GB1582796A

GB1582796A - Multi-speed hub for a bicycle

Info

Publication number: GB1582796A
Application number: GB2223577A
Authority: GB
Original assignee: Shimano Industrial Co Ltd
Current assignee: Shimano Inc
Priority date: 1976-05-26
Filing date: 1977-05-26
Publication date: 1981-01-14
Also published as: DE2723869C2; DE2723869A1; DE2759581B1; DE2759581C3

Description

(54) A MULTI-SPEED HUB FOR A BICYCLE (71) We, SHIMANO INDUSTRIAL COM- PANY LIMITED, a corporation brganized and existing under the laws of Japan, of 77, 3-cho, Oimatsu-cho, Sakai-shi, Osaka, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a multi-speed hub for a bicycle.

A conventional multi-speed hub for a bicycle comprises a hub shaft capable of being fixedly mounted on a bicycle frame, a hub shell rotatable about the hub shaft, a driving member housed within the hub shell and mounted for rotation about the hub shaft, a multi-speed transmission assembly housed within the hub shell and capable of transmitting torque from the driving member to the hub shell at any one of a plurality of different gear ratios and a gear selection member movable relative to the hub shaft amongst a plurality of gear selection positions equal in number to the number of the said gear ratios and co-operating with the transmission assembly such that when the gear selector assembly is in each of its gear selection positions the transmission assembly will transmit torque from the driving member to the hub shell at a corresponding one of its gear ratios. The movement of the gear selection member is effected by a movable member (such as a crank arm) engaged therewith, this movable member being attached to one end of either the wire or the sheath of a Bowden cable, the adjacent end of the other of the wire and sheath of a Bowden cable, the adjacent end of the other of the wire and sheath of the Bowden cable being fixed relative to the hub shaft and the opposed end of the Bowden cable being connected to a conventional control lever mounted on the handlebars of the bicycle.

Such a multi-speed hub has no means for locating the gear selector member exactly in its gear selection positions and thus a cyclist is obliged to select the correct position of the control lever for each gear ratio by touch. Obviously there is a risk that the gear selection member will be inaccurately positioned and thus that the multi-speed hub may be damaged.

It has been proposed to provide the control lever with holding means which will hold it in the various positions which it requires to adopt in order to hold the gear selection member in its gear selection positions. However, should the relative lengths of the wire and sheath of the Bowden cable used to connect the control lever to the multi-speed hub change as frequently happens after long use, the holding of the control lever in its various positions by the holding means will not position the gear selection member accurately in its gear selection positions and there is thus still a risk of damage to the multi-speed hub.

The present invention seeks to overcome this problem and provides a multi-speed bicycle hub whose gear selection member can be held correctly in its gear selection positions despite changes in the relative lengths of the wire and sheath of a Bowden cable used to connect the hub to a control lever.

Accordingly, the invention provides a multi-speed hub for a bicycle, the hub comprising: a hub shaft; a hub shell rotatable about the hub shaft; a driving member mounted on the hub shaft for rotation therearound, the driving member being housed within the hub shell; a multi-speed transmission assembly capable of transmitting torque from the driving member to the hub shell at any one of a plurality of different gear ratios, the transmission assembly being housed within the hub shell; a gear selector member movable rela tive to the hub shaft amongst a plurality of gear selection positions equal in num ber to the number of the said gear ratios and co-operating with the transmission assembly, such that when the gear selector member is in each of its gear selection positions the transmission assembly will transmit torque from the driving member to the hub shell at a corresponding one of its gear ratios; a support member fixed in position on or adjacent the hub shaft and provided with a first retaining means capable of retaining one end of one of the wire and sheath of a Bowden cable and with a first co-operating means; and a movable member movable relative to the support member and engaging the gear selector member, the movable mem ber being provided with a second retaining means capable of retaining one end of the other of the wire and sheath of the Bowden cable and with a second co operating means, the first and second co-operating means being capable of engaging each other in any one of a plurality of engaged positions equal in number to the number of the said gear ratios, said engaged positions being such that when the first and second co-operating means engage each other in any one of their engaged positions, the gear selector member will assume a corresponding one of its gear selection positions.

In the multi-speed hub of the invention, very desirably the movement of the gear selector member amongst its gear selection positions is effected by moving the gear selector member substantially axially of the hub shaft.

The gear selector member may have the form of a rod extending substantially axially of the hub shaft along an axial bore formed therein, the rod bearing a key portion which extends outwardly from the axis of the hub shaft through an aperture formed therein and which engages the transmission assembly.

Very desirably, the support member is fixedly mounted on one axial end of the hub shaft and preferably the movable member is mounted on the support member. The movable member may be mounted on the support member by means of a pivot, the second retaining means and the second cooperating means being spaced from the pivot, and in this case the second retaining means is desirably disposed at or adjacent one end of the movable member, the second co-operating means is disposed at or adjacent the opposed end thereof and the pivot lies between the second retaining means and the second co-operating means. Alternatively, the movable member may comprise a chain, the chain extending through a guide aperture formed in the support member, and in this case conveniently a single chain serves as both the gear selector member and the movable member and a rigid member provided at one end of the chain has formed thereon both the second retaining means and the second co-operating means.

The multi-speed hub of the invention may be designed for use with a Bowden cable of the push-pull type, so that the movement of the gear selection member in both directions amongst its various gear selection positions can be effected solely by moving the wire of the Bowden cable relative to the sheath thereof. Alternatively the multi-speed hub may be designed for use with a Bowden cable of the pull-only type, and such a multi-speed hub must therefore also comprise a biasing means biasing the speed control member relative to the hub shaft in a direction opposite to that in which the speed control member would be moved when the said one end of the wire of a Bowden cable attached to one retaining means is moved into the said one end of the sheath of a Bowden cable attached to the other retaining means, and the engagement between the first and second engagement means in any one of their engaged positions must be sufficient to prevent the speed control member being shifted by the force thereon exerted by the biasing means.

Preferred embodiments of the invention will now be described, though by way of illustration only, with reference to the accompanying drawings, in which: Figure 1 is a part cut-away front elevation of a first multi-speed hub of the invention; Figure 2 is a perspective exploded view of the support and movable members of the multi-speed hub shown in Figure 1; Figure 3 is a section along the line III--III in Figure 1; Figure 4 is a part cut-way front elevation of a second multi-speed hub of the invention; and Figure 5 is a section along the line V-V in Figure 4.

Both multi-speed hubs shown in the accompanying drawings are three-speed hubs having high, middle and low gear ratios.

However, the multi-speed hub of the invention may have any number of gear ratios from two upwards.

The first multi-speed hub of the invention shown in Figures 1 to 3 comprises a hub shaft 1 fixedly mounted on rear forks 2, 2a of a bicycle frame, a hub shell 4 rotatable about the hub shaft 1, a driving member 3 mounted on the hub shaft 1 for rotation therearound and housed within the hub shell 4, and a three-speed transmission assembly (generally designated 5), which is housed within the hub shell 4 and which is capable of transmitting torque from the. driving member 3 to the hub shell 4 at any one of three different gear ratios, the shifting between the three different gear ratios being effected by moving the transmission assembly 5 axially of the hub shaft 1.

The axial ends of the hub shaft 1 are provided with screw threads 10 and 11 respectively. The thread 10 engages a corresponding thread on a ball holder 12 provided with a ball race 12a and a plurality of ball bearings 13 are held between this ball race 12a and a ball race 31 provided on the driving member 3; thus, the ball bearings 13 render the driving member 3 rotatable about the shaft 1.

The driving member 3 is provided at its right side end outer surface with a sprocket wheel 32 fixed thereto to be engaged with a driving chain (not shown) so that the sprocket may be rotated by pedalling to forcibly drive the driving member 3, and at the left side end face with a spindle 35 carrying therewith middle speed transmitting pawls 33 and low ones 34, engageable with the transmission 5 to be rotatable in integration with the driving member 3.

The driving member 3 has at its outer periphery a ball race 36 carrying balls 37 through which the driving member 3 is made rotatable relative to a mounting cone 41 screwably fixed to the right side end of the hub shell 4. At the left side end of the hub shell is also fixed a mounting cone 42, and balls 15 are inserted between the mounting cone 42 and a ball race 14a of a ball holder 14 inserted onto the left end of the fixed shaft 1, the mounting cone 42 being supported to the shaft 1 in relation of being rotatable therewith through the balls 15.

The transmission 5, which serves to properly change the driving force from the driving member 3 to be transmitted to the hub shell 4, comprises; a plurality of planet gears 510 carried with a spindle 511 and meshed with a sun gear 16 formed at the fixed shaft 1; a gear frame 51 having at the right side inner surface thereof ratchet teeth 512 in mesh with the middle speed transmitting pawls 33 and at the left side a plurality of middle and low speed transmitting pawls 513 whose tips tend to be easily meshed with ratchet teeth 420 formed at the inner surface of the mounting cone 42, and being made rotatable and axially movable with respect to the fixed shaft; and a ring gear 52 provided around the gear frame 51 from the substantially central portion thereof to near the control portion of the driving member 3, and having at the left side inner surface opposite to the outer periphery of substantially center portion of the gear frame 51 inner teeth 520 in mesh with the planetary gears 510, at the substantially central portion a notched portion 521 to be abutted against the right end face of the gear frame 51, at the outer periphery of the right side end a plurality of high speed transmitting pawls 522 whose tips tend to be meshed with ratchet teeth 410 at the mounting cone 41 through a spring 523, and at the inner surface of the right side end ratchet teeth 524 in mesh with the low speed transmitting pawls 34 of the driving member 3.

The gear frame 51 and ring gear 52 are connected by a pin 53 projecting from the ring gear into an annular groove in the gear frame 51 so that the gear frame 51 and the ring gear 52 are movable together axially of the fixed shaft 1 through a control rod 17 inserted into the axial hollow at the center of the fixed shaft 1 but are relatively rotatable.

The fixed shaft/having therein the control rod 17 is provided at substantially the left side end of the shaft with a guide hole 18 radially penetrating through the shaft and axially extending in a given length. Within the guide hole 18 is inserted a key 19 axially movable to be engaged with an engaging portion 514 formed at the inner surface of the left side end of the gear frame 51 so that the key 19 may be abutted at its one side against one end face of the control rod 17, and between the other side of the key and the ball holder 14 is inserted a coiled spring 20.

This invention is directed to provide a control device at the multi-speed transmission hub constructed as aforegoing. The control device comprises; a support 6 provided at the right side end of the fixed shaft 1; a transmitting member 7, for example a bell crank, which is pivoted to the support 6 so as to be swingable to operate the control rod 17; and a positioning and maintaining means provided between the support 6 and the transmitting member 7.

The support is, as shown in Figs. 1 and 2, formed in a substantially U-like shape, and has at one of opposite arms thereof a threaded hole 61 to be screwably fixed to the thread 1 0a of the fixed shaft 1, at the other a mounting hole 62 into which a fitting 63 for securing one end of a sheath 92 covering an inner wire 91 of control cable 9 is insertably mounted by a snap ring 64, and at a body connecting both the arms a guide slot 65 which is formed elongate lengthwise of the body by cutting through the body at its widthwise central portion in parallel to the lateral surface thereof. To the guide 65 is pivoted the transmitting member 7 at the substantially center portion thereof through a pivot 66.

Between the support 6 and the transmitting member 7 is provided the positioning and maintaining means comprising engageable portions 71 formed of a plurality of bores as many as the number of speedchange stages and a retainer 8 engageable with one of the engageable portions 71, the engageable portions 71 being provided at the transmitting member 7. The retainer 8 is formed of a ball engageable with any one of the engageable portions 71 and is provided at the support 6. The engagement of the retainer 8 with the engageable portions 71 allows the control rod 17 to be positioned at a selected speed change stage.

The engageable portions 71 are formed at the outermost end of one arm of the transmitting member 7 and are arranged corresponding to the travel of the outermost end along the path of the one arm in swinging motion. In Fig. 1, one engageable portion 71a at the left side corresponds to the high speed stage, that 71b at the intermediate portion, to the medium, and that 71c at the right side, to the low. The engageable portions 71a, 71b and 71c are continued in series so that even if the retainer 8 rests between each portion, it can be insertably engaged with any one of the engageable portions.

Incidentally, the engageable portions 71 may be concaved other than bored through the outermost end of the transmitting member 7 as shown in the drawings.

The retainer 8 in engagement with the engageable portions 71 is composed of a rolling body such as a ball or a roller, biased towards the engageable portion 71 through a resilient body 81, such as a leaf spring.

The support 6 is provided at its portion abutting against any one of the engageable portions 71 with a through hole 67 penetrating lengthwise outward of the support from the guide slot 65, so that the retainer 8 is inserted into the through hole 67 in relation of being freely movable therethrough for being engaged with any one of the engageable portions 71, and the resilient body 81 is provided at the one side of the support 6 to cover the outer opening of the through hole 67.

In detail, when the resilient body 81 employs the leaf spring as shown in Figs. 2 and 3, the leaf spring is mounted to the support 6 in such a manner that at one outer side of the support 6 is formed an elongate recess 68 extending from the through hole 67 to the pivot 66, into which recess 68 the leaf spring is inserted and attached at its one end to the pivot 66. Besides this, a coiled spring or a spring washer is, when used as the resilient body, attached to cover the outer opening of the through hole 67 through a suitable supporting member.

The aforesaid engagement of the retainer 8 with any one of the engageable portions is kept by the spring force of the resilient body 81. The resilient body 81 is larger in its spring force than the spring 20 within the transmission hub so that the transmitting member 7 may swing to cause one of the engageable portions 71 to be engaged with the retainer 8, thus the desired speed-change position is defined for changing the speed, and at the same time, the transmission 5 is axially moved to be kept in the desired speed-change stage.

Furthermost, at the outermost end of the other arm of the transmitting member 7 is formed a bore 72 into which is pivoted a supporting pin 73 for supporting the inner wire 91 of the control cable 9 through a holder 74 attached to the pin 73 by a screw 75.

The control cable 9 comprises the wire 91 of the so-called push-pull type, relatively larger in diameter and less in flexibility and the sheath 92 for guiding the wire 91. One end of the wire 91 is gripped between the pin 73 and the holder 74 and the other end is pivoted to the control lever attached to the handle bar and the sheath 92 is fixed at its one end to the fitting 63 at the support 6 and attached at the other end to the fitting member of the control lever whereby the control lever pushes of pulls the wire 91 to cause the transmitting member 7 to swing.

In the aforesaid description, the engageable portions 71 are provided at the transmitting member 7 and the retainer 8 at the support 6, but the engageable portion 71 may be provided at the support 6, and the retainer 8 at the transmitting member 7, and also the transmitting member 7 may be provided at the outside of the support 6.

Now, the speed change by use of the control device constructed as aforegoing will be detailed in the following description.

First, for changing the speed from the middle speed stage to the high as shown in Fig. 1, the control lever pushes the wire 91 to allow the engageable portion 71a at the transmitting member 7 to be engaged with the retainer 8. Hence, the transmission 5 is biased by the spring 20 to moved toward the far right end of the hub, so that the driving force from the driving member 3 motion is transmitted to the hub shell 4 through the route of the middle speed transmitting pawls 33, ratchet teeth 512, gear frame 51, planetary gears 510, ring gear 52, high speed transmitting pawls 522, ratchet teeth 410 and fitting cone 41, thereby driving the hub shell under high speed transmitting condition for raising the bicycle speed.

Second, for changing the speed from the aforesaid high speed stage to the middle, the control lever pulls the wire 91 to allow the engageable portion 71b of the transmitting member 7 to be engaged with the retainer 8 of the support 6. In this instance, the transmitting member 7 swings to push the control rod 17 leftward in the Fig. 1 and the transmission 5 is moved leftward through the control key 19 against the spring 20, so that the driving force from the driving member 3 is transmitted to the hub shell through the middle speed transmitting pawls 33, ratchet teeth 512, gear frame 51, middle and low speed transmitting pawls 513, ratchet teeth 420 and fitting cone 42, thereby driving the hub shell under the middle speed stage in the direction connection exclusive of the ring gear.

Third, for changing from middle to low, the wire 91 is further pulled by the lever to allow the engageable portion 71c to be engaged with the retainer 8, in which the transmitfing member 7 swings leftward to allow the transmission to be moved toward the far left end of the hub through the control rod 17 and control key 19 against the spring 20, so that the driving force is transmitted from the driving member 3 through the low speed transmitting pawls 34, ratchet teeth 524, ring gear 52, planetary gears 510, gear frame 51, middle and low speed transmitting pawls 513, ratchet teeth 420 and fitting cone 42, thereby driving the hub shell under the low speed stage for reducing the speed.

In the embodiment as aforegoing, the bell crank is used as the transmitting member 7, but a chain may be used as shown in Figs. 4 and 5. In this instance, the support 6 is provided with a guide hole 69 for the chain, and the chain is connected at its one end with the control rod 17 through a pin and at the other end with a connector 76, so that the one end of the wire 91 of the control cable is fixed to the connector 76 through a fitting member 77 attached thereto, and between the connector 76 and the support 6 is provided the positioning and maintaining means.

In greater detail, the connector 76 is, as shown in Figs. 4 and 5, formed in a rodlike shape, and the engageable portions 71 as many as the speed change stages are arranged lengthwise of the connector, and the retainer 8 engageable with any one of the engageable portions 71 is provided at the support 6, so that the engagement thereor may position the control rod 17 at the selected speed change stage.

The engageable portions 71 shown in Figs. 4 and 5 are formed of annular grooves of each substantially semi-circular section and several grooves are axially arranged correspondingly to the travel of the connector 76 every speed-change stage, that is, the engageable portion 71a corresponding to the high speed stage is formed at the lower portion that 71b to the middle, at the intermediate and that 71c to the low, at the upper. The engageable portions 71a, 71b and 71c are connected in series so that the retainer 8 may, even if rest at between each portion, slip into a selective one of the engageable portions. In addition, the engageable portions 71 may, other than formed in the annular groove of the semi-circular section, be formed of the partially concaved outer surface of the connector 76, or of boxes penetrating through the connector at slightly spaced intervals.

The retainer 8 in engagement with the engageable portions 71, as shown in Fig. 5, composed of a ball or roller urged toward the engageable portions 71 by a resilient body 81, such as a coiled spring, and the support 6 is provided at the guide slot 69 with a cylindrical recess 70 extending radially outward thereof, into which recess 70 the resilient body 81 and the retainer 8 are both inserted in relation of being freely taken out or put in so that the retainer 8 may be engaged with any one of the engageable portions 71.

The engagement of the retainer 8 with the engageable portions 71 is kept by the spring force of the resilient body 81 biasing the retainer 8 toward the engageable portion 71, and the resilient body 81 in this modified embodiment is also made larger in the biasing force than the spring 20, whereby the speed-change stage is defined by the control rod 17 and simultaneously the transmission 5 is axially moved to be kept in the defined speed-change stage when changing the speed.

Incidentally, the spring 20 in this modified embodiment, is not shown in Fig. 4, but is provided between the control key and the sun gear so as to always bias the control key leftward.

Tn addition, in the aforesaid description, the engageable portions 71 and the retainer 8 are provided between the support 6 and the connector 76, besides this, the engageable portions and the retainer may be provided between the chain as the transmitting member 7 and the support 6. In case that the engageable portions 71 are not formable at the chain itself, any member having the portions 71 may be rigidly supported to the chain. In addition, in the modified embodiment, the control rod 17 is changeable into the chain similarly to the transmitting member 7.

As clearly understood from the aforesaid description, the control device of the invention is provided with the positioning and maintaining means between the support fixed to one end of the fixed shaft of the multi-speed transmission hub and the transmitting member, such as the bell crank or chain, carried by the support, or the connector fixed to the transmitting member, which means comprises a plurality of the engageable portions as many as the speedchange stages and the retainer in engagement with any one of the engageable portions. Hence, the positioning and maintaining means allows the transmission to be always properly positioned for changing the speed. Accordingly, the control device of the invention has the advantages such that the transmission does not rest at the intermediate portion adjacent to the desired speed change stage when changing the speed, so that the reliable speed-change may always be performed and also there is no fear such as damaging the transmission.

Furthermore, even when the control wire is extended or contracted, or the sheath of the wire is out of its mounting place, the transmission can always be settled in the proper position corresponding to the desired speed-change stage, thereby performing constantly the accurate speedchange with no fear of damaging the transmission.

WHAT WE CLAIM IS:- 1. A multi-speed hub for a bicycle, the hub comprising: a hub shaft; a hub shell rotatable about the hub shaft; a driving member mounted on the hub shaft for rotation therearound, the driving member being housed within the hub shell; a multi-speed transmission assembly capable of transmitting torque from the driving member to the hub shell at any one of a plurality of different gear ratios, the transmission assembly being housed within the hub shell; a gear selector member movable rela tive to the hub shaft amongst a plurality of gear selection positions equal in num ber to the number of the said gear ratios and co-operating with the transmission assembly, such that when the gear selector member is in each of its gear selection positions the transmission assembly will transmit torque from the driving member to the hub shell at a corresponding one of its gear ratios; a support member fixed in position on or adjacent the hub shaft and provided with a first retaining means capable of retaining one end of one of the wire and sheath of a Bowden cable and with a first co-operating means; and a movable member movable relative to the support member and engaging the gear selector member, the movable mem ber being provided with a second retaining means capable of retaining one end of the other of the wire and sheath of the Bowden cable and with a second co operating means, the first and second co-operating means being capable of engaging each other in any one of a plurality of engaged positions equal in number to the number of the said gear ratios, said engaged positions being such that when the first and second co-operating means engage each other in any one of their engaged positions, the gear selector member will assume a corresponding one of its gear selection positions.

2. A multi-speed hub as claimed in Claim 1, in which the movement of the gear selector member amongst its gear selection positions is effected by moving the gear selector member substantially axially of the hub shaft.

3. A multi-speed hub as claimed in Claim 2, in which the gear selector member has the form of a rod extending substantially axially of the hub shaft along an axial bore formed therein, the rod bearing a key portion which extends outwardly from the axis of the hub shaft through an aperture formed therein and which engages the transmission assembly.

4. A multi-speed hub as claimed in any of the preceding claims, in which the support member is fixedly mounted on one axial end of the hub shaft.

5. A multi-speed hub as claimed in any of the preceding claims, in which the movable member is mounted on the support member.

6. A multi-speed hub as claimed in Claim 5, in which the movable member is mounted on the support member by means of a pivot, the second retaining means and the second co-operating means being spaced from the pivot.

7. A multi-speed hub as claimed in Claim 6, in which the second retaining means is disposed at or adjacent one end of the movable member, the second co-operating means is disposed at or adjacent the opposed end thereof and the pivot lies between the second retaining means and the second co-operating means.

8. A multi-speed hub as claimed in any of Claims 1 to 4, in which the movable member comprises a chain, the chain extending through a guide aperture formed in the support member.

9. A multi-speed hub as claimed in Claim 8, in which a single chain serves as both the gear selector member and the movable member.

10. A multi-speed hub as claimed in Claim 8 or 9, in which a rigid member provided at one end of the chain has formed thereon both the second retaining means and the second co-operating means.

11. A multi-speed hub as claimed in any of the preceding claims, which further comprises biasing means biasi

Claims

**WARNING** start of CLMS field may overlap end of DESC **. speed. Accordingly, the control device of the invention has the advantages such that the transmission does not rest at the intermediate portion adjacent to the desired speed change stage when changing the speed, so that the reliable speed-change may always be performed and also there is no fear such as damaging the transmission. Furthermore, even when the control wire is extended or contracted, or the sheath of the wire is out of its mounting place, the transmission can always be settled in the proper position corresponding to the desired speed-change stage, thereby performing constantly the accurate speedchange with no fear of damaging the transmission. WHAT WE CLAIM IS:-

1. A multi-speed hub for a bicycle, the hub comprising: a hub shaft; a hub shell rotatable about the hub shaft; a driving member mounted on the hub shaft for rotation therearound, the driving member being housed within the hub shell; a multi-speed transmission assembly capable of transmitting torque from the driving member to the hub shell at any one of a plurality of different gear ratios, the transmission assembly being housed within the hub shell; a gear selector member movable rela tive to the hub shaft amongst a plurality of gear selection positions equal in num ber to the number of the said gear ratios and co-operating with the transmission assembly, such that when the gear selector member is in each of its gear selection positions the transmission assembly will transmit torque from the driving member to the hub shell at a corresponding one of its gear ratios; a support member fixed in position on or adjacent the hub shaft and provided with a first retaining means capable of retaining one end of one of the wire and sheath of a Bowden cable and with a first co-operating means; and a movable member movable relative to the support member and engaging the gear selector member, the movable mem ber being provided with a second retaining means capable of retaining one end of the other of the wire and sheath of the Bowden cable and with a second co operating means, the first and second co-operating means being capable of engaging each other in any one of a plurality of engaged positions equal in number to the number of the said gear ratios, said engaged positions being such that when the first and second co-operating means engage each other in any one of their engaged positions, the gear selector member will assume a corresponding one of its gear selection positions.

11. A multi-speed hub as claimed in any of the preceding claims, which further comprises biasing means biasing the speed control member relative to the hub shaft in a direction opposite to that in which the speed control member would be moved when the said one end of the wire of a Bowden cable attached to one retaining means is moved into the said one end of the sheath of a Bowden cable attached to the other retain

ing means, the engagement between the first and second engagement means in any one of their engaged positions being sufficient to prevent the speed control member being shifted by the force thereon exerted by the biasing means.

12. A multi-speed hub as claimed in any of the preceding claims, in which the first retaining means is capable of retaining one end of the sheath of the Bowden cable and the second retaining means is capable of retaining one end of the wire of the Bowden cable.

13. A multi-speed hub as claimed in any of the preceding claims, in which the two retaining means comprise a plurality of recesses and/or apertures equal in number to the number of the said gear ratios and an engagement member biased toward and capable of engaging any one of the recesses and/or apertures.

14. A multi-speed hub for a bicycle, the hub being substantially as herein described, with reference to and as illustrated in Figures 1 to 3 or Figures 4 and 5 of the accompanying drawings.