BODY FRAME FOR A MOTORCYCLE

FIELD OF THE INVENTION

[0001] The present subject matter relates generally to a scooter type motorcycle, and particularly to a body frame for a scooter type motorcycle.

BACKGROUND OF THE INVENTION

[0002] In general, a scooter type motorcycle rests on a step through body frame. Such a frame is broadly divided into four parts including a head pipe, a main pipe, a low floorboard and side tubes. However this construction of body frame is often inadaptable and inflexible to the needs of new variants of the vehicle. It compromises the frame strength when newly introduced vehicle parts are either mounted or attached on to this frame.

[0003] The usual joining method to connect the different parts of such a frame is welding, butt welding or lap welding, any of which reduces the yield strength at weld joints. Welding also decreases the production rate of the vehicle as the frame production timing is increased. Moreover, a usual frame structure is made of hollow tubes or pipes welded at joints. These joints may fail in case of any transfer of the bending loads from the tubes.

[0004] The present subject matter is directed to overcoming all or any of the problems as set forth above and obviate the lacunae in the prior art. It is therefore an object of the present subject matter to increase the frame strength of a scooter type motorcycle so as to avoid the occurrence of frame cracks and minimize the overall weight of the vehicle. Another object of this subject matter is to provide better stiffness to the frame and make provisions for other vehicle parts to be easily mounted on the frame without compromising the frame strength. Yet another object of the present subject matter to provide a flexible layout for a frame of a scooter type motorcycle which can readily be adapted to change the frame members as per the requirements of the different variants of the vehicle

SUMMARY OF THE INVENTION

[0005] To this end, the present subject matter discloses a light weight body frame assembly constituted by integrating, pipes made of aluminium and a plurality of aluminium cast parts, either by welding or bonding or weld-bonding. . This frame assembly is customizable according to the requirements of the different variants of the vehicle. The body frame assembly comprises of a hollow head pipe, a hollow main pipe, a low floorboard, at least two laterally spaced side tubes with varying cross section, a pillion handle and at least three brackets secured to the said body frame assembly for mounting vehicle parts.

[0006] According to an aspect of the present subject matter, the head pipe is provided at a front portion of the motorcycle and it further comprises an extension emanating obliquely downwardly from a rear end of the head pipe. The extension is provided with a plurality of X ribs at its rear end and has a rectangular out and circular in cross section. The hollow main pipe has a hybrid cross section. The low floorboard comprises a flat top surface and a bottom surface, the bottom surface including a plurality of ribs at either side of the bottom surface and a cooling passage with a drain hole passing midway through the bottom surface of the floorboard. The pillion handle comprises at least two curved tubes extending rearward along the long axis of the motorcycle, a plurality of ribs supporting the pillion handle and at least one securing member for vehicle part mounting.

[0007] According to an aspect of the present subject matter, various portions of the body frame are joined to each other in a way such that the bending loads are not transferred to outer body. Additionally, the frame layout aids in effective cooling of an engine in the motorcycle.

[0008] According to another aspect of the present subject matter, the head pipe of the body frame assembly is fabricated as a single cast unit by pressure die casting using aluminium alloy A3XX. The main pipe is fabricated by an extrusion process using aluminium alloy A6XXX. The low floorboard is fabricated as a single unit by gravity die casting using aluminium A3XX alloy. The laterally spaced side tubes are fabricated by aluminium A6XXX by extrusion process followed by hydroforming or bending. The pillion handle is fabricated as a single unit by gravity die casting using aluminium alloy A3XX followed by heat treatment.

[0009] According to a further aspect of the present subject matter, the body frame is used preferably with a scooter type motorcycle.

[00010] The foregoing objectives and summary provide only a brief introduction to the present subject matter. To fully appreciate these and other objects of the present subject matter as well as the subject matter itself, all of which will become apparent to those skilled in the art, the ensuing detailed description of the subject matter and the claims should be read in conjunction with the accompanying drawings. The summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in limiting the scope of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

[00011] The above and other features, aspects, and advantages of the subject matter will be better understood with regard to the following description, appended claims and accompanying drawings where:

Figure 1 shows a perspective view of a body frame assembly according to the present subject matter.

Figure 2(a) shows a left perspective view of a head pipe according to the present subject matter.

Figure 2(b) shows a right perspective view of the head pipe according to the present subject matter.

Figure 3 shows a side view of the main pipe according to the present subject matter.

Figure 4 shows a side view of a top surface of a floorboard according to thepresent subject matter.

Figure 5 shows a full view of a bottom surface of the floorboard according to the present subject matter.

Figure 6 shows a second embodiment of the bottom surface of the floorboard according to the present subject matter.

Figure 7 shows a perspective view of the prop stand mounting bracket according to the present subject matter.

Figure 8 shows a perspective view of a pillion handle according to the present subject matter.

Figure 9 shows a bottom view of the body frame assembly according to the present subject matter.

DETAILED DESCRIPTION OF THE INVENTION

[00012] The subject matter described herein relates to a light weight body frame assembly for a scooter type motorcycle with better stiffness and strength. The frame can flexibly accommodate various vehicle style parts depending upon the vehicle variant without compromising the strength of the frame. The body frame assembly is mainly a tubular frame assembly formed primarily from tubular members which may have round, rectangular or other suitable configurations and joined either by welding or bonding or weld bonding. In the present invention, the term 'weld bonding' refers to joining two surfaces by adhesives followed by spot welding.

[00013] Further "front" and "rear", and "left" and "right" referred to in the ensuing description of the illustrated embodiment refer to front and rear, and left and right directions as seen in a state of being seated on a seat of the motorcycle. Furthermore, a longitudinal axis, wherever referred to, refers to a front to rear axis relative to the vehicle and a lateral axis, wherever used, refers generally to a side to side, or left to right axis relative to the vehicle. Various other features and embodiments of the body frame assembly according to the present subject matter here will be discernible from the following further description thereof, set out hereunder.

[00014] The body frame assembly according to the present subject matter is now described in detail in connection with the rendered figures 1-9. The detailed explanation of the constitution of parts other than the subject matter which constitutes an essential part has been omitted at suitable places.
[00015] Figure 1 is a perspective view of a body frame for a scooter type motorcycle according to the present subject matter. From front to rear direction, the body frame assembly comprises a head pipe 1, a main pipe 2, a low floor board 3, a side tube 4a, and 4b on both side, and a pillion handle 5. A plurality of mounting brackets 6a, 6b, 6c for attaching other parts of the vehicle are provided in the frame at various locations which will be described in due course. A handlebar assembly (not shown) and a seat assembly (not shown) are supported at opposite ends of this frame assembly.

[00016] A conventional body frame for a scooter type motorcycle includes a head pipe made of cast aluminium which is generally devoid of brackets used for mounting other parts. The brackets are attached separately to the head pipe by other known means including welding which reduces the strength of the head pipe.

[00017] Figure 2(a) and 2 (b) respectively shows the left and right perspective views of the head pipe 1. In an embodiment of the present subject matter, the hollow head pipe 1 is provided with a circular cross section 11 along its long axis.

The head pipe is located at a front portion of the scooter type motorcycle so as to extend approximately vertically. At least one rib 15 is present externally on the head pipe 1 in the lateral direction thereby imparting stiffness to the head pipe. The head pipe 1 steerably supports a front wheel (not shown) and comprises a laterally integrated bracket 7 generally at the right side of the head pipe 1 for mounting directly or indirectly other vehicle parts like lockset and the like. The bracket 7 consists of at least two securing members that help in mounting of vehicle parts, a first securing member 9 for locating the mounted part and a second securing member 8 for mounting screw.

[00018] An extension 16 emanates from the head pipe 1 obliquely downwardly from a rear surface of the said head pipe. The extension 16 is having a rectangular out cross section portion 14 connected to the head pipe and a circular in cross section portion 13 further extending rearward and downward towards the main pipe 2. The rear end of the said extension 16 is provided with X shaped ribs 10 to optimize the weight of the frame and to bestow better strength to the frame in fatigue conditions. The front portion of the said head pipe is provided with a style and number plate mounting structure 12 extending axially outward and mostly parallel to the ground. A front panel (not shown) of the scooter type motorcycle as well as a horn (not shown) may be connected directly or indirectly to the said style and number plate mounting structure 12.

[00019] Conventional scooter type motorcycle frames have a main pipe in the form of a round tube which is weak in vertical and torsional stiffness. The present subject matter improves the torsional stiffness of the body frame assembly by including a separate hollow main pipe 2 preferably having a hybrid cross section i.e. a square out 19 and a circular in cross section 18. The main pipe 2 is descendingly inclined rearward from the rear end of the extension 16 of the head pipe as shown in Figure 3.

[00020] Further, the main pipe 2 is fabricated in such a way that it has more fabricating material in the direction of force to provide better stiffness and more inertia. In one aspect of this invention, the corners of the main pipe 2 have more fabricating material which culminates into more thickness at the corners for better stiffness of the frame. However, the said main pipe 2 may possess any of a round cross section, a rectangular cross section or other cross sections as well. The main pipe 2 is rigidly connected to the oblique downward end of the head pipe 1 at one end and the low floorboard 3 at the other end. In yet another embodiment of the body frame assembly, the orientation of the main pipe 2 can be changed by 45 degrees so that the square shaped main pipe turns into diamond shape for imparting better stiffness and strength.

[00021] The shape of the main pipe 2 provides good vertical and torsional stiffness to the front portion of the present frame. The front end and the rear end of the said main pipe 2 are respectively inserted to the rear end of the extension 16 of the head pipe 1 and a front end of the low floorboard 3 preferably through weld bonding. In conventional frames, the front end of the main pipe is directly welded to the circular surface of the head pipe. But in the present invention, the load on the head pipe is distributed by the said extension 16 in order to keep it away from the axial direction of the head pipe thereby removing the need for reinforcement at or below the head pipe axial surface. The weld-bonding point at the interface of head pipe and main pipe is thus not directly on the head pipe circular surface but on the extension 16.

[00022] Furthermore, the head pipe 1 is rigidly fixed to the main pipe 2 at one end including welding or bonding or weld bonding in such a way that the circular cross section portion 13 at the rear end of the said extension 16 of the head pipe gets inserted into the corresponding circular cross section portion 18 of the main pipe 2. According to an aspect, the entire head pipe structure 1 including all the embodiments described above is fabricated as a single cast unit by pressure die casting process using aluminium alloy A3XX. In yet another aspect of the invention, the said pipe due to its complex shape may be fabricated by gravity die casting process using aluminium where gases are not entrapped and the casting surface becomes excellent due to slow injection speed. Either of the process is followed by suitable heat treatment to achieve better stiffness and crashworthiness of the frame.

[00023] According to another aspect, the main pipe 2 is fabricated by extrusion process using aluminium alloy A6XXX.

[00024] Figure 4 shows a side view of the top surface of the low floorboard 3 according to the present subject matter. The floorboard 3 acts as a central portion of the body frame assembly present between the handlebar and the seat assembly (both not shown) and is lower than either of the front and the rear ends of the body frame to define a generally open central area, permitting 'step through' mounting of the scooter type motorcycle. It forms a bridge between rear end of the main pipe 2 and a front end of the side tubes thereby adding weight to the front portion.

[00025] According to an aspect, the low floorboard 3 comprises a flat top surface TS and a bottom surface BS. It also includes at least three conduits extending obliquely upwards from the top surface TS of the floorboard 3. According to an embodiment, the said floorboard comprises at least one front conduit 24a at a front end and at least two rear conduits 24b, 24c at a rear end of the floorboard 3 along the longitudinal axis of the motorcycle. The front conduit 24a of the said floorboard 3 has an inside circular cross section and comprises of X-ribs 20 at its top end. Likewise the top end of the rear conduits 24b, 24c also comprise of X-ribs 20. The rear end of the main pipe 2 engulfs the top end of the front conduit 24a and weld-bonded to provide good torsional and lateral stiffness to the body frame assembly. Additionally, a plurality of reinforcing ribs 21 are integrally provided at the base of the front and rear conduits present at the front and the rear portion of the floorboard for carrying torsional loads from the front portion of the vehicle thereby avoiding local deformation in the body frame.

[00026] In conventional frames, a plastic or rubber sheet is provided over the top surface of the floorboard for an operator of the scooter to step on the scooter and thereby functions as a foot rest for him. However in a preferred embodiment of the present subject matter, the top surface TS of the said floorboard 3 is flat on which the operator's feet are placed and this avoids plastic or rubber panels as footrest thereby reducing the vehicle weight and consequently the cost. The floorboard 3 however includes provisions 22 in the form of plurality of holes for optional plastic or rubber sheet mounting into which a rubber or plastic sheet can be secured. A plurality of brackets 23 is provided on either side of the floorboard 3 for mounting the style parts of the scooter type motorcycle onto the floorboard 3. The rear conduits 24b, 24c are adapted to be inserted into the front end of the respective side tubes. The rear end of the floorboard 3 contains circular bosses 25 for mounting a toggle link or a swing arm (not shown) on which the engine of the scooter type motorcycle is mounted thereon.

[00027] Figure 5 shows a full view of an embodiment of the bottom surface of the floorboard. The bottom surface BS including a plurality of cross ribs 27 at either side of the bottom surface to minimize the longitudinal loads. The ribs however may follow any other suitable pattern for material flow and strengthening the frame. In one aspect of the invention, all the ribs are at an angle of 45 degrees to each other to distribute loads felt on top of the floor board thereby increasing the torsional stiffness of the frame assembly. This 45 degree pattern is added to the material flow direction in order to avoid crack development in the direction of material flow.

[00028] Further, the bottom surface BS of the floorboard 3 is also provided with a long cooling passage 28 passing midway through the floorboard in such a way that the section with cross ribs 27 fall on the either side of the cooling passage 28 and the front end of the cooling passage is beneath the base of front conduit 24a provided on the top surface TS. In one aspect of this invention, the cooling passage 28 is in the shape of a tube open at both ends which aids in load distribution from the main pipe 2 to the rear end of the floor board 3. The cooling passage 28 channelizes the air when the motorcycle is in moving condition so as to aid in engine compartment cooling. In yet another embodiment of the present invention, the cooling passage may be provided with a drain hole passing midway through the bottom surface BS which helps to drain out any impurities like water present in the cooling passage 28.

[00029] Figure 6 shows a second embodiment of the bottom surface of the floorboard. Here the cross ribs 27 are spread out substantially throughout the surface area of the bottom surface of the floorboard. A plurality of short cooling passages 28 are present rearwardly to the cross ribs to channelize the incoming air towards the engine of the motorcycle.

[00030] The low floorboard 3 as described above is fabricated as a single unit by gravity die casting using aluminium A3XX alloy. The floor board 3 is attached with rear end of the main tube 2 and front end of the side tubes either by welding or bonding or weld bonding. The construction of the floorboard 3 allows the floorboard length to be varied to adapt to different variations in wheel base and to meet customer requirement for luggage and feet space in the motorcycle.

[00031] Still further, a securing member 26 in the form of a plurality of threaded holes for mounting a prop stand mounting bracket 6a is also provided lateral to the floorboard 3. The prop stand mounting bracket 6a is attached to the said floorboard 3 through the securing member 26. As shown in figure 7, the prop stand mounting bracket 6a has an upper plate portion 34 and a lower plate portion 35. The lower plate portion has two bores. A first bore 36 is at a position where a prop stand (not shown) is attached and configured to pivot around a pivot bolt (not shown). The first bore 36 traverses through the thickness of lower plate portion 35. A second bore 37 is also present through which a through pin (not shown) is passed through the lower plate portion 35 in the thickness direction. The through pin is preferably welded to the prop stand mounting bracket 6a and one end of the said through pin serves as an anchoring pin anchored to a return spring of the prop stand which in turn is attached to the bracket by the pivot bolt. The upper plate portion of the prop stand mounting bracket 6a has two recesses 38a, 38b for securing the prop stand mounting bracket 6a to the floorboard 3. The said bracket 6a can be bolted to the floorboard by inserting a bolt in each of the recesses in the upper plate portion 34 in such a way that the threaded end of the bolt passes through the upper plate portion in the thickness direction and secured to the floorboard via the securing member 26.

[00032] According to an aspect, the prop stand mounting bracket 6a may be fabricated by known mechanism including casting or sheet metal bonding using aluminium or steel.

[00033] At least two hollow laterally spaced side tubes 4a, 4b with varying cross section are provided rearwardly in the body frame, one each on either side of the longitudinal axis of the scooter type motorcycle. The side tubes extend rearwards and obliquely upward from the floorboard 3. Each side tube is having a rectangular but varying cross section. The side tubes are connected at one end to the respective rear conduits 24b, 24c of the floor board 3 and to the pillion handle 5 at the other end in such a way that they extend obliquely upward and gently bent midway to turn out to be almost parallel to the ground. The cross sectional area of a front end of the side tubes 4a, 4b connected to the floorboard is more than the cross sectional area at a rear end connected to the pillion handle 5. At least one bush or bracket 6c for mounting a rear suspension may be provided on each of the side tube. In a preferred embodiment of the present invention, the said bush 6c is included in the side tube by eliminating the side tube matter at one place close to the pillion handle 5 or by bashing the side tube so as to make space for the bush. The bush is connected to the respective side tubes by welding. Both the tubes may include various other provisions in the form of bushes and brackets for mounting other parts as required. In an embodiment of the present invention, a threaded hole is present on each of the side tube to mount the front end of the fuel tank as well as the storage box.

[00034] The body frame assembly is also provided with a storage box bracket 6b on which a storage box (not shown) is rested. The storage box bracket 6b acts as a bridge between the left and right side tubes 4a, 4b and consists of at least one securing member for mounting the storage box over it. The main function of the said bracket is to carry loads from the storage box. The respective ends of the storage box bracket 6b are rigidly connected to a middle portion of the side tubes through weld bonding. The storage box bracket 6b is fabricated using aluminium sheet metal or by casting.

[00035] According to an aspect, the side tubes are fabricated by aluminium A6XXX by extrusion process followed by hydroforming or bending as may be required. They are connected to the floorboard and to the pillion handle at the respective ends by welding or bonding or weld-bonding.

[00036] According to another aspect, the pillion handle 5 is provided on both sides of the rear end of a riding seat (not shown). Figure 8 shows a perspective view of the pillion handle according to the present subject matter. It is in the shape of curved tubes 5a, 5b on either side extending rearward along the longitudinal axis of the motorcycle from the rear end of the rising side tube to support the riding seat. The pillion handle 5 has an arrangement in the form of two tubes 29a, 29b extending forward longitudinally to directly attach it to the rear end of the side tubes 4a, 4b by weld bonding. The said pillion handle 5 is further supported by a plurality of ribs 30 at either of its corners. It is prospected that the said ribs 30 aid in increasing the lateral and vertical stiffness of the rear portion of the frame. The said pillion handle also has provisions to mount fuel tank, seat lock, tail lamps either directly or indirectly through threaded holes present on it. In an embodiment of the present invention, at least one securing member 31 is present for mounting the seat lock so that a seat hinged on the frame to be turned in a vertical plane can be locked and at least one securing member 32 present on either side for mounting the rear end of fuel tank. The securing members may be in the form of threaded holes. According to an aspect, the entire pillion handle may be fabricated as a single unit by gravity die casting owing to its complex shape using aluminium alloy A3XX followed by heat treatment.

[00037] Further, Figure 9 shows a bottom view of the body frame assembly according to the present subject matter.

[00038] The present subject matter and its equivalent thereof offer many advantages, including those which have been described henceforth. The present invention advantageously provides the body frame assembly for a scooter type motorcycle where the frame may be made of four or more separate components including the head pipe, main pipe, low floorboard, side tubes, pillion handle and various brackets for mounting other vehicle parts. These components are joined either by welding, bonding or weld boding as described above. This body frame is flexible to adapt to the forthcoming vehicle variants. It adapts to all other vehicle parts to be easily mounted on the frame without affecting the strength of the frame. The frame in the present invention is light weight and has good stiffness on account of ribs, cross ribs and X-ribs provided at respective places as well as the orientation of the main pipe. The lightweight design also aids in improving the motorcycle mileage. In a conventional frame, all the brackets for mounting the style parts are either welded or screwed which may weaken the frame strength. But the present invention enhances the frame strength by attaching such brackets through weld bonding which minimizes the heat affected zones to improve frame strength. The construction also minimizes the bending and shearing of the frame components.

[00039] According to the present subject matter, the body frame is fabricated by integrating aluminium series die cast products and aluminium series non-die cast products fabricated by a method other than die casting. Moreover, the various components of the frame are joined to each other through stiffeners inserted into the respective tubes and weld-bonded due to which the bending loads are not transferred to outer body. The frame production timing shall be decreased and as a result the production rate will increase. Additionally, the cooling of the engine becomes more effective since the cooling air is provided by the floorboard casting which removes the need for additional duct for air cooling.

[00040] The present subject matter is thus described. In the description, a reference to aluminium includes aluminium alloy. The description is not intended to be exhaustive nor is it intended to limit the invention to the precise form disclosed. It will be apparent to those skilled in the art that the disclosed embodiments may be modified in light of the above description. The embodiments described are chosen to provide an illustration of principles of the invention and its practical application to enable thereby one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore the forgoing description is to be considered exemplary, rather than limiting, and the true scope of the invention is that described in the appended claims.

I/We claim:

1. A body frame assembly for a scooter type motorcycle comprising:

a hollow head pipe provided at a front portion of the said motorcycle, the said head pipe further comprising an extension emanating obliquely downwardly from a rear end of the said head pipe, the said extension provided with a plurality of X ribs at its rear end and having a rectangular out and circular in cross section;

a hollow main pipe with hybrid cross section;

a low floorboard comprising a flat top surface and a bottom surface, the bottom surface including a plurality of cross ribs at either side of the bottom surface and a cooling passage with a drain hole passing midway through the bottom surface of the said floorboard, the said floorboard further comprising at least three conduits;

at least two laterally spaced side tubes with varying cross section;

a pillion handle comprising at least two curved tubes extending rearward along the long axis of the motorcycle, a plurality of ribs supporting the pillion handle and at least one securing member for vehicle part mounting;
and,

at least three brackets secured to the said body frame assembly for mounting vehicle parts.

2. The body frame assembly for a scooter type motorcycle as claimed in claim 1, where the said head pipe comprises at least one rib, a laterally integrated bracket and a style and number plate mounting structure,

wherein the said rib is placed laterally, the laterally integrated bracket contains at least two securing members for mounting vehicle parts and the style and number plate mounting structure is supported at a front end of the said head pipe.

3. The body frame assembly for a scooter type motorcycle as claimed in claim 1 or claim 2, wherein the said head pipe has a circular cross section along its long axis.

4. The body frame assembly for a scooter type motorcycle as claimed in claim 1, wherein the said main pipe is descendingly inclined rearward from the rear end of the said extension of the head pipe, the said main pipe having a square out and circular in cross section.

5. The body frame assembly for a scooter type motorcycle as claimed in claim 1, wherein the said low floorboard is disposed between a handlebar and a seat assembly, the said floorboard comprising at least one front conduit at a front end and at least two rear conduits at a rear end, the front and rear conduits extending obliquely upwards from the said floorboard and having X ribs at their top end, a plurality of reinforcing ribs integrally provided at the base of the said conduits, the said floorboard further comprising a plurality of brackets, circular bosses and a securing member in the form of a plurality of threaded holes for mounting a prop stand mounting bracket.

6. The body frame assembly for a scooter type motorcycle as claimed in claim 1, wherein the said side tubes with varying cross section are hollow, and extend rearward and obliquely upward, the said side tubes gently bent midway and further comprising of a means for mounting a rear suspension, a fuel tank, a storage box and appropriate vehicle parts.

7. The body frame assembly for a scooter type motorcycle as claimed in claim 1 or claim 6, wherein a storage box bracket connects the said side tubes and capable of holding a storage box, the respective ends of the storage box bracket rigidly connected to a middle portion of the respective side tubes through weld bonding.

8. The body frame assembly for a scooter type motorcycle as claimed in any of the preceding claims, wherein a front end of the said main pipe is connected to the rear end of the said extension of the head pipe, a rear end of the said main pipe is connected to the top end of the front conduit of the said low floorboard, the top end of the said rear conduits are connected to a front end of the respective side tubes,
a rear end of the respective side tubes is connected to a front end of the said pillion handle, either by welding or bonding or weld-bonding.

9. The body frame assembly for a scooter type motorcycle as claimed in any of the preceding claims wherein the said head pipe is fabricated as a single cast unit by pressure die casting using aluminium alloy A3XX;

the said main pipe is fabricated by an extrusion process using aluminium alloy A6XXX;

the said low floorboard is fabricated/^ a single unit by gravity die casting using aluminium A3XX alloy;

the said laterally spaced side tubes are fabricated by aluminium A6XXX by extrusion process followed by hydroforming or bending;

the said pillion handle is fabricated as a single unit by gravity die casting using aluminium alloy A3XX followed by heat treatment; and,

the said storage box bracket is fabricated using aluminium sheet metal by casting.

10. The body frame assembly for a scooter type motorcycle substantially as herein described and illustrated with reference to the accompanying drawings.