Bicycle handlebar with inboard master cylinder

Abstract

A brake handlebar for a bicycle comprising an elongate main body 9 having a longitudinal axis 12 and a brake assembly comprising: a brake lever 7 rotatably coupled to the elongate main body 9 and pivotable about a pivot axis 7; a master cylinder 22 and piston located inside the elongate main body 9 and inboard of the pivot axis 7; and wherein the master cylinder axis is substantially parallel to the longitudinal axis 12. A grip section 10 may be located on the outboard end of the handlebar and the brake lever may have a finger grip extension 6. The main body 9 may be rotatable about the axis 12 when released by a release lever (33, figure 7)

Description

Background There are two main categories of bicycle braking systems: mechanical wire pull actuated brakes and hydraulically actuated brakes. The most common arrangement of hydraulically actuated brake systems consists of a master cylinder and lever assembly connected by a hydraulic hose to a remote brake pad calliper. The remote brake pad calliper acts on a disc rotor to slow the bicycle wheel during braking. The master cylinder and lever assembly is typically mounted to bicycle handlebars using clamping arrangements. The brake lever is positioned such that the axis of the pivot of the lever is substantially orthogonal to the central axis of the grip part of the handlebar, where the rider positions the palm of their hand when actuating the brake lever. Mountain bicycles generally have so-called "straight" handlebars which the rider grips with palms facing downwards, in a similar orientation as one would have typing on a traditional keyboard or playing a piano. This "straight" handlebar arrangement and hand position is advantageous for steering and balance control when riding over rough and rocky terrain. Here the brake levers are oriented with the pivot axis orthogonal to the longitudinal axis of the handlebar. In this configuration the lever can be pulled ergonomically as the rider tightens their grip with their palm and fingers. So called "road bicycles" or "racing bicycles" have evolved to use hydraulic brakes with the master cylinder brake lever assembly fitted and designed for the classic "drop bar" handlebar arrangement. The drop handlebar arrangement offers the rider multiple hand positions and while operating the braking levers the rider's hands can be "on the hoods" or "in the drops" on the handlebars. In these positions the axis of the pivot of the brake lever is substantially orthogonal to the central axis of the grip portion of the handlebar where the rider positions their palm when actuating the brake lever. In folding bicycles the preferred handlebar configuration is the straight / flat bar, which can be folded next to the front wheel of the folding bicycle for a compact arrangement of brake levers and handlebar. However, this handlebar configuration comes with a suboptimal ergonomic hand position. In contrast, traditional racing drop handlebars used on road bicycles provide good ergonomics for hand positions. They are however far from optimal for a folding bicycle due to their high volumetric package size. Increasingly, bicycle users are seeking more integrated and seamless designs. Current state of the art hydraulic brake arrangements can however be considered cumbersome and busy with hoses, connections and mounting brackets that are exposed and collect dirt or catch on clothing or mark walls. Some designers have sought to create a more seamless mountain bicycle brake design by fitting the brake master cylinder inside the straight handlebar tube and outboard of the brake pivot. While these handlebar designs provide a more seamless and integrated appearance on mountain bicycles, they have limitations if applied to onroad commuting bicycles. Specifically, in onroad commuting bicycles aerodynamics and comfort are prioritised but straight handlebars place the rider's hands in the non-aerodynamic and non-ergonomic "piano playing" position. In this position the pivot axis of the lever is substantially orthogonal to the central axis of the grip part of the handlebar where the rider positions the palm of their hand when actuating the brake lever. Yet another drawback of the existing internal master cylinder designs is that access to the master cylinder is through an outer opening of the handlebar tube. This requires a sub-optimal removable grip portion if the handlebar is fitted with traditional bar ends. Alternatively, many existing grips are made with internal expanding bolts to stop rotation of the grip. These grips are more ergonomic, seamlessly designed, and aesthetically pleasing. However, they cannot be used with these existing internal master cylinder configurations. Furthermore, these existing internal master cylinder configurations will not work with handlebar designs with a completely sealed and seamless grip design with no opening, such as stitch leather similar to a car steering wheel. In case of handlebars designed to rotate into a folded position maximising space saving, the existing internal master cylinder configurations have an additional drawback in twisting the hydraulic hose during the folding process of up to 90 degrees. Over time this can loosen the threaded connection between the hydraulic hose and the master cylinder, thus compromising the safety of the brakes. Summary of the Invention According to an aspect of this disclosure, there is provided a brake handlebar for a bicycle, the brake handlebar comprising an elongate main body having a longitudinal axis and a brake assembly comprising: a brake actuator rotatably coupled to the elongate main body and pivotable about a pivot axis; a master cylinder; and a master cylinder piston received in and movable relative to the master cylinder; wherein the master cylinder and the master cylinder piston are located inside the elongate main body and inboard of the pivot axis; and wherein the master cylinder piston is movable along a piston axis substantially parallel to the longitudinal axis. Advantageously, the brake handlebar provides an ergonomic hand and brake lever position. The brake handlebar combines an aesthetically pleasing hydraulic brake handlebar assembly with an ergonomic hand and brake lever position. The handlebar also provides space for ergonomically placed finger-operated switch controls. Further still, it allows easy and simple brake bleeding. In some examples, the piston axis may be aligned with the longitudinal axis. Optionally, the brake assembly may further comprise an outer handlebar tube extending from the elongate main body, outboard of the pivot axis. In some examples, the outer handlebar tube may be rotatable about the longitudinal axis relative to the elongate main body. In other examples, the elongate main body and the outer handlebar tube may be integrally formed and rotatable together about the longitudinal axis. In some examples, the brake assembly may further comprise a palm grip portion extending from an outer end of the outer handlebar tube. Optionally, the palm grip portion may extend along a grip axis, the grip axis extending at an angle to the pivot axis from 0° to 25°. Optionally, the grip axis may be substantially parallel to the pivot axis. In some examples, the outer handlebar tube and the palm grip portion may form a T shape. In other examples, the outer handlebar tube and the palm grip portion may form an L shape. In some examples, the brake actuator may comprise a brake lever and a finger grip portion extending from an outer end of the brake lever. Optionally, the finger grip portion may extend substantially parallel to the palm grip portion. In some examples, the brake handlebar may further comprise an outer housing at least partly covering the elongate main body and adapted to constrain rotation of the outer handlebar tube. In some examples, the brake handlebar may comprise a pair of brake assemblies, each brake assembly configured relative to a respective side of the elongate main body. According to a further aspect of this disclosure, there is provided a bicycle comprising a brake handlebar according the aspect described above or any one of the associated examples. The features and advantages of the aforementioned aspect of the disclosure and its embodiments apply mutatis mutandis to this aspect of the disclosure and its embodiments. Brief Description of Drawings Examples of the present invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 shows a side view of the invention attached to a pedal cycle; Figure 2 shows a perspective view of the invention; Figure 3 shows a perspective view of the left side of the invention with top cover removed; Figure 4 shows a top view of the left side of the invention with top cover removed; Figure 5 shows a perspective cutaway view of the left side of the invention with top cover removed; Figure 6 shows a front view cross section of the left side of the invention; Figure 7 shows a front view cross section of the left side of the invention with alternative fold lever position; Figure 8 shows a vertical cross section of inner tube clamp from Figure 4; Figure 9 shows a vertical cross section of angle adjustment collar from Figure 4; Figure 10 shows a vertical cross section of fold stop from Figure 4; Figure 11 shows an example of the invention with a T handle; Figure 12 shows a cut away perspective view of an example of the invention with a T handle; Figure 13 shows an example of the invention with an L handle; and Figure 14 shows a rotatable clamped outer handlebar section. Detailed Description The brake handlebar with inboard master cylinder described herein combines an aesthetically pleasing hydraulic brake handlebar assembly with an ergonomic hand and brake lever position. The handlebar also provides space for ergonomically placed finger-operated switch controls. Further still, it allows easy and simple brake bleeding. The handlebar comprises a main body fitted with master cylinder such as a hydraulic master cylinder. The handlebar further comprises a master piston and a brake. The master cylinder and the longitudinal axis of the master piston may be centrally positioned inside the handlebar tube and aligned with the longitudinal axis of the handlebar tube. The master cylinder and master piston are positioned inboard of a brake pivot axis, i.e., between the centre of the main body and the brake pivot axis. This arrangement allows for the brake lever to be positioned such that it can be comfortably rotated by the rider, without compromising the function of the brake lever transmitting force through the brake master cylinder piston to the inboard mounted master cylinder. Because the brake master cylinder is mounted inboard and generally enclosed within the outer profile of the main body and handlebar tube form, providing a clean and aesthetically pleasing arrangement. Furthermore, the risks of parts catching on clothing or marking walls are reduced. The handlebar may have a cover over the master cylinder. In another example the master cylinder may be exposed. Both configurations allow easy access to the master cylinder and thus easy brake bleeding. The inboard mounting position of the master cylinder allows space for electronics switches to be fitted within the handlebar outboard of the brake lever pivot connection and in an ergonomic position relative to the rider's hands and fingers. The inboard mounting arrangement of the master cylinder described herein also allows the grip portions of the outer handlebar to rotate. The centrally positioned master cylinder piston within the handle tube allows any angle of rotation of the grip portions of the outer handlebar. This in turn allows the user to adjust the angle for an ergonomic comfortable hand position. The rotation also allows to align the grip portions of the outer handlebar substantially parallel with the stem of a folding bicycle, making the bicycle more compact when folded. Alternatively, the main body and the outer tube grip portion may be integrated within a unified single member. The outer tube grip portion is then "T" shaped as are the brake lever finger pull portions. In this arrangement, the uni-body handlebar can be fitted to a standard bicycle stem. Rotation of the outer tube grip portion for optimal ergonomic positioning to the rider's hands as well as a stowing position is enabled by loosening standard clamp bolts of the standard bicycle stem. This arrangement combines the advantages of easy access to the inboard mounted brake master cylinder and having space outboard of the brake lever pivot point for electronics switches to be placed in an ergonomic position close to the rider's hands and fingers. This example also provides an aesthetically pleasing handlebar design. Alternatively, the main body and the outer tube grip portion may be integrated within a unified single member, with the outer tube grip portion and the brake lever finger pull portions being substantially "L" shaped. Alternatively the main body has a width not extending wider than a pivot point of a brake lever finger pull portion and is coupled to a clamped rotatable outer handlebar portion such that the outer handlebar portion can be rotated independently of the short main body section and the bicycle stem. Figure 1 shows a bicycle 1 with a handlebar with inboard master cylinder 2 and a bicycle stem axis 67. Figure 2 shows an example handlebar with inboard master cylinder 2 of the present invention. The handlebar 2 comprises a top cover 3 fitted to a main body 16. The main body 16 comprises a handlebar stem adaptor 17 for attaching to a bicycle stem. The handlebar stem adaptor 17 may be attached to the bicycle stem by for example welding, bolting, or gluing. The main body 16 is configured to receive an outer handlebar tube body 9. The outer handlebar tube body 9 is configured with a brake actuator 4. In this example the brake actuator 4 is a lever. In other examples the brake actuator may be a button, slider or dial, for example. In the example shown the brake lever 4 is T-shaped. In other examples the brake lever may be L-shaped. The handlebar 2 is symmetrical about the vertical longitudinal plane of the bicycle 1, i.e., the left and right side are substantially mirror images of each other. The main body 16 may be manufactured by forging or casting in aluminium or magnesium materials, or produced using carbon fibre moulding construction. The top cover 3 may be manufactured by carbon fibre moulding or by plastic injection moulding. The top cover 3 provides dust and water protection. The top cover 3 also provides a seamless and aesthetically pleasing appearance to the handlebar 2. The top cover 3 can be attached to the main body 16 for instance by double-sided tape, screws, clips, and / or hooks. Figures 3 and 4 show a perspective view and a top view, respectively, of the left side of the handlebar 2 with the top cover 3 removed. Figure 5 shows a perspective cutaway view with the top cover 3 removed. The main body 16 comprises an outer housing 18 adapted to receive an outer handlebar tube body 9. The outer handlebar tube body 9 may be rotatable about an outer handlebar rotation axis 12. The outer handlebar rotation axis 12 is a longitudinal axis of the main body 16 and is central to the main body 16. Advantageously, the outer handlebar tube body 9 being rotatable allows the outer handlebar tube palm grip portion 10 to rotate. The outer handlebar tube body 9 and an outer handlebar tube palm grip portion 10 form a T shape in this example. A brake lever arm 5 and a brake lever finger grip portion 6 form a T shape in this example. The outer housing 18 has a substantially circular cross-section. The fit between the outer housing 18 and the outer handlebar tube body 9 is that of a clearance slip fit type such that the outer handlebar tube body 9 is able to rotate about the outer handlebar rotation axis 12 but is substantially constrained radially by the outer housing 18. The clearance between an interface of the outer housing 18 and the outer handlebar tube body 9 may be between about 0.05 mm and 0.25 mm. The clearance may be provided with lubrication such as grease. When the clearance is larger than about 0.25 mm it may be provided with a vibration damping gap filler such as silicone rubber or o-rings. The main body 16 is adapted to receive a fold lever pivot pin 34. The fold lever pivot pin functions as a rotational fixing pivot for a fold lever 33 about an axis substantially parallel with a brake lever pivot axis 13. The fold lever 33 enables folding of the bicycle. The main body 16 has a main body angle adjustment access hole 20 which provides access for adjusting an angle adjustment collar 26. The angle adjustment collar 26 sets the angle position of the handle bar grips so that the rider can adjust them to suit the most comfortable angle of the grips from an ergonomic position when the handlebars are in the normal riding position, i.e., not folded. A master cylinder assembly 22 is mounted to the main body 16 with master cylinder fixing bolts 32. The master cylinder assembly 22 in this example is a hydraulic brake. The master cylinder assembly 22 and a master cylinder piston 38 are axially aligned. The master cylinder piston is receivable by the master cylinder assembly 22. The master cylinder piston 38 is movable relative to the master cylinder assembly 22. Axial movement of the master cylinder piston 38 with respect to the master cylinder assembly 22 causes compression of oil fluid in the master cylinder assembly 22 by forcing the oil through the master cylinder assembly 22, out into a brake hose, and into the bicycle brake calliper system. Hydraulic brake assemblies typically have a top removable cap and access ports for bleeding the braking system either through gravity or pressure by syringe at the master cylinder assembly 22 and a master cylinder piston 38. The master cylinder fixing bolts 32 are arranged such that the master cylinder piston 38 is substantially aligned with the outer handlebar rotation axis 12. Consequently, during rotation of the outer handlebar tube body 9 about the outer handlebar rotation axis 12 the function of the master cylinder piston 38 the compression of the oil within the master cylinder assembly 22 is not compromised. An inner tube clamp 24 is attached to the main body 16 with one or more inner tube clamp adjustment bolts 47 and one or more inner tube clamp fixing bolts 46 in order to constrain the outer handlebar tube body 9 radially. Similar to the outer housing 18, the inner tube clamp 24 allows the outer handlebar tube body 9 to rotate about the outer handlebar rotation axis 12. The outer handlebar tube body 9 is shown in Figure 3 with the angle adjustment collar 26 positioned adjacent to the inner tube clamp 24. The interface between the outer handlebar tube body 9 and the angle adjustment collar 26 has a substantially circular cross section. The interface is of a high friction or mechanical engagement type. The mechanical engagement type may be for example a splined arrangement or roughened surface such as knurled or enhanced with a friction enhancing compound. The angle adjustment collar 26 may comprise a tube clamping arrangement rotatably fitted to the outer handlebar tube body 9 by one or more angle adjustment collar clamp bolts 45. Then the one or more angle adjustment collar clamp bolts 45 are loosened, the interface of the outer handlebar tube body 9 and the angle adjustment collar 26 is freed, allowing the outer handlebar tube body 9 to rotate about the outer handlebar rotation axis 12 with respect to the angle adjustment collar 26. Conversely, the one or more angle adjustment collar clamp bolts 45 can be tightened to rigidly fix the angle adjustment collar 26 to the outer handlebar rotation axis 12 to a degree able to withstand greater than about 50 Nm of torque about the outer handlebar rotation axis 12. A fold stop 30 is shown fitted to the outer handlebar tube body 9 with one or more fold stop fixing bolts 48. The fold stop 30 sets the position of the handlebars when they are moved to the folded position. The outer handlebar tube body 9 interfaces with a circlip 36. The circlip 36 constrains the outer handlebar tube body 9 axially in connection with an outer handlebar tube flange 11. Inboard and outboard axial movement of the outer handlebar tube body 9 with respect to the main body 16 along the outer handlebar rotation axis 12 is constrained by the circlip 36 reacting against the inner tube clamp 24. The inner tube claim 24 is rigidly connected to the main body 16 by the one or more inner tube clamp fixing bolts 46, the one or more inner tube clamp adjustment bolts 47, and by the outer handlebar tube flange 11. The outer handlebar tube flange is reacted against the main body outer housing 18. The circlip 36 may be removable from the outer handlebar tube body 9 to allow assembly and disassembly of the outer handlebar tube body 9 through the main body outer housing 18. The axis of rotation of the fold lever 33 about the fold lever pivot pin 34 is substantially parallel to the brake lever pivot axis 13. As shown in Figure 3 the mechanism may comprise a plurality of slider link pivot pins 42. A first slider link pivot pin is configured to rotatably connect a slider link 41 to a second slider link pivot pin. The slider link pivot pins thus rotatably connect the slider link 41 to a rotation stop slider keyway 39. The axis of rotation of slider link pivot pins 42 is substantially parallel to the brake lever pivot axis 13 and substantially to axis of rotation of the fold lever pivot pin 34. The outer handlebar tube body 9 is adapted to receive a brake lever arm 5. The brake lever arm 5 comprises a brake lever finger grip portion 6, connected through a brake lever pivot pin 7 such that the brake lever arm 5 can pivot about the brake lever pivot axis 13 when the brake lever finger grip portion 6 is moved closer to a palm grip portion axis 14. The brake lever finger grip portion 6 is configured to be comfortable and ergonomically pleasant for the rider's fingers to actuate during braking. The outer handlebar tube body 9 comprises an outer handlebar tube palm grip portion 10. The outer handlebar tube palm grip portion 10 comprises a palm grip portion axis 14 substantially parallel to the brake lever pivot axis 13. The brake lever arm 5 with the brake lever finger grip portion 6 has a finger grip portion axis 15 that is also substantially parallel to the brake lever pivot axis 13. The outer handlebar tube palm grip portion 10 is designed to be comfortable and ergonomically pleasant for a rider's palm to grip and hold on to outer handlebar tube palm grip portion 10 whilst allowing the rider to actuate the brake lever finger grip portion 6 with their fingers. The palm grip portion axis 14 extends at an angle to the brake lever pivot pin 7 from 0° to 25°. The finger grip portion axis 15 extends at an angle to the palm grip portion axis 14 from 0° to 25°. The brake lever pivot axis 13 is substantially orthogonal to the outer handlebar rotation axis 12. Figure 6 shows a front cross-section of the left side of the handlebar 2 with the top cover 3 removed, illustrating the mechanics of the movement of the brake lever arm 5 and brake lever finger grip portion 6 with respect to the main body 16. When activating the brake the rider pulls the brake lever finger grip portion 6 closer to the outer handlebar tube palm grip portion 10 with their fingers. The brake lever arm 5 rotates about the brake lever pivot pin 7, moving the master cylinder piston connecting pin 8 in a substantially inboard direction axially aligned with the outer handlebar rotation axis 12. The master cylinder piston connecting pin 8 may be a bicycle hydraulic brake lever and comprises a threaded connection with the master cylinder piston 38. Axial movement of the master cylinder piston 38 with respect to the brake master cylinder assembly 22 causes compression of oil fluid in the brake master cylinder assembly 22 by forcing the oil through the brake master cylinder assembly 22 and out of the master cylinder hose port 23. The master cylinder hose port 23 is adapted to receive a bicycle brake hose and calliper system. The arrangement of the brake master cylinder assembly 22 provides for a return spring force to return the brake lever arm 5 and brake lever finger grip portion 6 to an original position upon release of the brake lever finger grip portion 6 by the rider's fingers. In Figure 6, the outer handlebar tube body 9 is shown having an internal space outboard of the brake lever pivot pin 7 and the master cylinder piston connecting pin 8 to receive a toggle switch assembly 43. The toggle switch assembly 43 may be a switch arrangement such as a toggle, trigger, roller or push-button type having single or multiple positions. The toggle switch assembly 43 is positioned within the outer handlebar tube body 9 such that actuating the switch by the rider's fingers is ergonomic and naturally positioned with the riders' hands and palm positioned naturally on the outer handlebar tube palm grip portion 10. The rotation stop slider keyway 39, slider link 41, and fold lever 33 are shown in a "locked" position in Figure 6. The mechanism of the rotation stop slider keyway 39, slider link 41, and fold lever 33 in this example is an "over center" arrangement, where over center is the "locked" position. In the "locked" position shown, the rotation stop slider keyway 39 can be seen to be fully overlapped and extending beyond inboard and outboard of the angle adjustment collar stop flange 27 which is formed as part of the angle adjustment collar 26. In the "locked" position shown, the outer handlebar tube body 9 is prevented from rotating with respect to the main body 16 about the outer handlebar rotation axis 12 due to the rigid connection between the angle adjustment collar 26 and the outer handlebar tube body 9. Rotational force input through the outer handlebar tube palm grip portion 10 is reacted ultimately by the angle adjustment collar stop flange 27 connected with the rotation stop slider keyway 39 and the rotation stop slider keyway 39 reacting directly with the main body 16 as can be shown in more detail in Figures 8 and 9. Figure 6 also shows a flanged bush 37, fitted between the inner tube clamp 24 and the outer handlebar tube body 9. The flanged bush 37 may be a plain flanged bushing which provides a tight interface between the outer handlebar tube body 9 and the inner tube clamp 24 whilst maintaining low friction for rotation. The flanged bush 37 may be made of plastic such that tightening of the inner tube clamp 24 with the inner tube clamp adjustment bolt 47 compresses the flanged bush 37 to provide minimal or zero radial movement of the outer handlebar tube body 9 with respect to the inner tube clamp 24 and the main body 16. Figure 7 shows a front view cross section of the left side of the handlebar 2 with the top cover 3 removed and with the fold lever 33 in an "open" position. Figure 7 illustrates the mechanics of movement of the brake lever arm 5 and the brake lever finger grip portion 6 with respect to the main body 16. By manual opening of the fold lever 33 by the rider, rotation stop slider keyway 39 is moved by sliding outboard by the slider link 41 connection to the fold lever 33. In the "open" position of the fold lever 33 the rotation stop slider keyway 39 no longer overlaps the angle adjustment collar stop flange 27, thus allowing the angle adjustment collar stop flange 27 to rotate, together with the outer handlebar tube body 9, about the outer handlebar rotation axis 12. Figure 8 shows the vertical inner tube clamp cross section 25 of Figure 4 showing the arrangement and function of the inner tube clamp 24. The inner tube clamp 24 is rigidly fixed to the main body 16 by the inner tube clamp fixing bolt 46 and by adjustable tension fitting through the inner tube clamp adjustment bolt 47. The flanged bush 37 is contained within a generally round form of the main body 16 and inner tube clamp 24. By tightening of the inner tube clamp adjustment bolt 47, the flanged bush 37 can be compressed tightly about the outer handlebar tube body 9 to constrain the outer handlebar tube body 9 radially with respect to the main body 16. As also shown in Figure 8, the master cylinder piston 38 is positioned substantially centrally inside the outer handlebar tube body 9. The inboard portion of the rotation stop slider keyway 39 is shown positioned against the main body slider stop reaction face 40 such that force transmitted through the rotation stop slider keyway 39 about the axis of rotation of the outer handlebar tube body 9 acts against the main body slider stop reaction face 40. Figure 9 shows a vertical angle adjustment collar cross section 28 from Figure 4 showing the arrangement and function of the angle adjustment collar 26. The angle adjustment collar 26 in this example has a tube clamping arrangement rotatably fitted to the outer handlebar tube body 9 by one or more angle adjustment collar clamp bolts 45. Other clamping arrangements may be employed. When the one or more angle adjustment collar clamp bolts 45 are loosened the interface of the outer handlebar tube body 9 and the angle adjustment collar 26 is freed, allowing the outer handlebar tube body 9 to rotate about the outer handlebar rotation axis 12 with respect to the angle adjustment collar 26. Conversely, the one or more angle adjustment collar clamp bolts 45 can be tightened in order to rigidly fix the angle adjustment collar 26 to the outer handlebar rotation axis 12 to a degree able to withstand greater than about 50 Nm of torque about the outer handlebar rotation axis 12. The interface between the outer handlebar tube body 9 and the angle adjustment collar 26 has a substantially round cross section. The interface is of a high friction or mechanical engagement type, for instance a splined arrangement or a roughened surface such as knurled or enhanced with a friction enhancing compound. When the angle adjustment collar 26 and the outer handlebar tube body 9 are rigidly fixed, rotational movement of the outer handlebar tube body 9 is prevented or "locked" by the angle adjustment collar stop flange 27 being constrained between the rotation stop slider keyway 39 and grub screw 29. The rotation stop slider keyway 39 is shown in the "locked" position such that force transmitted to the rotation stop slider keyway 39 through the angle adjustment collar 26 via the angle adjustment collar stop flange 27 is reacted by the main body slider stop reaction face 40 of the main body 16. The function of the grub screw 29 is for adjustment of the interface of the rotation stop slider keyway 39 and the angle adjustment collar stop flange 27. Loosening the grub screw 29 provides more clearance between the rotation stop slider keyway 39, angle adjustment collar stop flange 27, and main body slider stop reaction face 40. This results in rotational movement of up to about 30° between the outer handlebar tube body 9 and the main body 16. Tightening the grub screw 29 reduces or eliminates all rotational movement between the outer handlebar tube body 9 and the main body 16. A preferred adjustment is determined by minimal rotational movement possible whilst still allowing sufficient clearance between the main body slider stop reaction face 40, rotation stop slider keyway 39, and angle adjustment collar stop flange 27 such that the rotation stop slider keyway 39 can slide into its open and locked position. The rotation stop slider keyway 39 may be of a hardened material and smooth surface material in order to reduce friction and facilitate sliding. Figure 10 shows a vertical fold stop cross section 31 from Figure 4 showing the arrangement and function of a fold stop face 51. The fold stop face 51 is shown rigidly fixed to the outer handlebar tube body 9 with a fold stop fixing bolt 48 and having a fold stop face 51. The main body 16 is shown with a fold main body stop face 50 and a rotation stop slider keyway 39 shown connected to slider link 41 by slider link pivot pin 42. The interface between the main body 16 and the rotation stop slider keyway 39 is of a sliding fit clearance nature. When the rotation stop slider keyway 39 is in the open position, the outer handlebar tube body 9 is free to rotate in a clockwise direction as shown in the Figure 10 and can be rotated from position aligning with the fold stop open axis 49 to position aligning with the fold stop stowed axis 35 whereby the rotation is stopped through the planar reaction of fold stop face 51 against fold main body stop face 50. The fold stop 30 enables the outer handlebar tube body 9 to be rotated and stowed compactly with the outer handlebar tube palm grip portion 10 being aligned substantially vertically and parallel with the bicycle stem axis 67. Such an arrangement is of particular benefit with known handlebar folding arrangements of typical folding pedal cycles to reduce protrusions from the minimal folding size such as handlebar grips. Figure 11 shows an alternative configuration showing a perspective view of the left side of the invention comprising a T handle 52 formed integrally with a T handle palm grip portion 53. The arrangement of the T handle palm grip portion 53 with respect to the T handle 52 is substantially "T" shaped. The arrangement of the brake lever arm 5 with respect to brake lever finger grip portion 6 is substantially "T"-shaped. A master cylinder 59 is mounted inboard relative to the brake lever pivot pin 7. The master cylinder 59 is contained within the outer envelope of the T handle 52 and accessible for brake bleeding. The T handle 52 is fitted to a bicycle stem 54 via a bicycle stem handlebar clamp 58 using one or more bicycle stem handlebar fixing bolts 56 to rigidly fix the T handle 52 to the bicycle stem 54. The bicycle stem 54 can be mounted to a typical bicycle steerer tube through a bicycle stem steerer clamp 57 and one or more bicycle stem steerer fixing bolts 55. The bicycle stem 54 including bicycle stem steerer clamp 57, the one or more bicycle stem steerer fixing bolts 55, bicycle stem handlebar clamp 58, and the one or more bicycle stem handlebar fixing bolts 56 are typical and well-known bicycle components. The master cylinder 59 is formed to facilitate connection to a brake hose 60. The master cylinder 59 and brake hose 60 may be a standard bicycle hydraulic system. In the example shown, the T handle 52 is of a unibody arrangement such that if the T handle 52 is rotated with respect to the bicycle stem 54 in order to adjust to the rider ergonomically, the master cylinder 59, brake lever arm 5, brake lever finger grip portion 6, T handle palm grip portion 53, brake lever pivot pin 7, palm grip portion axis 14, and finger grip portion axis 15 will all move together with no respective movement. The palm grip portion axis 14 extends at an angle to the brake lever pivot pin 7 from 0° to 25°. The finger grip portion axis 15 extends at an angle to the palm grip portion axis 14 from 0° to 25°. The brake lever pivot axis 13 is substantially orthogonal to the outer handlebar rotation axis 12. The T handle 52 may be manufactured by a hydroformed aluminium process or a carbon fibre moulding process. Figure 12 shows a cutaway view of the example of Figure 11 showing the nature and function of the brake lever arm 5 and 6. The master cylinder 59 is shown fitted to the T handle 52 with one or more master cylinder fixing bolts 61. As the brake lever finger grip portion 6 is moved closer to the outer handlebar tube palm grip portion 10 by the rider's fingers pulling, the brake lever arm 5 rotates about the brake lever pivot pin 7, moving the master cylinder piston connecting pin 8 in a substantially inboard direction axially aligned with outer handlebar rotation axis 12. The master cylinder piston connecting pin 8 may be a bicycle hydraulic brake lever and have a threaded connection with the master cylinder piston 38. Axial movement of master cylinder piston 38 with respect to the master cylinder 59 causes compression of oil fluid in the master cylinder 59 by forcing the oil through the master cylinder 59, out into the brake hose 60, and into the bicycle brake calliper system. The arrangement of the master cylinder 59 provides for a return spring force to return the brake lever arm 5 and brake lever finger grip portion 6 to an original position upon release of the brake lever finger grip portion 6 by the rider's fingers. The master cylinder piston 38 is shown with a piston adjustment flat 66 to rotate the master cylinder piston 38 about the outer handlebar rotation axis 12 with respect to the master cylinder piston connecting pin 8, allowing for adjustment of the position of the brake lever finger grip portion 6 and the brake lever finger grip portion 6 relative to the T handle 52 and T handle palm grip portion 53. Figure 13 shows a further example, showing a perspective view of the left side of the invention comprising a L handle 62 formed integrally with a L handle palm grip portion 63. The configuration of the L handle 62 with respect to the L handle palm grip portion 63 is substantially "L"-shaped. The configuration of a brake lever L form 64 with respect to a brake lever L form finger grip portion 65 is substantially "L"-shaped. The master cylinder 59 is mounted inboard relative to the brake lever pivot pin 7. The master cylinder 59 is substantially contained within the outer envelope of the alternative embodiment L handle 62 and accessible for brake bleeding. The L handle 62 is fitted to a bicycle stem 54 via a bicycle stem handlebar clamp 58 using one or more bicycle stem handlebar fixing bolts 56 to rigidly fix the L handle 62 to the bicycle stem 54. The bicycle stem 54 can be mounted to a bicycle steerer tube through the bicycle stem steerer clamp 57 and the one or more bicycle stem steerer fixing bolts 55. The master cylinder 59 is formed to facilitate connection to the brake hose 60. The master cylinder 59 and brake hose 60 is of a standard and well-known variety of bicycle hydraulic systems. The brake hose 60 allows rotation through the natural flexibility of the hose material. In the example shown, the L handle 62 is of a unibody arrangement such that if the L handle 62 is rotated about the outer handlebar rotation axis 12 with respect to the bicycle stem handlebar clamp 58 to adjust the position of the L handle palm grip portion 63 to the rider ergonomically, the brake lever L form 64, brake lever L form finger grip portion 65, L handle palm grip portion 63, brake lever pivot pin 7, palm grip portion axis 14, and finger grip portion axis 15 will all move together with no respective movement. The palm grip portion axis 14 extends at an angle to the brake lever pivot pin 7 from 0° to 25°. The finger grip portion axis 15 extends at an angle to the palm grip portion axis 14 from 0° to 25° The brake lever pivot axis 13 is substantially orthogonal to the outer handlebar rotation axis 12. The L handle 62 and the L handle palm grip portion 63 may be manufactured by a hydroformed aluminium process or a carbon fibre moulding process. Figure 14 shows a further example, showing a perspective view of the left side of the invention comprising a brake hose 60 formed to receive a clamped rotatable outer handlebar portion 69. The clamped rotatable outer handlebar portion 69 can be rotatably adjusted relative about the outer handlebar rotation axis 12 with respect to a short main body 68 by tightening or loosening one or more clamped rotatable outer handlebar fixing bolts 70. The means for connection between the brake hose 60 and the clamped rotatable outer handlebar portion 69 is well known and similar to the arrangement of standard bicycle stems such as the bicycle stem steerer clamp 57 and the bicycle stem handlebar clamp 58.

Claims

1. A brake handlebar for a bicycle, the brake handlebar comprising an elongate main body having a longitudinal axis and a brake assembly comprising:a brake actuator rotatably coupled to the elongate main body and pivotable about a pivot axis;a master cylinder; anda master cylinder piston received in and movable relative to the master cylinder;wherein the master cylinder and the master cylinder piston are located inside the elongate main body and inboard of the pivot axis; andwherein the master cylinder piston is movable along a piston axis substantially parallel to the longitudinal axis.

2. The brake handlebar of claim 1, wherein the piston axis is aligned with the longitudinal axis.

3. The brake handlebar of claim 2, wherein the brake assembly further comprises an outer handlebar tube extending from the elongate main body, outboard of the pivot axis.

4. The brake handlebar of claim 3, wherein the outer handlebar tube is rotatable about the longitudinal axis relative to the elongate main body.

5. The brake handlebar of claim 3, wherein the elongate main body and the outer handlebar tube are integrally formed and rotatable together about the longitudinal axis.

6. The brake handlebar of any preceding claim, wherein the brake assembly further comprises a palm grip portion extending from an outer end of the outer handlebar tube.

7. The brake handlebar of claim 6, wherein the palm grip portion extends along a grip axis, the grip axis extending at an angle to the pivot axis from 0° to 25°; optionally, the grip axis is substantially parallel to the pivot axis.

8. The brake handlebar of any of claims 6 or claim 7, wherein the outer handlebar tube and the palm grip portion form a T shape or an L shape.

9. The brake handlebar of any preceding claim, wherein the brake actuator comprises a brake lever and a finger grip portion extending from an outer end of the brake lever.5   10. The brake handlebar of claim 9 when dependent on claim 6 or any claimdependent thereon, wherein the finger grip portion extends substantially parallel to the palm grip portion.

11. The brake handlebar of any preceding claim, further comprising an outer 10 housing at least partly covering the elongate main body and adapted to constrain rotation of the outer handlebar tube.

12. The brake handlebar of any preceding claim, wherein the brake handlebar comprises a pair of brake assemblies, each brake assembly configured relative to a 15 respective side of the elongate main body.

13. A bicycle comprising a brake handlebar according to any preceding claim.

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