TECHNICAL FIELD
[0001] The present subject matter relates generally to a two-wheeled motor vehicle, and more particularly to a frame structure for the two-wheeled motor vehicles.
BACKGROUND
[0002] Generally, in a two-wheeled vehicle a frame assembly extends rearward from a head tube. The 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 frame assembly through one or more rear suspension(s). A power unit includes an internal combustion (IC) engine-that is mounted to the frame assembly of the vehicle. The IC engine is functionally connected to the rear wheel, which provides the .forward motion to the vehicle. Typically, plurality of panels is mounted to the frame assembly of the vehicle that covers various vehicle components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] 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.
[0004] Fig. 1 illustrates a left side view of an exemplary two-wheeled motor
vehicle, in accordance with an embodiment of the present subject matter.
[0005] Fig. 2 (a) depicts a left side perspective view of a frame structure, in
accordance with an embodiment of the present subject matter,
[0006] Fig. 2 (b) depicts a cross-sectional view of the frame structure, in
accordance with the embodiment depicted in Fig. 2 (a).
[0007] Fig. 3 (a) depicts a left side perspective view of a frame structure, in
accordance with another embodiment of the present subject matter.

[0008] Fig. 3 (b) illustrates another left side perspective of the frame structure
in accordance with embodiment of Fig. 3 (a).
[0009] Fig. 3 (c) depicts an enlarged view of the front portion of the frame
structure.
[00010] Fig. 3 (d) depicts a cross-sectional view of the frame structure
depicted in accordance with embodiment of Fig. 3 (a).
[00011] Fig. 3 (e) depicts another cross-sectional view of the frame structure.
[00012] Fig. 4 depicts a left side perspective of a frame structure, in
accordance with yet another embodiment of the present subject matter.
[00013] Fig. 5 (a) depicts a portion of a frame structure, in accordance with
an additional embodiment of the present subject matter.
[00014] Fig. 5 (b) depicts a cross-sectional view of the frame structure, in
accordance with theembodiment depicted in Fig. 5 (a).
DETAILED DESCRIPTION [00015] Typically, in the two-wheeled vehicle the frame assembly acts as the structural member of the vehicle. Also, the frame assembly is the load-bearing member of the vehicle. Generally, the frame assembly includes tubular sections, channels, gussets etc. that are formed by welded, rolling, or extruded steel or other metal alloys. The frame assembly is one of the heavy parts of the vehicle. With the advancements in technology, the number of components and accessories mounted to the frame assembly are increasing. Therefore, to withstand the weight, the frame assembly may be provided with more thickness or with • reinforced parts, this further increases the weight. Furthermore, the frame assembly in a scooter type vehicle is mounted with various components like continuously variable transmission (CVT) and is covered with various panels made of metal or plastic that further increases the weight of the vehicle resulting in low power to weight ratio of the vehicle.
[00016] Also, in the frame assembly, various joints are provided and many such joints are disposed at essential stress receiving points on the vehicle. For example, the joints provided at the step-through space of the vehicle in proximity to the floorboard portion. Especially, the frame assembly for scooter type vehicle

has poor transitions at critical joints, like joint between front portion and rear portion, due to the high load concentration at the floorboard portion. This also leads to high deflection of frame assembly with respect to floorboard portion.-Also, the scooter type vehicle has a rear mono-suspension that is disposed at a lateral offset and the rear portion of the frame assembly, which supports the -suspension, has stronger structure on one side that bears the shock load and the other side is weaker. This complicates the manufacturing process like welding and also results in weld distortion. Moreover, the tubes and especially the joints are prone to rusting or corrosion, which results in failures. Moreover, the conventional frame assembly is heavy and prone to failures. [00017] Nonetheless, conventionally a frame assembly made of carbon fiber may be used that reduces weight. However, the conventional frame assembly made of carbon fiber also includes multiple joints. Similar to the metal frame" assembly, the frame assembly made of carbon fiber also has many joints disposed at critical junctions of the vehicle. For example, one critical location is near the % floorboard, which is subjected to stress due to high load concentration. Therefore, the frame assembly is prone to failure due to slackness at these joints or due to improper load transfer between various members of frame assembly. Also, vibration transmission occurrence in frame assembly is known in the art, which
r
would further affect the joints. Moreover, the aforementioned frame assembly with multiple joints has low elastic modulus, which may result in failures. [00018] Therefore, the frame assembly structures made of metal or carbon fiber that are conventionally known are prone to failures due to various reasons that are explained above including the presence of joints at critical positions. Thus, there is a need for providing a structural member for a vehicle that is made of carbon fiber, which is rigid and of less weight, and which overcomes the above stated problems known in the existing carbon fiber frame assembly structures. [00019] The present subject matter is aimed at addressing the aforementioned and other problems in the prior art. Hence, it is an object of the present subject matter is to provide a frame structure for a two-wheeled vehicle. According to one aspect, the present subject matter provides a frame structure that includes

plurality of inner layer members that extend rearwardly downward from a head tube and the inner layer members diverge at one more diverging portion and extend in vehicle lateral direction and in a rearward direction towards a rear portion of the vehicle. Further, the frame structure includes plurality of outer core members that enclose at least a portion of the inner layer members. [00020] It is a feature of the present subject matter that the inner layer members and the outer layer members are made of a composite material thereby providing a frame structure that is rigid with reduced weight. [00021] It is one feature of the present subject matter that the frame structure eliminates joints, especially at critical stress receiving locations of the vehicle. The diverging portions of the frame structure enable elimination of joints. [00022] It is another aspect of the present subject matter that the frame structure enables improved load transfer as the frame structure is an integrated structure and the inner layer members extend from a front portion to a rear portion of the vehicle. According to another aspect, the frame structure has improved elastic modulus as at least a portion of the inner layer members is provided with outer layer members, which are disposed around. [00023] Further, the affect of vibration on the frame structure is reduced due to elimination of joints. According to yet another aspect, the frame structure has improved life and performance.
[00024] It is yet another feature of the invention that the frame structure includes outer layer members that provided additional structural rigidity. It is additional feature that, the outer layer members are integrally formed with the frame structure.
[00025] It is an additional aspect of the invention that the requirement for providing bridges for mounting various vehicle parts is substantially reduced. [00026] It is another additional feature that the frame structure is provided with gussets that are disposed at the diverging portions of the vehicle and the gussets provide support at the critical load receiving points.

[00027] It is an advantage of the present subject matter that the frame structure with structural rigidity- and provides improved power to weight ratio of the vehicle due to reduced weight.
[00028] In an embodiment, the present subject matter provides a frame structure for a two-wheeled vehicle. The vehicle comprises a frame structure. A power unit is mounted to the frame structure of the vehicle. The power unit includes at least one of an internal combustion engine or a traction motor. A frame structure is provided that acts as a structural member for the vehicle.
[00029] In an embodiment, the frame structure comprises of plurality of inner layer members. The inner layer members extend rearwardly downward from a front portion of the vehicle, and extend inclinedly rearward towards a rear portion of the vehicle. The plurality of inner layer members diverge into at least one right inner layer member and at least one left inner layer member at a first diverging portion of the vehicle, wherein the first diverging portion is a critical load receiving portion. However, the inner layer members are adapted to diverge at other diverging portions that requires accommodation of vehicle parts or for aesthetics
[00030] In an embodiment, the frame structure comprises a first portion and a second portion. The first portion of the frame structure, which is substantially in the front portion of the vehicle, includes the inner layer members that are disposed substantially along longitudinal axis of the vehicle. The second portion of the frame structure, which is rear portion of .the vehicle, has a left inner layer members and right inner layer members, which have diverged from the inner layer members and extend outward in the vehicle lateral direction and extending inclinedly rearward in the longitudinal direction of the vehicle. Further, the frame structure comprises one or more outer layer member(s). At least one outer layer member is disposed around the inner layer members that are disposed in the first portion. Further, one or more left outer layer member(s), and one or more right outer layer member(s) disposed around and securing at least a portion of the left inner layer member, and the right inner layer member, respectively.

[00031] In one embodiment, the inner layer members extend downward from a head tube in the first portion and extend inciinedly rearward in the second portion, wherein the inner layer member diverge into left inner layer members and right inner layer members at a first diverging portion. The frame structure in the present embodiment defines a step-through space. The inner layer members diverge near the floorboard portion, which is the first diverging portion, thereby enabling mounting of various vehicle components including floorboard. In an ' embodiment, the first portion is forward portion of a floorboard portion of the frame structure and the second portion is rearward portion of the floorboard portion.
[00032] In another embodiment, the frame structure comprises of one or more bridge member(s) made of a lightweight materials including composite materials and high rigidity polymers. The bridge members are supported by the left inner layer members and the right inner layer members, and disposed therebetween. In an embodiment, the bridge members are integrally formed with the frame structure. In another embodiment, the bridge members are separately provided. The bridge members enable in mounting and supporting various vehicle parts including a seat assembly, a floorboard, an auxiliary power source, a fuel tank, or electrical/electronic components.
[00033] In an embodiment, the left inner layer members includes at least one left inner layer member that diverges inwardly in a vehicle width at the rear portion of the vehicle at a second diverging portion. Similarly, the right inner layer members include at least one right inner layer member that diverges inwardly in a vehicle lateral direction at the rear portion at a third diverging portion. In a preferred embodiment, the at least one left inner layer member and the at least one outer layer member are integrally formed. In other words, the at least one inner layer member and the at least one outer layer member are integrally formed as a continuous structure. According to one embodiment, the second diverging portion and the third diverging portion are symmetrically disposed with respect to the longitudinal axis of the vehicle. According to another

embodiment, the second diverging portion and the third diverging portion are asymmetrically disposed.
[00034] Further, the frame structure further comprises of one or more gusset(s) that, provide reinforcement to the frame structure and being disposed at the" diverging portions of the one or more inner layer member(s), wherein the diverging portion is in proximity to the step-through space. Moreover, the gussets are made of composite material and provide structural to the frame structure.
[00035] In an embodiment, the layer members being made of a lightweight material including a composite material like a carbon fiber or a glass fiber, and high-density polymers. Also, the layer members may be hollow type or may include foam disposed therein. The frame structure provides structural rigidity without increasing the weight.
[00036] In one embodiment, the frame structure includes a plurality of inner layer members, and a plurality of outer layer members. The plurality inner layer members extend rearwardly downward from the head tube and diverge at a first diverging portion into one or more right inner layer members and one or more left inner layer members. The one or more right inner layer members and one or more right inner layer members extend substantially outward from lateral center of the frame structure, wherein the lateral centre can be an imaginary line passing through the center of the franie structure. Further, the one or more right inner layer members and one or more right inner layer members extend inclinedly rearward towards a rear portion. Furthermore, the plurality of outer layer members includes at least one outer layer member disposed about at least a portion of the inner layer members that are disposed together. This frame structure provides a continuous structure without any joints. [00037] The frame structure includes plurality of outer layer members disposed about at least a portion of the right inner layer members disposed together, and the about at least a portion of the left inner layer members disposed together.

[00038] "The inner layer members includes a hollow portion and a reinforcing material is selectively disposed thereat to provide structural strength and rigidity, wherein the reinforcing material is disposed at high load receiving portions of the frame.
[00039] With the essence of the embodiments provided below, the frame structure can have inner layer members with any regular or irregular geometrical cross-section. Correspondingly, outer layer members that are provided to secure the respective inner layer members take at least an outer peripheral shape of the inner layer members. Also, the frame structure having inner layer members, outer layer members, and gussets being made of composite material can be integrally formed with frame structure.
[00040] The aforesaid and other, advantages of the present subject matter would be described in greater detail in conjunction with the figures in the following description.
[00041] Fig. 1 illustrates a left side view of a two-wheeled vehicle 100, in accordance with an embodiment of the present subject matter. The vehicle 100 comprises a frame structure 200 with a step-through space. A power unit 110 is mounted to the frame structure 200 of the vehicle 100. The power unit 105 includes at least one of an internal combustion engine or a traction motor. The power unit 105 comprises of a starter system 110. Particularly, the starter system 110 includes an electric start system or a mechanical start system that is employed with power unit 105 including the IC engine. A rear wheel 120 is functionally coupled to the power unit 105 through a transmission system 115. The transmission system 115 may include a fixed gear chain drive or continuously variable transmission (CVT) or an automatic manual transmission (AMT) or the like. A rear fender 120A covers at least a portion of the rear wheel 120. Further, one or more rear suspension(s) 125 functionally connect the rear wheel 120 to the frame structure 200.
[00042] A steering shaft (not shown) is rotatably disposed about a head tube 201 of the frame.structure 200. Generally, the head-tube 201 is a hollow member

that rotatably support the steering shaft. A handle bar assembly 130 is connected to the steering shaft. One or more front suspension(s) 135 connect a front wheel 140 to the steering shaft. The front wheel 140 is rotatably supported by the one or more front suspension(s) 135. A front fender 140A covers at least a portion of the front wheel 140. Further, the vehicle 100 comprises a step-through space formed by the frame assembly 105. A floorboard 145 can be supported by the frame structure 200. A seat assembly 150 may be supported by the portion of the frame structure 200. In an embodiment, a utility box (not shown) is also supported by the frame structure and the seat assembly is supported by the utility box. In addition, the vehicle 100 has a front panel 135A disposed upwardly of the front fender 140A. A leg shield 135B is disposed rearwardly of the front panel 135A. The front panel 135A and the leg shield 135B cover at least portion of the frame structure 200 at the front portion of the vehicle 100. A below seat cover 135C being disposed forwardly of the power unit 110 and below the seat assembly 150. A pair of rear panels 135D are disposed below the seat assembly, which are extending downwardly covering at least a portion of the power unit 110. The internal combustion of the power unit 110 will be supplied with air fuel mixture supplied by a fuel tank (not shown) and an air induction system (not shown) that are coupled through a carburetor or a fuel injection system(not shown). The vehicle 100 comprises an auxiliary power source (not shown) that includes a battery or a hydrogen eel! or a fuel cell or the like. Further, the traction motor of the power unit 110 is powered by the auxiliary power source mounted to the vehicle 100.
[00043] Further, the vehicle 100 includes various electronic and electrical systems such as a vehicle control unit, an anti-lock braking system, or a synchronous braking system. Also, an electrical starter system, a headlamp 155A, and a tail lamp 155B.
[00044] Fig. 2 (a) illustrates a left side perspective view of a frame structure 200 for the vehicle depicted in Fig. 1, in accordance with an embodiment of the present subject matter. The frame structure 200 comprises of plurality of inner

layer members 205 that extend along longitudinal direction of the vehicle 100. The plurality of inner layer- members 205 is made of composite material like carbon fiber or glass fiber. In the current embodiment, a first inner layer member 205A and a second inner layer member 205B is provided. The inner layer members 205 extends downwardly from a head tube (shown in Fig. 1) in the first portion FP of the vehicle and extend inclinedly rearward towards the rear portion RP of the vehicle 100.
[00045] Further, in the present embodiment, the inner layer members 205 extends downward forming step-through space and for mounting the floorboard 145 (shown in Fig. 1). The inner layer members 205 diverge at a first diverging portion FD, which is in proximity to the floorboard 145 portion into'at least one right inner layer member 205A and at least one left inner layer member 205B, in the second portion SP of the vehicle. The right inner layer members 205A and the left inner layer members 205B each extend outwardly in the vehicle lateral direction from a lateral center C of the frame structure 200 and then extend inclinedly rearward towards a rear portion of the vehicle, which is towards the tail lamp 155B (shown in Fig. 1). Further, the inner layer members 205 are disposed about a utility box (not shown) for supporting the utility box. The lateral center C is imaginary line passing in longitudinal direction along the lateral center of the frame structure.
[00046] Further, the frame structure 200 comprises outer layer members 210C. The outer layer members 210C are made of composite material including carbon fiber or glass fiber and a resin. The outer layer member 210C is disposed around and secures at least a portion of the first inner layer member 205A, and. the second inner layer member 205B being disposed together. At the floorboard 145, the first inner layer member 205A extends outward, which is to the right side, in vehicle lateral direction and extends rearward. Similarly, the second inner ' layer member 205B extends outward, which is to the left side, in the vehicle lateral direction. Further, in the present embodiment, the first inner layer member 205A and the second inner layer member 205B acts as the right inner layer

member and left inner layer member, respectively. Furthermore, the right inner layer member and the left inner layer member are integrally formed and extend as a continuous structure around the utility box.
[00047] The terms first inner layer member and the right inner layer member are interchangeably used. Similarly, the terms second inner layer member and the left inner layer member are interchangeably used.
[00048] Fig. 2 (b) depicts a cross-section of the frame structure embodiment depicted in Fig. 2 (a), taken along axis A-A'. The cross-section depicts the inner layer members 205 that includes the first inner layer member 205A and the second inner layer member 205B disposed adjacently till a first portion of the frame structure, wherein said first portion is in front till floorboard portion 145. In the present embodiment, the first inner layer member 205A and the second inner layer member 205B are having a rectangular shape. The outer layer members 210C, which is disposed around outer periphery of the inner layer members 205, takes the shape of outer periphery of the inner layer members. In addition, a resin material is provided that secures the inner layer member 205 and the outer layer members 210C together.
[00049] Fig. 3 (a) illustrates a left side perspective view of a frame structure 300, in accordance with another embodiment of the present subject matter. Fig. 3 (b) depicts the inner layer members of the frame structure 300 in accordance with the embodiment depicted in Fig. 3 (a). The frame structure 300 comprises of inner layer members 305 that 305 diverge at a first diverging portion FD, which is in proximity to the floorboard 145 portion, into one or more right inner layer member(s) 305A and one or more left inner layer member(s) 305B, which is in the second portion of the frame structure 300 that is rear from the floorboard 145 portion. The inner layer members 305 extend in the longitudinal direction F-R of the vehicle 100. In the present embodiment, the inner layer members, includes a first inner layer member 305AA, a second inner layer member 305AB, a third inner layer member 305BA, and a fourth inner layer member 305BB The right inner layer members 305A includes the first inner layer member 305AA and the

second inner layer member 305AB. The left inner layer members 305B include the third inner layer member 305BA and the fourth inner layer member 305BB. Particularly, in the present embodiment, the inner layer members 305 diverge into right inner layer members 305A and the left inner layer members 305B at the first diverging portion FD, at the floorboard 145 portion, extending outwardly in the vehicle lateral direction and then extending inclinedly rearward towards a rear portion of the vehicle 100. Further, at least one left inner layer member 305BA of the left inner layer members 305BA, 305BB diverges inwardly at a second diverging SD portion and extending inwardly in the vehicle lateral direction. Similarly, at least one right inner layer member 305AA of the right inner layer members 305AA, 305AB diverges at a third diverging portion TD and extending inwardly in the vehicle lateral direction. In a preferred embodiment that is depicted, the at least one left inner layer member 305BA and the at least one outer layer member 305AA are integrally formed as a single continuous structure. This reduces the need for provision of bridges and also reduced the joints.
[00050] Furthermore, the second diverging portion SD and the third diverging portion TD are symmetrically disposed with respect to longitudinal axis F-R of the vehicle. In another embodiment, the second diverging portion SD and the third diverging portion TD are not symmetrically formed according to vehicle layout requirement. Additionally, the second diverging portion SD and the third diverging portion TD are at a substantial height with respect to the first diverging portion FD, when viewed from vehicle side.
[00051] Further, the frame structure 300 in the present embodiment is provided with outer layer members 310A, 310B, 310C, which are made of lightweight materials including composite material like carbon fiber or glass fiber, and high-density polymers. The outer layer members 310A, 310B, 310C includes at least one outer layer member 310C covering the plurality of inner layer members 305, in the.first portion of the frame structure 300, and extending till floor board 145 portion. Further, the outer layer members 310A, 310B, 310C include a right outer layer member 310A and a left outer layer member 310B.

The right outer layer member 310A covers at least a portion of the right inner layer members 305AA, 305AB and the left outer layer remember 310B covers at least a portion of the left inner layer members 305BA, 305BB. The right outer layer member 310A and left outer layer member 310B secure the right inner layer members 305AA, 305AB, and the left inner layer members 305BA, 305BB together, respectively.
[00052] Further, the right inner layer member 305AA, 305AB and the left inner layer members 305BA. 305BB support the seat assembly of the vehicle. Also, the rear panel assembly and parts in proximity to the right inner layer members 305AA, 305AB and left inner layer members 305BA, 305BB are mounted thereof. The frame structure 300 further comprises one or more gusset(s) 315C, 315A, 315B. Fig. 3 (c) depicts an enlarged view of the front portion of the frame structure depicted in Fig. 3 (a).
[00053] The frame structure 300 further comprises of one or more gusset(s) 315 for providing additional structural support. The present embodiment includes a first" gusset 315C that is disposed about the diverging portion FD of the plurality of inner layer members 305 of the frame structure 300, wherein the first gusset 315C covers at least a portion where the outer layer members 310 are not provided. Further, a second gusset 315A is disposed around the right inner layer members 305AA, 305AB at the diverging portions TD of the right inner layer members 305AA, 305AB. A third gusset 315B is disposed around the left inner layer members 305BA, 305BB at the diverging portion SD of the left inner layer members 305BA, 305BB. The one or more gussets 315A, 315B, 315C disposed at the diverging portions of the frame structure 300 provide reinforcement to the frame structure, wherein the gussets 315A, 315B, 315C are made of a lighter rigid material including composite material. For example, the composite material includes carbon fiber or glass fiber or the like material along with a resin, thereby providing structural rigidity without increasing the weight of the structure.
[00054] Fig. 3 (d) and Fig. 3 (e) depicts cross-sectional views of the frame structure depicted in Fig. 3 (a), taken along the axis B-B' and along axis C-C

respectively. In the present embodiment, each inner layer members 305BA, 305BB, 305BA, 305BB is having a square cross-section. The inner layer members 305 is secured by the at least one outer layer member 310C, which is disposed in the first portion of the frame structure 300. The at least one outer layer member 310C takes the shape of the outer circumferential faces of the inner layer members 305BA, 305BB, 305BA, 305BB. In the depicted embodiment, the at least one outer layer member 310C is having a square cross-section. Further, the cross-section taken along axis C-C depicts the cross-section of the left inner layer members 305BA, 305BB and left outer layer member 310B.
[00055] The left inner layer member 305BA, 305BB includes the second inner layer member 305BA and the fourth inner layer member 305BB, which are secured by the left outer layer member 310B. As the second inner layer member 305BA and the fourth inner layer member 305BB are having square cross-section, the left outer layer member 310B securing is having a rectangular cross-section.
[00056] Fig. 4 depicts a frame structure 400, in accordance with yet another embodiment of the present subject matter. The frame structure 400 comprises of plurality of inner layer members 405. The present embodiment includes four inner layer members namely, a first inner layer member 405AA, a second inner layer member 405AB, a third inner layer member 405BA and a fourth inner layer member 405BB. The inner layer members 405 extend rearwardly downward from the head tube 201 towards the floorboard 145. At the floorboard 145 the inner layer members 405 diverge at the first diverging portion FD into right inner layer members 405A including the first inner layer member 405AA and the second inner layer member 405AB, and into left inner layer members 405B including the third inner layer member 405BA and the fourth inner layer members 405BB. In the present embodiment, the first inner layer member 405AA and third inner layer member 405BA extends inclinedly rearward from the floorboard portion towards the rear portion of the vehicle. However, the second inner layer member 405AB and fourth inner layer member 405BB support the floorboard 145 and

extend towards a rear portion of the floorboard 145. Also, the floorboard 145 (not shown) is secured to the right inner layer members 405AA, 405AB and the left inner layer members 405BA, 405BB. The floorboard 145 is made of a rigid material that is capable of sustaining loads. From below the floorboard 145 the first inner layer member 405AA and the third inner layer member 405BA extend rearward and supporting at least a portion of the floorboard 145 towards the rear portion of the vehicle 100. The frame structure 400 includes plurality of outer layer members 410A, 410B, 410C. The outer layer member 410C is securely enclosing at least a portion of the inner layer members 405AA, 405AB, 405BA, 405BB that are disposed together. Further, a right outer layer member 410A and a left outer layer member 410B covers at least a portion of the right inner layer members 405AA, 405AB and the left outer layer remember 410B covers at least a portion of the left inner layer members 405BA, 405BB.
[00057] Further, the frame structure 400 of the present embodiment is provided with one or more bridge(s) 420, 425A, 425B that are secured to the right inner layer members 405A and the left inner layer members 405B, and disposed therebetween. A reinforcing bridge 420 of the one or more bridge(s) is disposed below the floorboard 145 to enable supporting loads. Furthermore, the cross-sectional area of the reinforcing bridge is substantially greater than the cross-sectional area of the right inner layer member. 405A or the left inner layer member 405B. Furthermore, a first bridge 425A of the one or more bridge(s) is affixed to the right inner layer member 405A and the left inner layer member 405B, therebetween. Also, one or more bridge bracket(s) 430AA secure the first bridge to the frame structure 400. Also, a second bridge 425B is disposed in the rear portion of the frame structure 400 and is secured to the frame structure 400 through one or more bridge bracket(s) 430BA. The one or more bridge(s) 420, 425A, 425B enable mounting of various vehicular parts including a fuel tank, a battery etc. The one or more bridge(s) 420, 425A, 425B and the one or more bridge bracket(s) 430AA, 430BA are made of lightweight materials including a composite material or high-density polymer.

[00058] Fig. 5 (a) depicts a portion of a frame structure, in accordance with an additional embodiment of the present subject matter. The frame structure includes inner layer members 505 that are having pie cross section and the peripheral surface of all the inner layer members 505 forms a circular shape. Plurality of outer layer members 510 having a circular cross-section secures the inner layer members 505.
[00059] In the present embodiment, four inner layer members 505 having a right-angular pie section are provided. The inner layer members 505 are disposed along the longitudinal axis F-R of the vehicle in the first portion and the inner layer members 505 diverge into right inner layer members formed by two inner layer members and into left inner layer members each including two inner layer members (not shown). The outer layer members 510 are enclosing at least a portion of the inner layer member in the first portion. Further, the frame structure includes a right outer layer member (not shown) and a left outer layer member (not shown) that are disposed about the right inner layer members and the left inner layer members.
[00060] However, in another embodiment, the inner layer members diverge into at least one right layer member and at least one left layer member. In an embodiment, each inner layer member has a cross-section that is having a semi-circular cross section. Therefore, two inner layer members are disposed in the first portion, the inner layer members diverge into the right inner layer member having a semicircular cross section, and the left inner layer member has a semicircular cross section in the second portion that extend inclinediy rearward in the second portion.
[00061] It is to be understood that the aspects of the embodiments are not necessarily limited to the features described herein. Many modifications and variations of the present subject matter are possible in the light of above disclosure. Therefore, within the scope of claims of the present subject matter, the present disclosure may be practiced other than as specifically described.

We claim:
1. A frame structure (200, 400) for a two-wheeled vehicle (100), said frame
structure (200, 400) acting as structural member of said vehicle (100), said frame
structure (200, 400) comprising:
a head tube (201),
wherein
said frame structure (200, 400) further comprises
a plurality of inner layer members (205A, 205B, 405AA, 405AB, 405BA, 405BB), and a plurality of outer layer members (210C, 410C, 410A, 410B),
said plurality inner layer members (205A, 205B, 405AA, 405AB, 405BA, 405BB) extend rearwardly downward from said head tube (201) and diverge at a first diverging portion (FD) into one or more right inner layer members (205A, 405AA, 405AB) and one or more left inner layer members (205B, 405BA, 405BB), said one or more right inner layer members (205A, 205B, 405AA, 405AB, 405BA, 405BB) and one or more right inner layer members (205B, 405BA, 405BB) extend substantially outward from lateral center (C) of the frame structure (200, 400) and extends inclinedly rearward towards a rear portion; and
■ said plurality of outer layer members (210C, 410C, 410A, 410B) includes at least one outer layer member (210C, 410C) disposed about at least a portion of said inner layer members (205A, 205B, 405AA, 405AB, 405BA, 405BB) disposed together.
2. The frame structure (200," 400) as claimed in claim 1, wherein said plurality of outer layer members (210C, 410C, 410A, 410B) includes one or more right outer layer member(s) (410A), and one or more left outer layer member(s) (410B), wherein said one or more right outer layer members (410A) are disposed about at least a portion of said right inner layer members (205A, 405AA, 405AB) disposed together, and said one' or more left outer layer member(s) (410B) disposed about at least a portion of said left inner layer members (205B, 405BA, 405BB) disposed together.
3. The frame structure (200, 400) as claimed in claim 1, wherein said plurality of inner layer members (205B, 405AA, 405AB, 405BA, 405BB) and said

plurality of outer layer members (210C, 410C, 410A. 410B) being made of a composite material.
4. The frame structure (200, 400) as claimed in claim 1, wherein said frame structure (200, 400) defines a step-through space (ST) adapted to accommodate a floorboard (145) of said vehicle (100), said first diverging portion (FD) is in proximity to said floorboard (155) disposed thereof is supported by said right inner layer members (205A, 405AA, 405AB) and said left inner layer members (205B, 205BA, 205BB).
5. The frame structure (400) as claimed in claim 1, wherein said frame structure (400) includes one or more bridge member(s) (425A, 425B, 425C) extending in a lateral direction (RH-LH) of said vehicle (100) connecting said right inner layer members (405AA, 405AB) and said left inner layer members (405BA, 405BB).
6. The frame structure (200, 400) as claimed in claim 1, wherein said inner layer members (205A, 205B, 405AA, 405AB, 405BA, 405BB) includes a hollow portion and a reinforcing material is selectively disposed thereat to provide structural strength and rigidity.
7. A frame structure (300) for a two-wheeled vehicle (100), said frame structure (300) acting as structural member of said vehicle (100), said frame structure (300) comprising:
a head tube (201),
wherein
said frame structure (300) further comprises
a plurality of inner layer members (305AA, 305AB, 305BA, 305BB), and a plurality of outer layer members (310A, 3iOB, 310C),
said plurality of inner layer members (305AA, 305AB, 305BA, 305BB) extend rearwardly downward from said head tube (201) and diverge at a first diverging portion (FD) into one or more right inner layer member(s) (305AA, 305AB) and one or more left inner layer member(s) (305BA, 305BB), said one or more right inner layer member(s) (305AA, 305AB) and said one or more left inner layer member(s) (305BA, 305BB) extend substantially outward from lateral center (C) of the frame structure (300) and extend inclinedly rearward towards a

rear portion, and at least one left inner layer member (305BB) of said one or more left inner layer members (305BA, 305BB) and at least one right, inner layer • member (305AB) of said one or more right inner layer members (305AA, 305AB) diverge at a second diverging portion (SD) and a third diverging portion (TD), respectively, and said at least one left inner layer member (305BB) and said at least one right inner layer member (305AB) are integrally formed; and
said plurality of outer layer members (310C, 310A, 310B) includes at least one outer layer member (310C) disposed about at least a portion of said inner layer members (305AA. 305AB, 305BA, 305BB) disposed together.
8. The frame structure (300) as claimed in claim 1,wherein said frame structure (300) includes a first gusset(s) (315C) being disposed at said first diverging portion (FD) of the one or more inner layer member(s) (305AA, 305AB, 305BA, 305BB), and said gusset (315) envelopes at least a portion of the one or more inner layer member(s) (305AA, 305AB, 305BA, 305BB) and at least a portion of said left inner layer members (305BA, 305BB) and said right inner layer members (305AA, 305AB).
9. The frame structure (300) as claimed in claim 7, wherein said frame structure (300) includes a second gusset (315B) and a third gusset (315A), said second gusset disposed at said second diverging portion (SD) enveloping at least a portion of said left inner layer members (305BA, 305BB) and said third gusset (315A) disposed at said third diverging portion (TD) enveloping at least a portion of said right inner layer members (305BA, 305BB).
10. The frame structure (300) as claimed in claim 7, wherein said second diverging portion (SD) and third diverging portion (TD) are substantially at said rear portion of the vehicle (100) and said second diverging portion (SD) and said third diverging portion (TD) are at a substantial height from said first diverging portion (FD). .