TECHNICAL FIELD
The present subject matter relates generally to a two-wheeled vehicle and more particularly, but not exclusively to a swing arm structure for the two-wheeled vehicle.
BACKGROUND
Generally, in a two-wheeled vehicle, a vehicle frame assembly acts as a skeleton for the vehicle that supports the vehicle loads. A front portion of the frame assembly connects to a front wheel through one or more front suspension(s). The frame assembly extends rearward of the vehicle, where a rear wheel is connected to a swing arm structure at a rear side through one or more rear suspension(s) and a front side of the swing arm structure is connected to a lower portion of the vehicle frame assembly. The swing arm structure acts as a support member for the one or more rear suspensions and other vehicular parts. Further, an internal combustion (IC) engine is mounted to the vehicle frame assembly of the vehicle. The IC engine is functionally connected to the rear wheel, which provides the forward motion to the vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed description of the present subject matter is described with reference to the accompanying figures. Same numbers are used throughout the drawings to reference like features and components.
Fig. 1 illustrates a left side view of an exemplary two-wheeled vehicle, in accordance with an embodiment of the present subject matter. [0005] Fig. 2 illustrates a top perspective view of a swing arm structure in assembled condition according to an embodiment.

[0006] Fig. 3 illustrates a top perspective view of a swing arm structure
according to a first embodiment.
[0007] Fig. 4 illustrates a top perspective view of a swing arm structure
according to a second embodiment.
[0008] Fig. 5 illustrates a top perspective view of a swing arm structure
according to a third embodiment of the present subject matter.
[0009] Fig. 6 illustrates a top perspective view of a swing arm structure
according to a fourth embodiment of the present subject matter.
[00010] Fig. 7 illustrates a top perspective view of a swing arm structure
according to a fifth embodiment of the present subject matter.
[00011] Fig. 8 illustrates a top perspective view of a swing arm structure
according to a sixth embodiment of the present subject matter.
[00012] Fig. 9 illustrates a top perspective view of a swing arm structure
assembled with a rear wheel according to an embodiment of the present subject
matter.
[00013] Fig. 10 illustrates a protective member mounted to the swing arm
structure, in accordance to an embodiment of the present subject matter.
[00014] Fig. 11 illustrates a perspective view of a swing arm structure according
to another embodiment of the present subject matter.
[00015] Fig. 12 illustrates a rear view of the swing arm structure along with a
muffler assembly.
[00016] Fig. 13 illustrates a side view of the swing arm structure in assembled
condition, in accordance to an embodiment of the present subject matter.
[00017] Fig. 14 illustrates a perspective view of the swing arm structure from a
vehicle front side, in accordance to an embodiment of the present subject matter.
[00018] Fig. 15 illustrates a sectional front view of the swing arm structure, in
accordance to an embodiment of the present subject matter.

DETAILED DESCRIPTION
[00019] Generally, in a two-wheeled vehicle the swing arm structure is made of metal tubes. Generally, the frame assembly is made of tubular sections, channels or the like, that are formed from welded or rolling or extruded steel or other metal alloys. Further, the swing arm structure supports various other vehicular parts made of metal or plastic. Such swing arm structures known in the art adds up to the overall increase in the weight of the vehicle.
[00020] Further, the conventional swing arm structure includes plurality of joints, which lowers stiffness of the structure. In addition, vibration transmission occurring in the swing arm structure is known in the art. Moreover, specific strength of the swing arm structure is less. Further, the conventional tubes are made of metal are prone to rusting or corrosion, which reduces the life of the swing arm structure, thereby affecting the vehicle performance. Importantly, weight of the swing arm structure is high due to metallic tubular frames. Therefore, results in low power to weight ratio. Moreover, the known swing arm structures made of composite material generally involve several joints. Similarly, in the conventional swing arm structure made of metal alloys, the load bearing parts of the swing arm, for example, the rear shock absorber mounting bridges are prone to failure due to load acting on them. Thus, there is a need to strengthen the load bearing zones of the swing arm structure to overcome such failures – the covering plates of the present swing arm takes care of this problem. Further, these covering plates also provide additional rigidity to the supporting structures. [00021] Moreover, the existing swing arm structures made of composite material also faces problems relating to durability, rigidity, strength and stiffness. Further, the existing swing arm structures were posed with the problems of heat radiation from the adjoining heat zones of the vehicle. Similarly, the existing swing arm structure made of composite material also faces problems with respect to wearing off of composite material due to adjoining rotating members of the vehicle. Further, any additional buffer plates added to overcome such problems were less

durable and resulted in other problems such as noise, vibration, heat absorption, corrosion and so on.
[00022] The present subject matter addresses the aforementioned and other problems in the prior art. Hence, it is an objective of the present subject matter to provide a swing arm structure for a two-wheeled vehicle for overcoming the above mentioned problems. According to one aspect, the present subject matter proposes a swing arm structure that is lightweight. The lighter weight of the swing arm structure reduces the unsprung mass and results in comfortable riding of the vehicle. According to another aspect, the swing arm structure has improved elastic modulus. According to yet another aspect, the swing arm structure has improved life.
[00023] In an embodiment, the present subject matter provides a two-wheeled vehicle. The vehicle comprises a swing arm structure. A rear wheel is mounted to one end of the swing arm structure of the vehicle. Another end of the swing arm structure is connected to the frame assembly. The proposed swing arm structure acts as a structural member for other vehicular parts including one or more rear suspensions, etc. In another embodiment, the swing arm structure is capable of supporting a powerhouse including battery, motor, or engine, in addition to rotatably support a wheel.
[00024] According to a first embodiment of the present invention, the swing arm structure is formed by connecting two curved structures of lightweight material including composite material, fiber reinforced polymer, or fiber reinforced resin. The curved structure includes a right-side member and a left side member. This improves stiffness of the structure. The contact portion of the two-curved structure is capable of mounting a vehicular part including rear suspension in case of a mono shock absorber.
[00025] Further, in accordance with a second embodiment, a swing arm structure is formed by connecting two curved structures made up of a light weight material including a composite material like carbon fiber. Further, additional support to

the swing arm structure is provided by integrating one or more top support structures made up of composite materials including carbon fiber and glass fiber.
[00026] In accordance with a third embodiment, a swing arm structure is formed by connecting two curved structures made up of light weight material including a composite material reinforced by resin. Further, to provide additional strength to the swing arm structure, one or more side support structures are integrated with the swing arm structure. The one or more side support structures are made up of light weight material including a fiber reinforced polymer.
[00027] Furthermore, the contact portion of the two curved structures is configured to mount a shock absorber. The mounting area of the shock absorber weakens upon usage over a period. The shock absorber mounted in the contact portion of two curved structures may become unstable and fails to provide appropriate damping to the vehicle. Hence, the mounting area is provided with additional one or more support members and one or more covering members. In the present embodiment, covering members are used to provide additional strength and stability to the mounting area on the swing arm structure.
[00028] Further, the one or more covering members increase the stability of the swing arm structure. Therefore, the overall performance of the shock absorber and the vehicle is increased. The covering members include different orientations to cover the contact portion in the swing arm. The different orientations of the covering members include front and rear covering members, right and left covering members, and top-bottom covering members.
[00029] Further, according to yet another embodiment, the swing arm structure is capable of mounting one or more rear shock absorbers. Accordingly, the one or more covering members in any of the above-mentioned orientations are employed to provide additional support to the portion of the swing arm structure configured to mount the one or more rear shock absorbers. Typically, the one or more rear shock absorbers are mounted to a substantially rear end of the swing arm structure.

[00030] In an embodiment, the present subject matter provides a swing arm structure that achieves protection of swing arm structure from adjoining moving parts and prevent any sort of damage to the swing arm structure. For instance, in vehicle riding conditions, especially while accelerating or decelerating, there is a high likelihood of establishing a contact between a drive chain of the vehicle transmission system and the swing arm structure. Any such contact may potentially lead to the damage of the swing arm structure. The present subject matter provides a swing arm structure that overcomes the above-mentioned drawback of the existing swing arm structures.
[00031] Further, it is a known practice in the state of the art, to provide separate buffer chain structures to eliminate any such problem associated with the wear and tear of the swing arm structure. The present subject matter provides a swing arm structure that eliminates the need for a separate buffer chain structure.
[00032] In an embodiment, the swing arm structure include one or more-layer member(s) being made of a light weight material including composite material like carbon fiber or a glass fiber reinforced by resin. In addition, the layer member(s) may be hollow type or may include one or more layers disposed therein. The swing arm structure provides structural rigidity without increasing the weight.
[00033] In addition to the above-described embodiments of the swing arm structure, the swing arm structure can have inner layer member(s) with any regular or irregular geometrical cross-section. Correspondingly, outer layer member(s) that are provided to secure the respective inner layer member(s) take at least an outer peripheral shape of the inner layer member(s). In addition, the swing arm structure having inner layer member(s), outer layer member(s), and covering members being made of composite material can be integrally formed into integral swing arm structure.
[00034] According to an embodiment of the present invention, the swing arm structure made of composite material includes one or more protective members to protect the swing arm structure and other surrounding parts from erosion

occurring due to deposition of mud/other foreign particles on the swing arm structure. Further, the protective member prevents the heat radiated towards the swing arm structure from the surrounding parts including a muffler.
[00035] In an embodiment, the swing arm structure of the present subject matter structure is made of composite material, for example, resin reinforced with high-strength fibers. Further, in an embodiment, the drive chain of the transmission system passes substantially upwardly of the swing arm structure, for instance, both the LH and RH swing arm structures. In an embodiment, the resin material on the top most surface of the swing arm structure is protruded upwardly along the drive chain line in order to guide the chain rollers and ensuring elimination of direct contact of the chain with the swing arm structure. In an embodiment, an additional layer of resin thickness is provided on the swing arm structure that is along the drive chain line.
[00036] The previously mentioned and other advantages of the present subject matter would be described in detail in conjunction with the figures in the following description.
[00037] Fig. 1 illustrates a left side view of a two-wheeled vehicle, for example, a motorcycle 1 according to an embodiment. The motorcycle 1according to an embodiment includes a front wheel 101 steered by a handlebar 102 and a rear wheel 103 supported by a swing arm structure 104. Steering assembly parts including the handlebar 102 and the front wheel 101 are supported for pivotal steering operation on a head pipe 105 at the front end of the vehicle body frame 106. A seat 110 for a driver and a pillion is placed rearward to a fuel tank 114. An engine assembly 113 is disposed below the fuel tank 114. A front fender 111 is provided above the front wheel 101 to avoid the said vehicle 1 and its occupants from being splashed with mud. Likewise, a rear fender 112 is placed above the rear wheel 103, and to the outer side in the radial direction of rear wheel 103. Rear fender 112 inhibits rainwater or the like from being thrown up by rear wheel 103.

[00038] The swing arm 104 along with a shock absorber 109 is supported at a front portion thereof for pivotal motion and upward and downward rocking motion on the rear side of a lower portion of the vehicle body frame 106. The swing arm 104 according to an embodiment is capable of supporting one or more rear suspensions. A suspension assembly including a pair of front forks 108 and the shock absorber 109 is provided in the two-wheeled vehicle for providing better ride comfort to the rider. In general terms, the shock absorbers help cushion vehicles on uneven roads. In the two-wheeled vehicle, shock absorbers reduce the effect of traveling over rough ground, leading to improved ride quality and vehicle handling.
[00039] The vehicle body frame 106 includes the head pipe 105, a main pipe 116, a pair of left and right rear frames 107 extending from a rear end of the main pipe 116. The head pipe 105 is positioned at a front-end portion of the vehicle body frame 106. The rear frames 107 extend in a leftwardly and rightwardly branching state obliquely downwardly rearwardly from a lower portion of the main pipe 116. A down tube 115 extending rearwardly downward from the rear end of the main pipe 116.
[00040] Fig. 2 illustrates atop perspective view of a swing arm structure in assembled condition according to an embodiment. The swing arm structure 100 is attached to the vehicle body frame 106 through a front end axle 150 disposed at a front end AB of the swing arm structure 100. The swing arm structure is capable of being attached to a rear wheel 103 through one or more slots 160 disposed at a rear end BB of the swing arm structure 100. Further, the swing arm structure 100 is capable of holding at least one rear shock absorber 109 situated in front of the rear wheel 103. The at least one rear shock absorber 109 is mounted to a holding member 140 disposed in front of the rear wheel 103 and on the swing arm structure 100. Furthermore, the swing arm structure 100 is configured to hold a fender member 112 disposed at the rear end BB of the swing arm structure 100.
[00041] The swing arm structure 100 according to an embodiment is made up of a light weight material including composite material like carbon fiber, a fiber

reinforced polymer, or a resin reinforced composite material making the proposed swing arm structure 100 lighter compared to the conventional swing arm structure. Hence, the entire weight of the vehicle is decreased comparatively making it easy to handle the vehicle by the user. Further, the problems including rust and corrosion of the swing arm structure is overcome by the resin reinforced composite material.
[00042] In accordance with another embodiment, the swing arm structure 100 is capable of mounting more than one rear shock absorbers 109.
[00043] Fig. 3 illustrates top perspectives view of a swing arm structure according to a first embodiment. The swing arm structure 200 is formed by connecting two curved structures made up of a light weight material including a fiber reinforced polymer or carbon fiber material. The swing arm structure 200 obtained by connecting two curved structures is an integrated swing arm structure. A first curved structure 201 is integrated to a second curved structure 202 to form a swing arm structure 200 including a first lateral member 202-1 and a second lateral member 202-2 that are extending towards a right side and left hand side, respectively, with respect to contact portion CP. A contact portion CP between the first curved structure 201 and the second curved structure 202 serves as a mounting point to mount a vehicular part including the rear shock absorber 109. Further, a holding member 203 is disposed at the contact portion. The holding member 203 is capable of mounting the rear shock absorber 109.
[00044] Further, the swing arm structure 200 comprises of two ends including a front end AB, and a rear end BB. The swing arm structure 200 is attached to the lowest point of the vehicle body frame 106 through one or more provisions 204 at the front end AB of the swing arm structure 200. The swing arm structure is attached to a rear wheel (not shown) through one or more slots 205 provided at the rear end BB of the swing arm structure 200.The swing arm structure200 is made up of a light weight material including a fiber reinforced polymer/plastic like carbon fiber reinforced polymer. The holding member 203 is made up of a material including metals.

[00045] Fig. 4 illustrates a top perspective view of a swing arm structure according to a second embodiment. The swing arm structure 300 is formed by integrating a first curved structure 301 and a second curved structure 302. A holding member 303 is disposed at a contact portion CP of the first curved structure 301 and the second curved structure 302. The holding member 303 is capable of holding a rear shock absorber 109. The swing arm structure 300 is attached to the vehicle body frame at the front end AB and further, the swing arm structure 300 is attached to the rear wheel 103 at the rear end BB. The first end AB comprises of one or more provisions 304 capable of being mounted to the vehicle body frame. Further, one or more slots 305 are provided to facilitate mounting of the rear end BB of the swing arm structure 300 to the rear wheel 103. To provide further stability and adequate support to the swing arm structure 300, one or more support members 306 are integrated with the swing arm structure. According to the present embodiment, the one or more support members 306 are disposed on top of the swing arm structure 300. The one or more support members 306 extend from the front end AB to the rear end BB. However, according to yet another embodiment, one or more support members 306 are integrated to a bottom surface of the swing arm structure 300. According to yet another embodiment, the swing arm structure 300 includes one or more support members 306 both on top and bottom surfaces.
[00046] The swing arm structure 300 is made up of a composite material like carbon fiber. Further, the one or more support members 306 are made up of carbon fiber. Furthermore, according to another embodiment of the present invention, a rear face 307 of the rear end BB is a single member capable of enhancing chain adjusters.
[00047] Fig. 5 illustrates a top perspective view of a swing arm structure according to a third embodiment of the present invention. The swing arm structure 400 is formed by integrating a first curved structure 401 and a second curved structure 402. A holding member 403 is disposed at a contact portion CP of the first curved structure 401 and the second curved structure 402. The holding

member 403 is capable of holding a rear shock absorber 109. The swing arm structure 400 is attached to the vehicle body frame at the front end AB and further, the swing arm structure 400 is attached to the rear wheel 103 at the rear end BB. The first end AB comprises of one or more provisions 404 capable of being mounted to the vehicle body frame. Furthermore, one or more slots 405 are provided to facilitate mounting of the rear end BB of the swing arm structure 400 to the rear wheel 103. To provide further stability and adequate support to the swing arm structure 400, one or more support members 406 are integrated with the swing arm structure 400. According to the third embodiment, the one or more support members 406 are disposed on sides of the swing arm structure 400.
[00048] The one or more support structures 406 are disposed each on right hand side and on left hand side of the swing arm structure 400. The one or more support members 406 extend from the front end AB to the rear end BB. The swing arm structure 400 is made up of a fiber reinforced polymer. Further, the one or more support structures 406 are made up of a composite material including carbon fiber and resin. In an embodiment, at least one outer wrapping structure 410 on both left hand side and the right side of the swing arm structure 400 enables enveloping the first curved structure 401 and the support member 406 on a side facing the first end AB of the swing arm structure 400, and enveloping the second curved structure 402 and the support member 406 on a side facing the second end BB of the swing arm structure 400. The curved structure 201,301, 401, 202,302,402 are integrally formed at least by one process selected from a group consisting of molding, die-casting, gluing. Furthermore, the curved structure 201,301, 401, 202,302,402 are having at least one of ‘U’ shape, or a reverse turn shape.
[00049] Fig. 6 illustrates a top perspective view of a swing arm structure according to a fourth embodiment of the present invention. The swing arm structure 500 extends from the front end AB to the rear end BB. The swing arm structure 500 is attached to the lowest point of the vehicle body frame 106 through one or more provisions 501 at the front end AB of the swing arm

structure 200. A holding member 503 capable of holding a rear shock absorber 109 is disposed at a substantially center portion of the swing arm structure 500. To provide additional support to the substantially center portion of the swing arm structure 500, one or more covering members 504, 505 are disposed around the center portion. According to the present embodiment, one or more covering members 505 are disposed at proximity to the substantially center portion. A front covering member 504 is disposed forwardly to the holding member 503. The front covering member 504 is situated close to the front end AB of the swing arm structure 500. Further, a rear covering member 505 is disposed rearwardly to the holding member 503. The rear covering member 505 is situated substantially closer to the rear end BB.
[00050] The one or more covering members 504, 505 provide support to one or more areas capable of mounting other vehicular parts including the swing arm structure 500. In the present embodiment, the one or more covering members 504, 505 are disposed around the region of mounting the rear shock absorber 109. The one or more covering members 504, 505 provide adequate stability and support to the area wherein the rear shock absorber 109 is mounted. Furthermore, one or more slots 502 are provided to facilitate mounting of the rear end BB of the swing arm structure 500 to the rear wheel 103.
[00051] Fig. 7 illustrates a top perspective view of a swing arm structure according to a fifth embodiment of the present invention. The swing arm structure 600 as illustrated in the figure is configured to mount a rear shock absorber 109. The swing arm structure 600 is attached to the lowest point of the vehicle body frame 106 through one or more provisions 601 at the front end AB of the swing arm structure 600. A holding member 605 is disposed on a substantially mid portion of the swing arm structure 600. The holding member 605 holding the rear shock absorber 109 is a load bearing member, hence, making the substantially mid portion of the swing arm structure 600 vulnerable to forces acting due to loads acting upon and eventually leading to reduced efficiency of the swing arm structure 600.In the present embodiment, one or more covering

members 603, 604 are provided in the swing arm structure 600. The one or more covering members 603, 604 are configured to substantially cover a portion of the swing arm structure 600 capable of holding the rear shock absorber 109. According to an embodiment, the one or more covering members 603, 604 provide adequate support around the area wherein the external forces are acting upon the load.
[00052] According to an embodiment, a right covering member 604 and a left covering member 603 are disposed on right hand side and left hand side respectively of the swing arm structure 600. The right covering member 604 and the left covering member 603 extend from the two main legs 600-a, 600-b of the swing arm structure 600 upto the mounting portion of the holding member 605. Further, the right covering member 604 and the left covering member 603 functions as brackets holding the two main legs 600-a, 600-b to the substantially mid portion of the swing arm structure 600. Furthermore, the right covering member 604 and the left covering member 603 enclose completely at least a portion of the two main legs 600-a, 600-b. Hence, according to the present invention, a more stable swing arm structure 600 is provided. Further, the swing arm structure 600 and the one or more covering members 603, 604 are made up of a fiber reinforced plastic. Hence, the swing arm structure 600 is lighter compared to the conventional swing arm structure 600 and the problems of corrosion and rust are overcome.
[00053] Further, according to another embodiment of the present invention, the right covering member 604 and the left covering member 603 are each split into two halves for easier assembly on to the swing arm structure 600. Furthermore, one or more slots 602 are provided to facilitate mounting of the rear end BB of the swing arm structure 600 to the rear wheel 103.
[00054] Fig. 8 illustrates a top perspective view of a swing arm structure according to a sixth embodiment of the present invention. The swing arm structure 700 is configured to hold a rear shock absorber 109 through a holding member 703 disposed at a substantially mid portion of the swing arm structure

700. The substantially mid portion of the swing arm structure 700 is a load-bearing member and hence, additional support has to be provided in order to prevent the load-bearing member from being worn out. Further, according to an embodiment, one or more covering members are provided to substantially cover a portion around the swing arm structure 700 capable of mounting the holding member 703.
[00055] According to an embodiment, four covering members including two covering members disposed on a top and a bottom portion of the front side and two covering members disposed on a top and a bottom portion of the rear side of the swing arm structure 700 respectively.
[00056] The front side covering member each on the top surface and on the bottom surface including at least one top front covering member 704 and at least one covering member 705a, 705b functions as external bridge members to hold the front main leg to the substantially mid portion of the swing arm structure 700. Furthermore, one or more slots 702 are provided to facilitate mounting of the rear end BB of the swing arm structure 700 to the rear wheel 103.
[00057] Further, the swing arm structure 700 and the one or more covering members are made up of a fiber reinforced plastic. Hence, the swing arm structure 700 is lighter and the problems including corrosion and rusting is overcome. Further, the overall performance of the swing arm structure 700 is improved.
[00058] Fig. 9 illustrates a top perspective view of a swing arm structure 803 assembled with a rear wheel 103 according to an embodiment of the present invention. The swing arm structure 803 includes a protective member 801 disposed to face the rear wheel 103. The protective member 801 functions in protecting the mid portion of the swing arm structure 803 from erosion occurring due to foreign particles such as mud and other tiny particles which splashed by the rear wheel 103 during vehicle riding condition. Further, the protective member 801 strengthen the area of the swing arm structure 803 which is there to

hold the rear shock absorber 109 through the holding member (not shown) disposed at a substantially mid portion of the swing arm structure
[00059] Fig. 10 illustrates a protective member 801 mounted to the swing arm structure 803. According to an embodiment of the present invention, the protective member 801 is enmolded to the swing arm structure 803 to protect the swing arm structure 803 from wearing out. The protective member 801 provides extended life to the swing arm structure 803. Therefore, the other vehicular parts mounted on the swing arm structure 803 have more stable functioning.
[00060] Fig. 11 illustrates a perspective view of a swing arm structure 901 according to another embodiment of the present invention. A second protective member 902 protects the swing arm structure 901 from heat radiations that are emitted by the surrounding parts including a muffler assembly 903. The muffler assembly 903 is also being termed as a heat radiating member 903. The second protective member 902a is disposed in between the muffler assembly 903 and the swing arm structure 901. The heat radiations emitted by the muffler assembly 903 are obstructed by the second protective member 902 amounted on the swing arm structure 901. Further, the second protective member 902a enhances the strength of the swing arm structure 901. Hence, the durability of the swing arm structure 901 improves. Further, the stability of the shock absorbers 109 mounted on such a swing arm is not affected. Furthermore, another protective member 902b to protect the swing arm structure 901 from heat radiated by external parts, for example, adjacent vehicle parked in a parking lot is disposed on the swing arm structure 901.
[00061] Fig. 12 illustrates a rear view of the swing arm structure 901 along with a muffler assembly. The second protective member 902a is disposed along the length of the portion of the swing arm structure 901 located at a proximity to the muffler assembly 903.The second protective member 902a covers the portion of the swing arm structure 901 facing the muffler assembly 903. According to an embodiment of the present invention, the second protective member 902a is made of known metals.

[00062] Fig. 13 illustrates a side view of the swing arm structure 950 in assembled condition, in accordance to an embodiment of the present subject matter. In an embodiment, the swing arm structure 950 is made of composite material, for example, resin reinforced with high-strength fibres. For instance, the resin reinforced composite material may be carbon fiber, and the swing arm structure 950 may be a carbon fiber swing arm structure 950. Further, in an embodiment, a drive chain 955 of the transmission system passes substantially upwardly of the swing arm structure 950, for instance, the LH swing arm structures 950-2.
[00063] Fig. 14 illustrates a perspective view of the swing arm structure950 from a vehicle front side, in accordance to an embodiment of the present subject matter. In an embodiment, the resin material on a top most surface 965 of the swing arm structure 950 is protruded upwardly along the drive chain 955 line, in order to guide one or more chain rollers 980 and ensuring elimination of direct contact of the drive chain 955 with the swing arm structure 950. In an embodiment, an additional layer of resin thickness is provided on the swing arm structure 950 that is along the drive chain line. In one embodiment, the additional layer is disposed on the top surface 965 of a body 960 of the swing arm structure 950, which in an embodiment has a rectangular cross-section. For instance, the additional layer may be glued to the body 960 of the swing arm structure 950 in one embodiment. In an alternative embodiment, the additional layer may be integrally formed on the swing arm structure 950. In yet another embodiment, the additional layer may be welded to the body 960 of the swing arm structure 950. In one embodiment, the top surface 965 of the swing arm structure 950 may form a hump-like structure that protrudes for a predetermined portion of the swing arm structure 950 that is proximal to the drive chain 955 as compared to a portion of the swing arm structure 950 that is distal to the drive chain 955, especially during the rotational movement of the drive chain 955. In one embodiment, the hump-like structure may be provided throughout the length of the swing arm structure 950 on LH and RH sides that extends along a vehicle longitudinal

direction, such that contact between the drive chain 955 and the swing arm structure 950 is prevented during all conditions of drive chain 955 rotation.
[00064] Fig. 15 illustrates a sectional front view of the swing arm structure 950, in accordance to an embodiment of the present subject matter. In one embodiment, the hump-like structure provided on the top surface 965 of the swing arm structure 950 is provided with two portions, for instance, a main buffer element 990, and a projecting buffer rib structure 985. In an embodiment, the main buffer element 990 is disposed substantially adjoining the top surface of the body 960 of the swing arm structure 950. In an embodiment, the main buffer element 990 extends laterally along a vehicle width-wise direction above the top surface of the body 960 of the swing arm structure 950. In an embodiment, the main buffer element 990 is provided with a centrally disposed buffer rib structure 985. In an embodiment, the buffer rib structure 985 projects substantially upwardly towards the drive chain 955 rotational plane. In one embodiment, a top most surface of the main buffer element 990 is disposed substantially farther from a bottom most point of one or more chain rollers 980 of the drive chain 955. In an embodiment, the height ‘b’ of the buffer rib structure 985 is substantially greater than a distance ‘a’ between the bottom most point of one or more chain rollers 980 and a bottom most point of one or more links disposed on either side of the chain rollers 980 separated by the intermittently disposed buffer rib structure 985. In an embodiment, the one or more chain rollers 980 is provided with at least one outer link 975 and at least one inner link 970, while the drive chain 955 is provided with plurality of chain rollers 980 that are connected continuously throughout the rotational direction of the drive chain 955. In one embodiment, the height of the buffer rib structure 985 is determined depending on the size of the drive chain 955. In an embodiment, more the height of the buffer rib structure 985, higher the life of the swing arm structure 950. In one embodiment, the buffer rib structure 985 and the main buffer element 990 may be made of a material that is different from that of the swing arm structure 950. In another embodiment, the

buffer element 990 and the buffer rib structure 985 may also be made of a resin material similar to that of the swing arm structure 950.
[00065] Further, the swing arm structure 104, 100, 200, 300, 400, 500, 600, 700, 803, 901, 950 has a longitudinal length from said front end AB to the contact portion CP is lesser than a longitudinal length from said rear end BB to said contact portion CP. Furthermore, according to an embodiment of the present invention, the protective member 902a covers at least a portion around the swing arm structure 901 facing the muffler assembly 903.
[00066] Many modifications and variations of the present subject matter are possible within the spirit and scope of the present subject matter, in the light of above disclosure.

We claim:
1. A two-wheeled vehicle (1) comprising:
a vehicle body frame (106) including a head tube (105) and a downtube (115) extending rearwardly downward from said head tube (105);
a rear wheel (103) disposed at a rear end of the two-wheeled vehicle (1);
a swing arm structure (104, 100, 200, 300, 400, 500, 600, 700, 803, 901, 950) disposed in between said downtube (115) and said rear wheel (I03), said swing arm structure (104, 100, 200, 300, 400, 500, 600, 700, 803, 901, 950) comprises a front end AB capable of being attached to a lower end of said downtube (115), and a rear end BB capable of being attached to said rear wheel (103), wherein, said swing arm structure (104, 100, 200, 300, 400, 500, 600, 700, 803, 901, 950) comprises a first curved structure (201, 301 and 401) and a second curved structure (202, 302 and 402), said first curved structure (201, 301 and 401) and said second curved structure (202, 302 and 402) having a contact portion (CP) substantially at a center of the swing arm structure (104, 100, 200, 300, 400, 500, 600, 700, 803, 901, 950).
2. The two-wheeled vehicle (1) as claimed in claim 1, wherein said swing
arm structure (104, 300,400) is integrated with one or more support
members (306,406), said support members (306,406) are disposed each on
a RH side and on a LH side of the swing arm structure (104,300,400) and
the one or more support members (306) extend from the front end AB to
the rear end BB.

3. The two-wheeled vehicle (1) as claimed in claim 1, wherein said swing arm structure (104, 803, 901, 950) comprises one or more protective members (801, 902) disposed at a proximity to a heat radiating member (903).
4. The two-wheeled vehicle (1) as claimed in claim 3, wherein said one or more protective members (801, 902) are disposed on said swing arm structure (104, 803, 901, 950) and in front of the rear wheel (103).
5. The two-wheeled vehicle (1) as claimed in claim 1, wherein said first curved structure (201, 301 and 401) and said second curved structure (202, 302 and 402) are integrally formed at least by one process selected from a group consisting of molding, die-casting, gluing.
6. The two-wheeled vehicle (1) as claimed in claim 1, wherein said first curved structure (201, 301 and 401) and said second curved structure (202, 302 and 402) are having shape selected from a group consisting ‘U’ shape, or a reverse turn shape.
7. The two-wheeled vehicle (1) as claimed in claim 1, wherein said first curved structure (201) comprises a first lateral member (202-1), and said second curved structure (202) comprises a second lateral member (202-2), said first and said second lateral members (202-1, 202-2) are integrally formed with at least one holding member (203), said holding member (203) capable of holding at least one rear shock absorber (109).
8. The two-wheeled vehicle (1) as claimed in claim 1, wherein said swing arm structure (104, 100, 200, 300, 400, 500, 600, 700, 803, 901, 950) has

a longitudinal length from said front end (AB) to said contact portion (CP) lesser than a longitudinal length from said rear end (BB) to said contact portion (CP).
9. The two-wheeled vehicle (1) as claimed in claim 1, wherein a top most surface (965) of the swing arm structure (950) is protruded upwardly along a drive chain (955) for guiding one or more chain rollers (980) and ensuring elimination of direct contact of the drive chain (955) with the swing arm structure (950).
10. The two-wheeled vehicle (1) as claimed in claim 9, wherein the top surface (965) of the swing arm structure (950) is provided with a main buffer element (990) extending laterally along width-wise direction of the two-wheeled motorcycle (1) and a projecting buffer rib structure (985) projecting substantially upwardly towards the drive chain (955) rotational plane.
11. The two-wheeled vehicle (1) as claimed in claim 10, wherein said main buffer element (990) comprises a top most surface that is disposed substantially farther from a bottom most point of one or more chain rollers (980) of the drive chain (955), and wherein the height (b) of the projecting buffer rib structure (985) is substantially greater than a distance (a) between the bottom most point of one or more chain rollers (980) and a bottom most point of one or more links (970, 975) disposed on either side of the chain rollers (980) separated by the intermittently disposed buffer rib structure (985).

12. The two-wheeled vehicle (1) claimed in claim 1, wherein said first curved structure (201, 301, 401) and said second curved structure (202, 302, 402) are supported by one or more covering members (504, 505, 603, 604) disposed in at least one of a top and bottom direction, front and rear direction, or in lateral direction to provide adequate support around the area.