Claims:WE CLAIM:
1. A frame assembly (200) for a two-wheeled vehicle (100), the frame assembly (200) comprising a plurality of frame structure members joined together using joining means for providing support to vehicle components, the frame assembly (200) comprising:
a head tube (210);
a pair of down tubes (220), each tube extending downwards on either sides of the vehicle 100;
a pair of seat rails (240) for supporting a seat assembly of the vehicle 100;
a reinforcement assembly (400) including a plurality of members joined together to form the reinforcement assembly (400), the reinforcement assembly (400) being joined to the head tube (210), the pair of seat rails (240) being joined to the sides of the reinforcement assembly (400), the pair of down tubes (220) extending downwards from the reinforcement assembly (400); and
a main tube (230) joined to the reinforcement assembly (400), the main tube (230) extending downwards from the reinforcement assembly (400).

2. The frame assembly (200) as claimed in claim 1, wherein the reinforcement assembly (400) extends from the head tube (210) to the seat rails (240) and supports a fuel tank (116) of the vehicle (100).
3. The frame assembly (200) as claimed in claim 1, wherein the plurality of reinforcement assembly members includes a first pair of reinforcement members (410) and a second pair of reinforcement members (420) disposed on either sides of the frame assembly (200), the first pair (410) being joined to the second pair (420) through joining means.

4. The frame assembly (200) as claimed in claim 3, wherein the joining means is a circular weld (430), the circular weld (430) joining the rear of first pair members (410) to the front of the second pair members (420), the first pair (410) being disposed in front of the second pair (420) with respect to the vehicle direction.

5. The frame assembly (200) as claimed in claim 1, wherein the pair of seat rails (240) includes a left side rail (240l) and a right-side rail (240r), the left side rail (240l) being welded to a left side portion of the reinforcement assembly (400) and the right-side rail being welded to a right side portion of the reinforcement assembly (400).

6. The frame assembly (200) as claimed in claim 1, wherein the pair of down tubes (220) is joined to the sides of the reinforcement assembly (400) by joining means.

7. The frame assembly (200) as claimed in claim 6, wherein each of the down tubes (220) is joined to the either of the front sides of the reinforcement assembly (400) by a weld, the down tubes (220) being joined to respective members of the first pair of reinforcement members (410).

8. The frame assembly (200) as claimed in claim 1 including an elliptical member (460) for connecting the plurality of reinforcement members, wherein the plurality of reinforcement members are joined together by top weld (412).

9. The frame assembly (200) as claimed in claim 8, wherein the elliptical member (460) connects the first pair of reinforcement members (410) to each other, the elliptical member being step welded to the reinforcement assembly (400).

10. The frame assembly (200) as claimed in claim 8, including a bridge bracket (700) running over the reinforcement assembly (400) and a shock absorber mounting bracket (600) resting on a rear face of the reinforcement assembly (400) for mounting a shock absorber (128) of the vehicle (100) on the reinforcement assembly (400), the shock absorber (128) being connected to the bridge bracket (600), the seat rails being connected to the reinforcement assembly (400) through the bridge bracket (700).

11. The frame assembly (200) as claimed in claim 1, wherein the reinforcement assembly (400) has a threaded opening (320) at the rear end for mounting an air cleaner of the vehicle (100).

12. The frame assembly (200) as claimed in claim 1, wherein the reinforcement assembly (400) has a rear opening (450r) at a rear bottom portion adapted for welding to the main tube (130) and a front opening (450f) at a front portion adapted for welding the head tube (210).

13. The frame assembly (200) as claimed in claim 1, wherein the reinforcement assembly (400) extends to the middle of the vehicle (100).

Dated this 10th day of March 2022

TVS MOTOR COMPANY LIMITED
By their Agent & Attorney

(Nikhil Ranjan)
of Khaitan & Co
Reg No IN/PA-1471 , Description:FIELD OF THE INVENTION
[001] The present invention relates to a frame structure for a two-wheeled saddle type vehicle such as a motorcycle type vehicle.

BACKGROUND OF THE INVENTION
[002] A frame structure in a two-wheeler vehicle is the backbone of the vehicle. Typically, the frame structure is a frame assembly of a head tube, a pair of down tubes, a main tube, and a pair of seat rails which extends towards rear of the vehicle. The main tube extends from the head tube in vehicle rearward direction till the seat rails and then bends downwards to support the engine of the vehicle using engine mounting brackets. The seat rails are welded to either sides of the main tube and extend in vehicle rearward direction to support the seat of the vehicle. The headtube forms a castor angle for the vehicle.
[003] In conventional commuter motorcycles, a mono main tube is permanently connected with a frame head tube. The main tube is used for withstanding and transferring the loads borne by the vehicle during driving. The pair of down tubes on the left and the right side of the vehicle running parallelly downwards from the main tube are connected permanently on either sides of the main tube. The down tubes also support and share some weight of the engine mounted on the main tube through the engine mounting brackets.
[004] Conventionally, a bridge tube welded to the head tube and the main tube near a joint between the head tube and the main tube, is provided which increases the torsional strength of the frame. A fuel tank is disposed on the top of the main tube. A shock absorber mounting bracket is mounted to a portion of the main tube, such that a top portion of the shock absorber is mounted to the main tube and the end portion is mounted to a swing arm.
[005] It is apparent that the top portion of the front frame has more load bearing because of the engine, the shock absorber and the fuel tank. Therefore, the frame requires to be constructed to have a higher load bearing capacity at the front portion of the frame. Moreover, with the advancing technology, there has been an increased requirement of vehicular elements and packaging of various vehicle operating elements. As a result, optimization of space in vehicle is crucial.
[006] In the prior art, the lower end portion of the shock absorber is attached to a bracket welded to a cross member joining the left and right swing arm in front of the rear wheel through linkage mechanism. The upper end portion of the shock absorber is supported by a bracket connected to the main tube. The bracket is secured to a cross pipe disposed bridge wise between the pair of left and right seat rails.
[007] However, such designs are used for racing motorcycles where vehicle compete in most extreme conditions. This arrangement cannot be adapted to commuting type motorcycles where it is not possible to directly mount the single shock absorber on to the rear part of frame. This is because provision of such a cross pipe is not feasible in the commuting type vehicle due to the space limitation of the configuration of the vehicle body frame.
[008] As an alternative to mono tube construction, it is known in the art to provide a frame structure for motorcycles having sheet metal sections forked left and right sides from the head tube in vehicle width direction. Such a construction is preferred in view with the purpose of avoiding an in-vehicle structure (e.g., air cleaner). The structure of the frame from the head tube till the vehicle rear end is a forked structure and includes a pair of a left half portion and a right half portion. Each of the half portions is made of flat sheet metal layers joined by metal casting techniques.
[009] As a result of splitting the frame structure into two halves, the rear suspension mounting bracket for a mono suspension can be mounted on only one of either the left half portion or the right half portion of the frame structure. This leads to unequal load distribution in the frame of the vehicle. The load transfer from the seat to the mono shock absorber is not distributed evenly on the frame since the one half portion (either left or right) on which suspension bracket is mounted takes all the load. This gives rise to stability and manoeuvrability issues. Besides, as rear suspension mounting width is not controlled along the vehicle width direction, any variations in manufacturing can lead to improper vehicle geometry.
[010] Further, in such constructions, the pair of seat rails are formed and welded to the frame structure. Due to manufacturing variations, the tubes are subjected to revising and lot of welding distortions happen at the main frame bending area. This further weakens sections connecting the shock absorber. Hence, under load bearing conditions, the main frame junction becomes weak and subject to crack and is prone to failure.
[011] In the existing frame assembly in the art, mono tube construction of frame is preferred as it is simple and efficient in load bearing. However, the scope for optimization of weight of the frame and space for packaging of other vehicle components is difficult since the cross section of the tubes cannot be varied based on load requirements. The frame assembly member’s cross section cannot be altered as per requirement because that would eventually lead to alteration of other vehicular components which are mounted to the frame members such as fuel tank.
[012] In some prior art designs, as an alternative to varying the cross section of the frame members, number of tubes are provided for increasing the tensile strength of the frame. This, however, adds to the weight of the frame which becomes very heavy and adds to the weight of the vehicle which is not desired as that adversely impacts the handling, milage and manoeuvrability. The cost of the frame is also high due to the heavy weight.
[013] Furthermore, high power engine is bigger in size. Since the packaging volume is very limited in the conventional frame structure, high-capacity engines cannot be mounted.
[014] Thus, there is a need in the art for a frame structure for a saddle type two wheeled vehicle such as a motorcycle type vehicle, which addresses at least the aforementioned problems.

SUMMARY OF THE INVENTION
[015] In one aspect, the present invention is directed at a frame assembly for a two-wheeled saddle type vehicle such as a motorcycle. The frame assembly includes a plurality of frame structure members joined together using joining means for providing support to various vehicle components such as a fuel tank, seat, etc. The frame assembly includes a head tube, a pair of down tubes extending downwards on either sides of the vehicle, a pair of seat rails for supporting a seat of the vehicle, a reinforcement assembly for supporting a fuel tank, and a main tube joined to the reinforcement assembly extending downwards from the reinforcement assembly. The reinforcement assembly includes a plurality of members joined together to form a box like structure. The reinforcement assembly is joined to the head tube, the main tube, and the pair of seat rails. The reinforcement assembly extends from the head tube to the seat rails. The seat rails are joined to either sides of the reinforcement assembly towards a rear end of the reinforcement assembly and the pair of down tubes is connected to either sides of the reinforcement assembly in the front.
[016] In an embodiment, the reinforcement assembly includes a first pair of reinforcement members and a second pair of reinforcement members. The first pair of reinforcement members is disposed in front of and joined to the second pair of reinforcement members through joining means. Each member of each of the pairs is disposed on either sides of the vehicle. In an embodiment, the joining means is a circular weld joining the rear of the first pair of members to the front of the second pair of members.
[017] In an embodiment, the pair of seat rails includes a left side rail and a right-side rail. The left side rail is welded to a left side portion of the reinforcement assembly and the right-side rail is welded to a right side portion of the reinforcement assembly.
[018] In an embodiment, the pair of down tubes is joined to the sides of the reinforcement assembly by joining means. Each of the down tubes is joined to the respective members of the first pair of reinforcement members of the reinforcement assembly by a weld.
[019] In an embodiment, the reinforcement assembly of the frame assembly includes an elliptical member for joining together the first pair of reinforcement members. Each of the members of each of the pairs of reinforcement members are welded together at the top by a top weld. In an embodiment, the elliptical member is step welded to the reinforcement assembly.
[020] In a further embodiment, the frame assembly includes a bridge bracket running over the reinforcement assembly and a shock absorber mounting bracket resting on a rear face of the reinforcement assembly for mounting a shock absorber of the vehicle. The shock absorber is connected to the bridge bracket. The seat rails are connected to the reinforcement assembly through the bridge bracket.
[021] In a further embodiment, the reinforcement assembly has a threaded opening at the rear end for mounting an air cleaner of the vehicle. The reinforcement assembly also has opening at a bottom and front portion adapted for welding to the main tube and the head tube, respectively.

BRIEF DESCRIPTION OF THE DRAWINGS
[022] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates a right-side view of an exemplary motor vehicle, in accordance with an embodiment of the invention.
Figure 2A illustrates a perspective view of the frame assembly, in accordance with an embodiment of the invention.
Figure 2B illustrates a front view of the frame assembly in accordance with an embodiment of the invention.
Figures 3A-B illustrate perspective views of the front portions of the frame assembly, in accordance with another embodiment of the invention.
Figure 4A illustrates a perspective view,
Figure 4B illustrates another perspective view of a front portion of the reinforcement assembly; and
Figure 4C illustrates an exploded view of the reinforcement assembly, in accordance with an embodiment of the invention.
Figure 5A and Figure 5B illustrate the shock absorber mounting bracket in a perspective view and a side view respectively, in accordance with an embodiment of the invention.
Figure 6 illustrates the bridge bracket in a perspective view in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION
[023] The present invention relates to a frame structure for a two wheeled saddle type vehicle. More particularly, the present invention relates to a frame assembly for carrying and supporting the various components of a two wheeled vehicle such as a motorcycle.
[024] Figure 1 illustrates a schematic view of a vehicle 100, in accordance with an embodiment of the present invention. As an example, the vehicle 100 is a two-wheeled vehicle. The vehicle 100 comprises a prime mover 110 that is adapted to provide motive force for movement of the vehicle 100. In an embodiment, the prime mover 110 is an internal combustion engine, which is preferably a single-cylinder engine. In another embodiment, the prime mover 110 is an electric motor. The vehicle 100 comprises a front wheel 112, a rear wheel 108, a frame assembly 200 (shown in Figure 2), a seat assembly (114 and 114’) and a fuel tank 116. In an embodiment, the seat assembly includes a seat 114 for a rider and a pillion seat 114’ for a pillion.
[025] Further, the upper portion of the front wheel 112 is covered by a front fender 120 mounted to the lower portion of a telescopic suspension unit 118 at the end of the steering shaft. A handlebar 122 is fixed to an upper bracket (not shown) and can rotate about the steering shaft for turning the vehicle 100. The rear wheel 108 arranged below the seat 114 rotates by the motive force of the prime mover 110. In an embodiment, the motive force is transmitted through a chain drive (not shown).
[026] Further, a rear fender 134 is disposed above the rear wheel 108. In an embodiment, for prime mover 110 of internal combustion engine type, an exhaust pipe 136 extends vertically downward from the prime mover 110 and then extends below the prime mover 110 longitudinally along the length of the vehicle 100 before terminating in a muffler 138. The muffler 138 is typically disposed adjoining the rear wheel 108.
[027] A swingarm tube 102 is connected to the frame assembly 200 to swing vertically. The swingarm tube 102 has a front end that is pivotally mounted to the frame assembly 200 and a rear end adapted to receive or support the rear wheel 108 via an axle shaft. The rear wheel 108 is connected to the rear end of the swingarm tube 102. Generally, a shock absorber 128 is supported on the swingarm tube 102 which can be a mono shock absorber (as shown in Figure 1) or through two shock absorbers on either side of the vehicle. The rear end of the swingarm tube 102 is also adapted to support a rear axle adjuster.
[028] Figure 2A illustrates a perspective view of the frame assembly 200 and Figure 2B illustrates a front view of the frame assembly 200 in accordance with an embodiment of the invention. As illustrated in Figures 2A and 2B, the frame assembly 200 includes a plurality of frame structure members joined together using joining means to form the frame assembly 200. The frame assembly 200 is the backbone of the vehicle 100 and carries and provides support to various components such as the seat (114, 114’), fuel tank (116), the engine (110) and the like, of the vehicle 100 as described with reference to Figure 1.
[029] In accordance with an embodiment of the invention, the frame assembly 200 includes a plurality of frame structure members joined together using joining means. The frame assembly includes a head tube 210, a pair of down tubes 220 extending downwards on either sides of the vehicle 100, a pair of seat rails 240 for supporting the seat assembly, a reinforcement assembly 400 for supporting the fuel tank 116, and a main tube 230 joined to the reinforcement assembly 400 extending downwards from the reinforcement assembly 400.
[030] The reinforcement assembly 400 includes a plurality of reinforcement members joined together to form a box like structure. The reinforcement assembly 400 is joined to the head tube 210 and the main tube 230. The pair of seat rails 240 is joined to the sides of the reinforcement assembly 400.
[031] In another embodiment, the joining means used for joining the various frame structure members together is a butt weld.
[032] The head tube 210 supports a steering shaft (not shown) and the telescopic suspension unit 118 attached to the steering shaft through a lower bracket (not shown). The telescopic suspension unit 118 supports the front wheel 112. A headlight 124, a visor guard (not shown) and instrument cluster 126 is arranged on an upper portion of the head tube 210. The seat rails 240 extend rearward to support the seat assembly. A grab rail 132 is also provided to the seat rails 240. A taillight unit 130 is disposed at the end of the vehicle 100 and at the rear of the seat assembly.
[033] Figures 3A-3B illustrate perspective views of the front portions of the frame assembly 200 in accordance with another embodiment of the invention. The frame assembly also includes a bridge bracket 600 running over the reinforcement assembly 400 and a shock absorber mounting bracket 500 resting on a rear face of the reinforcement assembly 400 for mounting a shock absorber 128 of the vehicle 100. The shock absorber mounting bracket 500 is connected to the bridge bracket 600. The bridge bracket 600 provides support to the seat rails 240 for welding on to the sides of the reinforcement assembly 400. A detailed description of the bridge bracket 600 is given with reference to Figure 6 and description in greater details for the shock absorber mounting bracket 500 is provided with reference to Figure 5 later in this section.
[034] In another embodiment, the reinforcement assembly 400 has a threaded opening 320 at a rear side end for mounting an air cleaner of the vehicle 100. In an embodiment, one of the second pair of reinforcement members has the threaded opening 320. Also shown in Figures 3A-B is an engine mounting bracket 310 for mounting the engine 110 and a fuel tank mounting bracket 330 of the vehicle 100. The engine mounting bracket is provided on the main tube 230. The fuel tank mounting bracket 330 is provided on the first pair of reinforcement members 410.
[035] Figure 4A illustrates a perspective view, Figure 4B illustrates another perspective view of a front portion of the reinforcement assembly 400 and Figure 4C illustrates an exploded view the reinforcement assembly 400, in accordance with an embodiment of the invention. The reinforcement assembly 400 includes a first pair of reinforcement members 410 and a second pair of reinforcement members 420 joined together through joining means. The first pair of reinforcement members 410 is disposed in front of the second pair of reinforcement members 420 with respect to the vehicle.
[036] Referring to Figure 4C, in an embodiment, the first pair of reinforcement members 410 includes a front left reinforcement member 410l and a front right reinforcement member 410r. Similarly, the second pair of reinforcement members 420 includes a rear left reinforcement member 420l and a rear right reinforcement member 420r. The front and rear left reinforcement members (410l, 420l) are disposed on the left side of the vehicle 100, and the front and rear right reinforcement members (410r, 420r) are disposed on the right side of the vehicle 100.
[037] In an embodiment, the pair of down tubes 220 includes a left side down tube 220l welded to a left side portion of the reinforcement assembly 400 and a right-side down tube 220r welded to a right side portion of the reinforcement assembly 400. The left side down tube 220l welded to the left reinforcement member 410l (shown in Figure 4C) and a right-side down tube (220r) is welded to the front right reinforcement member 410r (shown in Figure 4C).
[038] The pair of seat rails 240 includes a left side rail 240l welded to the rear left reinforcement member 420l (shown in Figure 4C) and a right-side rail 240r welded to the rear right reinforcement member 420r (shown in Figure 4C) of the reinforcement assembly 400.
[039] In an embodiment, the joining means between the first pair of reinforcement members 410 and the second pair of reinforcement members is a circular weld 430. The circular weld 430 joins the reinforcement member 410l to the reinforcement member 420l and similarly, the circular weld 430 joins the reinforcement member 410r to the reinforcement member 420r. The first pair of the reinforcement members (410l, 410r) are joined together by a top front weld 412f at the top and similarly the second pair of reinforcement members (420l, 420r) are joined together by a top rear weld 412r at the top. The plurality of the reinforcement members of the reinforcement assembly are thus joined together by welding to form a box type structure. In an embodiment the top front weld 412f and the top rear weld 412r is a single continuous weld.
[040] The left side rail 240l is welded to rear left reinforcement member 420l and the right side rail is welded to rear right reinforcement member 420r. The left side down tube 220l is welded to the front left reinforcement member 410l and the right side down tube is welded to the front right reinforcement member 420r.
[041] In another embodiment, the reinforcement assembly 400 also includes an elliptical member 460 for connecting the first pair of reinforcement members 410 to each other. The elliptical member 460 is an elliptical tube joining the front left reinforcement member 410l to the front right reinforcement member 410r. In an embodiment, the elliptical member 460 is step welded to the reinforcement assembly 400.
[042] In another embodiment, the reinforcement assembly 400 extends to approximately the middle of the vehicle 100. The reinforcement assembly 400 has a rear opening 450r (not shown in Figures 2A-B) at the rear bottom portion for welding the main tube 230. The reinforcement assembly 400 also has a front opening 450f (not shown in Figures 2A-B) at the front portion for welding of the head tube 210.
[043] Figure 5A and Figure 5B illustrate the shock absorber mounting bracket 500 in a perspective view and a side view respectively, in accordance with an embodiment of the invention. The shock absorber mounting bracket 500 in a front portion 502 and through a side profile 510 with shoulders 512 connects to the rear end of the reinforcement assembly 400. A bottom profile 530 of the shock absorber mounting bracket 500 hugs the main tube 230 and helps to align and maintain the position of the shock absorber 128 centrally with respect to the vehicle 100 when viewed from a vehicle width direction.
[044] Referring to Figure 5B, in accordance with an embodiment of the invention, the height of the shock absorber mounting bracket 500 traverses the neutral axis 240a of the seat rails 240. Since the shock absorber mounting bracket traverses the neutral axis of the seat rails, better load distribution is achieved. This also supports integration of the shock absorber mounting bracket integration with the reinforcement assembly.
[045] Figure 6 illustrates he bridge bracket 600 in a perspective view in accordance with an embodiment of the invention. The bridge bracket 600 is a formed as a cross bracket member. A side profile 620 of the bridge bracket 600 formed with flanges at front and rear runs over the pair of the seat rails 240 and crosses the neutral axis 240a (axis 240a being shown in Figure 5B) of the seat rails 240 when viewed from the top of the vehicle 100. The bridge bracket 600 at a front portion has a front flange 610, which runs over the reinforcement assembly 400 and has a central relief to have clearance with the reinforcement assembly 400. The front flange 610 connects the reinforcement members 420l and 420r at the rear end and has a central relief to have clearance with the reinforcement assembly 400.
[046] It may be appreciated that if clearance is not provided then weld on weld problem may arise which weakens the welding. The bridge bracket 600 has a bottom formed portion which rests on top of the shock absorber mounting bracket 500 and has a central flat to have provisions for butt welding to the shock absorber mounting bracket 500.
[047] Advantageously, the frame assembly provided by the invention increases the rigidity of the frame of the vehicle. The reinforcement members forming joining together to form a box like structure - the reinforcement assembly add to the structural rigidity of the frame by eliminating the weakening of the frame which was unavoidable because of the requirement of bending for accommodating the shock absorber. The invention thus obviates the use of a bent profile in the frame for accommodating a shock absorber via gusset. It may be appreciated that a straight profile of frame for supporting the shock absorber enabled by the invention adds to the strength of the frame assembly.
[048] Further, the reinforcement assembly provided by the invention forms an integration of a front portion and a rear portion of the frame assembly and helps in splitting the reinforcement front and rear to improve the structural rigidity of the frame assembly reducing the stress on the main frame of the vehicle.
[049] Additionally, the front stiffener (eg. elliptical member 460) connecting the reinforcement assembly and the pair of down tubes reinforce the load from the shock absorber towards the main frame of the vehicle. This highly increases the rigidity of the frame structure. The elliptical member provides most cross section and is step welded such that the height of the cross section does not increase beyond limit. The cross-section area thus achieved is maximum at the elliptical member location.
[050] Further, the front half of the bridge bracket is joined to the reinforcement assembly and the rear half is joined to the shock absorber mounting and supported by the seat rails on either sides. This improves rigidity of the shock absorber mounting structure. Thus, impact loads transmitted from the rear suspension via the shock absorber bracket are supported by the bridge bracket.
[051] Furthermore, the load on the vehicle from the seat is transmitted to the mainframe of the vehicle through the seat rails and the reinforcement assembly. The load is also transmitted through the shock absorber mounting bracket and the reinforcement assembly. Thus, the load from the seat is supported effectively by making effective use of the reinforcement assembly provided as a part of the frame assembly provided by the invention. Since the shock absorber mounting bracket traverses the neutral axis of the seat rails, better load distribution is achieved. This also supports integration of the shock absorber mounting bracket integration with the reinforcement assembly.
[052] Furthermore, the reinforcement assembly extends to approximately the middle of the vehicle which obviates the use of a bridge tube for increasing strength of the frame. The extended reinforcement assembly also enables using a shorter length for the main tube by replacing a length of the main tube extending till the head tube. The use of a bridge tube for increasing strength is removed, by an extended reinforcement member. The extended reinforcement members also shortens the length of the main tube, wherein as per conventional art the main tube extends directly from the headtube till the lower central portion of the vehicle. However as per present invention, the main tube extends only from the central axis of the vehicle till the reinforcement assembly.
[053] Also, the size of the main frame with respect to the diameter and thickness is significantly reduced except only at the location connecting the reinforcement assembly.
[054] Further, the invention enables for the shock absorber to be located substantially centrally when viewed in vehicle width direction and also enables for the construction of the main tube support to maintain the position.
[055] Further, since the first mounting position of the air filter is on the left of the vehicle on the reinforcement assembly and is located in front of the mono shock absorber mounting, no separate bracket is required. This reduces requirement of an additional part – bracket.
[056] Furthermore, the shock absorber mounting bracket top mounting face is raised to cross the neutral axis of the upper tubes (the seat rails). This ensures better load bearing.
[057] The frame assembly and the arrangement of the invention also increases the torsional stiffness of the frame through a cross member connecting the head pipe and the main frame. The main frame, the seat rails and the down tubes are neatly formed and butt welded to the reinforcement assembly. This enables avoidance of any weld distortions.
[058] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.