Patent Publication Number: US-2017349233-A1

Title: Vehicle with structure for improved engine output

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 12/344,388 filed Dec. 26, 2008, the contents of which are fully incorporated herein by reference. Further, this application claims priority under 35 U.S.C. §119 from Japanese Patent Application No. 2008-300072, filed Nov. 25, 2008, Japanese Patent Application No. 2007-341417, filed Dec. 28, 2007, and Japanese Application No. 2008-066233, filed Mar. 14, 2008. The entirety of each of the foregoing applications is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Technical Field 
     Embodiments of the present invention relate to generally to a vehicle, such as a straddle-type vehicle. The vehicle can include an air cleaner coupled to an engine, and a catalyst for purifying exhaust gas discharged from the engine. 
     Background Art 
     Conventionally, a configuration wherein an air cleaner is disposed above an engine is widely used in straddle-type vehicles such as motorcycles. For example, JP-A-Sho 58-152115 discloses a construction for a straddle-type vehicle wherein an air cleaner is disposed above a crankcase provided in a lower part of the engine and in the rear of a cylinder block. 
     An exhaust pipe of the engine typically includes a catalyst for purifying exhaust gas. For example, JP-A-Sho 58-152115 further discloses a catalyst disposed in the exhaust pipe disposed below the engine. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention relate to a vehicle with a structure for improved engine output. The vehicle can be a straddle-type vehicle, such as a motorcycle. The vehicle can include an engine, a catalyst and an air cleaner. The catalyst can be disposed in an expansion chamber of the vehicle, thereby reducing the influence of heat from the catalyst on the air cleaner. At least a part of the air cleaner can be disposed above a swing arm of the vehicle, and at least a part of the expansion chamber can be disposed below the swing arm. Thus, the air cleaner and the expansion chamber can be sufficiently separated from each other that the influence of heat from the catalyst on the air cleaner can be further reduced. The air cleaner can further be disposed to the rear of a shock absorber of the vehicle. Thus, the air cleaner can be disposed in a position sufficiently remote from the engine that the influence of heat from the engine on the air cleaner can be reduced. Consequently, efficiency of air induction into the engine can be increased, thereby improving engine output. 
     More particularly, in embodiments of the invention, the straddle-type vehicle can comprise an engine, a vehicle body frame supporting the engine, a swing arm having a front part disposed to a rear of the engine and swingably supported by the vehicle body frame, and a rear part supporting a rear wheel. The straddle-type vehicle can further comprise a shock absorber having a lower part supported by the swing arm, and an upper part supported by the vehicle body frame and provided in front of the lower part. 
     The straddle-type vehicle can still further comprise an air cleaner disposed to a rear of the shock absorber and connected to the engine, and an expansion chamber provided below the shock absorber and including a catalyst for purifying exhaust gas discharged from the engine. At least a part of the air cleaner can be provided above the swing arm, and at least a part of the expansion chamber can provided below the swing arm. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a left side view of a vehicle, for example, a motorcycle, in accordance with a first exemplary embodiment of the present invention; 
         FIG. 2  is a right side view of the motorcycle in accordance with the first exemplary embodiment; 
         FIG. 3  is a partially enlarged perspective view showing structures of a swing arm, a shock absorber, and an air cleaner in accordance with the first exemplary embodiment; 
         FIG. 4  is a perspective view of an exhaust system in accordance with the first exemplary embodiment; 
         FIG. 5  is a perspective view showing an inner construction of an exhaust chamber in accordance with the first exemplary embodiment; 
         FIG. 6  is a side view showing a general construction of a motorcycle in accordance with a second exemplary embodiment of the present invention; 
         FIG. 7  is a view as seen from a direction of arrow P in  FIG. 8 ; 
         FIG. 8  is a side view of a vicinity of a main stand in a traveling state of the motorcycle in accordance with the second exemplary embodiment shown in  FIG. 6  as seen from one side; 
         FIG. 9  is a side view of a vicinity of the main stand in the traveling state of the motorcycle in accordance with the second exemplary embodiment shown in  FIG. 6  as seen from the other side; 
         FIG. 10  is a plan view of a vicinity of an exhaust chamber and the main stand in the traveling state of the motorcycle in accordance with the second exemplary embodiment shown in  FIG. 6 ; 
         FIG. 11  is a side view of a vicinity of the main stand in a standing-still state of the motorcycle in accordance with the second embodiment shown in  FIG. 6  as seen from one side; and 
         FIG. 12  is a left side view of a rear part of the motorcycle in accordance with the second exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention will now be described in more detail by way of example with reference to the embodiments shown in the accompanying Figures. It should be kept in mind that the following described embodiments are only presented by way of example and should not be construed as limiting the inventive concept to any particular physical configuration. It should further be understood that “exemplary” as used herein means “serving as an example, instance or illustration.” Any aspect referred to herein as “exemplary” is not necessarily to be construed as preferred over other aspects. 
     Further, if used and unless otherwise stated, the terms “upper,” “lower,” “front,” “back,” “over,” “under,” and similar such terms are not to be construed as limiting the invention to a particular orientation. Instead, these terms are used only on a relative basis. 
     Moreover, any term of degree used herein, such as “substantially”, “essentially” and “nearly”, means a reasonable amount of deviation of the modified word is contemplated such that the end result is not significantly changed. For example, such terms can be construed as allowing a deviation of at least 5% of the modified word if this deviation would not negate the meaning of the word the term of degree modifies. 
     First Exemplary Embodiment 
       FIG. 1  is a left side view of a vehicle  1010 , specifically, a motorcycle, according to a first exemplary embodiment of the invention. As shown in  FIG. 1 , the motorcycle  1010  can include a front wheel  1020  and a rear wheel  1090 . The motorcycle  1010  can further include an engine  1040  that can generate a driving force to drive the rear wheel  1090 . The engine  1040  can be mounted on a vehicle body frame  1030  forming a framework of the motorcycle  1010 . The engine  1040  can be, for example, a single-cylinder four-cycle engine. The engine  1040  can be air-cooled and have a comparatively small displacement. It should be understood that embodiments of the invention are not limited in respect of the kind of engine used, and that the use of other kinds of engines is possible. 
     A fuel tank  1051  for storing fuel can be disposed above the engine  1040 . A seat  1052  for seating a rider can be disposed in the rear of the fuel tank  1051 . 
     The rear wheel  1090  can be supported by a swing arm  1060  that is swingable in a generally vertical direction. It should be understood that as used herein, “vertical” or “vertical direction” refers, for example, to a substantially up-and-down direction or arrangement or posture, with respect to the ground, for the motorcycle  1010  or a motorcycle  2001  (see  FIG. 6 ) or components thereof, in a view as in  FIG. 1  or  FIG. 6 , for example, which can be assumed by the motorcycle  1010  or  2001  when it is standing still or traveling in a substantially upright position. 
     The swing arm  1060  can be provided to the rear of the engine  1040 . The swing arm  1060  can include a pair of arms  1062 L and  1062 R (see  FIG. 3 ) for rotatably supporting an axle  1091  of the rear wheel  1090 . The vehicle body frame  1030  can include a pivot part  1034  (see  FIG. 2 ) for swingably supporting the swing arm  1060 . 
     A shock absorber  1070  for absorbing shocks to the rear wheel  1090  can be coupled to a front part  1060   a  of the swing arm  1060 . A rear part  1060   b  of the swing arm  1060  can rotatably support the rear wheel  1090 . The shock absorber  1070  can extend upward from the front part  1060   a  of the swing arm  1060 . In the first exemplary embodiment, the swing arm  1060  and the shock absorber  1070  can form a suspension unit on which the rear wheel  1090  is suspended. The shock absorber  1070  can include a lower part  1070 D (see  FIG. 2 ) supported by the front part  1060   a  of the swing arm  1060 , and an upper part  1070 U (see  FIG. 2 ) supported by the vehicle body frame  1030  and provided in front of the lower part  1070 D. 
     An exhaust system  1100  can be coupled to the engine  1040 . In the exhaust system  1100 , an exhaust pipe  1110  can be coupled to a cylinder head  1040   a  of the engine  1040 . 
       FIG. 2  is a right side view of the motorcycle  1010  (from a perspective of rider, for example, seated on the seat  1052  and facing forward toward the front wheel  1020 ). It should be understood that the motorcycle  1010  can include a vehicle body cover, not shown in  FIG. 2 , which would ordinarily cover at least a part of the motorcycle  1010  in the right side view. 
     As shown in  FIG. 2 , the vehicle body frame  1030  can include a main frame  1031 , a down tube  1032 , seat rails  1033 , and a center frame  1037 . The main frame  1031  can extend rearward from a head pipe  1038 . The down tube  1032  can extend downwardly obliquely rearward from the head pipe  1038 . 
     The seat rails  1033  can be coupled to the main frame  1031  via a bracket  1035 . Stays  1036  for supporting a silencer  1190  can be coupled to the seat rail  1033 . 
     The center frame  1037  can extend along a substantially vertical direction with respect to the motorcycle  1010 , to the rear of the engine  1040 . For example, the center frame  1037  can be positioned in a substantially central (with respect to an overall front-to-rear or rear-to-front length of the motorcycle  1010  as seen, for example, in the views of  FIG. 1  or  FIG. 2 ) part of the motorcycle  1010 ,. The center frame  1037  can include an upper part  1037 U for supporting the shock absorber  1070 , an intermediate part  1037 M for supporting the swing arm  1060 , and a lower part  1037 D for supporting an exhaust chamber  1120 . The shock absorber  1070  can be supported by the upper part  1037 U via the bracket  1035 . 
     The pivot part  1034  can be provided in the intermediate part  1037 M of the center frame  1037 . In other words, the center frame  1037  can pivotably support the swing arm  1060 . The motorcycle  1010  can comprise a single center frame  1037 , or a plurality of center frames  1037 . In the first exemplary embodiment, the center frame and a part of the bracket  1035  can form a vertical frame part. 
     An upper end  1070   b  (see  FIG. 3 ) of the shock absorber  1070  can be coupled (e.g., directly coupled, with no link mechanism interposed therebetween) to the bracket  1035 . A lower end  1070   a  (see  FIG. 3 ) of the shock absorber  1070  can be coupled (e.g., directly coupled) to the swing arm  1060 . 
     An air cleaner  1041  for purifying air to be supplied to the engine  1040  can be disposed between the right and left seat rails  1033 . The air cleaner  1041  can be disposed to the rear of the shock absorber  1070 , and above the swing arm  1060 . The air cleaner  1041  can be disposed to the rear of the center frame  1037 . 
     More particularly, the air cleaner  1041  can be disposed adjacent to or adjoining the upper end  1070   b  of the shock absorber  1070  to the rear of the upper end  1070   b  (or the upper part  1070 U). At least a part of the air cleaner  1041  can be provided below the upper part  1070 U of the shock absorber  1070  and below an upper end  1090   a  of the rear wheel  1090 . 
     Still referring to  FIG. 2 , the air cleaner  1041  can be coupled to the cylinder head  1040   a  via an intake duct  1043 . A carburetor  1042  for injecting fuel can be mounted on the intake duct  1043 . Air from the air cleaner  1041  can be mixed with fuel by the carburetor  1042 , and thereafter introduced into the engine  1040 . 
     The exhaust system  1100  can include the exhaust pipe  1110 , an exhaust chamber  1120  and the silencer  1190 . The exhaust chamber  120  can be provided below the shock absorber  1070  and communicatively connected to the exhaust pipe  1110 . The silencer  1190  can be communicatively connected to the exhaust chamber  1120  via a connecting pipe  1170  (see  FIG. 3 ). Thus, the exhaust chamber  1120  can be provided between the engine  1040  and the silencer  1190 . 
     The exhaust chamber  1120  can be disposed below the suspension unit formed by the swing arm  1060  and the shock absorber  1070 . More specifically, the exhaust chamber  1120  can be provided between the vehicle body frame  1030  and the rear wheel  1090  below the swing arm  1060 . The exhaust system  1100  can include a reflux pipe  1160  communicatively connected to a lower part of the exhaust chamber  1120 . The reflux pipe  1160  can reflux exhaust gas to the exhaust chamber  1120 . The reflux pipe  1160  can extend from the exhaust chamber  1120  to a part below a rear part of the engine  1040 . 
     Exhaust gas discharged from the engine  1040  via the exhaust pipe  1110  can expand in the exhaust chamber  1120 . Thus, in the first exemplary embodiment, the exhaust chamber  1120  can form an expansion chamber. 
     The silencer  1190  can be positioned at a rear end of the exhaust system  1100 . For example, the silencer  1190  can disposed on the right side (as seen, for example, from the perspective of a rider seated on the seat  1052  and facing the front wheel  1020 ) of the rear wheel  1090 . Exhaust gas can be discharged from a rear end  1190   a  of the silencer  1190 . 
     The exhaust chamber  1120  and the silencer  1190  can reduce exhaust noise generated by the engine  1040 . Because the exhaust chamber  1120  can be provided, the silencer  1190  can be made smaller in size than would be the case if the exhaust chamber  1120  were not provided. Thus, the overall length of the exhaust system  1100  can be shorter compared to the case where the exhaust chamber  1120  is not provided. 
     Suspension Unit and Air Cleaner 
     As noted above, a suspension unit according to embodiments of the invention can include the swing arm  1060  and the shock absorber  1070 .  FIG. 3  is a partially enlarged perspective view showing aspects of the swing arm  1060  and the shock absorber  1070 .  FIG. 3  further illustrates aspects of the air cleaner  1041 . 
     As shown in  FIG. 3 , the swing arm  1060  can include supported parts  1061 L and  1061 R, the arms  1062 L and  1062 R, a bridge  1063 , and a rear fender  1065 . The rear fender  1065  can cover a part of the rear wheel  1090 . 
     The supported parts  1061 L and  1061 R can be supported by the vehicle body frame  1030 . The arms  1062 L and  1062 R can be integral with the supported parts  1061 L and  1061 R and rotatably support the axle  1091  of the rear wheel  1090 . 
     The bridge  1063  can couple the arms  1062 L and  1062 R together. A gap G can be formed between the supported parts  1061 L and  1061 R and the bridge  1063 . 
     A bracket  1064  can be mounted on the bridge  1063 . The lower end  1070   a  of the shock absorber  1070  can be coupled to the bracket  1064 . 
     The exhaust chamber  1120  can be disposed to the rear of the supported parts  1061 L and  1061 R, and below a part at which the shock absorber  1070  and the swing arm  1060  are coupled together. Specifically, the exhaust chamber  1120  can be disposed below the gap G and the bridge  1063 . 
     The shock absorber  1070  can include a damper  1071  and a coil spring  1072 . The damper  1071  can absorb shocks to the rear wheel  90  by reciprocal motion. The damper  1071  can, for example, be formed in the shape of a cylinder. The damper  1071  can be disposed such that a component of a direction in which it is arranged is substantially vertical (e.g., substantially or approximately parallel to a direction of the center frame  1037  as described above). The coil spring  1072  can be disposed around an outer periphery of the damper  1071 . 
     A recess  1041   a  curved along a shape of the outer periphery of the shock absorber  1070  can be formed at a front end of the air cleaner  1041 . The intake duct  1043  can be disposed on the left side (e.g., from the perspective of a forward-facing rider as described above) of the recess  1041   a.  The air cleaner  1041  can be formed to become thinner in a rearward direction, to correspond to an interval between the upper and lower seat rails  1033 . 
     Exhaust System 
       FIG. 4  is a perspective view of the exhaust system  1100 . As shown in  FIG. 4 , the exhaust chamber  1120  can be communicatively connected to the exhaust pipe  1110 . The reflux pipe  1160  can be communicatively connected to a front end  1120   a  of the exhaust chamber  1120 . A protrusion  1120   b  protruding upward can be formed on the exhaust chamber  1120 . The protrusion  1120   b  can be positioned below the gap G. 
     A mounting part  1123  (see  FIG. 5 ) can be provided on the exhaust chamber  1120 . Furthermore, a mounting part  1124  (see  FIG. 5 ) can be provided on the reflux pipe  160 . The exhaust chamber  1120  can be mounted on the vehicle body frame  1030  using the mounting parts  1123  and  1124 . 
     The connecting pipe section  1170  can be communicatively connected to the exhaust chamber  1120 . The silencer  1190  can be communicatively connected to the connecting pipe  1170 . A protector  1191  can be provided on the outside of the silencer  1190 . 
       FIG. 5  is a perspective view of the exhaust chamber  1120  and the reflux pipe  1160  which can form the expansion chamber according to the first exemplary embodiment.  FIG. 5  illustrates an inner construction of the exhaust chamber  1120 . In  FIG. 5 , on the lower right-hand side, “F” indicates “Front” and “R” indicates “Rear.” 
     As shown in  FIG. 5 , a catalyst  1121  for purifying exhaust gas discharged from the engine  1040  can be disposed in the exhaust chamber  1120 . The exhaust chamber  1120  can, for example, be box-shaped, but other shapes are possible for the exhaust chamber  1120 . The catalyst  1121  can be coupled to the exhaust pipe  1110 . Exhaust gas having passed through the exhaust pipe  1110  can be guided into the catalyst  1121 . 
     A communication section  1122  can be communicatively connected to the catalyst  1121 . The communication section  1122  can be communicatively connected to the reflux pipe  1160 , specifically, to a first pipe section  1131 . 
     An opening  1122   a  can be formed in the communication section  1122 . For example, the opening  1122   a  can be formed in the immediate rear of the catalyst  1121 . The opening  1122   a  can be formed in an upper surface of the communication section  1122 . An opening (not shown) similar to the opening  1122   a  can be formed in a lower surface of the communication section  1122  facing the opening  1122   a.  In other words, two openings can be formed in the communication section  1122 . A mesh part  1125  can be provided on an inner bottom surface of the exhaust chamber  1120 . 
     The reflux pipe  1160  can include the first pipe section  1131 , a second pipe section  1132 , and a folded pipe section  1133 . The first pipe section  1131  can extend from the exhaust chamber  1120  to the front of the motorcycle  1010  (direction F in  FIG. 2 ). 
     The second pipe section  1132  can be communicatively connected to the first pipe section  1131  via the folded pipe section  1133  and to the exhaust chamber  1120 . The second pipe section  1132  can be communicatively connected to the exhaust chamber  1120  from the front side of the motorcycle  1010 . In the first exemplary embodiment, the exhaust pipe  1110  can be disposed generally or substantially in parallel with the first pipe section  1131  and the second pipe section  1132 . In other words, the exhaust pipe  1110  can also be communicatively connected to the exhaust chamber  1120  from the front side of the motorcycle  1010 . 
     The folded pipe section  1133  can couple the first pipe section  1131  and the second pipe section  1132  together. In other words, exhaust gas having passed through the first pipe section  1131  can be guided to the second pipe section  1132  via the folded pipe section  1133 . 
     The second pipe section  1132  can include a protrusion  1141  protruding into the exhaust chamber  1120 . Exhaust gas discharged from the communication section  1122  to the reflux pipe  1160  can be discharged from the protrusion  1141  into the exhaust chamber  1120 . Exhaust gas discharged from the protrusion  1141  can expand in the exhaust chamber  1120 . Thus, exhaust chamber  1120  can function as an expansion chamber. 
     Exhaust holes  1141   a  can be formed in an outer periphery of the protrusion  1141 . Each exhaust hole  1141   a  can be circular, for example, though other shapes are possible for the exhaust holes  1141   a.  A large number of exhaust holes  1141  can be formed in the outer periphery of the protrusion  1141 . Exhaust gas can be discharged into the exhaust chamber  120  via the exhaust holes  1141   a.    
     In the first exemplary embodiment, an end of the protrusion  1141  can be sealed. For example, a cap  1142  can be mounted on the end of the protrusion  1141 . 
     In view of the foregoing discussion, embodiments of the invention have a number of advantages. For example, the embodiments can facilitate a reduction in the influence of heat generated by the catalyst  1121  and the engine  1040  on the air cleaner  1141 . Thus, efficiency of air induction into the engine, and consequently engine output, can be improved. 
     The advantages can be realized at least in part by the above-described structures. For example, the catalyst  1121 , which emits heat, can be disposed in the exhaust chamber  1120 . The exhaust chamber  1120  can function as an expansion chamber, as described above. Because the catalyst  1121  can be disposed in the expansion chamber, it can be made more difficult for heat emitted by the catalyst  1121  to be transmitted to the outside of the expansion chamber. 
     As another example, the air cleaner  1041  can be disposed to the rear of the shock absorber  1070 , and above the swing arm  1060 . In addition, the exhaust chamber  1120  can be disposed below the shock absorber  1070  and the swing arm  1060 . Accordingly, the air cleaner  1041  and the exhaust chamber  1120  can be sufficiently separated from each other that the influence of heat from the catalyst  1121  on the air cleaner  1141  can be reduced. Further, the swing arm  1060  and the shock absorber  1070  can be disposed to the rear of the engine  1040 . The air cleaner  1041  can be disposed to the rear of the center frame  1037  positioned to the rear of the engine  1040 . Thus, the air cleaner  1041  can be disposed in a position sufficiently remote from the engine  1040  that the influence of heat from the engine  1040  on the air cleaner  1041  can be reduced. 
     Further, in the first exemplary embodiment, the air cleaner  1041  can be disposed to the rear of the upper end  1070   b  of the shock absorber  1070 . The air cleaner  1041  can be adjacent to or adjoin the upper end  1070   b  of the shock absorber  1070 . Thus, the air cleaner  1041  can be disposed in a position sufficiently remote from the catalyst  1121  and the engine  1040  to allow further reduction in influence of heat emitted by the engine  1040  and the catalyst  1121  on the air cleaner  1041 . 
     Still further, in the first exemplary embodiment, the exhaust chamber  1120  can be disposed below the swing arm  1060 . Accordingly, the exhaust chamber  1120  can be remotely positioned from the air cleaner  1041 , to allow further reduction in influence of heat emitted by the catalyst  1121  in the exhaust chamber  1120  on the air cleaner  1041 . 
     Still further, in the first exemplary embodiment, the recess  1041   a  curved along the shape of the outer periphery of the shock absorber  1070  can be formed at the front end of the air cleaner  1041 . Therefore, a sufficient capacity of the air cleaner  1041  can be secured and at the same time the air cleaner  1041  can be disposed to be adjacent to or adjoin the shock absorber  1070 . Accordingly, reduction in influence of heat emitted by the engine  1040  and the catalyst  1121  on the air cleaner  1041  can be made compatible with prevention of a size increase of the motorcycle  1010 . 
     Still further, in the first exemplary embodiment, the intake duct  1043  extending from the air cleaner  1041  toward the engine  1040  can be disposed on the left side of the recess  1041   a.  Therefore, interference between the intake duct  1043  and the shock absorber  1070  can be prevented and at the same time the air cleaner  1041  can be disposed to be adjacent to or adjoin the shock absorber  1070 . 
     Still further, in the first exemplary embodiment, the lower end  1070   a  of the shock absorber  1070  can be directly coupled to the swing arm  1060  with no link mechanism interposed therebetween. Therefore, the shock absorber  1070  does not project below the swing arm  1060  when the swing arm  1060  swings. Accordingly, the exhaust chamber  1120  can be disposed close to the swing arm  1060  without interference between the exhaust chamber  1120  and the swing arm  1060 . 
     Still further, in the first exemplary embodiment, the reflux pipe  1160  can be provided outside the exhaust chamber  1120 . This can facilitate securing an exhaust passage of a required length. Moreover, this can increase the substantial capacity of the exhaust chamber  1120  compared to the case wherein an exhaust pipe of a length equivalent to the reflux pipe  1160  is disposed in the exhaust chamber  1120 . Accordingly, a reduction in exhaust noise can be achieved. 
     Still further, in the first exemplary embodiment, the swing arm  1060  can include the pair of arms  1062 L and  1062 R and the bridge  1063  coupling the pair of arms  1062 L and  1062 R together. The lower end  1070   a  of the cushion unit  1070  can be coupled to the bridge  1063 . Thus, the heavy cushion unit  1070  can be disposed in the central position of the vehicle, and traveling stability of the motorcycle  1010  can be enhanced. This allows absorption of shocks to the rear wheel  1090  by the single cushion unit  1070 . 
     Second Exemplary Embodiment 
       FIG. 6  is a side view showing a general construction of a vehicle  2001 , such as a motorcycle, in accordance with a second exemplary embodiment of the present invention.  FIGS. 7 through 12  are drawings to illustrate details of structures of an exhaust chamber and a vicinity of a main stand of the motorcycle in accordance with the second embodiment shown in  FIG. 6 . In the figures, “FWD” (see, e.g., the upper left-hand side of  FIG. 6 ) indicates the forward traveling direction of the motorcycle. A construction of a motorcycle  2001  in accordance with the second exemplary embodiment will be described hereinafter in detail with reference to  FIGS. 6 through 12 . 
     In the motorcycle  2001 , as shown in  FIG. 6 , a main frame  2003  extending in the front-to-rear or rear-to-front direction can be disposed to the rear of a head pipe  2002 . As shown in  FIGS. 6 and 7 , a pair of pivot supporting plates  2004  and  2005  extending downward can be provided in a vicinity of a substantially central (e.g., with respect to an overall front-to-rear or rear-to-front length of the motorcycle  2001  as seen, for example, in the view of  FIG. 6 ) part of the main frame  2003 . 
     As shown in  FIG. 8 , a pivot part  2004   a  for swingably supporting a swing arm  2006  around a vicinity of a front end of the swing arm  2006  can be provided on the pivot supporting plate  2004 . As shown in  FIG. 9 , a pivot part  2005   a  for supporting a swing arm  2007  swingably around a vicinity of a front end of the swing arm  2007  can be provided on the pivot supporting plate  2005 . A rear wheel  2008  can be rotatably mounted on a vicinity of a rear end of each of the swing arms  2006  (see  FIGS. 8 ) and  2007  (see  FIG. 9 ). As shown in  FIG. 7 , a connecting member  2009  extending in the vehicle width direction (corresponding to arrows X 1  and X 2 , indicating a direction substantially transverse to a front-to-rear or rear-to-front direction as illustrated, for example, in  FIG. 6 ) can be mounted on a lower end of each of the pair of pivot supporting plates  2004  and  2005 . Referring to  FIG. 7 , each of a pair of mounting members  2010  and  2011  can be mounted on a lower surface of the connecting member  2009  to extend downward. Each of the mounting members  2010  and  2011  can be provided for rotatably mounting a main stand  2026 . The main stand  2026  can include a pair of support legs for supporting the vehicle  2001  in a stationary of standing-still state, and a coupling part coupling the pair of the support legs together. The main stand  2026  can be capable of being positioned into a moving or traveling state. The main stand  2026  is described in more detail further on. 
     Returning now to  FIG. 6 , a back stay  2012  can be mounted between a rear part of the main frame  2003  and the pivot supporting plate  2004 . A back stay  2013  can be mounted between the rear part of the main frame  2003  and the pivot supporting plate  2005 . A vehicle body frame can be formed by the head pipe  2002 , the main frame  2003 , the pivot supporting plates  2004  and  2005 , the connecting member  2009  (see  FIG. 7 ), and the back stays  2012  and  2013 . 
     Handlebars  2014  can be rotatably mounted on an upper part of the head pipe  2002 . A headlight  2015  can be provided in front of the head pipe  2002 . A pair of front forks  2016  having suspensions for absorbing shocks in the vertical direction can be disposed below the head pipe  2002 . A front wheel  2017  can be rotatably mounted on lower ends of the pair of the front forks  2016 . 
     A seat  2018  can be disposed in an upper part in the rear of the main frame  2003 . A fuel tank  2019  can be disposed in front of the seat  2018 . 
     An engine retaining member  2020  can be mounted below the main frame  2003 . An engine  2021  can be suspended on the engine retaining member  2020 . The engine  2021  can be a parallel four-cylinder engine in which four cylinders (not shown) are arranged in the vehicle width direction. It should be understood that embodiments of the invention are not limited in respect of the kind of engine used, and the use of other kinds of engines is possible. The engine  2021  can include a crankcase  2021   a  in which a crankshaft (not shown) is disposed to extend in the vehicle width direction, and a cylinder block  2021   b  extending upwardly forward from an upper part of the crankcase  2021   a.  The four cylinders (not shown) can be arranged in the crankcase  2021   a  in the vehicle width direction. A cylinder head  2021   c  can be disposed in an upper part of the cylinder block  2021   b.    
     A drive chain  2022  for transmitting driving force generated in the engine  2021  to the rear wheel  2008  can be guided out from a rear part of the crankcase  2021   a.  The drive chain  2022  can be guided out to extend rearward and meshed with a driven sprocket  2008   a  provided in the rear wheel  2008 . 
     One end of each of four exhaust pipes  2023  for guiding out exhaust gas can be mounted on a front side of the cylinder head  2021   c.  Each of the exhaust pipes  2023  can extend downward from the front side of the cylinder head  2021   c,  thereafter curve rearward, and extend to a lower part in the rear of the engine  2021 . 
     In the second exemplary embodiment, as shown in  FIGS. 8 and 10 , the other end of each of the four exhaust pipes  2023  can be connected to a single exhaust chamber  2024 . As shown in  FIG. 6 , the exhaust chamber  2024  can be disposed between the engine  2021  and the rear wheel  2008 , and can have a function of purifying exhaust gas discharged from the engine  2021  and of reducing exhaust noise. The exhaust chamber  2024  can form an expansion chamber in the second exemplary embodiment. 
     The exhaust chamber  2024  can be disposed such that its rear end  2024   a  (see  FIG. 10 ) is positioned in front of the rear wheel  2008  and a prescribed interval is interposed between the rear end  2024   a  and a front part of the rear wheel  2008 . The interval between the front part of the rear wheel  2008  and the rear end  2024   a  (see  FIG. 10 ) of the exhaust chamber  2024  can be configured such that an upper part of the interval is wider than a lower part of the interval (e.g., due to an upward curvature of the rear wheel  2008  out of the plane of  FIG. 10 ). 
     In the second exemplary embodiment, as shown in  FIG. 10 , an exhaust outlet  2024   b  for discharging exhaust gas can be mounted on a rear part of the exhaust chamber  2024   a.  The exhaust outlet  2024   b  can extend rearward substantially in the direction of arrow X 2 . As shown in  FIG. 9 , the exhaust outlet  2024   b  can be disposed between the main stand  2026  (see, e.g.,  FIG. 6 ) in a traveling state that will be described later and the swing arm  2007 , and thus can be formed such that exhaust gas discharged from the exhaust outlet  2024   b  does not directly hit the rear wheel  2008 . A cover member  2025  can be provided to cover an outer periphery of the exhaust outlet  2024   b.  As shown in  FIG. 10 , an end of the exhaust outlet  2024   b  can be housed in the cover member  2025  so as not to project out from the cover member  2025  in a plan view. 
     Still referring to  FIG. 10 , an end (outermost part)  2024   c  of the exhaust outlet  2024   b  can be positioned further in the direction of arrow X 1  (e.g., further inward or leftward in the view of  FIG. 10 ) than an outermost part  2026   a  of the main stand  2026 , described in more detail further on. Further, similarly to the exhaust outlet  2024   b,  an end  2025   a  of the cover member  2025  can be positioned further in the direction of arrow X 1  than the outermost part  2026   a  in of the main stand  2026 . 
     In the second exemplary embodiment, the main stand  2026  can have a rotational center or axis  2026   b  on either side of the exhaust chamber  2024  in the vehicle width direction (directions of arrows X 1  and X 2 ). The main stand  2026  may be referred to herein as a “first stand.” The main stand  2026  can be formed to be capable of being positioned into a traveling state, for example by being turned or rotated upward. For example, the vehicle  2001  can travel with a pair of support legs  2027  and  2028  turned up rearward (see, e.g., the state illustrated in  FIG. 8 ). As shown in  FIG. 8 , the rotational center or axis  2026   b  of the main stand  2026  can be provided above a lowest part  2024   d  of a lower surface of the exhaust chamber  2024 . The main stand  2026  can be constructed such that a lowest part  2026   c  of the main stand  2026  is positioned above the lowest part  2024   d  of the exhaust chamber  2024  in the traveling state (the state of  FIG. 8 ). In other words, the main stand  2026  can be constructed such that a whole of the main stand  2026  is positioned above the lowest part  2024   d  of the exhaust chamber  2024  in the traveling state. 
     In the second exemplary embodiment, as shown in  FIGS. 10 and 11 , the main stand  2026  can include the pair of support legs  2027  and  2028  described above for supporting the vehicle in a stationary or standing-still state (e.g. a state as illustrated in  FIG. 11 ) and a cross pipe  2029  for coupling the pair of support legs  2027  and  2028  together. The cross pipe  2029  may be referred to herein as a “coupling part.” As shown in  FIG. 10 , the support leg  2027  can be positioned on a side of the exhaust chamber  2024  in the direction of arrow X 1 , and the support leg  2028  can be positioned on a side of the exhaust chamber  2024  in the direction of arrow X 2 . In other words, the main stand  2026  can be constructed such that, in the traveling state (see  FIGS. 8 and 10 ), components of the main stand  2026 , such as the support legs  2027  and  2028 , are respectively positioned outside, in the vehicle width direction (directions of arrows X 1  and X 2 , respectively), of outer surfaces of the exhaust chamber  2024 . 
     Referring now to  FIGS. 7 and 10 , one end of the support leg  2027  can be rotatably mounted on the mounting member  2010 . Specifically, as shown in  FIGS. 7 and 10 , a bearing member  2027   a  can be mounted on the one end of the support leg  2027 . The support leg  2027  can be fixed or fastened, for example, by one or more fixing or fastening members, such as a screw member  2050  and a nut  2051 , with the bearing member  2027   a  inserted between a plate  2010   a  for one side and a plate  2010   b  for the other side of the mounting member  2010 . As shown in  FIG. 10 , the support leg  2027  can be formed into a curved shape in which the other end (the end for contacting with the ground) curves outward (direction of arrow X 1 ). A reinforcing member  2027   b  can be mounted on the curved part of the support leg  2027 . This placement of the reinforcing member  2027   b  can be advantageous because a load of the vehicle  2001  may concentrate at the curved part in the standing-still state. An end of the cross pipe  2029  in the direction of arrow X 1  can be fixed or fastened to, e.g., welded to, a vicinity of the other end (the end for contacting with the ground) of the support leg  2027 . A side protruding member  2027   c,  for the rider to engage with his/her foot (e.g. to push) to easily turn or otherwise position the main stand  2026  to or in the standing-still state can be formed on, or fixed or fastened to, e.g., welded to, a vicinity of the part of the support leg  2027  to which the cross pipe  2029  is fastened. 
     A ground contacting plate  2027   d  which can contact with the ground with a surface can be mounted on the end of the support leg  2027  for contacting with the ground. As shown in  FIG. 7 , an end  2027   e  of the ground contacting plate  2027   d  can be formed to incline at an angle equal to or less than bank angle α 1  described in more detail further on. 
     As shown in  FIG. 10 , one end of the support leg  2028  can be rotatably mounted on the mounting member  2011 . Specifically, as shown in  FIGS. 7 and 10 , a bearing member  2028   a  can be mounted on the one end of the support leg  2028 . The support leg  2028  can be fixed or fastened, for example, by one or more fixing or fastening members, such as a screw member  2052  and a nut  2053 , with the bearing member  2028   a  inserted between a plate  2011   a  for one side and a plate  2011   b  for the other side of the mounting member  2011 . As shown in  FIG. 10 , a spring mounting member  2028   b  extending in the direction of arrow X 2  can be mounted between the one end and the other end of the support leg  2028 . One end of a tension coil spring  2030  can be mounted on the spring mounting member  2028   b.  The other end of the tension coil spring  2030  can be connected to an end of the connecting member  2009  in the direction of arrow X 2  via a member  2030   a,  which may, for example, be formed from sheet metal. The outermost part  2026   a  of the main stand  2026 , as illustrated in  FIG. 10 , for example, may correspond to a part of the tension coil member  2030 . As described above, the outermost part  2026   a  of the main stand  2026  can be positioned outside, in the direction of arrow X 2 , of the end  2024   c  of the exhaust outlet  2024   b  of the exhaust chamber  2024 , and of the point  2025   a  of the cover member  2025 . An end of the cross pipe  2029  in the direction of arrow X 2  can be fixed or fastened to, e.g., welded, the support leg  2028  in a vicinity of the other end of the support leg  2028 . 
     A ground contacting plate  2028   c  which can contact with the ground with a surface is mounted on the other end (the end contacting with the ground) of the support leg  2028 . As shown in  FIG. 7 , an end  2028   d  of the ground contacting plate  2028   c  can be formed to incline at an angle equal to or less than bank angle α 1  described later. 
     In the second exemplary embodiment, as shown in  FIG. 8 , the cross pipe  2029  can be positioned between the exhaust chamber  2024  and the rear wheel  2008  in the traveling state. Specifically, as shown in  FIG. 7 , a vicinity of a central part of the cross pipe  2029  in the vehicle width direction (directions of arrows X 1  and X 2 ) can extend downward in the traveling state. As shown in  FIG. 8 , the vicinity of the central part of the cross pipe  2029  in the vehicle width direction (directions of arrows X 1  and X 2 ) can be positioned in a lower part of the interval between the exhaust chamber  2024  and the rear wheel  2008 , a region where the interval is wider than in an upper part, due to a rearward curvature of the wheel  2008  as it approaches a point where it contacts the ground. A lower end of the cross pipe  2029  can be positioned above a lower end of the exhaust chamber  2024 . Therefore, decrease in the ground clearance of the motorcycle  2001  can be prevented even if the cross pipe  2029  extends downward as in the second exemplary embodiment. 
     As shown in  FIG. 10 , the cross pipe  2029  can at least partly overlap with the rear wheel  2008  in a plan view in the traveling state. Thus, the cross pipe  2029  can be formed to avoid a part protruding forward of the rear wheel  2008 , by being positioned below the part protruding forward. 
     In the second exemplary embodiment, as shown in  FIG. 7 , vicinities of both ends of the cross pipe  2029  in the vehicle width direction (directions of arrows X 1  and X 2 ) can be formed to incline at inclination angles α 2  and α 3 , respectively, that are equal to or less than the maximum leaning angle (bank angle α 1 ) of the vehicle with respect to the vertical direction in the traveling state (e.g., a substantially up-and-down posture, with respect to the ground, assumed by the vehicle  2001  when it is moving or traveling). Thus, the cross pipe  2029  can avoid the part protruding forward of the rear wheel  2008  by being positioned below the part and at the same time can be formed within bank angle α 1 . It should be understood that inclination angles α 1 , α 2  and α 3  can be described as inclined inward (e.g., toward a center or vertical axis of  FIG. 7 ). 
     In the second exemplary embodiment, bank angle α 1  described above may be the maximum leaning angle of the vehicle in the case that the motorcycle  2001  is leaned in direction A 1  or A 2  in  FIG. 7 . Further, the motorcycle  2001  in accordance with the second exemplary embodiment can include bank sensors  2031  and  2032  for making the rider conscious of bank angle α 1 . Specifically, as shown in  FIGS. 8 and 9 , brackets  2033   a  and  2034   a  can be mounted on a pair of plate members  2033  and  2034  (see  FIG. 7 ). Steps  2035  and  2036 , on which the rider can place his/her feet, can be mounted on the brackets  2033   a  and  2034   a,  respectively. The steps  2035  and  2036  can be provided to extend in the directions of arrows X 1  and X 2 , respectively. The bank sensors  2031  and  2032  can be mounted on lower parts of the steps  2035  and  2036 , respectively. Each of the bank sensors  2031  and  2032  may be referred to herein as a “restraint member.” 
     As shown in  FIG. 7 , the bank sensor  2031  may first contact with the ground when the motorcycle  2001  is leaned in direction A 1  in  FIG. 7 . Accordingly, the bank sensor  2031  can make the rider conscious of bank angle α 1  (maximum leaning angle) of the vehicle with respect to the vertical direction when the vehicle is leaned in direction A 1 . The bank sensor  2032  may first contact with the ground when the motorcycle  2001  is leaned in direction A 2  in  FIG. 7 . Thus, the bank sensor  2032  can make the rider conscious of bank angle α 1  (maximum leaning angle) of the vehicle with respect to the vertical direction when the vehicle is leaned in direction A 2 . 
     As shown in  FIG. 10 , a side stand  2037  for supporting the vehicle in a leaned state can be mounted on an end of the connecting member  2009  in the direction of arrow X 1 . The side stand  2037  may be referred to herein as a “second stand.” The side stand  2037  can include a support leg  2038  and can rotate around one end of the support leg  2038 . A spring mounting member  2038   a  can be mounted on a side of the support leg  2038  in the direction of arrow X 2 . One end of a tension coil spring  2039  can be mounted on the spring mounting member  2038   a.  The other end of the tension coil spring  2039  can rotatably retain the support leg  2038  and can be connected to a mounting member  2037   a  capable of mounting the side stand  2037  on the connecting member  2009 . 
     In the second exemplary embodiment, as shown in  FIG. 8 , a lowest part  2037   b  of the side stand  2037  can be positioned above the lowest part  2026   c  of the main stand  2026  in the traveling state. As shown in  FIG. 7 , the side stand  2037  can be positioned above a borderline for bank angle α 1  shown in  FIG. 7  in the traveling state. 
       FIG. 12  is a left side view of a rear part of the motorcycle  2001 . It should be understood that the motorcycle  2001  can include a vehicle body cover, not shown in  FIG. 12 , which would ordinarily cover at least a part of the motorcycle  2001  in the view of  FIG. 12 . 
     As shown in  FIG. 12 , the pivot supporting plate  2004  can extend in the vertical direction (e.g., a substantially up-and-down direction with respect to the orientation of the motorcycle  2001  as shown  FIG. 12 , or in as in a substantially upright posture for traveling), to the rear of the engine  2021 . The pivot supporting plate  2004  can include an upper part  2004 U for supporting a shock absorber  2070 , an intermediate part  2004 M for supporting the swing arm  2006 , and a lower part  2004 D for supporting the exhaust chamber  2024 . The exhaust chamber  2024  can include a catalyst  2121 . 
     The shock absorber  2070  can be supported by the upper part  2004 U of the pivot supporting plate  2004  via a bracket  2003   a.  The pivot part  2004   a  can be provided in the intermediate part  2004 M of the pivot supporting plate  2004 . In other words, the pivot supporting plate  2004  can pivotably support the swing arm  2006 . In the second exemplary embodiment, the pivot supporting plate  2004  and a part of the bracket  2003   a  can form a vertical frame part. 
     The swing arm  2006  can include a front part  2006   a  swingably supported by the pivot part  2004   a,  and a rear part  2006   b  supporting the rear wheel  2008 . 
     An air cleaner  2041  can be disposed to the rear of the shock absorber  2070 . The air cleaner  2041  can be provided above the swing arm  2006 . The air cleaner  2041  can be disposed to the rear of the pivot supporting plate  2004 . 
     More specifically, the air cleaner  2041  can be disposed to be adjacent to or adjoin an upper part  2070 U of the shock absorber  2070  to the rear of the upper part  2070 U. At least a part of the air cleaner  2041  can be provided below the upper part  2070 U of the shock absorber  2070  and below an upper end  2008   a  of the rear wheel  2008 . A lower part  2070 D of the shock absorber  2070  can be coupled to the swing arm  2006 . The air cleaner  2041  can be coupled to the cylinder head  2021   c  via an air intake  2043 . 
     The exhaust chamber  2024  can be disposed below the shock absorber  2070 . Further, the exhaust chamber  2024  can be provided between the pivot supporting plate  2004  and the rear wheel  2008  below the swing arm  2006 . 
     Referring now to  FIG. 10 , in the second exemplary embodiment, as described above, the exhaust chamber  2024  can be provided such that the rear end  2024   a  is disposed in front of the rear wheel  2008 . The cross pipe  2029  of the main stand  2026  can be positioned between the rear end  2024   a  of the exhaust chamber  2024  and the rear wheel  2008  in the traveling state. Thus, the main stand  2026  having the pair of support legs  2027  and  2028  can be provided to effectively use a small gap between the rear end  2024   a  of the exhaust chamber  2024  and the rear wheel  2008 . Accordingly, in the case that the exhaust chamber  2024  is interposed between the engine  2021  and the rear wheel  2008 , a stand can be provided that supports the motorcycle  2001  at two positions on both sides of the vehicle in the vehicle width direction. 
     In view of the foregoing discussion, embodiments of the invention have a number of advantages. For example, in the second exemplary embodiment, as described above, the main stand  2026  can be constructed such that the whole of the main stand  2026  is positioned above the lowest part  2024   d  of the exhaust chamber  2024  in the traveling state. Therefore, decrease in the ground clearance of the motorcycle  2001  can be prevented even if the main stand  2026  is provided. 
     Further, in the second exemplary embodiment, as described above, the main stand  2026  can be constructed such that both the ends of the main stand  2026  in the vehicle width direction (directions of arrows X 1  and X 2 ) are positioned outside, in the vehicle width direction, of outer surfaces of the exhaust chamber  2024  in the vehicle width direction. Thus, the main stand  2026  can be prevented from interfering with the lower surface of the exhaust chamber  2024  in the case that the main stand  2026  is turned upward in to the traveling state or position. The lowest part of the main stand  2026  can be positioned above the lowest part of the exhaust chamber, thereby forming the main stand  2026  so as to be positioned above the lowest part of the exhaust chamber  2024 . With such an arrangement, the main stand  2026  can be positioned above the lowest part of the exhaust chamber  2024  without forming a recess in the exhaust chamber  2024 . Therefore, decrease in the volume of the exhaust chamber  2024  can be prevented, while preventing decrease in the clearance from the main stand  2026  to the ground in the traveling state. 
     Still further, in the second exemplary embodiment, as described above, the vicinity of the central part of the cross pipe  2029  in the vehicle width direction (directions of arrows X 1  and X 2 ) extends downward in the traveling state. Accordingly, the cross pipe  2029  can be disposed to avoid the part protruding the most on the front side of the rear wheel  2008 . 
     Still further, in the second exemplary embodiment, as described above, the vicinities of both the ends of the cross pipe  2029  of the main stand  2026  in the vehicle width direction (directions of arrows X 1  and X 2 ) can be formed to incline at inclination angles α 2  and α 3 , respectively, that are equal to or less than the maximum leaning angle (bank angle α 1 ) of the vehicle with respect to the vertical direction in the traveling state. Accordingly, the cross pipe  2029  of the main stand  2026  can allow prevention of decrease in bank angle α 1  of the vehicle. 
     Still further, in the second exemplary embodiment, as described above, the rotational centers or axes  2026   b  of the main stand  2026  can be provided above the lowest part of the exhaust chamber  2024 . Thus, the main stand  2026  can be easily disposed above the lowest part of the exhaust chamber  2024  in the case that the main stand  2026  is positioned in the traveling state. 
     Still further, in the second exemplary embodiment, as described above, the exhaust outlet  2024   b  can be provided to the rear of the exhaust chamber  2024  and between the main stand  2026  in the traveling state and the swing arm  2007 . Accordingly, the exhaust outlet  2024   b  can be prevented from contacting with the rear wheel  2008  disposed in the rear of the exhaust chamber  2024 . Further, burnt gases can be discharged with effective use of a space between the main stand  2026  and the swing arm  2007 . 
     Still further, in the second exemplary embodiment, as described above, the lowest part  2037   b  of the side stand  2037  can be positioned above the lowest part  2026   c  of the main stand  2026  in the traveling state. Therefore, decrease in the ground clearance of the motorcycle  2001  can be prevented although the side stand  2037  is provided. 
     Still further, in the second exemplary embodiment, as described above, the end  2024   c  (the outermost part) of the exhaust outlet  2024   b  in the vehicle width direction (direction of arrow X 2 ) can be positioned inside (in the direction of arrow X 1 ) of the outermost part  2026   a  of the main stand  2026  in the vehicle width direction (direction of arrow X 2 ). Accordingly, the main stand  2026  can protect the exhaust outlet  2024   b  from physical impacts from a side (from the direction of arrow X 2 ). 
     Other Embodiments 
     In the foregoing description of the first exemplary embodiment, the air cleaner  1041  can be disposed to the rear of the upper end  1070   b  of the shock absorber  1070 . In alternative embodiments, the air cleaner  1041  can be disposed in front of or at the side of the upper end  1070   b.  Additionally, instead of being disposed to be adjacent to or adjoin the upper end  1070   b  of the shock absorber  1070  as described above, the air cleaner  41  can be remotely disposed from the upper end  1070   b.    
     Further, in the above description of the first exemplary embodiment, the exhaust chamber  1120  can be disposed below the swing arm  1060 . However, the exhaust chamber  1120  need not necessarily be disposed below the swing arm  1060 . 
     Still further, in the above description of the first exemplary embodiment, the recess  1041   a  can be formed at the front end of the air cleaner  1041 . However, the recess  1041   a  need not necessarily be formed at the front end of the air cleaner  1041 . Additionally, in the above description of the first exemplary embodiment, the intake duct  1043  can be disposed on the left side of the recess  1041   a.  However, the intake duct  1043  can be disposed on the right side of the recess  1041   a.    
     Still further, in the above description of the first exemplary embodiment, the lower end  1070   a  of the shock absorber  1070  can be directly coupled to the swing arm  1060  with no link mechanism interposed therebetween. However, the lower end  1070   a  can be coupled to the swing arm  1060  via a link mechanism. 
     Still further, in the above description of the first exemplary embodiment, the whole of the air cleaner  1041  can be provided above the swing arm  1060 . However, alternatively, only a part of the air cleaner  1041  may be provided above the swing arm  1060 . Moreover, in the above description of the first exemplary embodiment, the whole of the exhaust chamber  1120  can be provided below the swing arm  1060 . However, alternatively, only a part of the exhaust chamber  1120  may be provided below the swing arm  1060 . 
     Similarly, in the above description of the second exemplary embodiment, the whole of the air cleaner  2041  can be provided above the swing arm  2006 . However, alternatively, only a part of the air cleaner  2041  may be provided above the swing arm  2006 . Moreover, in the above description of the second exemplary embodiment, the whole of the exhaust chamber  2024  can be provided below the swing arm  2006 . However, alternatively, only a part of the exhaust chamber  2024  may be provided below the swing arm  2006 . 
     In the above description of the second exemplary embodiment, the side stand can be provided in addition to the main stand. However, alternatively, the main stand may be provided without the side stand. 
     Further, in the above description of the second exemplary embodiment, the vicinity of the central part of the cross pipe in the vehicle width direction can extend downward. However, alternatively, not only does the vicinity of the central part of the cross pipe in the vehicle width direction extend downward, but also the vicinities of both the ends of the cross pipe in the vehicle width direction may extend downward. 
     Still further, in the above description of the second exemplary embodiment, the exhaust outlet for discharging exhaust gas can be provided in the rear part of the exhaust chamber. However, alternatively, an exhaust outlet having functions for purifying exhaust gas discharged from the engine and for reducing exhaust noise may be additionally provided in a rear part of the exhaust chamber having the functions for purifying exhaust gas discharged from the engine and for reducing exhaust noise. In this case, an exhaust outlet having the functions for purifying exhaust gas discharged from the engine and for reducing exhaust noise may be provided to a whole of the exhaust outlet. As a still further alternative, the exhaust outlet having the functions for purifying exhaust gas discharged from the engine and for reducing exhaust noise may be provided in a part in front of the rear wheel 
     It should be understood that the first and second exemplary embodiments, or parts, components, alternatives, modifications, changes and adaptations thereof may be combined together. 
     It will be apparent to one skilled in the art that the manner of making and using the claimed invention has been adequately disclosed in the above-written description of the preferred embodiments taken together with the drawings. 
     It will be understood that the above description of the preferred embodiments of the present invention are susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.