception of wider rear tire 21 and rear
 fender by the struts and wide swing arm 20. Essentially, the struts spacer
 60 widens the distance between the struts of motorcycle 74 in order to
 enable wider rear tire 21 and fender to fit. However, once the distance
 between the struts is widened, several components, including the original
 rotor, the original pulley, and the original swing arm, of the original
 drive are also not properly aligned. Thus, the wider swing arm 20, which
 includes the additional width, is installed instead of the original swing
 arm. In addition, the offset pulley 30 is installed instead of the
 original factory pulley. And the rotor spacer 50 is installed in between
 rear wheel 28 and the rotor.
 Drive 10 allows for the centered installation of wider rear tire 21 because
 [1] the wider swing arm 20 is also centered onto rear wheel 28; and [2]
 the distance of rotor spacer spacing 58 is substantially equal to the
 distance of offset spacing 37. Thus, rotor spacer spacing 58 and offset
 spacing 37 each encompasses one-half of the total additional width
 necessary to enable the installation of wider rear tire 21. And, because
 the rotor spacer spacing 58 is at one side of the wider rear tire and the
 offset spacing 37 is at the other side of wider rear tire 21, equal
 spacing at each side of wider rear tire 21 is achieved which results on
 the centering of wider rear tire 21 along center line 23, as shown in FIG.
 8.
 Other components of motorcycle 74 may also have to be spaced out of their
 original location in order to allow the insertion of wider rear tire 21.
 These components include the battery box, which can be offset by the
 battery box spacers (comprising regular annular spacers with corresponding
 bolts and nuts); the pulley cover, which can be offset by the pulley cover
 spacer 120; and the muffler mounting bracket, which can be offset by the
 muffler bracket nut and bolt spacer 140.