Patent Publication Number: US-2023139934-A1

Title: A saddle riding vehicle with an elongated tank

Description:
The present invention relates to the field of manufacturing of a saddle riding motorcycle, preferably but not exclusively, of the desert type or, more generally, of an enduro type. In particular, the present invention relates to a saddle riding vehicle provided with a tank supported in the upper part of the frame and elongated towards the rear wheel of the vehicle, wherein a lower section of the tank is located substantially underneath the saddle of the vehicle. 
     PRIOR ART 
     Two-wheeled enduro vehicles comprise a frame which includes a steering tube to which a steering assembly is pivotally connected which controls a steering wheel, or front wheel. The frame comprises a central portion to which a swingarm supporting a driving wheel, or rear wheel, is hinged by means of a pin. Between the central portion and the steering tube, a front portion of the frame extends to which an engine which generates a driving torque is typically connected. This is transferred to the rear wheel through a mechanical chain transmission or through the use of a transmission shaft. The frame is completed by a rear portion which extends from the central portion towards the rear wheel and which typically supports the saddle of the vehicle. 
     In most of the known solutions, the rear part of the motor assembly is connected to the central part of the frame using the swingarm pin as a connection element. The front part of the motor assembly is instead connected to the front part of the frame and remains suspended underneath the same. Typically, a tank is connected to the front part of the frame containing the fuel necessary for the operation of the motor assembly. 
     Patent application EP3461729 describes a vehicle provided with a tank made of two superimposed parts in which a lower part extends between the two sides of the front part of the frame. The upper part is connected to the lower part and emerges markedly above the front part of the frame. The two parts of the tank are configured so as to define two side chambers that emerge outside the two sides. In order to allow the filling thereof, the tank comprises a feeding inlet which remains closed, by means of a removable cap, while the motorcycle is running. Such an inlet is defined in the highest part of the tank. 
     In the solution described in EP3461729, as well as in other conceptually similar ones, the tank is installed in a particularly advanced position of the frame, very close to the steering tube. The closing cap and the two side chambers are placed in a position adjacent to the steering assembly. As a result of this arrangement, the position of the center of gravity of the motorcycle in a full tank condition is significantly different from that with an empty tank. This translates into a different driving sensation for the rider who in full tank conditions will find the motorcycle more unbalanced forward, and therefore more difficult to control, than in the empty tank condition in which the center of gravity will be lower and more rearward. This drawback is extremely accentuated in enduro motorcycles which have a particularly large tank to ensure high autonomy. 
     The Applicant has therefore noted the need to provide a motor vehicle in which the imbalance effect due to the fuel contained in the tank is eliminated or strongly reduced. 
     SUMMARY 
     The main task of the present invention is therefore to provide a saddle riding vehicle which allows the limits indicated above to be overcome. Within this task, a first object of the present invention is to provide a saddle riding vehicle, particularly for enduro, in which the unbalancing effect, when the vehicle is full, is eliminated or at least reduced. Another object of the present invention is to provide a saddle riding vehicle in which the structure of the tank has no impact on the position of the other components of the vehicle and does not affect the vertical dimensions of the tank itself. Last but not least, an object of the present invention is to provide a saddle riding vehicle which is reliable and easy to be implemented in a cost-effective manner. 
     The Applicant has found that the intended task and objects can be achieved by extending the tank vertically so as to reduce the distance between the position of the center of gravity of the vehicle when the tank is full and the position of the center of gravity when the tank is empty. In particular, the predetermined objects are achieved by a saddle riding vehicle comprising a motor assembly and a frame to which the motor assembly is connected. The vehicle is provided with a tank supported by the frame and comprising a feeding inlet. The tank includes:
         a front part which comprises a steering tube to which a steering assembly which controls a front wheel is rotatably connected;   a central part which comprises a swingarm to which a rear wheel is rotatably connected;   a rear part extending from said central part in a direction opposite to the front part;   a group of mechanical suspensions operatively interposed between the frame and the wheels of the vehicle, wherein said suspensions are configured to assume an extended condition and a compressed condition.       

     The vehicle is characterized in that the tank is a single monobloc tank and extends at least between said front part and said central part of said frame, said tank having a height greater than or equal to half an overall height of the vehicle. The overall height is the distance measured on said vehicle with fully extended suspension, between a ground support surface on which said vehicle rests and an upper end of said steering tube. The height of the tank, on the other hand, is the distance between said feeding inlet and the point of the tank closest to said support surface. 
     According to a possible embodiment, the tank, which extends at least between said front part, said central part and said rear part, has a longitudinal extension greater than half of the vehicle&#39;s wheelbase. In particular, the wheelbase of the vehicle is considered as the distance between the rotation axes of the two wheels of the vehicle, while the longitudinal extension of the tank is the length of the tank according to a direction orthogonal to the rotation axis of the rear wheel. The longitudinal extension of the tank and wheelbase are measured at fully extended suspension. Advantageously, the tank, considered in a side view, extends substantially above the motor assembly by the entire longitudinal length of the motor assembly itself. This solution leads to an advantageous condition whereby the center of mass of the tank is immediately above the center of mass of the motor and therefore in a position closest to the center of gravity of the vehicle. 
     According to a possible embodiment, the tank comprises at least a first section in a position proximal to the steering tube of the frame, wherein such an upper section comprises two side portions which depart from a central portion which defines the feeding inlet, said side portions being spaced apart from each other along the width direction. 
     Preferably, each of the side portions extends in an external position and adjacent to a corresponding front side of the front portion. 
     Always preferably said side portions, in a side view, extend at least partially astride the steering tube. 
     According to a possible embodiment, the tank further comprises a second section communicating with the first section and extending towards the rear wheel according to the upper profile of the front part of said frame and a third section communicating with the second section and included between the rear sides of the rear part of the frame. 
     According to an embodiment, the tank comprises a lower surface which includes a first surface portion referred to said first section, a second surface portion referred to said second section and a third surface portion referred to said third section. The first surface portion extends along a substantially horizontal plane; the second surface portion extends along an inclined plane in accordance with the upper profile, as seen in the longitudinal direction, of the front part of the frame; the third surface portion partially faces the central part of the frame and partially faces the rear wheel. 
     According to an embodiment, the central section of the tank is configured in such a way that its extension along the width direction of the vehicle is less than the distance between the front sides of the front part of the frame. 
     In a possible embodiment, the tank comprises an upper surface which includes a first surface portion, referred to said first section, a second surface portion referred to the second section; on said second surface portion of said upper surface rests at least in part a saddle of said vehicle. 
     In a possible embodiment, a first side portion of the tank is delimited internally by a first inner surface, at least partially flat, and externally by a first curved surface; similarly, the second side portion is delimited internally by a second inner surface, at least partially flat, and externally by a second curved surface; such curved surfaces impart an outwardly rounded shape to the side portions. 
     Preferably, the inner surfaces are longitudinally delimited by a transverse inner surface which extends along the width direction of the vehicle; the inner surfaces (side and transverse) define as a whole a recess of the first section of the tank having a substantially polygonal shape with respect to a plan view of the tank. 
     In an embodiment thereof, the transverse inner surface is located in a position spaced from the steering tube so that the recess of the first section defines a space in which a component accessory for the operation of the motor assembly is positioned. 
     According to a possible embodiment thereof, the front part of the frame comprises at least one transverse element which extends in the width direction of the vehicle connecting the front sides; the position of the transverse element identifies, for each of the front sides, a first trellis portion which extends from the steering tube to the transverse element and a second portion which extends between the corresponding first portion and the central part of the frame. 
     According to a possible embodiment, the recess of the first section of the tank extends from the steering tube to a position close to said transverse element. 
     In one embodiment, the tank is fixed, directly or indirectly, to each of said front sides substantially proximal to the transverse element; the tank rests, for each of the front sides, on a component of the corresponding first trellis portion. 
     Preferably, the first section of the tank is connected to each of the front sides of the frame through a pair of connecting brackets each of which extends from a corresponding one of said side portions. 
     In one embodiment, the tank is supported by fastening means installed at the rear part of the frame. Preferably, the fastening means comprise a transverse bracket to which the second section of the tank is connected; such a transverse bracket extends between the rear sides of the rear part of the frame. 
     Preferably, the tank is fixed to the front portion and/or to the rear portion of the frame such that, for each of the front sides, the second section of the tank is located above the second portion of the corresponding front side. 
     In a preferred embodiment, the tank has a decreasing extension, along the width direction of the vehicle, from said second section to said third section, according to a plan view of the tank. 
    
    
     
       LIST OF FIGURES 
       Further features and advantages of the invention will become clearer from the examination of the following detailed description of some preferred, but not exclusive, embodiments of the vehicle, illustrated by way of non-limiting example, with the aid of the enclosed drawings, in which: 
         FIG.  1    is a side view of a saddle riding vehicle according to the present invention; 
         FIG.  2    is a perspective view of the vehicle of  FIG.  1    without the saddle; 
         FIG.  3    is a plan view of the vehicle of  FIG.  1    without the saddle and the air filter box; 
         FIGS.  4  to  7    are a perspective view, a side view, a front view and a plan view, respectively, of a tank of a vehicle according to the present invention; 
         FIGS.  8  to  11    are a perspective view, a side view, a front view and a plan view, respectively, of a frame of a vehicle according to the present invention; 
         FIG.  12    is a partially sectioned side view to show a possible embodiment of an air filter of a vehicle according to the invention; 
         FIG.  13    is a perspective view of the filter shown in  FIG.  12   . 
     
    
    
     The same reference numerals and letters in the figures identify the same elements or components. 
     DETAILED DESCRIPTION 
     With reference to the aforementioned figures, the present invention therefore relates to a saddle riding vehicle, meaning by this expression any two-wheeled moped or motorcycle, i.e. provided with a front wheel and a rear wheel. In the following description, the vehicle  1  will also be indicated with the expression motor vehicle  1  or motorcycle  1 . 
     The motorcycle  1  comprises a motor assembly  2  and a frame  10  to which the motor assembly  2  is connected. The frame  10  comprises a front part  15  which includes a steering tube  11  to which a steering assembly  5 , which controls a steering wheel  3  (or front wheel  3 ), is rotatably connected. The configuration of the steering assembly, known to a man skilled in the art, is not relevant for the present invention. 
     The vehicle  1  comprises a tank  7  to contain the liquid fuel necessary for the operation of the motor assembly  2 . The tank  7  comprises a feeding inlet  700 , closed by a removable cap, to allow the filling thereof. The vehicle  1  is provided with a fuel suction device  750  having a per se known configuration. 
     The frame  10  comprises a central part  12  to which a first end  8 A of a swingarm  8  is hinged. A driving wheel  4  (or rear wheel  4 ) is rotatably connected to a second end  8 B of the swingarm  8 . According to a widely known technical solution, and for this reason not described in detail, the drive torque generated by the motor assembly  2  is transferred to the driving wheel  4  through a mechanical transmission, for example of the chain type. 
     The front part  15  of the frame  10  extends between the steering tube  11  and the central part  12 . 
     The front part  15  includes a first front side  15 A and a second front side  15 B which are spaced apart in the width direction X of the vehicle. 
     The frame  10  also comprises a rear part  18  which extends from the central part  12  in the opposite direction to the front part  15 , i.e. towards the rear wheel  4 . Typically, the rear part  18  supports at least the rear part of the saddle  400  of the vehicle  1 . The rear part  18  comprises a first rear side  18 A and a second rear side  18 B spaced apart in the width direction X of the vehicle. With respect to a vertical reference plane PV contending the steering axis  501 , the first rear side  18 A is in the same half space and adjacent to the first front side  15 A. Similarly, the second rear side  18 B extends in the same half space and adjacent to the second front side  15 B. 
     In the remainder of the description, the sides  15 A,  15 B of the front part  15  will be referred to simply as “front sides  15 A,  15 B”, while the rear sides  18 A,  18 B will be referred to as “rear sides  18 A,  18 B”. 
     The expression “steering axis” indicates the rotation axis configured by the steering tube  11  for the steering assembly  5 . 
     For the purposes of the present invention, the expression “width X”, “width direction X” or “transverse direction X” is meant to indicate a direction substantially parallel to the rotation axis T 2  of the rear wheel. Instead, the expression “length direction” or “longitudinal direction Y” is meant to indicate a direction substantially orthogonal to the transverse direction (i.e. orthogonal to said rotation axis T 2 ). 
     For the purposes of the present invention, the terms “upper” and “lower” refer, respectively, to the position furthest from and closest to a reference plane PO (indicated in  FIG.  1   ) on which the vehicle  1  rests. The terms “inferiorly” and “superiorly” therefore indicate the position of a part or an end of a component which is furthest from or closest to said reference plane PO. 
     The vehicle  1  comprises suspension means interposed between said frame  10  and said wheels  3 ,  4  having a per se known configuration. The suspension means comprise a plurality of mechanical suspensions configured to assume a compressed configuration, due to the loads imposed on the vehicle, and an extended configuration, characteristic of a condition of absence of loads bearing on the vehicle. In the illustrated solution, the suspension means comprise two front suspensions  80  and a rear shock absorber  88  interposed between the swingarm and the frame  10 . 
     With reference to  FIG.  1   , according to the present invention the tank  7  is made as a single monobloc tank. Said tank  7  extends at least between said front part and said central part. In particular, the tank  7  extends for a height (indicated with A) greater than or equal to half the overall height (indicated with B) of the vehicle  1 . The overall height B of the vehicle corresponds to the distance between a support surface PO on the ground, on which the vehicle  1  rests, and the upper end  111  of the steering tube  11 . The height of the tank  7 , on the other hand, is considered as the distance between the feeding inlet  700  of the tank  7  and the point of the latter closest to the support plane P 0 . 
     For the purposes of the present invention, the two subject heights (height A and height B) are considered in a condition of fully extended suspensions, i.e. in a condition in which the vehicle  1  is unloaded, stationary, without the rider, and with an empty tank  7 . In other words, in a condition in which there are no loads acting on the vehicle  1  other than those relating to the masses of the vehicle. 
     Still with reference to  FIG.  1   , according to a possible embodiment, the tank  7  extends between the front part  15 , the central part  12  and the rear part  18  of the frame  10  and has a longitudinal extension (indicated with C), greater than half the wheelbase (indicated with D) of the vehicle  1 . The wheelbase D of the vehicle  1  is the distance between the rotation axes T 1 , T 2  of the two wheels  3 ,  4  of the vehicle  1  when both wheels  3 , 4  are on the same plane, i.e. when the front wheel  3  is coplanar to the rear wheel  4 . The longitudinal extension C of the tank  7  corresponding to its length measured along a longitudinal direction Y orthogonal to the rotation axis T 2  of the rear wheel  4 . Again, the longitudinal extension C and the wheelbase D are considered in a condition of fully extended suspension. 
     According to a possible embodiment, the tank  7 , considered in a side view of the vehicle  1  as in  FIG.  1   , extends above the motor assembly  2  for the entire longitudinal length of the motor assembly itself. In other words, the tank  7  is located above the motor assembly  2  and is equal to or longer than the motor assembly  2 , again considering these components (tank  7  and motor assembly  2 ) in the side view of  FIG.  1   . As indicated above, this condition allows bringing the center of mass of the tank  7  closer to that of the motor assembly  2  and therefore in general to that of the vehicle  1  to the advantage of greater stability even in full tank conditions. 
     According to a possible embodiment, the tank  7  comprises an upper section  71  (or first section  71 ) in a position close to the steering tube  11 . This first section  71  includes two side portions  71 A,  71 B which extend, by at least a section, spaced in the width direction X of the motorcycle  1 . Said side portions  71 A,  71 B depart from a central portion  71 C at which the feeding inlet  700  for filling the tank  7  is defined. 
     As illustrated, preferably, the two side portions  71 A,  71 B emerge outside the space defined between the front sides  15 A,  15 B of the front part  15  of the frame  10 . Always preferably, each of said side portions  71 A,  71 B is located in an outer position adjacent to a corresponding one of said front sides  15 A,  15 B. 
     Even more preferably, the side portions  71 A  71 B, considered in a side view, extend at least partially astride the steering tube  11 . In other words, the side portions  71 A  71 B, in a side view, are at least partially superimposed on the steering tube  11 . This configuration identifies the extension of the tank  7 , which extends substantially from the steering tube  11  of the motor vehicle  1 , towards the central part  12  of the frame  10 , up to, in certain cases, also in the rear part  18  thereof. A tank  7  thus shaped is therefore more capacious, for the same overall dimensions (by using a space next to the steering tube which is notoriously unused), and its longitudinal extension, which follows the extension of the motor vehicle  1 , allows the distribution of the masses on the motorcycle  1  to be optimized. 
     According to a possible embodiment shown in the figures, the body of the tank  7  comprises a central section  72  (or second section  72 ), communicating with the upper section  71 , which extends according to the upper profile, as seen in the longitudinal direction, of the front part  15  of the frame  10 . In other words, this profile is seen on a longitudinal plane of the motorcycle  1 . The expression “longitudinal plane” means a vertical plane substantially orthogonal to the rotation axis of the rear wheel  4 . Furthermore, the tank  7  also comprises a lower section  73  (or third section  73 ), communicating with the central section  72  and extending between the rear sides  18 A,  18 B of the rear part  18  of the frame  10 , in a position comprised between the central part  12  of the frame  10  and the rear wheel  4 . The third section  73  is identified by the volume of the tank  7  which is located between the rear sides  18 A,  18 B and which remains below the upper profile of the rear part  15 , where this rear profile is seen with respect to a side plane ( FIG.  1   ). 
     For the purposes of the present invention, the terms “upper” and “lower” refer to the position furthest from and closest to, respectively, a reference plane PO (indicated in  FIG.  1   ) on which the vehicle  1  rests. The terms “below” and “above” have a similar meaning. Overall, therefore, according to the present invention, the tank  7  has an elongated configuration which substantially extends along the entire length of the front part  15  of the frame  10 , even occupying a space between the rear sides of the frame  18 A,  18 B. This condition also contributes to making the position of the center of gravity of the vehicle  1 , in an empty tank condition, in any case close to that occupied with a full tank. Therefore, when the tank is full, the feeling of imbalance for the rider is strongly contained, if not completely eliminated. 
     The fuel suction device  750  is operatively connected to the tank  2  and, as mentioned above, has a configuration per se known to a man skilled in the art, comprising a fuel suction pump (not shown) located inside the tank  2 . In this regard, according to the invention, this suction pump is inserted in the third section  73 , so as to suck the fuel in the lowest point of the tank  7 . According to a preferred embodiment, visible in particular in  FIG.  3   , the central section  72  of the tank  7  is configured in such a way that its extension, measured in the width direction X of the motorcycle  2 , is less than the distance between the front sides  15 A,  15 B of the frame  10 . In other words, with respect to a plan view of the tank  7 , the transverse extension of the central section  72  is smaller than the transverse extension of the front part  15  of the frame  10 . According to this embodiment, the second section  72  is identified by the volume of the tank  7  which remains included laterally between the front sides  15 A,  15 B and the rear sides  18 A,  18 B mainly, and preferably completely, above the upper profile of the front part  15  and of the rear part  18  of the frame  10 . 
     As already indicated above, the lower section  73  however remains included between the rear sides  18 A,  18 B of the rear portion  18 , but below said upper profile of the rear part  18 . In other words, the width of the third section  73  is always less than the transverse distance between said rear frame sides  18 A,  18 B. 
       FIGS.  1  to  3    show a possible embodiment of the motorcycle  1  according to the invention. The motor assembly  2  comprises at least one thermal engine  2 A, which generates the driving torque transferred to the driving wheel  4  through the aforementioned transmission. The thermal engine  2 A comprises a base  21  and a head  22  which emerges above the base  21 . The term “head  22 ” is intended to indicate the upper part of the engine which closes the cylinders and incorporates the combustion chambers. For the purposes of the present invention, the term “base” is meant to indicate the rest of the motor assembly, therefore not only the part in which the motor shaft rotates and in which it moves, but also the other motion transmission parts included between the motor shaft and the transmission to the rear wheel. These “transmission parts” therefore include the clutch and the gear change, where the clutch, as known, will be interposed between the motor shaft and the gearbox to allow a gradual start and to change gears. 
     According to a possible embodiment, the rear part  21 B of the base  21  of the motor assembly  2  is connected, preferably directly and to the central part  12  of the frame  10  through a plurality of connecting elements  91 ,  92 ,  93 . The plates  16 A,  16 B, on the other hand, are designed to support the head  22  of the heat engine  2 A and/or the front part of the base  21 . According to a per se known solution, one of the connecting elements  91  corresponding to the pin which allows the swingarm  8 , or the rear wheel  4 , to oscillate with respect to the frame  10 . 
     The motor assembly  2  is supported by the front part  15  of the frame  10 . For this purpose, in the possible, and therefore non-exclusive, embodiment shown in the figures, two first connection plates  16 A,  16 B (indicated in  FIGS.  10  and  11   ) are provided to connect the head  22  and the front part  21 A of the base  21  to the front part  15  of the frame  10 . In detail, a first plate  16 A connects the motor assembly  2  to the first frame side  15 A and a second plate  16 B connects the motor assembly  2  to the second frame side  15 B. In the solution shown in the figures, two second plates  17 A,  17 B are also provided, each to connect one of said front sides  15 A,  15 B to the head  22  of the motor assembly  2  in a position closer to the central portion  12  with respect to the position occupied by a corresponding one of said first plates  16 A,  16 B. Alternatively, however, the motor assembly  2  may be connected directly to the frame  10  without using the indicated plates. The way in which the motor assembly  1  is connected to the frame  10  is not however relevant for the purposes of the present invention. 
     With reference to  FIG.  1   , the motor assembly  2  remains in any case included, in the length direction Y, between the position of the steering assembly  5  and the central part  12  of the frame  10 . Therefore, the motor assembly  2  does not extend rearward beyond the central part  12 . As clearly visible from  FIG.  1   , the upper section  71  and the central section  72  of the tank  7  are mainly located in a position above the motor assembly  2 . Instead, the lower section  73  of the tank  7  is located on the opposite side of the motor assembly  2 , with respect to the central part  12  of the frame  10 . 
     The tank  7  comprises a lower surface  740  (highlighted with a dashed line in  FIG.  5   ) that includes a first surface portion  741 , a second surface portion  742  and a third surface portion  743  of the first section  71 , the second section  72  and the third section  73 , respectively. The expression “lower surface  740 ” is intended to substantially indicate the surface of the tank  7  which remains facing the support plane PO of the motorcycle, i.e. the surface closest to the ground. 
     According to a preferred embodiment, shown in the figures, the first surface portion  741  extends parallel, or in any case slightly inclined, to the support plane PO of the motorcycle  1 . The second surface portion  742  extends inclined with respect to the first surface portion  741  according to the upper profile, considered in the longitudinal direction, of the front part  15  of the frame  10 . Finally, the third surface portion  743  remains partially facing the central portion  12  of the frame  10  and partially facing the rear wheel  4 , again considering this condition on a longitudinal plane. 
     Therefore, the two side portions  71 A,  71 B of the first section  71  have a substantially planiform lower surface, while the lower surface of the other sections  72 ,  73  substantially follows the pattern of the frame  10 . 
     The tank  7  also comprises an upper surface  760  (highlighted by the dashed line hatching in  FIG.  5   ), meaning with this expression the surface opposite to the lower one, that is, the one that remains facing upwards or towards the rider. In particular, the upper surface  760  comprises a first surface portion  761  of the first section  71  of the tank  7  and a second surface portion  762  of the second portion  72 . According to the invention, a front portion  401  of the vehicle saddle  400  rests at least partially on the second surface portion  761 , as can be seen in  FIG.  1   . A rear portion  402  instead rests on the rear part  18  of the frame. The third section  73  of the tank  7  is placed under the saddle  400  in a longitudinal position close to the lowest point of the saddle  400 . 
     According to a preferred embodiment, visible in particular in  FIGS.  3  and  7   , the first portion  71 A of the tank  7  is delimited internally by a first flat planiform inner surface  711 A and externally by a second curved surface  712 A. Similarly, the second chamber  71 B is delimited internally by a second planiform inner surface  711 B and externally by a second curved surface  712 B (see  FIG.  7   ). In particular, the two curved surfaces  712 A,  712 B impart an outwardly rounded shape to the two chambers  71 A,  71 B. The two chambers  71 A,  71 B are substantially specular with respect to the vertical plane PV passing through the steering axis  401 . 
     The two inner surfaces  711 A,  711 B are longitudinally delimited by a transverse inner surface  713  which extends in the width direction X of the motorcycle  1 . Overall, the inner surfaces  711 A,  711 B, and the transverse surface  713  define a recess of the first polygonal section  71  with respect to a plan view of the tank  7  (see  FIG.  7   ). The transverse surface  713  is located in a position spaced from the steering tube  11  so that said recess defines a space (indicated with S) useful for positioning a component accessory for the operation of the motor assembly  2 . 
     In particular, according to a preferred embodiment, this accessory component is the box containing the air filter which typically, in known solutions, is placed below the tank or in any case in a position that is difficult to access. Advantageously, the recess defined between the side portions  71 A,  71 B allows the filter to be placed in a more comfortable position, easily accessible for any inspection and maintenance operations. 
     With reference in particular to  FIG.  3   , it can be seen that the two side chambers  71 A,  71 B extend forward so as to be at least partially flanked to the steering tube  11  and preferably also to the steering assembly  5 . In  FIG.  3    the references  715 A,  715 B indicate the ends of the two side chambers  71 A,  71 B which are placed side by side with a corresponding side  5 A,  5 B of the steering assembly  5 . 
       FIGS.  8  to  11    allow observing a preferred embodiment of the frame  10  according to the invention. The front sides  15 A,  15 B, as well as the rear sides  18 A,  18 B have a substantially specular conformation with respect to the vertical plane PV defined above. Similarly, the central part  12  is also specular with respect to the vertical plane PV. The central part  12  comprises a first flank  12 A and a second flank  12 B opposite to each other. Such flanks  12 A,  12 B are preferably formed by plate-shaped bodies and are connected by a lower pin  31  and an upper pin  32  which extend in the width direction X of the vehicle. With respect to the vertical plane PV defined above, the first flank  12 A is located on the same side as the first front side  15 A and the first rear side  18 A, while the second flank  12 B is located on the same side as the second front side  15 B and the second rear side  18 B. 
     The front part  15  of the frame  10  comprises at least one transverse element  15 C which extends in the width direction X connecting the two front sides  15 A,  15 B. For each of these, the position of the transverse element  15 C identifies a first portion  151 A,  151 B which extends from the steering tube  11  up to the same transverse element  15 C and a second portion  152 A- 152 B which extends between the corresponding first portion  151 A,  151 B and the central part  12  of the frame  10 . 
     As can be seen in  FIG.  11   , substantially in proximity to the longitudinal position of the transverse element  15 C, the front part  15  of the frame  10  has its maximum extension in the width direction X. The first portion  151 A of the first front side  15 A and the first portion  151 B of the second front side  5 B converge towards the steering tube  11 . Instead, the second portion  152 A of the first front side  15 A and the second portion  152 B of the second front side  15 B converge towards the central part  12 . It is however seen that, for each frame side  15 A,  15 B, the inclination of the front portion  151 A,  151 B towards the vertical plane PV (containing the steering axis  501 ) is greater than the inclination of the corresponding rear portion  152 A,  152 B towards the same plane. 
     The polygonal recess defined by the inner surfaces  711 A,  711 B and  713 , preferably extends between the steering tube  11  and substantially the transverse element  15 C indicated above. In other words, all the space above the first portion  151 A,  151 B of the front sides  15 A,  15 B can be used for the positioning of one or more accessory components of the motor assembly  2  or generically for another component of the motorcycle  1 . 
     For each front side  15 A,  15 B, the first part  151 A,  151 B has a substantially reticular or trellis configuration in which it is possible to identify a plurality of components  52 A,  52 B- 53 A,  53 B- 54 A,  54 B. Preferably, the latter have a tubular shape. 
     The second part  152 A,  152 B has a single component configuration (i.e. comprising a single component) which extends between the corresponding first part  151 A,  151 B and the central part  12  of the frame  10 . 
     With reference to  FIGS.  1 ,  2  and  3   , according to a preferred embodiment, the tank  7  is fixed, directly or indirectly, to each front side  15 A,  15 B on the front part  15  of the frame  10  substantially in a position proximal to the transverse element  15 . In particular, for each front side of frame  15 A,  15 B the tank  7  is fixed to, and rests on, a component of the corresponding first portion  151 A,  151 B with a reticular or trellis configuration. 
     The first section  71  of the tank  7  is fixed to each front side  15 A,  15 B through a pair of connecting brackets  721 A,  721 B. Each of these extends from one of the side portions  71 A,  71 B. 
     Preferably each side portion  71 A,  71 B is connected to an upper end  161 A,  161 B of a corresponding one of the first plates  16 A,  16 B designed to support and to connect the motor assembly  2  to the frame  10 . Therefore, in this embodiment the first section  71  is, overall, connected to the frame  10  indirectly through the first plates  16 A,  16 B. 
     The front sides  15 A,  15 B each comprise an upper element  155 A,  155 B of which a front section  511  is a component of the corresponding first portion  151 A,  151 B, while a rear section  512  defines the corresponding second portion  152 A,  152 B. The upper element  155  of the first front side  15 A and the upper element  155 B of the second frame front side  15 B extend on a first inclined plane P 1  (indicated in  FIG.  9   ). The upper elements  155 A,  155 B of the front sides  15 A,  15 B are connected to the central part  12  of the frame  10  at opposite ends of the upper pin  32  indicated above. The upper elements  155 A,  155 B essentially define the upper profile of the front part  15  of the frame  10 . 
     The rear sides  18 A,  18 B are connected to each other in the width of the vehicle through one or more transverse connecting elements  19 . In general, the rear part  18  can be made from a plurality of tubular components welded together and made of the same material of which the other portions  12 ,  15  of the frame  10  are made. 
     Each rear side  18 A,  18 B comprises at least one upper element  81 A,  81 B of which a front end  811 A,  811 B is connected to the central portion  12 , preferably to an end of the upper pin  32  opposite to a corresponding upper element  155 A,  155 B of the front part  15 . Such upper elements  81 A,  81 B essentially define the upper profile of the rear part  18  of the frame  10 . Each rear side  18 A,  18 B further comprises a lower element  82 A,  82 B connected to the upper one through a connecting element  83 A,  83 B. 
     The upper element  81 A of the first side  18 A and the upper element  81 B of the second rear side  18 B extend parallel for at least a portion thereof identifying a second inclined plane P 2  (also indicated in  FIG.  9   ). 
     The first inclined plane P 1  and the second inclined plane P 2  substantially intersect at the upper pin  32  of the central portion  12  and together with a corresponding flank  12 A,  12 B of the central part  12  give the frame  10  a substantially Y-shape with respect to a view side thereof visible in  FIG.  9   . 
     According to a preferred embodiment, the tank  7  is supported at the back via fixing means  78  connected to the rear part  18  of the frame. In a preferred embodiment visible in  FIGS.  1  and  2   , these fixing means  78  comprise a transverse bracket  78 A to which the second section  72  of the tank  7  is connected through screw connecting elements  78 B or other functionally equivalent elements. Preferably, the transverse bracket  78 A emerges above the rear sides  18 A,  18 B so that the tank  7  is suspended below it. 
     According to a preferred embodiment, the tank  7  is fixed either to the front portion  15  of the frame  10  and/or to the rear portion  18  in such a way that, for each of the two front sides  15 A,  15 B, the second section  72  of the tank  7  remains above the corresponding second portion  152 A,  152 B (see  FIG.  3    in this regard) or above the plane P 1  indicated above. 
     With reference to  FIGS.  3  and  7   , the second section  72  of the tank  7  has a width (extension in the transverse direction X) which decreases towards the third section  73 . In other words, the width of the second section  72  decreases from a maximum value, at the connection with the first section  71 , to a minimum value at the connection with the third section  73 . Basically, with reference to a plan view ( FIG.  7   ), the second section  72  has a substantially “funnel” conformation towards the third section  73 . This conformation is imparted by two connecting portions  79 A,  79 B which develop laterally from each of the two side chambers  71 A,  71 B up to the base of the second section  72 , i.e. up to the connection of the latter with the third section  73 . 
     With reference to  FIGS.  4  and  7   , according to an embodiment, the feeding device  750  is operationally installed as a bridge between the second section  72  and the third section  73  and occupies a position substantially below the saddle of the motorcycle  400 . Advantageously, the simple removal of the saddle  400  allows easy access to the device  750  for any maintenance or inspection operations. 
     According to a preferred embodiment, the third section  73  of the tank  7  is located in a position sufficiently distant from the second part  12  of the frame  10  to allow the positioning of a shock absorber  88  immediately in contact with the same central portion. As shown in the figures, preferably, the third section  73  has a downward tapered conformation with respect to a side view ( FIG.  1   ) of the motorcycle. At the same time, the third section  73  has a tapered conformation towards the lower end also with respect to a plan view ( FIG.  3   ) of the motorcycle. 
     In one of its possible embodiments, the vehicle also comprises an air filter  8 , (see  FIGS.  2 ,  12  and  13   ) installed on the front part  15  of the frame and  10  comprising a box  80  containing at least one filtering element  800 . 
     The filter box  80  comprises a lower hollow body  81 , fixed to the front part  15  of the frame  10  by means of suitable fixing means  87 A- 87 B. The box  80  further comprises an upper hollow body  82  connected in a removable manner to the lower hollow body  81 , wherein at least one air intake duct  85 A,  85 B is connected to the upper hollow body  82  and wherein at least one air delivery duct  89 A,  89 B is connected to the lower hollow body. The hollow bodies  81 ,  82  are communicating through an opening  88  whereby the air sucked into the upper hollow body  82  passes into the lower hollow body  81 . According to the invention, the upper hollow body  82  occupies a position, considered along the length of the vehicle, comprised between the steering tube  11  and the tank  7  of the vehicle  1 , wherein no part of the tank  7  stand above the upper hollow body  82  of the filter  8 . 
     The two-piece conformation of the filter  8  and the arrangement of the upper hollow body  82  make the inspection and/or maintenance of the filter  8  particularly simple for the motorcyclist who can also perform it while sitting on the saddle of the motor vehicle  1 . 
     The filtering element  800  is installed inside the upper hollow body  82  and extends above said opening  88  occupying the entire width thereof. In this way, by removing the upper hollow body  82 , the rider has immediate access to the filtering element  800  which can be removed together with the same upper hollow body  82 . 
     According to a possible embodiment, the filter  8  comprises two intake ducts  85 A,  85 B which emerge on opposite sides of the upper hollow body  82  in the direction of the front wheel  3 ; the two intake ducts  85 A,  85 B are substantially specular with respect to a vertical reference plane containing the steering axis  501  (see  FIG.  2   ). According to a preferred embodiment, each of the side portions  71 A,  71 B of the first section  71  of the tank  7  supports a corresponding intake ducts  85 A,  85 B. More precisely, each of said side portions  71 A,  71 B defines a seat  74 A,  74 B (indicated for example in  FIGS.  6  and  7   ) in which a corresponding one of said suction elements  85 A,  85 B is positioned or on which at least rests. 
     In a possible embodiment, the lower hollow body  81  is located at least partially below the central portion  71 C of the first section  71  of the tank  7 . 
     In another possible embodiment, the air delivery ducts  89 A,  89 B are instead located partially below the central portion  71 C of the first section  71  and/or partially below the second section  72  of the tank  7  defined above, wherein such a second section has an extension, measured in the direction of the vehicle width, less than the distance between the front sides  15 A,  15 B of the frame  10 . 
     The technical solutions described above allow fully accomplishing the intended tasks and objects. In particular, the elongated shape of the tank allows eliminating, or in any case strongly attenuating, the imbalance effect of the vehicle when the tank is full. In particular, the single-component configuration of the tank allows the fuel to flow continuously towards the lower part of the tank in order to optimize the position of the vehicle&#39;s center of gravity in any driving condition and with any level of fuel inside the tank.