Abstract:
A glue-on attachable flywheel weight adds rotational mass to a flywheel allowing for a vehicle operator to alter the power characteristics of an engine. Different flywheels require different shapes of attachable weights. The attachable weights can be machined to fit a multitude of different flywheels to add the rotational mass. Applying an adhesive secures the weight onto the flywheel and adds the rotational mass in a user-friendly convenient manner.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority to U.S. Provisional Patent Application No. 61/611,998, titled GLUE-ON ATTACHABLE FLYWHEEL WEIGHT, filed Mar. 16, 2012, the entire contents of which are incorporated herein by reference in their entirety for all purposes. 
     
    
     BACKGROUND 
       [0002]    The power characteristics of an engine can be changed by increasing or decreasing the internal rotating mass, which may be commonly referred to as flywheel weight or flywheel inertia. Decreasing the flywheel inertia will cause the engine speed (RPMs) to increase at a quicker rate during acceleration conditions. Such increases in engine speed during acceleration conditions may make drivability or handling of a vehicle (e.g., a motorcycle) more difficult to control. Accordingly, during acceleration conditions, the rider must use more throttle control, concentration, strength, and energy to maintain traction and control of the vehicle. 
         [0003]    Increasing the flywheel inertia will make the engine speed increase at a slower rate during acceleration conditions that may make vehicle acceleration easier to control. Since the engine speed increases at a slower rate, engine torque may be transferred to the vehicle&#39;s tires at a slower rate that makes the tires less likely to lose traction. Further, the rider has more time to make corrections. Moreover, the increased engine inertia, or engine momentum, may also keep the engine from stalling or dying out. Accordingly, the vehicle may travel at lower engine speeds with less of a possibility of the engine suddenly stalling. In other words, the increase in flywheel inertia allows a rider to “chug” at lower engine speeds with less of a possibility of the engine suddenly stalling. 
         [0004]    Thus, for ease of control, some riders prefer to add more weight to their ignition flywheels. One prior approach that has been employed is to bolt on or screw on a steel disc to the existing ignition flywheel, while this approach is easily implemented by an amateur mechanic, it suffers from the drawback that sufficient space must be present within the flywheel case for clearance of the bolt or screw, and the bolt or screw may become loose over time, potentially leading to catastrophic failure at high engine speeds. 
         [0005]    Other prior approaches include welding a steel ring to the existing ignition flywheel, pressing on an interference fit metal ring to the flywheel, adding heavy metal to the crankshaft, building a larger or heavier crankshaft, building a larger or heavier ignition flywheel, or building a clutch basket out of heavier material. While each of these approaches increases the rotational mass of the powertrain, most of these methods are too expensive or beyond the engineering capabilities of an amateur mechanic. Although the bolt on/screw on weight disc discussed above is within the technical ability of an amateur mechanic to install, this approach is becoming more difficult to implement because four stroke engines with increasingly compact configurations are becoming more popular in motorcycles as compared to two stroke engines. Since four stroke engines are generally larger, heavier, and have more parts than a two stroke engine of the same displacement, manufacturers are making the four stroke engines more compact, leaving less room to add flywheel weight in the ignition area. Four stroke engines generally have the ignition flywheel in the same oil cavity as the rest of the vital engine parts, so if a fastener comes out of a flywheel weight, damage to the engine can be extensive. In addition, ignition flywheels have generally changed in design, due in part to electronic fuel injection, making it much more difficult to attach a weight disc using fasteners. 
         [0006]    For manufacturers of aftermarket flywheel weights, the challenge has been to find an inexpensive and easily implemented way to add more inertia to compact engine and ignition designs. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  shows an exploded view of a first embodiment of a glue-on attachable flywheel weight and a flywheel of a motorcycle engine. 
           [0008]      FIG. 2  shows a perspective view of the first embodiment of the glue-on attachable flywheel weight attached to the flywheel of the motorcycle engine of  FIG. 1 . 
           [0009]      FIG. 3  shows a cross-sectional view of the first embodiment of the glue-on attachable flywheel weight with adhesive applied. 
           [0010]      FIG. 4  shows a cross-sectional view of a second embodiment of the glue-on attachable flywheel weight. 
           [0011]      FIG. 5  shows a cross-sectional view of a third embodiment of the glue-on attachable flywheel weight. 
           [0012]      FIG. 6  shows a cross-sectional view of a fourth embodiment of the glue-on attachable flywheel weight. 
           [0013]      FIG. 7  shows a cross-sectional view of a fifth embodiment of the glue-on attachable flywheel weight. 
           [0014]      FIG. 8  shows one side of a close-up cross-sectional view of the first embodiment of the glue-on attachable flywheel weight of  FIG. 3 . 
           [0015]      FIG. 9  shows one side of a close-up cross-sectional view of the second embodiment of the glue-on attachable flywheel weight of  FIG. 4 . 
           [0016]      FIG. 10  shows one side of a close-up cross-sectional view of the third embodiment of the glue-on attachable flywheel weight of  FIG. 5 . 
           [0017]      FIG. 11  shows one side of a close-up cross-sectional view of the fourth embodiment of the glue-on attachable flywheel weight of  FIG. 6 . 
           [0018]      FIG. 12  shows one side of a close-up cross-sectional view of the fifth embodiment of the glue-on attachable flywheel weight of  FIG. 7 . 
           [0019]      FIG. 13  shows a cross-sectional view of an embodiment of an adhesive including friction balls that attaches a flywheel weight to a flywheel. 
           [0020]      FIG. 14  shows an embodiment of a method for adding rotational mass to an engine flywheel. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    The present description relates to methods and apparatuses for increasing a rotational mass or inertia of a flywheel of a vehicle engine. More particularly, the present description relates to a glue-on attachable flywheel weight and methods for attaching the glue-on attachable flywheel weight to a flywheel of a motorcycle engine. The glue-on attachable flywheel weight may have a small form factor that allows the weight to fit in a compact engine of a motorcycle. In some embodiments, the glue-on attachable flywheel weight may be attached to a flywheel without fasteners that may become loose over time. However, it is to be understood that, in some embodiments, the flywheel weight may be attached to a flywheel using a combination of adhesive and set screws. The glue-on attachable flywheel weight may provide an inexpensive solution for an amateur mechanic to install in order to increase flywheel inertia. 
         [0022]      FIG. 1  shows an exploded view of an embodiment of a glue-on attachable flywheel weight  100  (referred to below as a “flywheel weight”) and a flywheel  102  of a motorcycle engine  104 . The engine may be any suitable type of engine. For example, the engine may be a two-stroke engine. In another example, the engine may be a four-stroke engine. The flywheel may be any suitable shape or design to correspond with the engine type. Typically, the flywheel may be cylindrical in shape and may couple to a crankshaft of the motorcycle engine. For example, the flywheel may be an original equipment merchandise (OEM) ignition flywheel. 
         [0023]    The flywheel weight may be a continuous shape of revolution, such as a ring or disk that substantially conforms to a shape of the flywheel. The flywheel weight may be made from metal or a similar material. In one particular example, the flywheel weight may be machined steel. 
         [0024]    The flywheel weight may be attached to the flywheel via an adhesive  106 . The adhesive may be any suitable adhesive, glue, resin, epoxy, or other suitable material to attach the flywheel weight to the flywheel. In one example, the adhesive may include an epoxy that is oil and heat tolerant. In some embodiments, the adhesive may be applied via injection through one or more holes in the flywheel weight. In one particular example, a 0.006 inch thick layer of epoxy applied to inner interface surfaces of the flywheel weight may be suitable to attach the flywheel weight to the flywheel. It is to be understood that this is merely one example and the clearance and thickness may vary depending on the strength characteristics of the adhesive. For example, a range from 0.005-0.007 inches may be used may be used for the epoxy layer. 
         [0025]      FIG. 2  shows a perspective view of the flywheel weight  100  attached to the flywheel  102  of the motorcycle engine of  FIG. 1 . The flywheel weight may be machined to conform to dimensions of a circumference and/or a face of the flywheel, such that the flywheel weight attaches to a cylindrical or curved face of the flywheel. The flywheel weight may further attach to a face that is perpendicular to the cylindrical face of the flywheel. When attached to the flywheel, the flywheel weight may extend beyond an edge of the flywheel and partially cap the flywheel so that the flywheel weight attaches to two surfaces of the flywheel that are orthogonal. By attaching to two orthogonal surfaces, an attachment strength between the flywheel weight and the flywheel may be increased relative to a configuration with a single attachment surface. 
         [0026]    In the illustrated embodiment, the flywheel weight is configured to fit to an outer circumference of the flywheel. However, in some embodiments, the flywheel weight may be configured to fit an inner circumference of the flywheel. 
         [0027]      FIG. 3  shows a cross-sectional view of the flywheel weight  100 . The flywheel weight  100  has dimensions shown as an example, although it will be appreciated that variations on the depicted dimensions are possible without departing from the scope of the present description. The flywheel weight  100  includes a weight ring or body  108 . The body  108  includes a latitudinal section  112  elongated in a latitudinal direction, a longitudinal section  110  elongated in a longitudinal direction, and a shoulder section  114  that connects the latitudinal and longitudinal sections at an angle (e.g., a ninety degree angle). In the illustrated embodiment, the latitudinal section may be substantially perpendicular to the longitudinal section. The shoulder section may be square such that the edges of the longitudinal and latitudinal section are orthogonal. 
         [0028]    Adhesive  106  is shown applied to an interior of the body. In particular, adhesive is applied to the interior of the latitudinal section and adhesive is applied to the interior of the longitudinal section so as to contact the flywheel. 
         [0029]    In more detail,  FIG. 8  shows an expanded cross-sectional portion of the body  108  of the flywheel weight  100 . The ring body  108  includes the latitudinal section  112  elongated in the latitudinal direction, the longitudinal section  110  elongated in the longitudinal direction and the shoulder section  114  that connects the latitudinal and longitudinal sections at an angle. 
         [0030]    The latitudinal section further includes an outer latitudinal adhesive channel  116  and an inner latitudinal adhesive channel  118  that are separated by a latitudinal guide structure  120 . For example, there may be 0.006 inches of clearance between the latitudinal adhesive channels and the flywheel for suitable adhesion to attach the flywheel weight to the flywheel, although other clearances may be used to obtain suitable adhesion, as discussed above. The latitudinal guide structure  120  directs the flywheel into longitudinal alignment with the flywheel weight, to help ensure that the position of the weight ring is sufficiently deeply mounted on the flywheel for proper adhesive bonding, and to avoid contact with an engine casing. For example, there may be 0.001 inches of clearance between the latitudinal guide structure  120  and the flywheel for proper alignment, although other clearances may be used to obtain proper alignment. 
         [0031]    The longitudinal section  110  further includes a longitudinal guide structure  122  and a longitudinal adhesive channel  124 . For example, there may be 0.006 inches of clearance between the longitudinal adhesive channel  124  and the flywheel for proper adhesion, although other clearances may be used to obtain proper adhesion as discussed above. The longitudinal guide structure  122  directs the flywheel into latitudinal alignment with the flywheel weight, to help ensure the flywheel is centered on the rotational axis of the flywheel. For example, there may be 0.001 inches of clearance between the longitudinal guide structure  122  and the flywheel for proper alignment, although other clearances may used to obtain proper alignment. The longitudinal guide structure  122  may include an interface surface that is curved to fit a cylindrical side surface of the flywheel and the latitudinal guide structure  120  may include an interface surface that is flat to fit an end surface of the flywheel. 
         [0032]    The latitudinal guide structure  120  and the longitudinal guide structure  122  may be raised portions, such as ribs or bumps that may form channels for the adhesive. Moreover, the raised portions may provide surface area contact between the flywheel weight and the flywheel when the adhesive is applied in between them. In particular, the raised portions may contact the flywheel and increase friction that helps the flywheel weight maintain a fixed position on the flywheel. These raised portions may keep the flywheel weight centered and in balance on the flywheel, so that the flywheel weight does not float on the adhesive. 
         [0033]    It is to be understood that the shape of the first embodiment of the flywheel weight may be machined to fit a specific flywheel (e.g., flywheel  102 ). In the illustrated embodiment, a thickness of the longitudinal section  110  is narrower with respect to the latitudinal section  112 . The longitudinal section  110  is comprised of the rectangular longitudinal guide structure  122  and longitudinal adhesive channel  124 . The longitudinal guide structure  122  elongates along a segment of the longitudinal section  110  in the longitudinal direction beginning at the shoulder section  114 . The longitudinal guide structure  122  ends at a right angle along the segment of the longitudinal section  110  wherein the longitudinal adhesive channel  124  continues along the remainder of the longitudinal section  110  to the end of the longitudinal section  110 . 
         [0034]    Similarly, the latitudinal section  112  is comprised of the rectangular latitudinal guide structure  120  and latitudinal adhesive channels  116  and  118 . The latitudinal guide structure  120  elongates along a central segment of the latitudinal section  112 . The latitudinal guide structure  112  may be positioned substantially in the middle of the latitudinal section  112 . The shoulder section  114  connects the latitudinal section  112  and the longitudinal section  110  to form a diagonal exterior surface between the latitudinal and longitudinal sections that may be beveled. Furthermore, a thickness of the longitudinal section  110  may be substantially thinner than a thickness the latitudinal section  112 . 
         [0035]    The flywheel weight  100  may contact two surfaces of a flywheel to attach the flywheel weight to the flywheel. The attachment surfaces of the flywheel may be orthogonal. In particular, the longitudinal guide structure  122  may contact the cylindrical side of the flywheel. As such, a contact surface of the longitudinal guide structure may be curved to fit the shape of the flywheel cylinder. Furthermore, the latitudinal guide structure  120  may contact an end surface of the flywheel. As such, a contact surface of the latitudinal guide structure may be substantially flat. 
         [0036]      FIGS. 4 and 9  show a second embodiment of a glue-on attachable flywheel weight  400 . The flywheel weight  400  is machined to fit a specific flywheel that differs from the flywheel referred to with respect to the first embodiment. In particular, the flywheel weight  400  may be configured to attach to a flywheel having a rounded edge or attachment interface, whereas the flywheel weight  100  may be configured to attach to a flywheel having a straight edge or orthogonal attachment interface. Like the flywheel weight  100 , the flywheel weight  400  is configured to attach to an exterior cylindrical side surface and an end surface of a flywheel. 
         [0037]    In  FIG. 4 , the flywheel weight  400  has dimensions shown as an example, although it will be appreciated that variations on the depicted dimensions are possible without departing from the scope of the present description. The ring body  408  includes the latitudinal section  412  elongated in the latitudinal direction, the longitudinal section  410  elongated in the longitudinal direction and the shoulder section  414  that connects the latitudinal and longitudinal sections at an angle. In the second embodiment, the longitudinal section  410  is comprised of a rectangular longitudinal guide structure  422  and a longitudinal adhesive channel  424 . The longitudinal guide structure  422  elongates along a segment of the longitudinal section  410  in the longitudinal direction beginning at the shoulder section  414 . For example, the longitudinal guide structure  422  ends at a right angle along the segment of the longitudinal section  410  wherein the longitudinal adhesive channel  424  continues along the remainder of the longitudinal section  410  to the end of the longitudinal section  410 . The latitudinal section  412  is comprised of a continuous rectangular latitudinal guide structure  420  portion and a latitudinal adhesive channel  416  that arches away from the latitudinal guide structure  420 . 
         [0038]    Similar to the longitudinal guide structure  422 , the latitudinal guide structure  420  elongates along a segment of the latitudinal section  412  in the latitudinal direction beginning at the shoulder section  414  and ending at a right angle at a middle segment of the latitudinal section  412 . At a middle segment of the latitudinal section  412 , the latitudinal adhesive channel  416  contours away from the latitudinal guide structure  420  to form an arc that connects the latitudinal guide structure  420  to an exterior surface of the latitudinal section  412 . In some cases, the arc of the latitudinal adhesive channel  416  may match a contour of the corresponding flywheel. For example, the flywheel may include rounded portions that match the shoulder section  414  and the latitudinal adhesive channel  416 . Moreover, the flywheel may extend to or beyond an exterior edge of the latitudinal adhesive channel  416  such that the flywheel may extend beyond the body  408  in the longitudinal direction. In some cases, the arc may provide additional space to form a thicker layer of adhesive. An exterior portion of the shoulder section  414  joins the latitudinal section  412  and the longitudinal section  410  at a right angle. An interior portion of the shoulder section  414  joins the latitudinal section  412  and the longitudinal section  410  via an arc that is contoured to fit a rounded edge of the corresponding flywheel to which the flywheel weight  400  is configured to attach. In other words, the shoulder section may be rounded. The latitudinal section  412  and the longitudinal section  410  may be perpendicular to each other. Furthermore, a thickness of the longitudinal section  410  may be slightly thinner than a thickness of the latitudinal section  412 . 
         [0039]    The flywheel weight  400  may contact two surfaces of a flywheel to attach the flywheel weight to the flywheel. The attachment surfaces of the flywheel may be rounded. In particular, the longitudinal guide structure  422  may contact the cylindrical side of the flywheel. As such, an interface surface of the longitudinal guide structure may be curved to fit the shape of the flywheel cylinder. Furthermore, the latitudinal guide structure  420  may contact a flat end surface of the flywheel. As such, an interface surface of the latitudinal guide structure may be substantially flat. 
         [0040]      FIGS. 5 and 10  show a third embodiment of a glue-on attachable flywheel weight  500 . The flywheel weight  500  is machined to fit a specific flywheel that differs from the flywheels referred to with respect to the first embodiment and the second embodiment. In particular, the flywheel weight  500  may be configured to attach to a rounded attachment surface that mirrors an attachment surface of the flywheel to which the flywheel weight  400  attaches. Moreover, the flywheel weight  500  may include a flange portion that extends in the latitudinal direction. The flange portion may extend beyond an exterior surface of the longitudinal section away from the cylindrical side surface of the flywheel. In some cases, the flange portion shifts a moment of inertia of the flywheel. 
         [0041]    In  FIG. 5 , the flywheel weight  500  has dimensions shown as an example, although it will be appreciated that variations on the depicted dimensions are possible without departing from the scope of the present description. The ring body  508  includes the latitudinal section  512  elongated in the latitudinal direction, the longitudinal section  510  elongated in the longitudinal direction and the shoulder section  514  that connects the latitudinal and longitudinal sections at an angle. In the third embodiment, the longitudinal section  510  is comprised of a rectangular longitudinal guide structure  522  portion and a longitudinal adhesive channel  524  that continues uninterrupted to the latitudinal adhesive channel  516 . The longitudinal guide structure  522  elongates along a segment of the longitudinal section  510  and produces the shoulder section  514 . The longitudinal adhesive channel  524  begins at the shoulder section  514  and contours continuously into the latitudinal adhesive channel  516  to form an arc between the longitudinal adhesive channel  524  and the latitudinal adhesive channel  516 . The arc collectively formed by the longitudinal adhesive channel  524  and the latitudinal adhesive channel  516  may contour to an arc formed in an attachment surface of the flywheel. The longitudinal adhesive channel  524  may be perpendicular to the latitudinal adhesive channel  516 . The latitudinal adhesive channel  516  meets the rectangular latitudinal guide structure  520  along the latitudinal section  512 . Extending in the latitudinal direction, and as part of the latitudinal section  512 , is an additional rectangular flange portion  526  that provides supplementary weight to the flywheel weight  500 . The flange portion  526  may extend beyond an exterior surface of the longitudinal section  510 , away from a cylindrical side surface of the flywheel. Moreover, the flange portion  526  may shifts a moment of inertia of the flywheel when the flywheel weight  500  is attached to the flywheel. The flange portion  526  connects the longitudinal section  510  with the latitudinal section  512  via an arc of an exterior surface of the shoulder section  514 . In other words, the exterior surface of the shoulder section may be rounded. Furthermore, a thickness of the longitudinal section  510  may be slightly thicker than a thickness of the latitudinal section  512  and/or the flange portion  526 . 
         [0042]    The flywheel weight  500  may contact two surfaces of a flywheel to attach the flywheel weight to the flywheel. The attachment surfaces of the flywheel may be rounded. In particular, the longitudinal guide structure  522  may contact the cylindrical side of the flywheel. As such, an interface surface of the longitudinal guide structure may be curved to fit the shape of the flywheel cylinder. Furthermore, the latitudinal guide structure  520  may contact a flat surface of the flywheel. As such, an interface surface of the latitudinal guide structure may be substantially flat. 
         [0043]      FIGS. 6 and 11  show a fourth embodiment of a glue-on attachable flywheel weight  600 . The flywheel weight is machined to fit a specific flywheel that differs from the flywheels referred to with respect to the first embodiment, the second embodiment, and the third embodiment. In particular, the flywheel weight  600  may be configured to attach to flat attachment surfaces of the flywheel. Moreover, the flywheel weight  600  may include a latitudinal section having a thickness that is substantially thinner that a thickness of a longitudinal section. 
         [0044]    In  FIG. 6 , the flywheel weight  600  has dimensions shown as an example, although it will be appreciated that variations on the depicted dimensions are possible without departing from the scope of the present description. The ring body  608  includes the latitudinal section  612  elongated in the latitudinal direction, the longitudinal section  610  elongated in the longitudinal direction and the shoulder section  614  that connects the latitudinal and longitudinal sections at an angle. In the fourth embodiment, the longitudinal section  610  is comprised of a rectangular longitudinal guide structure  622  and a longitudinal adhesive channel  624 . The longitudinal guide structure  622  elongates along a segment of the longitudinal section  610  in the longitudinal direction beginning at the shoulder section  614 . The longitudinal guide structure  622  ends at a right angle along the segment of the longitudinal section  610  wherein the longitudinal adhesive channel  624  continues along another segment of the longitudinal section  610 . The longitudinal adhesive channel  624  ends at a right angle about two-thirds the length of the longitudinal section  610  wherein a rectangular space continues along the remainder of the longitudinal section  610  to the end of the longitudinal section  610 . 
         [0045]    Similarly, the latitudinal section  612  is comprised of a rectangular latitudinal guide structure  620  and a latitudinal adhesive channel  616 . The latitudinal guide structure  620  elongates along a segment of the latitudinal section  612  in the latitudinal direction beginning at the shoulder section  614 . The shoulder section may be square such that the edges of the longitudinal and latitudinal section are orthogonal. The latitudinal guide structure  620  ends at a right angle along the segment of the latitudinal section  612  wherein the latitudinal adhesive channel  616  continues along the latitudinal section  612  until the end of the latitudinal section  612 . Furthermore, the fourth embodiment includes a rectangular channel on the latitudinal section  612  opposite the latitudinal adhesive channel  616  and the latitudinal guide structure  620 . Furthermore, a thickness of the longitudinal section  610  may be substantially thicker than a thickness of the latitudinal section  612 . 
         [0046]    The flywheel weight  600  may contact two surfaces of a flywheel to attach the flywheel weight to the flywheel. In particular, the longitudinal guide structure  622  may contact a cylindrical side of the flywheel. As such, an interface surface of the longitudinal guide structure may be curved to fit the shape of the flywheel cylinder. Furthermore, the latitudinal guide structure  620  may contact a flat end surface of the flywheel. As such, an interface surface of the latitudinal guide structure may be substantially flat. 
         [0047]      FIGS. 7 and 12  show a fifth embodiment of a glue-on attachable flywheel weight  700 . The flywheel weight  700  is machined to fit a specific flywheel that differs from the flywheel referred to with respect to the first, second, third, and fourth embodiments. In particular, the flywheel weight  700  may be configured to attach to a flywheel via adhesive injection holes and supplemental set screws. The flywheel weight  700  is configured to attach to an exterior cylindrical side surface and an end surface of a flywheel. Moreover, the flywheel weight  700  may include a latitudinal section having a thickness that is substantially thinner that a thickness of a longitudinal section. 
         [0048]    In  FIG. 7 , the flywheel weight  700  has dimensions shown as an example, although it will be appreciated that variations on the depicted dimensions are possible without departing from the scope of the present description. The ring body  708  includes the latitudinal section  712  elongated in the latitudinal direction, the longitudinal section  710  elongated in the longitudinal direction and the shoulder section  714  that connects the latitudinal and longitudinal sections at an angle. In the fifth embodiment, a longitudinal section  710  is comprised of a rectangular longitudinal guide structure  722  and a longitudinal adhesive channel  724 . The longitudinal adhesive channel  724  elongates along a segment of the longitudinal section  710  in the longitudinal direction beginning at the shoulder section  714 . For example, the longitudinal adhesive channel  724  ends at a right angle along the segment of the longitudinal section  710  wherein the longitudinal guide structure  722  continues along the remainder of the longitudinal section  710  to the end of the longitudinal section  710 . 
         [0049]    The latitudinal section  712  is comprised of a rectangular latitudinal guide structure  720 . The latitudinal guide structure  720  elongates along a segment of the latitudinal section  712  in the latitudinal direction beginning at the shoulder section  714 . In this embodiment, a latitudinal adhesive channel is omitted. An interior portion of the shoulder section  714  joins the latitudinal section  712  and the longitudinal section  710  via a bevel or angle that is contoured to fit a beveled edge of the corresponding flywheel to which the flywheel weight  700  is configured to attach. In other words, the shoulder section may be beveled. The latitudinal section  712  and the longitudinal section  710  may be perpendicular to each other. 
         [0050]    The flywheel weight  700  may contact two surfaces of a flywheel to attach the flywheel weight to the flywheel. The attachment surfaces of the flywheel may be rounded. In particular, the longitudinal guide structure  722  may contact the cylindrical side of the flywheel. As such, an interface surface of the longitudinal guide structure may be curved to fit the shape of the flywheel cylinder. Furthermore, the latitudinal guide structure  720  may contact a flat end surface of the flywheel. As such, an interface surface of the latitudinal guide structure may be substantially flat. 
         [0051]    The flywheel weight  700  may include adhesive injection holes  726  that are formed in the longitudinal section  710 . The adhesive injection holes  726  may be oriented perpendicular to the longitudinal section and may extend entirely through the ring body  708 . The adhesive injection holes  726  may include threads  728  to receive set screws that may provide additional friction/clamping strength to the flywheel weight. For example, the flywheel weight may include four adhesive injection holes that are offset by ninety degrees around the circumference of the body  708 . 
         [0052]    When attaching the flywheel weight  700  to a flywheel adhesive may be injected to the adhesive injection holes into the adhesive channel  724 . Set screws  730  can be used to plug and unplug the adhesive injection holes to get the injected adhesive to fill all of the adhesive channels of the flywheel weight. The set screws  730  may hold the flywheel weight in place on the flywheel while the adhesive is injected and sets up. When the set screws are tightened down so that they protrude through the adhesive injection holes and contact the flywheel, the set screws may provide additional friction/clamping strength to attach the flywheel weight to the flywheel. The set screws may become permanently attached when the adhesive hardens, such that the set screws do not require re-tightening over time. The set screws may be employed in configurations where the flywheel weight is larger/heavier, such that the adhesive alone may not provide suitable attachment strength. 
         [0053]    In some embodiments, the flywheel weight may be attached to the flywheel with adhesive that includes friction balls that may increase friction between the flywheel weight and the flywheel in order to keep the flywheel weight centered and in balance on the flywheel. In particular, the friction balls may increase a contact surface area that is not covered by adhesive.  FIG. 13  shows an embodiment of the adhesive  106  that includes friction balls  109 . The adhesive  106  may be applied in a layer between the flywheel weight  100  and the flywheel  102 . For example, the friction balls  109  may be sized to fit the thickness of the adhesive layer. In one particular example, the friction balls may have a 0.005-inch diameter. In some embodiments, the friction balls may be sized slightly larger than the adhesive layer and may be compressed when the flywheel weight is attached to the flywheel to further increase the contact surface area. 
         [0054]    The friction balls may comprise any suitable material. For example, the friction balls may be made from silica or some other heat resistant material. Although the friction balls are depicted as being round in the illustrated embodiment, it will be appreciated that the friction balls may take any suitable shape. 
         [0055]    In some embodiments, the friction balls may be mixed into the adhesive and used instead of the raised portions/adhesive guide structures on the inner circumference of the flywheel weight, and the raised portions may be omitted from the flywheel weight such that the surfaces of the longitudinal and latitudinal sections are smooth. The channel guides and friction balls, alone or in combination, may prevent the flywheel weight from floating on the adhesive and moving off center and putting the flywheel out of balance when the flywheel weight is attached to the flywheel. The move off-center may cause the thickness of the adhesive to vary from the thickness needed for suitable strength for adherence. Accordingly, by keeping the flywheel weight centered on the flywheel a possibility of a reduction in strength of the attachment between the flywheel weight and the flywheel may be reduced. 
         [0056]      FIG. 14  shows an embodiment of a method  1400  for adding rotational mass to an engine flywheel. At  1402 , the method  1400  may optionally include mixing friction balls into adhesive. The friction balls may be mixed into the adhesive in any suitable manner. For example, the friction balls may be mixed with the adhesive until they are substantially evenly distributed throughout the adhesive. The friction balls may be applied to the adhesive prior to applying the adhesive to the flywheel weight. The friction balls may displace the adhesive and increase a contact surface area between the flywheel and the flywheel weight in order to increase the likelihood of the flywheel weight being centered and balanced on the flywheel when attached to the flywheel. In some embodiments, the friction balls may be used in place of adhesive guide structures or raised portions, and such structures may be omitted from the flywheel weight. 
         [0057]    At  1404 , the method  1400  may include applying adhesive to the flywheel weight. In one example, the adhesive may be applied to the flywheel weight in a 0.006 inch thick layer. 
         [0058]    In some embodiments, the flywheel weight may include a longitudinal adhesive channel. At  1406 , the method  1400  may optionally include applying adhesive to the longitudinal adhesive channel of the flywheel weight. 
         [0059]    In some embodiments, the flywheel weight may include a latitudinal adhesive channel. At  1408 , the method  1400  may optionally include applying adhesive to the latitudinal adhesive channel of the flywheel weight. 
         [0060]    In some embodiments, the flywheel weight may include adhesive injection holes. At  1410 , the method  1400  may optionally include applying adhesive through the adhesive injection holes to the adhesive channels. In some embodiments, the adhesive injection holes may be plugged with set screws to hold the flywheel weight in place on the flywheel while the adhesive is being applied. As such, the set screws may be removed one at a time to expose the corresponding adhesive injection hole in order to apply the adhesive to that hole. 
         [0061]    At  1412 , the method  1400  may include attaching the flywheel weight to the flywheel. For example, the flywheel weight may be attached to the flywheel such that a longitudinal section attaches to a cylindrical side surface of the flywheel and the latitudinal section attaches to an end surface of the flywheel that is perpendicular to the cylindrical side surface. Further, the latitudinal guide structure may direct the flywheel into longitudinal alignment with the flywheel weight, such that a position of the flywheel weight ring is sufficiently deeply mounted on the flywheel for proper adhesive bonding, and to avoid contact with an engine casing. 
         [0062]    In some embodiments, the flywheel weight may include adhesive injection holes and set screws. At  1414 , the method  1400  may optionally include tightening the set screws into the adhesive injection holes to provide additional friction/clamping strength. 
         [0063]    The above described method may provide an inexpensive solution for an amateur mechanic to increase a rotational inertia of a flywheel of a motorcycle. Moreover, by attaching a flywheel weight to the flywheel with adhesive (and set screws in some cases), repeated maintenance (e.g., tightening fasteners) to keep a flywheel weight attached to a flywheel may be eliminated. 
         [0064]    It is to be understood that references to “latitude” and “longitude” are relative to a position of the flywheel weight and not relative to geographic coordinates. Furthermore, the longitudinal axis corresponds to a rotational axis of the flywheel, and the latitudinal axis is orthogonal to the longitudinal axis of the flywheel. 
         [0065]    Although in many of the above described embodiments adhesive is described as being added to both the longitudinal and latitudinal channels, it will be appreciated that in some embodiments adhesive may be filled into only one channel and not the other of the longitudinal and latitudinal channels, even when both channels are provided. Further, in other embodiments only one of the longitudinal and latitudinal channels may be provided, and filled with adhesive. 
         [0066]    The embodiments disclosed herein are presented in view of the present invention. Other embodiments, forms, modes and applications are achievable while remaining within the scope of the description. Finally, it will be understood that the articles and methods described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense, because numerous variations are contemplated. Accordingly, the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various articles and methods disclosed herein, as well as any and all equivalents thereof.