This invention relates to a gas fuelled motorcycle.

Gas fuelled vehicles are growing ever more popular as a sustainable option enabling commuting whilst using a cleaner fuel, a fuel that can be combusted in an internal combustion engine with lower emissions of fewer pollutants. For example, many gas fuelled three wheeler vehicles are seen on the roads of India. Increasingly, gas fuelled motorcycles and scooters are also becoming popular as well.

Past vehicle gas fuelling systems, such as CNG and LPG gas fuelling systems are bulky, being constructed to handle high pressure operation. As well as the gaseous fuel tank, other components that need to be included are the safety shut off valve, a gas pressure reducer - which may be described as a first stage reducer, and a solenoid controlled ON/OFF gas flow control valve various of which are connected with lightweight high pressure hose or ductwork which may extend over some distance. There is also a requirement, in many cases, for the motorcycle to be provided with an auxiliary fuel tank, typically a liquid fuel tank to enable vehicle operation when gaseous fuel is not available. Then, mounting components must be accommodated to mount all of these components on to the vehicle frame which requires significant strength in the region accommodating the gas fuelling system. A frame "cradle" is typically provided for this purpose. Particularly in 2 wheeler vehicle applications, but in 3 and 4 wheeler vehicle applications as well, packaging space available to accommodate all these components is very limited. A better frame is needed to meet all these requirements.

It is therefore an object of the present invention to provide a motorcycle with a frame better designed for mounting key components of the gas fuelling system, the frame easing the packaging difficulty.

It is a further object of the invention to provide a frame which may also be applied to other motorcycles, such as liquid fuelled or gas/liquid fuelled motorcycles, with resultant packaging benefits.

With this object in view, the present invention provides a motorcycle comprising a frame having a front frame portion comprising a head tube, a down tube extending downwardly and rearwardly from the head tube and at least two upper side tubes extending rearwardly from the head tube, and located above the down tube, for supporting a fuelling system for the motorcycle; and a fuelling system wherein said side tubes are braced to said down tube by brace members with at least one brace member extending from said down tube to one of the upper side tubes, a space between said brace member and said head tube being provided for components of said fuelling system to extend through said space.

The fuelling system is generally a gas fuelling system in which case the components of the fuelling system extending through said space is a gas carrying components. However, the fuelling system may also be a dual fuelling system allowing liquid or gaseous fuels to be supplied to an engine of the motorcycle.

The brace members are conveniently in the form of tubes and this has maximum advantage for serviceability and packaging. However, one or more of the brace members could be provided in the form of plate(s) with aperture(s) of sufficient dimension to enable the gas carrying component of the gas fuelling system to extend through the space.

The former tube embodiment of brace member is much preferred as this reduces manufacturing cost. In addition, the brace members may be shaped to diverge at their upper ends forming a portion in which the neck of a gaseous fuel tank may be supported. Such support is enhanced by provision of a cross member between the brace members at, or just below, a location where the upper ends of the brace members become divergent.
Brace member(s) are connected, between upper side tube(s) and down tube, on both sides of the motorcycle frame; the sides corresponding with each of the side tubes. While tubes are preferred, if needed to provide required structural strength, it is still possible for a gusset plate to be provided for connection of down tube to a side tube at least on one side of the vehicle. For additional strength, cross member(s) may be provided joining brace members on both sides of the motorcycle frame. In addition, the head tube may still be gusseted to the down tube, usefully by a C section gusset, to form a box section imparting strength to the head tube region. Each brace member may be connected, for example being welded, between this gusset and each side tube.

Support bracket(s) are provided to give sufficient strength to the frame to support a gaseous fuel tank which must be accommodated in this region. In particular, support is provided to the neck portion of the gaseous fuel tank, typically provided in the form of a cylinder by these brackets and design of the brace members as above described. Additional support is provided for, or along, the outer diameter of the gaseous fuel cylinder, preferably at or near the middle of the gaseous fuel tank and at or near the rear of the gaseous fuel tank. The frame, as here described with three cylinder support areas, allows for a more uniform weight distribution of gaseous fuel cylinder over it.

In prior motorcycle frame constructions, the role of the brace members would typically be filled by solid gusset plates, provided to confer the required strength on the front frame portion. In such constructions, and assuming a left side tube and a right side tube are provided as part of the front frame portion, both side tubes would be gusseted to the down tube. Gussets are solid metal plates defining a recess between them and the head tube. The relatively small volume and enclosed nature of the recess places a serious constraint on the space available for packaging the gas fuelling system. In particular, a gas fuelling component in the form of a duct communicating a gaseous fuel ON/OFF control valve with a gaseous fuel pressure regulator, typically a pressure reducer for reducing gaseous fuel pressure from gaseous fuel tank pressure towards engine gaseous fuel supply pressure, must be packaged in this space. This causes difficulty for both motorcycle manufacturer and service operator, the service operator being involved in the maintenance of these critical components of the gas fuelling system. The difficulty comes from the need to instal and service gas fuelling system components in a confined area.

Manufacturing and serviceability is much easier when a space, particularly one of sufficient dimensions to enable convenient working with components, is left between the brace members and down tube. Gas fuelling components may also be more readily installed during manufacture and more accessible for servicing.

The front frame portion of the motorcycle supports a gaseous fuel tank, such as a CNG fuel tank. This tank, typically of generally cylindrical geometry, is mounted to the side tubes, braced by a transversely extending cradle member for supporting the fuel tank in a more or less conventional manner with suitable mounting bracket(s) and clamp(s).

The motorcycle is also provided with some capacity to run on a liquid fuel, typically petrol though other liquid fuels could be used. Therefore, a liquid fuel tank - typically an auxiliary liquid fuel tank - is also provided for the motorcycle to provide some operating capacity in regions where access to gaseous fuel may be difficult, such as in rural areas of India. In this case, the gaseous fuel tank and the liquid fuel tank are accommodated within a fuel tank body located above the front frame portion, and supported by that front frame portion, as above described. This fuel tank body advantageously has an outer surface with the same shape as fuel tanks used for conventional motorcycles. The gaseous fuel tank is desirably located below the liquid fuel tank which may be of shape to occupy the maximum available/space over the gaseous fuel tank. Actual shape and volume will depend on a selected fuel volume to enable effective limp home mode. A filling point for the liquid fuel tank may be provided in the body, desirably in a readily accessible position located in the surface of the fuel tank body. Volume of the liquid fuel tank may also be optimized such that space for a luggage or glove box is provided internally of the fuel tank body. The filling point may be provided with a cap, the liquid fuel tank cap advantageously having the same design as liquid fuel tank caps used for conventional motorcycles.

The liquid fuel tank is not mounted directly to the motorcycle frame. Rather the liquid fuel tank may be mounted to an internal surface of the fuel tank body, for example by suspending it from the internal surface of the fuel tank body, this internal surface being provided towards the top of the fuel tank body. The fuel tank body may also be described as a fuel tank cover. The liquid fuel tank is preferably provided with a lockable cap. The fuel tank body is mounted to the motorcycle frame.

Preferably, to enable easier and more efficient packaging, the fuel tank body may not be provided with a lid which must first be opened to access a closure, or cap, of the liquid fuel filling point. In other words, the fuel cap is uncovered and directly accessible on the fuel tank body. The omission of such a lid allows space to be made available for increasing liquid or gaseous fuel capacity on board the motorcycle. A closure or cap for the filling point may have an upper surface flush with, or perhaps slightly proud of, a surface of the fuel tank body to enable direct rider access to it when filling and re-filling with liquid fuel is required.

Gas fuelled motorcycles must be provided with a manual shut-off valve for the gaseous fuel tank as a mandatory safety feature, as the gaseous fuel tank has a high pressure, typically about 200 bar. In the present motorcycle, it may be most convenient to have this shut-off valve located just forward of the fuel tank body, at a point where the valve of the gaseous fuel tank emerges from the fuel tank body to enable access to the shut-off valve during manufacture and servicing. However, it is also important for the rider to have ready access to this shut-off valve. Such access may be restricted to a small space through which the rider may need to stretch some distance to reach the shut-off valve. This is unlikely to be safe during vehicle operation. Advantageously, to assist in overcoming this problem, an actuator for the shut-off valve is provided in a location more readily accessed by the rider. This form of actuator may be extended to vehicles other than motorcycles also.

Therefore, in a further aspect of the invention, there is provided a gas fuelling system for a vehicle comprising:

a gaseous fuel shut-off valve having a body located proximate a gaseous fuel supply tank for the vehicle in a portion of the gas fuelling system not easily and/or safely accessible by an operator of the vehicle during operation of the gas fuelling system; and
an actuator for actuating said gaseous fuel shut-off valve between open and closed positions

wherein said actuator includes a linkage extending from said body of said gaseous fuel shut-off valve to a position more easily and/or safely accessible by said operator of said vehicle.

For example, in the case of a motorcycle, the gaseous fuel supply tank may be enclosed by a tank cover such that the gaseous fuel shut-off valve is not safely accessible or is inaccessible to the rider. This tank cover may be mounted to the front frame portion of
the motorcycle. Such a construction enables favourable aesthetics for the motorcycle. In that case, the linkage may extend to a location closer to the handlebars of the motorcycle.

A location at the top of the tank cover is favoured. In that case, a knob or switch, located at or adjacent the top of the tank cover, is available allowing safer access by the rider. This knob or switch has ON and OFF positions corresponding with open and closed positions of the gaseous fuel shut-off valve.

One variation to the location of the ON-OFF valve linkage can be at right angles to the position as described above either on the left or right hand side of the rider when in use and preferably not protruding outside the width of vehicle. This can be done by rotation of the CNG cylinder in either direction with jiecessary changes in gas pipe connections.

The linkage is advantageously in the form of a rod, the linkage being connected to a body of the shut-off valve by a bracket. The bracket is advantageously designed to ensure that the torque required to operate the shut-off valve remains the same even after attachment of the linkage to the shut-off valve. A pivotal connection between bracket and linkage is particularly advantageous.

The gaseous shut-off valve is preferably a quarter turn type rather than a hand wheel type to make packaging easier still. While the preferred arrangement is basically mechanical, it may be understood that- the actuator could include electro-mechanical or electronic components.

The gas fuelling system is not to be limited by the nature of the gaseous fuel selected for vehicle operation. Typical gaseous fuels include CNG and LPG fuels. Other gaseous fuels are not excluded.

The motorcycle and other aspects of the present invention may be more fully understood from the following non-limiting description of preferred embodiments thereof made with reference to the accompanying drawings in which:

Fig. l is a side view of a prior art frame for a gas fuelled motorcycle.

Fig. 2 is a top isometric view of the prior art frame as shown in Fig. 1.

Fig. 3 is a view of portion of a motorcycle having a frame in accordance with one embodiment of the present invention.

Fig. 4 is a side view of a frame used in the motorcycle shown in Fig. 3.

Fig. 5 is a top view of the frame shown in Fig. 4

Fig. 6 is a detail view of a front portion of the frame shown in Figs. 4 and 5 showing connection between head tube, side tubes and down tube of the frame.

Fig. 7 is a bottom isometric view of the frame shown in Figs. 4 and 5.

Fig. 8 is a bottom aspect view of the frame shown in Figs. 4,5 and 7.

Fig. 9 is a detail view of the front portion of the frame shown in Fig. 8 showing packaging of components of a gas fuelling system used in the motorcycle shown in Fig. 3.

Fig. 10 is a side sectional view of the fuel tank body of the motorcycle shown in Fig. 3.

Fig. 11 is a top view of the fuel tank body shown in Fig. 10.

Fig 12 is a side exploded view showing how a cap of an auxiliary liquid fuel tank contained in the fuel tank body shown in Figs. 10 and 11 is located in, and removed from, the liquid fuel tank.

Fig. 13 is a side section view of a fuel tank body showing connection of the liquid fuel tank to a fuel tank body opening.

Fig 14 is a top view of a fuel tank body showing an alternative form of connection of the liquid fuel tank to a liquid fuel tank body opening.

Fig. 15 is a sectional view along section line A-A of the fuel tank body shown in Fig. 14.

Fig. 16 is a side view of a motorcycle showing location of its gaseous fuel supply.

Fig. 17 is a side view of neck portion of gaseous fuel tank for the motorcycle of Fig. 16 showing CNG shut-off valve according to one actuator arrangement.

Fig. 18 is a top view of the neck portion of the gaseous fuel tank shown in Fig. 17.

Fig. 19 is a front view of the neck portion of the gaseous fuel tank shown in Fig 18.

Fig. 20 is a side view of neck portion of gaseous fuel tank for a motorcycle showing CNG shut-off valve according to a second actuator arrangement,

Fig. 21 is a top view of the neck portion of the gaseous fuel tank shown in Fig. 20.

Fig. 22 is a front view of the neck portion of the gaseous fuel tank shown in Fig. 20.

Fig. 23 is a top view of a motorcycle showing rider access to the actuator for a CNG shut-off valve for a motorcycle.

Fig. 24 is a CNG fuel tank with shut-off valve as used in a 3 wheeler vehicle.

Referring first to Figs. 1 and 2, there is shown a frame 1 used in a gas fuelled motorcycle of the prior art. The motorcycle is fuelled with CNG gaseous fuel. The frame 1 has a front portion 2 comprising a head tube 4, a down tube 5 extending downwardly and rearwardly from the head tube 4 and two side tubes 6a (left hand side) and 6b (right hand side) extending rearwardly from the head tube 4, and located above the down tube 5 for supporting the-CNG fuelling system in co-operation with cradle member 8. Down tube 5 is connected to the head tube 4 and two upper side tubes 6a and 6b by brace members in the form of gusset plates 7 welded between each upper side tube 6a and 6b and head tube 4. These gusset plates 7, which are of generally triangular shape, brace the down tube 5 and upper side tubes 6a and 6b forming a C section. Such gusset plates 7 interfere with - connection between various components of the CNG fuel system, an undesirable effect. If relief is provided, the strength of frame 1 is reduced.

Referring now to Figs. 3 to 9, there is shown a motorcycle 100 having a frame 102 having a front frame portion 103 comprising a head tube 104, a down tube 105 extending downwardly and rearwardly from the head tube 104 and two upper side tubes 106a (left hand side) and 106b (right hand side) extending rearwardly from the head tube 104, and located above the down tube 105, for supporting a gas fuelling system 10 for the motorcycle 100 again, in co-operation with cross or cradle member 108. As components of the gas fuelling system 10 for the motorcycle engine are relatively heavy, the front frame portion 103 must have sufficient strength and rigidity to support those components of the gas fuelling system 10.

The gas fuelling system 10 - certain components of which are shown in Figs. 3, 8 and 9 - are used to supply CNG, a gaseous fuel, to the engine of motorcycle 100. The gas fuelling system 10 includes a cylindrical CNG fuel tank 15 having a primary gaseous fuel flow control valve in the form of CNG ON-OFF valve 20. This CNG ON-OFF valve 20 is turned on {open) and off (closed) as required by the operating state of the vehicle. In normal motorcycle 100 operating conditions, the CNG ON-OFF valve 20 will be turned "on".

Downstream from the CNG ON-OFF valve 20 is located a gaseous fuel pressure regulator 30 in the form of a first stage reducer as above described. The first stage reducer 30, of which no more detail will be provided here as it is a conventional part, acts to reduce pressure of CNG fuel from the cylindrical CNG fuel tank 15 pressure to a pressure suitable for supply to the engine. Further reduction in CNG fuel pressure may be required prior to delivery to the engine. The actual CNG fuel supply to the engine will be controlled in accordance with vehicle operating conditions and further description is not required in the context of the present invention.

It may be understood from the above description that the gas fuelling system 10 shown in Figures includes a number of critical components. Further, the CNG ON-OFF valve 20 and first stage reducer 30 may require to be connected by a lightweight high pressure duct or hose 25 which extends over some length.

The objectives of ready packaging of gas fuelling system 10 components and sufficient strength and rigidity of the front frame portion 103 are achieved by providing brace members in the form of brace tubes 109 extending from down tube 105 to the upper side tubes 106a and 106b. Brace tubes 109 are connected to upper side tubes 106a and 106b by welding. While providing rigidity, brace tubes 109 are also located to leave a space 191 between brace tube 109 and head tube 104, this space 191 being generally open towards the side of the motorcycle 100.

The head tube 104 is gusseted to the down tube 105 by a gusset 119 of C section. The resulting box section imparts strength to the frame 102 in the head tube region. The brace tubes 109 are also welded to the C section gusset 119.

Brace tubes 109 diverge at their upper ends, this divergence forming a portion in

- which the neck of the cylindrical CNG fuel tank 15 may be supported. Such support is
enhanced by provision of a cross member 111 between the brace members 109 at, or just below, a location where the upper ends of the brace members 109 become divergent. Cylindrical CNG fuel tank 15 is also supported, by support brackets, at positions along its outer diameter, namely at the middle of the fuel tank and towards the rear of the fuel tank (as shown in Fig.16). The frame 102 , having at least three CNG fuel tank 15 support areas, allows for a more uniform weight distribution of CNG fuel tank 15 over it.

The spaces 191 may allow a gas carrying component of gas fuelling system 10 to extend through the space 191 as conveniently illustrated by Figs. 3, 8 and 9 showing a CNG gas carrying pipe 25 connecting the CNG ON-OFF valve 20 and first stage reducer 30. As described above, the CNG ON-OFF valve 20 and first stage reducer 30 are connected by a lightweight high pressure duct or hose 25 which extends over some length. As may conveniently be seen in Figs. 3, 8 and 9, such a layout for the gas fuelling system is readily accommodated by frame 102 with duct 25 extending through a space 191.

Connection of the duct 25 to first stage reducer 30 may be made outboard of space 191.

These views also show how serviceability is enhanced since access to various components of gas fuelling system 10 may be gained without needing to remove covers and suchlike.

In a variant, frame 102 is also well suited to packaging of an assembly, itself a gas carrying component of gas fuelling system 10, the assembly being formed by directly connecting the CNG ON/OFF valve 20 to first stage reducer 30 as described in our co-pending Indian Patent Application No. 1603/CHE/2010 filed 9 June 2010 and the contents of which are hereby incorporated herein by reference.

The motorcycle 100 is also provided with some capacity to run on a liquid fuel, here petrol. Therefore, an auxiliary petrol tank 16 is also provided for the motorcycle 100 to provide some reserve fuel capacity in regions where access to gaseous fuel may be difficult, such as in rural areas of India. In this case, the CNG fuel tank 15 and the auxiliary petrol tank 16 are accommodated within a fuel tank body 126, which acts as fuel tank holder. Description of this arrangement follows with reference to Figs. 10 to 15.

Auxiliary petrol tank 16, which is conveniently made of sheet metal (blow moulded plastic is an alternative), has a generally flattened volume, selected to achieve a required limp home mode, as shown in Figs. 10,12,13 and 14, though a cylindrical filling tube 16a is provided at the top of tank 16, this filling tube having a wall portion also extending some way into the internal volume of the tank 16. Filling tube 16a extends co-axially to an extended cylindrical opening 161 at the top of the fuel tank body 126.

The flattened volume of auxiliary petrol tank 16 allows for sufficient auxiliary fuel capacity without compromising desired, and market acceptable, volume of the CNG fuel tank 15. Auxiliary petrol tank 16 is mounted, by bracket 16c welded to auxiliary petrol tank 16, from an internal surface 127 formed within the fuel tank body 126 and is connected to that internal surface 127 by suitable fastening means in the form of nuts and screws 16e. A washer or gasket 128 is positioned between the bracket 16c of the auxiliary petrol tank 16 - and internal surface 127. The auxiliary petrol tank 16 is not directly mounted to front frame portion 103 of motorcycle frame 102. but rather suspended within fuel tank body 126. The fuel tank body 126, which has an outer surface having the same shape as used for conventional motorcycles, is mounted to frame 102 by mounting brackets including bracket 1261.

Fuel tank body 126 forms a shell for the fuel tanks 15 and 16, this shell being made
of a light sheet metal. Decals, though not shown, would be applied to the outer surface of
fuel tank body 126. Fuel tank body 126 is located above the front frame portion 103, and
supported by that front frame portion 103, as above described. The CNG fuel tank 15 is
" located below the auxiliary petrol tank 16.

The opening mouth of filling tube 16a for the auxiliary petrol tank 16 is provided in a readily accessible position located just above the surface of the fuel tank body 126. A closure or cap 16b for the filling point 16a may have an upper surface slightly proud of a surface 17 of the fuel tank body 126 to enable direct rider access to it when filling and re-filling with petrol is required. The cap 16b has the same design as caps used for conventional motorcycles. The rider can open the filling point 16a without first opening a
Valid forming part of the fuel tank body 126. Cap 16b is lockable with a key slot 16d being provided. Cap 16b may be pressed into position in a conventional manner.
A first variant to the auxiliary petrol tank 16 described above is now described with reference to Fig. 13. Here, auxiliary petrol tank 16 is of even flatter volume and the cylindrical filling tube 16a is connected to the filling point by a rubber or PVC duct 163. Duct 163 is connected to filling tube 16a by a wire clamp 164 and hose clip 165 arrangement. The fuel tank has mounting lugs 168 with holes 169. Fuel tank body 126 is also provided with a mounting bracket 172 with weld nuts 173. The fuel tank 16 is clamped on to the fuel tank body 126 through the bracket, fastening being made using bolts/screws.

A second variant for the auxiliary petrol tank 16 arrangement is shown in Figs. 14 and 15. Here, the petrol tank 16 is of approximately rectangular section and is again suspended from a surface of the fuel tank body 126 by a mounting bracket 1270, welded to petrol tank 16, and connected to the fuel tank body by fastening means 1271 and 1273. Petrol cap 16b is hingedly connected to the body of the fuel tank also by hinge 16f.

Referring further to Fig. 16, in motorcycle 100, CNG shut-off valve 154 is located just forward of the fuel tank body 126, at a point where the shut-off valve 15a of CNG fuel tank 15 emerges from the fuel tank body 126. This position for the shut-off valve 154 enables access to the shut-off valve 15a during manufacture and servicing. However, it is also important for the rider to easily operate CNG shut-off valve - 154 and the position of the shut-off valve 15a in the gas fuelling system 10 is not safely and/or conveniently accessible to the rider during operation of motorcycle 100.

Therefore, an actuator, includes a linkage 152 extending upwardly from the body of the shut-off valve 15a to enable safer rider actuation. The linkage 152 extends from shut-off valve 15a terminating in a manually adjustable knob 154 located just forward of fuel tank body 126, close to handlebars 270, a position more safely and /or conveniently accessed by the rider.

Linkage 152, in the form of a rod, may be connected to the body of the CNG shut-off valve 15a in a variety of ways. In a first arrangement, shown in Figs. 17 to 19, the linkage may be connected to a bracket 155, which is fixed to the head of CNG shut-off valve 15a by a threaded joint. In a second arrangement, shown in Figs. 20 to 22, bracket 155 is provided with a fixing lug 156 which is fixed to the head of CNG shut-off valve 15a.
In either case, bracket 155 is provided with two upwardly extending lugs 155a separated and positioned symmetrically around the centerline of shut-off valve 15a. Each lug 155a is provided with concentric holes 155b. A pivot pin 157 is mounted, by fasteners (nut and bolt), to extend through the holes 155b. Linkage 152 is connected to pivot pin 157, thereby being pivotable relative to bracket 155.

At the knob 154 end of linkage 152, the linkage 152 is threaded enabling knob 154 to be screwed on to it. The bracket 155 is designed to ensure that the torque required to operate the shut-off valve 15a remains the same even after attaching the linkage 152 to the shut-off valve 15a.

Space constraints, for packaging of the shut-off valve, are addressed by using a responsive CNG shut-off valve 20 actuable between ON and OFF positions over only a quarter turn as illustrated by Fig. 23. A handwheel CNG 1502 shut-off valve as used for the cylindrical CNG fuel tank 1500 of a three wheeler vehicle, as schematically illustrated in Fig. 24 would not be suitable.

Modifications and variations to the motorcycle of the present invention may be apparent to the skilled reader of this disclosure. Such modifications and variations are to be deemed within the scope of the present invention.

WE CLAIM:

1. A motorcycle comprising

a frame comprising a front frame portion comprising a head tube, a down tube extending downwardly and rearwardly from the head tube and at least two upper side tubes extending rearwardly from the head tube, and located above the down tube, for supporting a fuelling system for the motorcycle; and

a fuelling system wherein said side tubes are braced to said down tube by brace members with at least one brace member extending from said down tube to one of the upper side tubes, a space between said brace member and said head tube being provided for at least one component of said fuelling system to extend through said space.

2. The motorcycle of claim 1 wherein said fuelling system is a gas fuelling system and the at least one component extending through said space is a gas carrying component.

3. The motorcycle of claim 1 or 2 wherein said brace members are in the form of tubes.

4. The motorcycle of claim 3 wherein brace members are shaped to diverge to form a portion for supporting a neck of a gaseous fuel tank.

5. The motorcycle of claim 4 wherein a cross member is provided between said diverging brace members at, or just below, a location where the upper ends of the brace members become divergent.

6. The motorcycle of claim 1 or 2 wherein a brace member is provided in the form of a plate with aperture(s) of sufficient dimension to enable said gas fuelling system component to extend through the space.

7. The motorcycle of any one of the preceding claims wherein brace member(s) are connected, between upper side tube(s) and down tube, on both sides of the motorcycle frame; the sides corresponding with each of the side tubes.

8. The motorcycle of any one of the preceding claims wherein a gusset plate is provided for connection of down tube to a side tube at least on one side of the motorcycle.

9. The motorcycle of any one of the preceding claims wherein cross member(s) join brace members on both sides of the motorcycle frame.

10. The motorcycle of any one of the preceding claims in which the head tube is gusseted to the down tube to form a box section imparting strength to the head tube region.

11. The motorcycle of claim 10 wherein said head tube is gusseted to said down tube by a C-section.

12. The motorcycle of any one of the preceding claims wherein support bracket(s) are provided to support a gaseous fuel tank at a neck portion of the gaseous fuel tank and at positions along the outer diameter of the gaseous fuel tank, preferably at or near the middle of the gaseous fuel tank and at or towards the rear of the gaseous fuel tank.

13. The motorcycle of claim 2 wherein said gas carrying component is a duct communicating a gaseous fuel ON/OFF control valve with a gaseous fuel pressure regulator.

14. The motorcycle of any one of the preceding claims wherein said fuelling system comprises a gaseous fuel tank and an auxiliary liquid fuel tank accommodated within a fuel tank body located above, and supported by, the front frame portion.

15. The motorcycle of claim 14 wherein the fuel tank body has an outer surface the same shape as fuel tanks used for conventional motorcycles.

16. The motorcycle of claim 14 or 15 wherein said gaseous fuel tank is located below the liquid fuel tank.

17. The motorcycle of any one of claims 14 to 16 wherein said liquid fuel tank is mounted to an internal surface of the fuel tank body, said fuel tank body being mounted to the motorcycle frame.

18. The motorcycle of claim 17 wherein said liquid fuel tank is suspended from an internal surface of the fuel tank body, said internal surface being provided towards the top of the fuel tank body.

19. The motorcycle of claim 18 wherein said liquid fuel tank has a filling point provided in the fuel tank body and a liquid fuel tank cap having the same design as that used for conventional motorcycles.

20. The motorcycle of any one of claims 14 to 19 wherein said fuelling system comprises a gaseous fuel tank and a manual shut-off valve for the gaseous fuel tank, said manual shut-off valve having an actuable portion located forward of the fuel tank body.
21. The motorcycle of any one of claims 14 to 20 wherein said fuelling system includes an rider actuable actuator for said shut-off valve.

22. A gas fuelling system for a vehicle having handlebars comprising:
a gaseous fuel shut-off valve having a body located proximate a gaseous fuel supply tank for the vehicle in a portion of the gas fuelling system not easily and/or safely accessible by an operator of the vehicle during operation of the gas fuelling system; and
an actuator for actuating said gaseous fuel shut-off valve between open and closed - positions wherein said actuator includes a linkage extending from said body of said gaseous fuel shut-off valve to a position more easily and/or safely accessible for actuation by said operator of said vehicle.

23. The gas fuelling system of claim 22 wherein said linkage extends to a vehicle operator accessible location towards the handlebars of the vehicle at the top of a cover for said gaseous fuel supply tank.

24. The gas fuelling system of claim 23 wherein said linkage is connected with a switch actuable by the vehicle operator, said switch being located at or adjacent the top of the tank cover, and having ON and OFF positions corresponding with open and closed positions of the gaseous fuel shut-off valve.

25. The gas fuelling system of claim 22 wherein said linkage, in use, extends to one side of the vehicle operator without protruding outside the width of said vehicle.

26. The gas fuelling system of any one of claims 20 to 25 wherein said linkage is in the form of a rod, the linkage being connected to a body of the shut-off valve by a bracket.

27. The gas fuelling system of any one of claims 20 to 26 wherein said bracket and linkage are connected by a pivotal connection.

28. The gas fuelling system of any one of claims 20 to 27 wherein said gaseous shut-off valve is a quarter turn type.

29. A vehicle comprising the gas fuelling system of any one of claims 20 to 28.