The present invention relates to a vehicle, in particular to a two-wheeled vehicle, a squat- or-anti-squat-characteristic-adjustable vehicle and specifically a squat-or-anti-squat- characteristic-adjustable two-wheeled vehicle. The invention further relates to a method of adjusting the squat or anti-squat characteristic of a two-wheeled vehicle and to a twowheeled vehicle component.

Two-wheeled vehicles, such as bicycles, electric bicycles and motorcycles, typically have a rear wheel which is driven by an endless drive transmitter, such as a chain or belt. The rear wheel has a rear sprocket which is rotated by the drive transmitter, which in turn is moved around a drive path by a drive sprocket. The drive sprocket may be rotated by pedals, an electrical motor, and/or an engine. There may be multiple rear sprockets, and the drive transmitter may be moved therebetween by a rear derailleur.

Some two-wheeled vehicles, in particular mountain bikes and motorcycles, have a rear suspension or suspended rear wheel. The rear wheel may be mounted to a swingarm which moves relative to a main frame of the vehicle. A shock absorber or other dampener dampens the movement of the swingarm.

When such a vehicle accelerates, the weight of the user and vehicle is transferred backwards which causes the rear suspension to compress. This is typically termed squat.

However, since the drive sprocket is mounted to the main frame, the drive transmitter can be configured so that when the drive transmitter drives the rear wheel, the drive transmitter extends the suspension. This is typically termed anti-squat.

Squat and anti-squat are generally opposing forces and can counterbalance. The amount of anti-squat applied by a configuration of a drive transmitter is typically given as a percentage. A given design of a two-wheeled vehicle can have no squat or anti-squat in the rear suspension during acceleration, if the two forces counterbalance exactly. The drive transmitter would apply 100% anti-squat in such an instance. Otherwise, a given design will have a certain degree of squat or anti-squat in the rear suspension during acceleration. A certain level of squat or anti-squat in the rear suspension can be advantageous or disadvantageous, depending on terrain or riding style. Therefore, a given vehicle may be advantageous for one part of a route having one type of terrain or requiring a certain riding style, but may be disadvantageous for another part of a route having another type of terrain or requiring another riding style.

The present invention seeks to provide a solution to this problem.

According to a first aspect of the present invention, there is provided a squat-or-anti- squat-characteristic-adjustable two-wheeled vehicle comprising: handlebars for a user to hold while riding the vehicle; a vehicle main frame; a rear wheel moveably connected to the vehicle main frame via a suspension element; an endless drive transmitter for driving the rear wheel, the endless drive transmitter being moveable around a drive path having a drive portion and a return portion; a squat-or-anti-squat-characteristic-adjusting idler which in part defines the drive path, the squat-or-anti-squat-characteristic-adjusting idler being on the drive portion of the drive path; an idler-actuation mechanism configured to move an axis of rotation of the squat-or-anti-squat-characteristic-adjusting idler so as to change the drive portion of the drive path which adjusts a squat or anti-squat characteristic of the two-wheeled vehicle; and a user control configured to control the idler-actuation mechanism, the user control being mounted to the handlebars.

As such, the idler can be selectably moved between fixed positions. The position of the idler changes the direction or shape of a line of the drive portion of the drive path. This changes the amount of anti-squat applied by the endless drive transmitter. This is since the direction and position of the line of the drive portion relative to the direction and position of a line of the suspension determines the amount of anti-squat. The line of the suspension may be defined as being a line between the axle or centre of the rear wheel and the instantaneous centre of the rear wheel about the main frame.

The drive portion of the drive path may otherwise be referred to as the tension side of the endless drive transmitter. This is the portion which is downstream of the rear sprocket and pulls on the rear sprocket to cause rotation.

The user control mounted to the handlebars allows for the rider to conveniently change the squat or anti-squat characteristics of the vehicle whilst riding. Therefore, the vehicle can be adapted to suit different portions of a route. Preferably, the idler may be mounted to the suspension element. In this case, the idler would most likely be mounted to a swingarm of the suspension.

Advantageously, the idler may be mounted to the main frame. For example, the idler would be mounted to a rear portion of the main frame.

Beneficially, the axis of rotation of the idler may be moveable via cable, hydraulic, or electrical actuation. Cable and hydraulic arrangements may allow for the idler to be moveable without the use of a power supply. Electrical actuation may allow for more a greater range of motion of the idler, since a user is not necessarily required to provide the force for moving the idler.

In a preferable embodiment, the suspension element may be of a single pivot arrangement, or a multi-link arrangement such as a 4-bar, or 6-bar arrangement. Of course, the idler can be used with any kind of suspension design or multi-link arrangement.

Optionally, the idler-actuation mechanism may comprise a rotatable element having a rotatable-element axis of rotation, the idler being mounted to the rotatable element away from the rotatable-element axis of rotation so that when the rotatable element rotates around the rotatable-element axis of rotation the position of the idler moves. This provides a straightforward and reliable means of moving the idler. Additionally, it allows for non-linear movement of the idler which may provide a more suitable change in position. Of course, other mechanisms could be used, such as a linear rail or a linkage mechanism. The idler may be moveable in a slot or along a channel and may be moveable via a linear actuator, such as a small hydraulic cylinder, for example. The idler may instead be moveable via other single-link mechanisms, or via a multi-link mechanism, such as via a four-bar linkage. In such instances, the single or multi-link mechanism would be moved by an actuator.

Additionally, the idler-actuation mechanism may further comprise a first biasing element configured to bias the rotatable element to a first rotational condition so that the idler is in a first position, and a second biasing element configured to be actuatable to bias the rotatable element in a second rotational condition so that the idler is in a second position. Thus, the second biasing element can be controlled by the user to selectively overcome the biasing force provided by the first biasing element. As such, the user can cause the second biasing element to overcome the biasing force of the first biasing element to move the idler into a second position, and relax the second biasing element so that the biasing force of the first biasing element moves the idler into the first position.

Preferably, the first biasing element may be a torsion spring, and the second biasing element is a tensionable cable. In other words, the second biasing element is a cable which can be tensioned. The tensionable cable may be tensioned via a user control on the handlebars in the manner of a gear shifter.

Advantageously, the rotatable element may be in an over-centre position in the first and second rotational conditions so that a force which drives the endless-drive transmitter holds the idler in position. Therefore, a force applied by pedalling does not cause the idler to be moved and the idler is stable or substantially stable.

Beneficially, the two-wheeled vehicle has a rear sprocket and a drive sprocket, and the idler is mounted above the rear sprocket and/or drive sprocket. As such, the idler may be considered to be mounted to an upper portion of the drive path of the endless drive transmitter. Of course, in some arrangements the idler may not be mounted above the rear sprocket, particularly when the suspension is in compression.

Preferably, the two-wheeled vehicle may be at least any one of a bicycle, an electric bicycle, a mountain bike, and a motorcycle.

Optionally, the endless drive transmitter may be a chain drive. However, belt drives or even rope drives may be considered.

Additionally, the drive portion may be an upper portion of the drive path.

In a preferable embodiment, the squat-or-anti-squat-characteristic-adjusting idler may be at or adjacent to a drive sprocket of the two-wheeled vehicle.

According to a second aspect of the invention, there is provided a squat-or-anti-squat- characteristic-adjustable vehicle comprising: handlebars for a user to hold while riding the vehicle; a vehicle main frame; a rear wheel moveably connected to the vehicle main frame via a suspension element; an endless drive transmitter for driving the rear wheel, the endless drive transmitter being moveable around a drive path having a drive portion and a return portion; means for adjusting the drive portion of the drive path; a mechanism configured to actuate the means so as to change the drive portion of the drive path which adjusts a squat or anti-squat characteristic of the two-wheeled vehicle without changing a gear ratio of the vehicle; and a user control configured to control the mechanism. Preferably the means includes a drive sprocket or a gearbox output sprocket having a moveable axis of rotation, and the mechanism is configured to move the axis of rotation of the drive sprocket or the gearbox output sprocket.

The drive sprocket or gearbox output sprocket may be considered to be translatable, although an angular component of movement is not necessarily excluded.

Advantageously, the means may comprise a moveable guide for guiding the endless drive transmitter. Beneficially, the moveable guide comprises an idler or pulley having a moveable axis of rotation, or a moveable non-rotating bearing surface upon which the endless drive transmitter is slidable.

The moveable guide may be moveable in a slot or along a channel and may be moveable via a linear actuator, such as a small hydraulic cylinder, for example. Additionally or alternatively, the moveable guide may be mounted to a rotatable element at an off-centre position. The guide may instead be moveable via other single-link mechanisms, or via a multi-link mechanism, such as via a four-bar linkage. In such instances, the single or multi-link mechanism would be moved by an actuator.

Preferably, the user control is mounted to the handlebars. This allows convenient user control of the mechanism.

The mechanism may be a mechanically, hydraulically, or electrically operated mechanism.

According to a third aspect of the invention, there is provided a method of adjusting the squat or anti-squat characteristic of a two-wheeled vehicle, the method comprising the steps of providing the vehicle of the first or second aspects of the invention and changing the drive portion of the drive path with the user control whilst riding the vehicle.

According to a fourth aspect of the invention, there is provided a two-wheeled vehicle component for a two-wheeled vehicle, the component comprising: a body; a squat-or- anti-squat-characteristic-adjusting idler for at least in part defining a drive portion of a drive path of an endless drive transmission for driving a rear wheel of the two-wheeled vehicle; an idler-actuation mechanism configured to move an axis of rotation of the squat- or-anti-squat-characteristic-adjusting idler relative to the body for changing the drive portion of the drive path which adjusts a squat or anti-squat characteristic of the twowheeled vehicle.

Preferably, the body may be a suspension element, such as a swingarm. Advantageously, the body may be a main frame.

According to a fifth aspect of the invention, there is provided a squat-or-anti-squat- characteristic-adjustable vehicle comprising: handlebars for a user to hold while riding the vehicle; a vehicle main frame; a rear wheel moveably connected to the vehicle main frame via a suspension element; an endless drive transmitter for driving the rear wheel, the endless drive transmitter being moveable around a drive path having a drive portion and a return portion; a squat-or-anti-squat-characteristic-adjusting idler which in part defines the drive path, the squat-or-anti-squat-characteristic-adjusting idler being on the drive portion of the drive path; an idler-actuation mechanism configured to move an axis of rotation of the squat-or-anti-squat-characteristic-adjusting idler so as to change the drive portion of the drive path which adjusts a squat or anti-squat characteristic of the two-wheeled vehicle; a control configured to control the idler-actuation mechanism. The control may include an automatic controller operated by a sensor, for example, along with manual user controls.

The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows an embodiment of a two-wheeled vehicle in accordance with first, second and fifth aspects of the invention;

Figure 2 shows a perspective embodiment of a two-wheeled vehicle component in accordance with a fourth aspect of the invention for use with a two-wheeled vehicle in accordance with first, second and fifth aspects of the invention;

Figure 3a shows the two-wheeled vehicle component of Figure 2, with an idleractuation mechanism exploded;

Figure 3b shows a rotatable element of the idler-actuation mechanism of Figure 3a from an opposing perspective;

Figure 4 shows an end view of the two-wheeled vehicle component of Figure 2;

Figure 5 shows a partial side perspective view of the two-wheeled vehicle component of Figure 2;

Figure 6a shows a squat-or-anti-squat-characteristic-adjusting idler of the twowheeled vehicle component of Figure 2 in a first position; Figure 6b shows the squat-or-anti-squat-characteristic-adjusting idler of Figure 6a in second position;

Figure 7a shows the idler-actuation mechanism in the first position with the squat- or-anti-squat-characteristic-adjusting idler omitted for clarity; and

Figure 7b shows the idler-actuation mechanism in the second position with the squat-or-anti-squat-characteristic-adjusting idler omitted for clarity.

Referring firstly to Figure 1 , there is shown a two-wheeled vehicle 10, which is here a bicycle, and in particular a mountain bike.

The bicycle 10 has a main frame 12, to which is connected handlebars 14 or a handlebar element, a front wheel 16, and a rear wheel 18 which is moveably connected to the vehicle main frame 12 via a suspension element 20. The suspension element 20 comprises a swingarm 22 and a dampener or shock absorber. The suspension element 20 may otherwise be referred to as a part or portion of a vehicle suspension. The main frame 12 may also be referred to as the main triangle or front triangle. The front wheel 16 is preferably connected to the main frame 12 by a fork 24. Preferably, there is also a seat 26 connected to the main frame 12.

The swingarm 22 is here a single pivot swingarm. However, it will be appreciated that any other arrangements of swingarms may be considered, such as a 4-bar, or 6-bar arrangement, or any multi-link arrangement and so the suspension element may comprise several components.

The rear wheel 18 is driven by an endless drive transmitter 28, which is here a chain although belt driven arrangements or rope driven arrangements could be considered. The chain 28 is moved around a drive path, which is therefore defined by the travel of the chain 28.

The drive path is generally defined by a drive sprocket 30 at one end and at least one rear sprocket 32 at the other end. There may be multiple rear sprockets 32, defining multiple gears, and the chain 28 may be moveable therebetween. This may also be true for the drive sprocket 30, which may have multiple chainrings. A drive portion 34 or tension side of the drive path is generally an upper portion of the drive path. This extends in a direction from the rear sprocket 32 to the drive sprocket 30 which would result in forward movement of the bicycle 10, which is a clockwise direction from the perspective of Figure 1 . In other words, the drive portion 34 is downstream of the rear sprocket and upstream of the drive sprocket. A return portion 36 of the drive path is generally a lower portion of the drive path which extends in a direction from the drive sprocket 30 to the rear sprocket 32. In other words, the return portion 36 is downstream of the drive sprocket and upstream of the rear sprocket.

A squat-or-anti-squat-characteristic-adjusting idler 38 or idler-wheel additionally in part defines the drive path, and is on the drive portion 34 or tension side of the drive path. As can be seen from Figure 1 , the inclusion of the idler 38, compared to if it were not present, redirects a line of the drive portion 34 of the drive path adjacent to the rear sprocket 32. The idler preferably has chain teeth, although an idler with belt teeth or no teeth may be considered.

A rear derailleur 40 also in part defines the drive path, and is positioned on the return portion 36 of the drive path. The rear derailleur 40 moves the chain 28 between rear sprockets 32 and assists with tensioning the chain 28, as is well understood. It will be appreciated that a rear derailleur may not be used if the bicycle has a gearbox or if the bicycle is a single speed bicycle.

The squat-or-anti-squat-characteristic-adjusting idler 38 is mounted or secured to either the swingarm 22, or to the main frame 12. The idler 38 is mounted so as to be selectively moveable, in other words having a selectively moveable axis of rotation, relative to the component to which it is mounted, in other words relative to either the swingarm 22 or main frame 12 as appropriate. As such, the idler 38 can be moved between fixed positions.

This is achieved via an idler-actuation mechanism configured to move an axis of rotation of the squat-or-anti-squat-characteristic-adjusting idler 38. This thereby changes the drive portion 34 of the drive path which adjusts a squat or anti-squat characteristic of the two-wheeled vehicle 10.

When the squat-or-anti-squat-characteristic-adjusting idler 38 moves, this moves and reangles a line of the chain 28. This adjusts the squat and anti-squat characteristic of the bicycle 10. The amount of anti-squat applied by the chain 28 can be found by a geometric construction of the intersection between the chain line and a swingarm line. The swingarm line would be defined between an axis of rotation of the rear wheel 18, and an instantaneous centre of the swingarm 22 and the main frame 12. Movement of the squat- or-anti-squat-characteristic-adjusting idler 38 moves the angle or direction of the chain line relative to that of swingarm line, thus adjusting the calculated squat or anti-squat characteristics.

Since the described two-wheeled vehicle 10 is a conventionally powered bicycle 10, the drive sprocket 30 is driven by pedals and a crankarm 42. If the bicycle 10 has a gearbox, then the drive sprocket may be an output sprocket from a gearbox. However, it will be appreciated that the bicycle 10 may be an electrically assisted bicycle 10, and so the drive sprocket 30 may be driven in addition, or instead, by the output shaft of an electric motor. Additionally, whilst a rear derailleur 40 is described, it will be appreciated that a gearbox may be considered for the conventional bicycle 10 or electrically assisted bicycle 10. Furthermore, if the two-wheeled vehicle 10 were a motorcycle, then the drive sprocket 30 may be driven by the output shaft of a gearbox, which may be driven by a conventional internal combustion engine or an electrical motor.

Referring to Figures 2 to 7b, an example embodiment of an idler-actuation mechanism 44 is described in greater detail. However, it will be appreciated that other idler-actuation mechanisms may be considered, as conditions or requirements dictate. The present idler-actuation mechanism 44 is for use with a mountain bike with a gearbox, although may be applied to other two-wheeled vehicles 10 such as those with a cassette and rear derailleur.

The squat-or-anti-squat-characteristic-adjusting idler 38 is mounted to the idler-actuation mechanism 44, which is in turn mounted to a swingarm 22 which is pivotally connectable to the main frame 12 of the bicycle 10 at a pivot point 45. The swingarm 22 includes a rear wheel connection hub 46.

Referring in particular to Figure 3a, which shows the components of the idler-actuation mechanism 44 exploded, the squat-or-anti-squat-characteristic-adjusting idler 38 is mounted to a rotatable element 48. The rotatable element 48 rotates about an axis of rotation, and the axis of rotation of the rotatable element 48 and that of the idler 38 are misaligned or offset. As such, when the rotatable element 48 rotates about its axis of rotation, the axis of rotation of the idler 38 is shifted. The rotatable element 48 may otherwise be referred to as a rotor or rotating mechanism.

The idler 38 sits on a shaft 50, boss or mounting which protrudes from the rotatable element 48 and is secured thereto via a bolt 52. A bearing or bushing may allow for the idler 38 to freely spin on the shaft 50 as it is driven by the chain 28. The shaft 50 is off- centre from the axis of rotation of the rotatable element 48.

At least part of the rotatable element 48 is received in a circular or substantially circular opening 54 in the swingarm 22, and a bearing 56 is preferably used to permit or ease rotation between the rotatable element 48 and the swingarm 22. A C-clip 58 or circlip preferably retains the rotatable element 48 in position, whilst permitting rotation. However, it will be appreciated that such a fastener may not be required or that other forms of fasteners may be considered.

At or adjacent to the circular opening 54, there are preferably two stops 60a, 60b or abutment surfaces. The stops 60a, 60b are spaced apart from each in a circumferential direction about the circular opening 54. Each of the stops 60a, 60b abut, engage or impinge a surface on the rotatable element 48 which is preferably perpendicular to the direction of motion. Thus, the stops 60a, 60b act to restrict or limit the extent of the rotational movement of the rotatable element 48. The positioning of the stops defines the two positions of the idler. It will be appreciated that moveable and lockable stops could feasibly be provided so as to allow alteration of the limit of motion of the rotatable element, and therefore allow for customisation of the squat or anti-squat characteristics of the vehicle. Although stops 60a, 60b are described, it will be appreciated that other means of restricting the rotational movement of the rotatable element 48 may be considered.

The stops 60a, 60b are each positioned so that the rotatable element 48 is in an overcentre position, with respect to a force vector applied by the drive chain to the idler. As such, force applied by pedalling does not move the rotatable element 48 and the rotatable element 48 is stable or substantially stable in its position against the stop. Alternatively, only one of the stops may be so positioned.

The rotatable element 48 is here actuated by first and second biasing elements. Each biasing element can bias the rotatable element 48 against one of the stops 60a, 60b.

The first biasing element 62 biases the rotatable element 48 relative to the swingarm 22 so as to force the rotatable element 48 to abut a first stop 60a. The second biasing element is adjustable or tensionable and, when placed under tension, biases the rotatable element 48 relative to the swingarm 22 so as to force the rotatable element 48 to abut a second stop 60b. When the second biasing element is not under tension or when it is under a reduced tension, the first biasing element 62 has a force sufficient to force the rotatable element 48 to abut the second stop 60b.

More specifically, the first biasing element 62 is preferably a spring, and in particular a torsion spring 62. The second biasing element is an extendable cable, such as a metal cable, and is most preferably a braided wire cable. However, other actuation means, mechanisms, or general actuators may be considered. The biasing elements may otherwise be referred to as biasing means, biasing mechanisms, or force applicators.

The torsion spring 62 is preferably housed within the rotatable element 48. One end of the torsion spring 62 is fixed to the rotatable element 48, and the other end of the torsion spring 62 is fixed to the swingarm 22.

One end of the cable is attached to the rotatable element 48, preferably at a cable lug 64. The rotatable element 48 may include a cable guide groove 66 for guiding the cable around the rotatable element 48 to the cable lug 64. The cable preferably has an outer coating, although the coating terminates and/or is attached at a coating boss 68 at or adjacent to the swingarm 22, before the cable extends to the rotatable element 48.

The other end of the cable is attached to a user control, which is preferably a handlebar control, in the manner of a gear shifter, which allows the user to selectively apply tension to the cable. The idler is unable to move of its own accord without actuation via the user control.

As such, when the cable is not under tension or is under reduced tension, the rotatable element 48, and thus the idler 38, is in first position, as shown in Figures 6a and 7a. The rotatable element 48 abuts the first stop 60a, and the torsion spring 62 and/or the overcentre position prevents the rotatable element 48 from moving therefrom.

When the user control is actuated, the cable is put under tension or greater tension which pulls the rotatable element 48 to the second stop 60b, working against and rotating the torsion spring 62 in the process. The rotatable element 48 and thus the idler 38 is therefore in a second position, as shown in Figures 6b and 7b. The tension in the cable and/or the over-centre position prevents the rotatable element 48 from moving therefrom.

When the user control is actuated again to release or reduce the tension in the cable, the torsion spring 62 rebounds, pulling the rotatable element 48 and the idler 38 back to the first stop 60a. In this way, the idler 38 can be moved on the fly, whilst riding the vehicle. This can allow for a user to adjust the squat and/or anti-squat properties of the vehicle to suit the terrain and/or their riding style, such as a pedalling style.

For the present configuration of using the idler 38 and mechanism 44 on a bicycle 10 with a gear box, the idler 38 in the first position results in an anti-squat value of around 80%. The idler 38 in the second position results in an anti-squat value of around 130%. The displacement of the idler in the X-axis or horizontal direction is 10 mm and in the Y- axis or vertical direction the displacement is 13 mm. This results in a total displacement of the idler 38 of around 16.4 mm.

However, if a similar idler 38 and mechanism 44 were used with a standard rear gear changer having a rear derailleur and multiple rear sprockets, such as shown in Figure 1 , the idler 38 in the first position results in an anti-squat value of around 80% in a given gear. The idler 38 in the second position results in an anti-squat value of around 135% in said gear. The displacement of the idler in the X-axis or horizontal direction is 15 mm and in the Y-axis or vertical direction the displacement is 10 mm. This results in a total displacement of the idler 38 of around 18 mm. The anti-squat values change if different gears are used.

It will be appreciated that the cable actuator may be replaced by a hydraulic actuator. Additionally, an electrical or electronic user control may be considered. For example, the position of the idler may be moved via an electrically operated piston or motor, which is controlled via an electrical switch or button mounted to the handlebars.

The or another idler actuation mechanism may be combined with other features which cause adjustment of other vehicle characteristics. For example, the idler actuation mechanism may be controlled by the same user control which adjusts a level of damping of the front and/or rear shock absorber. This can allow for the damping and anti-squat characteristics to be adjusted at the same time to more appropriately suit a particular terrain. Additionally or alternatively, the idler actuation mechanism may be controlled by the same user control which controls a dropper seat post actuation. As such, when the seat post is in an extended position, the idler location might be set to provide an antisquat suitable for cross-country riding. Conversely, when the seat post is in a compressed position, the idler location might be set to provide an anti-squat suitable for downhill riding. This might be further linked, so that the seat post has an extension on which the idler is mounted. Therefore, when the seat post is moved, the idler also moves. Whilst a handlebar control is described, it will be appreciated that a user control may be mounted elsewhere, for example adjacent to the seat or on the mainframe. Furthermore, a manual user control may not be required, and electronic sensors may control the actuation of the position of the idler, for example by measuring the movement of the vehicle and thereby determining the terrain and thus the most appropriate squat and/or anti-squat characteristics. Furthermore, electronic sensors may scan the terrain in front of the vehicle, and adjust the squat and/or anti-squat characteristics appropriately.

In some instances, the squat-or-anti-squat-characteristic-adjusting idler and associated mechanism may not be required, and instead the drive sprocket itself or a gearbox output sprocket may have a moveable axis of rotation, via a similar or identical mechanism as the squat-or-anti-squat-characteristic-adjusting idler. This may allow for the squat or antisquat to be adjusted via alteration of the position of the drive sprocket itself.

Although a two-wheeled vehicle is preferred, it will be appreciated that the adjustable idler concept may apply to any vehicle which has a chain, belt or rope drive. For example, four or three wheeled vehicles including adaptive bicycles.

Handlebars may not be necessary since a steering wheel or other control may be considered in some instances.

Possibly, similar principles to the above-described could be applied to vehicles with shaft drives.

It is therefore possible to provide a means for adjusting the squat or anti-squat characteristic of a vehicle which has an endless drive transmitter, in other words a vehicle with a chain, belt or rope drive. A drive portion or tension side of the endless drive transmitter can be adjusted, in other words the shape or angle of the path of travel can be changed, by the use of an idler having an adjustable position controlled by a user. This can permit for the squat or anti-squat characteristics of the vehicle to be varied by the user to suit user preferences. In particular, the squat or anti-squat characteristics of the vehicle can be adjusted on the fly when riding the vehicle.

The words ‘comprises/comprising’ and the words ‘having/including’ when used herein with reference to the present invention are used to specify the presence of stated features, integers, steps or components, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.

The embodiments described above are provided by way of examples only, and various other modifications will be apparent to persons skilled in the field without departing from the scope of the invention as defined herein.