Claims:1. A step-through frame structure (200) for a saddle-type vehicle (100) comprising:
a head tube (205);
a down frame member (210) extending rearwardly and downwardly from the head tube (205); and
a side frame portion comprising left and right step-through frame members (220) extending sidewardly and rearwardly from the down frame member (210);
said left and right frame step-through frame members (220) are configured with an integral box geometry cross section.
2. The step-through frame structure (200) as claimed in claim 1, wherein the left and right step-through frame members (220) have varying width along their respective lengths.
3. The step-through frame structure (200) as claimed in claim 2, wherein width of the left and right step-through frame members (220) is greater at attachment portions (222) thereof.
4. The step-through frame structure (200) as claimed in claim 3, wherein the attachment portions (222) includes an area containing a mounting provision (345) for a bridge member (340) and a left recess (370-1) and a right recess (370-2) for a toggle link member (340).
5. The step-through frame structure (200) as claimed in claim 1, wherein the left and right step-through frame members (220) are respectively constituted by a first piece (223-1) and a second piece (223-2) having a C shaped cross-section each.
6. The step-through frame structure (200) as claimed in claim 6, wherein the first piece (223-1) and the second piece (223-2) are joined to form a box configuration of the left and right step-through frame members (220).
7. The step-through frame structure (200) as claimed in claim 1, wherein the left and right step-through frame members (220) are integrated with a stepped bush member each for mounting a toggle link member (340).
8. The step-through frame structure (200) as claimed in claim 1, wherein the left and right step-through frame members (220) are designed to accommodate vehicle components including one or more battery packs.
9. The step-through frame structure (200) as claimed in claim 1, wherein the side frame portion includes a left and right rear frame members (255).
10. A saddle-type vehicle (100) having a step-through frame structure (200) comprising:
a head tube (205);
a down frame member (210) extending rearwardly and downwardly from the head tube (205); and
a side frame portion comprising left and right step-through frame members (220) extending sidewardly and rearwardly from the down frame member (210);
said left and right frame step-through frame members (220) have a box configuration.
, Description:TECHNICAL FIELD
[0001] The present subject matter described herein generally relates to a saddle-type vehicle, and particularly but not exclusively relates to a step-through frame structure for the saddle-type vehicle.

BACKGROUND
[0002] Typically, a frame is the main supporting structure of a motor vehicle, including saddle-type motor vehicles and serves to support different parts of the motor vehicle. Besides acting as the main supporting structure of the vehicle, the construction of the frame also defines the outward appeal and looks of the motor vehicle. For example, saddle-type motor vehicles are majorly classified as saddle-type vehicles of the step over kind, and saddle-type vehicles of the step through kind, based on the construction of the frame defining such vehicles.
[0003] The structure and construction of the frame also plays a critical role for the packaging of components of the saddle-type vehicle. Challenges especially lie in designing a reliable frame capable of supporting heavy parts such as a large battery unit, without involving the use of additional structural members such as gussets for improving the reliability of the frame.

BRIEF DESCRIPTION OF DRAWINGS

[0004] 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.
[0005] Fig.1 illustrates a left side view of a saddle-type vehicle in accordance with an embodiment of the present subject matter.
[0006] Fig.2 illustrates a perspective view of a step-through frame structure in accordance with an embodiment of the present subject matter.
[0007] Fig.3 illustrates a top view of the step-through frame structure in accordance with an embodiment of the present subject matter.
[0008] Fig.4 illustrates a detailed perspective view of a front portion of the step-through frame structure in accordance with an embodiment of the present subject matter.
[0009] Fig.5 illustrates a side view of the step-through frame structure in accordance with an embodiment of the present subject matter.
[00010] Fig.6a illustrates an exploded view depicting constituent members of the left and right step-through frame members in accordance with an embodiment of the present subject matter.
[00011] Fig.6b illustrates a detailed view of the left and right step-through frame members integrated with a stepped bush member in accordance with an embodiment of the present subject matter.
[00012] Fig.7a illustrates a cross-sectional view taken along line W-W in Fig.4 and depicts the installation of one of the step-through frame members in accordance with an embodiment of the present subject matter.
[00013] Fig.7b illustrates an enlarged view of an encircled portion of the step-through frame member shown in Fig.7a in accordance with an embodiment of the present subject matter.
[00014] Fig.8a illustrates a cross sectional view of one of the step-through frame members depicting the formation of a box section in accordance with a first embodiment of the present subject matter.
[00015] Fig.8b illustrates a cross sectional view of one of the step-through frame members depicting the formation of a box section in accordance with a second embodiment of the present subject matter.
[00016] Fig.8c illustrates a cross sectional view of one of the step-through frame members depicting the formation of a box section in accordance with a third embodiment of the present subject matter.
[00017] Fig.8d illustrates a cross sectional view of one of the step-through frame members depicting the formation of a box section in accordance with a fourth embodiment of the present subject matter.
[00018] Fig.8e illustrates a cross sectional view of one of the step-through frame members depicting the formation of a box section in accordance with a fifth embodiment of the present subject matter.
[00019] Fig.8f illustrates a cross sectional view of one of the step-through frame members depicting the formation of a box section in accordance with a sixth embodiment of the present subject matter.
[00020] Fig.8g illustrates a cross sectional view of one of the step-through frame members depicting the formation of a box section in accordance with a seventh embodiment of the present subject matter.
DETAILED DESCRIPTION OF THE INVENTION
[00021] The frame forms the core structure of a saddle-type vehicle. It typically supports the engine, the front and rear suspensions, the fuel tank etc. and also defines the location of parts such as the battery, motor, controller etc. The construction of the frame in saddle-type vehicles such as a scooter, typically involves providing a step through space formed by left and right step-through frame members extending sidewardly and rearwardly from a down frame member. Further, the frame also comprises left and right rear frame members extending rearwardly and upwardly from the left and right step-through frame members. Conventionally, the left and right step-through frame members and the left and right rear frame members are tubular members. While the left and right step through frame members (tubular members) are typically welded to the down frame member on either side, the left and right rear frame members are welded to the left and right step-through frame members. Further, the joints where the welding takes place are reinforced by providing independent frame strengthening members at the joints. Particularly, the strengthening of the joints is achieved by welding independent frame strengthening members in the joint between the left step-through frame member and the down frame on one side and in the joint between the right step-through frame member and the down frame on the other side. Welding depletes the strength of the down frame member and that of the left and right step-through frame members. Therefore, there is need to avoid welding of additional members on the down frame member and the left and right step-through frame members. Further, using tubular members for the construction of the left and right step-through frame members also affects the design degrees of freedom associated with the step-through frame members. For example, it is difficult to achieve a customized step-through space in order to securely package components such as batteries of varying dimensions using tubular frame members. Particularly, for tubular configuration of frames, additional brackets are required to be welded to support the battery or battery casing and these additional brackets occupy additional space, eating into the available volumetric space available for the battery. In other words, there is a need to overcome the disadvantages associated with use of tubular members. It is also essential to achieve desirable structural strength & stiffness of the frame to provide a secure, rigid & stable frame structure for the vehicle.
[00022] It is therefore desirable to provide a step-through frame structure comprising left and right step-through frame members extending from a left side and a right side respectively of a down frame member, wherein the left step-through frame member and the right step-through frame member are secured to the down frame member without involving the use of any additional reinforcing members such as gussets.
[00023] In view of the above, it is an object of the present subject matter to provide a step-through frame structure for a saddle type vehicle, wherein a side frame portion including a left and right step-through frame members are designed to have an integral box configuration.
[00024] It is another object of the present subject matter to provide a step-through frame structure, wherein the left and right step through-frame members are designed to have varying width along their lengths.
[00025] It is yet another object of the present subject matter to provide a step-through frame structure for a saddle type vehicle, wherein a portion of both the left and right step-through frame members is integrated with a mounting member each.
[00026] Accordingly, the above and other objects are achieved by providing a saddle-type vehicle having a step-through frame structure comprising a head tube, a down frame member extending downwardly and rearwardly from the head tube, a left and right step-through frame members extending sidewardly and rearwardly from the down frame member, a left and right rear frame members extending upwardly and rearwardly from the left and right step-through frame members, and a toggle link member attached to the left and right step-through frame members. The left and right step-through frame members and the left and right rear frame members together constitute a side frame portion as per the present subject matter.
[00027] As per an aspect of the present subject matter, the side frame portion including the left and right step-through frame members and the left and right rear frame members of the step-through frame structure are designed to have an integral box configuration.
[00028] As per one embodiment of the present subject matter, the left and right step-through frame members and the left and right rear frame members are made of sheet metal. The box configuration of each of the left step-through frame member and the right step-through frame member is achieved by joining two sheet metal pieces. Particularly, each of the two sheet metal pieces has a C cross-section. Thus, two sheet metal pieces, each having a C cross-section are joined to form the box configuration. Providing a box configuration for the side frame portion including the left and right step-through frame members enables in improving the stiffness of the left and right step-through members significantly.
[00029] Further, as per an aspect of the present subject matter, the box configuration of the left and right step-through frame members is formed in such a way that the width of each of the left and right step-through frame members varies along its length. For example, the attachment portions of the left and right step-through frame members are formed to have a larger width as compared to a central portion of the left and right step-through frame members. For example, as per one embodiment, a front section of the left and right step-through frame members that is joined to the down frame member has a greater cross-sectional area/width. Providing a greater cross-sectional area at the attachment portions ensures that the surface area available for welding the left and right step-through frame members to the down frame member is significantly large. This enables easy welding and stable, rigid and safe joint structure. Moreover, since the joining area available is large, strong and durable attachment of the left and right step-through frame members with that of the down frame member is established. As a result, no additional reinforcement members are required to be provided at the joint between the left step-through frame member and the down frame member and at the joint between the right step-through frame members and the down frame member. Moreover, since the stiffness of the left and right step-trough members is high due to the box configuration, it is ensured that strength, stiffness and rigidity of the left and right step-through frame members is not compromised due to welding.
[00030] As per one more aspect of the present subject matter, the left and right step-through frame members are integrally provided with a mounting member each. In one embodiment, the mounting member is a stepped bush member designed to receive the toggle link member. Providing the mounting member integrally in the box configuration of the left and right step-through frame members ensures that assembly time involved in inserting the mounting bush in the provision created in the left and right step-through members and subsequent attachment of the toggle link member to the mounting bush is also reduced. Moreover, integrating the mounting member in the left and right step-through frame members also helps in maintaining the desired assembly gap between the two sheet metal pieces forming each of the left and right step-through frame members.
[00031] Similarly, in another embodiment the left and right rear frame members can also be designed to have a box configuration, obtained by forming each of the left and right rear frame members from two sheet metal pieces having a C cross-section each.
[00032] Thus, the construction of the step-through frame structure as per the present subject matter aids in minimising the number of reinforcement members required for reinforcing parts of the frame including the left and right step-through frame members and the left and right rear frame members. Thus, part count and associated cost is reduced. Moreover, use of a non-tubular frame in the step-through region enhances design degrees of freedom associated with creation of step-through space for accommodating different components including battery packs having varying dimensions, ranging from small length and width to a large length and width.
[00033] Summary provided above explains the basic features of the invention and does not limit the scope of the invention. The nature and further characteristic features of the present invention will be made clearer from the following descriptions made with reference to an embodiment in the accompanying drawings.
[00034] Exemplary embodiments detailing features of the step-through frame structure and its construction, in accordance with the present subject matter will be described hereunder with reference to the accompanying drawings. Various aspects of different embodiments of the present subject matter will become discernible from the following description set out hereunder. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the present subject matter. Further, it is to be noted that terms “upper”, “lower”, “right”, “left”, “front”, “forward”, “rearward”, “downward”, “upward”, “top”, “bottom” and like terms are used herein based on the illustrated state or in a standing state of the saddle-type vehicle with a driver sitting thereon unless otherwise elaborated. Furthermore, a longitudinal axis refers to a front to rear axis relative to the saddle-type vehicle, defining a vehicle longitudinal direction; while a lateral axis refers to a side to side, or left to right axis relative to said vehicle, defining a vehicle lateral direction. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[00035] The present invention along with all the accompanying embodiments and their other advantages would be described in greater detail in conjunction with the figures in the following paragraphs
[00036] With reference to FIG.1, a description is made of an entire schematic structure of a saddle riding vehicle 100 having a frame structure 200 (shown in Fig.2). The frame structure 200 supports different parts of said vehicle 100. The frame structure 200 supports a steering assembly including a steering shaft (not shown), and a handlebar assembly 105 in a front portion of the saddle-type vehicle 100. A front fork 121 is rotatably supported to the steering shaft through an upper bracket and a lower bracket (not shown). The handlebar assembly 105 provided above the front fork 121 allows steering of a front wheel 125. A headlamp assembly 110 is disposed in front of the handlebar assembly 105.
[00037] Further, a front cover 115 is provided to cover a forward-facing side of the frame structure 200. A front fender 120 is provided to cover an upper portion of the front wheel 125. A leg shield 130 is disposed to cover an inward facing side of the frame structure 200, below the handlebar assembly 105. The leg shield 130 protects the rider’s legs rested on a floorboard 145 from running wind. The floorboard 145 protects one or more battery packs (not shown) disposed below it. An under-seat cover 140 is provided that extends upwards from the floorboard 145 towards a lower side of a seat 135. In an embodiment, the under-seat cover 140 serves to protect an IC engine 102 disposed under the seat 135. The seat 135 is disposed above the left and right side covers 175. A pillion-handle 165 extending rearwardly behind the seat 135 is provided as a gripping means for a pillion rider seated on the seat 135.
[00038] For safety of the rider and in conformance with the traffic rules, the headlamp assembly 110 and a turn signal lamp unit 111 are provided in a front portion of said vehicle 100, and tail lamp unit 170 is provided in a rear portion of said vehicle 100. Safety of said saddle-type vehicle 100 is also improved by providing a braking system, for example a linked type braking system which controls braking operation of a front brake device (not shown) and a rear brake device (not shown) of the front wheel 125 and the rear wheel 190 respectively. The braking system includes a front brake lever 132 and a rear brake lever (not shown) to be operated by the rider and connected to said front brake device and said rear brake device respectively through one or more cables including a front brake cable (not shown) and a rear brake cable (not shown).
[00039] For comfortable riding, suspension systems are provided for comfortable steering of said vehicle 100 on the road. The front fork 121, which forms the front suspension system, serves as rigidity component just like the frame structure200. The front fork 121 clamped to the head tube 205 (shown in Fig.2) is capable of being moved/steered to the left and right. Further, a rear suspension 250 (shown in Fig.2), which is a hydraulic damped arrangement, is connected to the frame structure 200 at a rear portion thereof. Particularly, at the rear portion of the frame structure 200, the rear wheel 190 is suspended by the rear suspension 250.
[00040] To enhance the overall aesthetics of said vehicle 100 and to prevent undesired foreign particles from entering parts of said vehicle 100, left and right side covers 175 are disposed to cover left and right side surfaces of a rear portion of the frame structure 200. A rear fender 180 is also provided for preventing mud/water splashed by the rear wheel from entering other parts of said vehicle 100.
[00041] As per one embodiment of the present subject matter and as may be seen in Fig.1, the saddle-type vehicle 100 is designed to be powered either by the only the IC engine 102, or by only said one or more battery packs or by the IC engine and a motor. The IC engine 102 is equipped with an exhaust system that includes an exhaust pipe 184 connected to the IC engine 102 and a muffler 185 connected to the exhaust pipe 184. The muffler 185 extends rearwards along the right side of the rear wheel 190.
[00042] Power from the IC engine 102 is transmitted to the rear wheel 190 through a transmission assembly (not shown), so as to drive and rotate the rear wheel 190. The transmission assembly includes a gear unit containing gear train and a drive mechanism connecting the gear unit to the rear wheel 190. Thus, power from the IC engine 102 is transmitted to the rear wheel 190.
[00043] Fig.2 illustrates a perspective view of the step-through frame structure 200 of the saddle-type vehicle as per an embodiment of the present subject matter. The step-through frame structure 200 comprises a head tube 205, a down frame member 210 extending downwardly and rearwardly from the head tube 205, a left and right step-through frame members 220 extending sidewardly and rearwardly from both sides of the down frame member 210, and a left and right rear frame members 255 extending rearwardly and upwardly from a rear portion of the pair of step-through frame members 220. The right and left step-through frame members 255 are connected by a front connecting bridge frame member 215 in a front portion thereof and by a rear connecting bridge frame member 235 in a rear portion thereof.
[00044] Fig.3 illustrates a top view of the step-through frame structure 200. As may be seen in Fig.2 and Fig.3, the left and right step-through frame members 220 extending sidewardly and rearwardly from the down frame member 210 have an integral box configuration. Further, the left and right step-through frame members 220 are connected to one another and by two or more bridge members 360 and 365. A longitudinal bridge member 355 connects the down frame member 210 to one of said two or more bridge members 360,365. In one embodiment and as may be seen in Fig.3 and Fig.4, one of said two or more bridge members 360, 365 is a tubular bridge member 365. The tubular bridge member 365 connects the left step-through member 220 to the right step through member 220 at a rear portion 221 thereof. The tubular bridge member 365 is secured at a left recess 370-1 and a right recess 370-2 formed in the left and right step-through frame members 220. Further, a toggle link member 340 is also provided that enables in connecting a rear portion of the saddle-type vehicle including the IC engine or a swing arm (not shown) to a front frame portion including the left and right step-through frame members 220.
[00045] As per an embodiment and as may be seen in Figs. 2-5, the left and right step-through frame members 220 extending from the down frame member 210 up to the left and right rear frame members 255 have a box configuration. Further, as may be seen in Fig.4 and Fig.5, the width of the left and right step-through frame members 220 varies along its length. Particularly, the width of the left and right step-through frame members 220 decreases gradually as the left and right step-through frame members 220 extends away from the down frame member 210 and finally increases at the rear portion 221 of the left and right step-through frame members 220. More particularly, the left and right step-through frame members 220 have a larger width at front downtube attachment portions 222 thereof. For example, the width of the left and right step-through frame members 220 is larger where the joint to the down frame member 210 is made and larger at the joint where the tubular bridge member 365 and the toggle link member 340 are attached to the left and right step-through frame members 220. For example, in one embodiment, the tubular bridge member 365 is joined at the first recess 370-1 and the second recess 370-2 formed in the left and right step-through members 220 and the toggle link member 340 is attached to a stepped bush member 335 integrated with the left and right step-through frame members 220. The first recess 370-1, the second recess 370-2 and a mounting provision 345 (Shown in Fig.6a) where the stepped bush member 335 is integrated, constitute attachment portions of the left and right step-through members 220 in the rear portion 221 thereof.
[00046] Fig.6a illustrates the constituent members of the left and right step-through frame members 220. As per an aspect of the present subject matter and as may be seen in Fig.6a, the left and right step-through frame members 220 are made of two sheet metal pieces 223-1 and 223-2 including a first piece 223-1 and a second piece 223-2 having a substantially C shaped cross section each. Particularly, while the first piece 223-1 of the left step-through frame member 220 faces an outside of the step-through frame structure 200, the first piece 223-1 of the right step-through frame member 220 faces an inside of the step-through frame structure 200, and especially faces the second piece 223-2 of the left step-through frame member 220 (see Fig.3). Summarily, the open sides of the C shaped members face each other & away from the outside view of the vehicle. As may be seen in Fig.6a, the two sheet metal pieces 223-1 and 223-2 formed by stamping are provided with stepped openings. For example, in one embodiment the first piece 223-1 is formed with a first opening 224 flanked by a first top step 224a and a first bottom step 224b. Further, the second piece 223-2 is formed with a second opening 225 and flanked by a second top step 225a and a second bottom step 225b. The first opening 224 faces the second opening 225 and vice versa. Further, the first piece 223-1 and the second piece 223-2 are also formed to include an attachment portion 222 each at respective rear portions 221 thereof. The attachment portion 222 at the rear portion 221 includes the mounting provision 345 for the toggle link member 340. The second piece 223-2 of the left step-through member 220 and the first piece 223-1 of the right step-through member 220 are formed with a left recess 370-1 and a right recess 370-2 respectively for receiving the tubular bridge member 365. The left recess 370-1 and the right recess 370-2 are formed besides the mounting provision 345 formed to accommodate the toggle link member 340 (shown in Fig.3). The left recess 370-1, the right recess 370-2 and the mounting provision 345 are integrally formed in the constituent members of the left and right step-through frame members 220. Forming the left and right step-through members 220 by sheet metal stamping ensures that the shape and dimensions of the left and right step-through members 220 can be customized based on the corresponding shape and dimensions of the components to be accommodated between the left and right step-through frame members 220, unlike the case wherein tubular members are used as the step-through frame members.
[00047] Fig.6b illustrates a detailed perspective view depicting the left step-through frame member of the left and right step-through frame members 220 being integrated with the stepped bush member 335. The right step through frame member of the left and right step-through frame members 220 is also integrated with the stepped bush member 335. The stepped bush member 335 is integrated between the constituent members namely the first piece 223-1 and the second piece 223-2 of the left and right step-through frame members 220. The stepped bush member 335 integrated in the mounting provision 345 (shown in Fig.6a) receives the toggle link member 340. The toggle link member 340 helps in mounting one or components of the saddle-type vehicle including the IC engine, and a swing arm (not shown), so that a front portion of the vehicle is connected with a rear portion of the vehicle including the rear wheel.
[00048] The integral box configuration of the left and right step-through members 220 is obtained by joining the first piece 223-1 and the second piece 223-2 respectively of the left and right step through members 220. In one embodiment, the first piece 223-1 and the second piece 223-2 are welded. As per one embodiment and as may be seen in Fig.7a, the second piece 223-2 is welded to the first piece 223-1 by overlapping the second top step 225a of the second piece 225 with the first top step 224a of the first piece 224 and by overlapping the second bottom step 225b of the second piece 225 with the first bottom step 224b of the first piece 224. As may be seen in Fig.7b and Fig.7a, the first top step 224a comprises a first top edge 701 and a second top edge 702, while the first bottom step 224b comprises a first bottom edge 801 and the second bottom edge 802, wherein a first outer diameter (OD1) between the first top edge 701 and the first bottom edge 801 is lesser than a second outer diameter (OD2) between the second top edge 702 and the second bottom edge 802. The second piece 223-2 is overlapped with the first piece 223-1 by placing the second top step 225a against the second top edge 702 of the first piece and subsequently welding is performed along a length of the second top step 225a. Similarly, the second bottom step 225b is overlapped with the second bottom edge 802 of the first piece 223-1 and welding is performed along length of the second bottom step 225b. In other words, the second top step 225a and the second bottom step 225b of the second piece 223-2 are inserted to be placed against a portion of the first top step 224a and the first bottom step 224b respectively, before welding is performed along length of the second top step 225a and the second bottom step 225b. Thus, in order to achieve the insertion of the second top step 225a and the second bottom step 225b against first top step 224a and the first bottom step 224b respectively, an inner diameter (ID2) (not shown) of the second piece 223-2 is provided to be lesser than the second outer diameter (OD2) of the first piece 223-1.
[00049] The first piece 223-1 and the second piece 223-2 of the left and right step-through members can have different configurations as shown in Figs. 8a-8g. For example, in certain embodiments, as shown in Figs.8a, 8b, 8c and 8e, the step profile may be formed at only one of its ends, i.e the first piece 223-1 may be formed with either the first top step 224a or the first bottom step 224b. Correspondingly, the second piece 223-2 overlapping the first piece 223-1 may or may not be formed with either the second top step 225a or the second bottom step 225b so that the second piece 223-2 can either be partially inserted into the first piece 223-1 for overlapping with the first piece or merely directly overlapped.
[00050] As per another embodiment and as may be seen in Fig.8d, the box configuration of the left and right step-through frame members 220 is obtained by directly overlapping the first piece 223-1 formed with both the first top step 224a and the first bottom step with the second piece 223-2. The overlapping is achieved by inserting the first piece 223-1 having a smaller inner width into the second piece 223-2 having a greater outer width.
[00051] The construction of the step-through frame structure as per the present subject matter therefore enables in eliminating the use of additional support members such as gussets. The present subject matter therefore enables in achieving significant weight reduction and also provides a cost-effective means for producing a step-through frame. Moreover, the construction of the step-through frame structure as per the present subject matter also enables the accommodation of components of varying size and dimensions in the step-through space.

Reference Numerals:
100 – Saddle-type vehicle 222 – Attachment portions
102 – Internal combustion engine 223-1 – First piece
105 – Handlebar assembly 223-2 – Second piece
110 – Headlamp Assy 224 – First opening
115 – Front cover 224a – First top step
120 – Front fender 224b – First bottom step
121 – Front fork 225 – Second opening
125 – Front wheel 225a – Second top step
130 – Leg shield 225b – Second bottom step
135 – Seat 255 – Left and right rear frame members
140 – Under-seat cover 335 – Stepped bush member
145 – Floorboard 340 – Toggle link member
165 – Pillion-handle 345 – Mounting provision
170 – Tail lamp unit 370-1 – Left recess
175 – Left and right side covers 370-2 – Right recess
180 – Rear fender 701 – First top edge
185 – Muffler 702 – Second top edge
190 – Rear wheel 801 – First bottom edge
200 – Frame structure 802 – Second bottom edge
205 – Head tube 705 – Multi purpose bracket
210 – Down frame
215 – Connecting frame member
220 – Left and right step-through frame members
221 – Rear portion