FIELD

The invention relates to a hub assembly for a bicycle.

BACKGROUND

Hub assemblies for bicycles generally include a hub shell for connection to a wheel. The hub shell is rotatably driven about an axis through a sprocket that is connected to the hub shell. The sprocket is typically part of an offset drive, which includes a chainwheel that is rotatably driven by a pedal force of a rider of the bicycle. Power is transferred from the chain wheel to the sprocket of the offset drive by a chain or belt.

Some hub assemblies include a unidirectional clutch, e.g. a oneway clutch, or freewheel coupling, for transferring torque from the sprocket to the hub assembly in only one rotation direction.

The sprocket may be part of a cassette of sprockets and a derailleur may be used for shifting the chain between the sprockets of the cassette. In such systems, the cassette of sprockets is typically mounted on a driver body. Some hub assemblies, for example as shown in WO2017/039422A2, further include a hub transmission in addition to the cassette of sprockets and rear derailleur. This known hub transmission operates between the cassette of sprockets and the hub shell. The known hub transmission is housed by the driver body on which the cassette of sprockets is mounted. The driver body is substantially conically shaped to provide sufficient space for the hub transmission to be housed by the driver body. The cassette of sprockets for being mounted on this driver body is adapted accordingly.

SUMMARY It is an object to propose an improved hub assembly and wheel for a bicycle. In a more general sense it is an object to overcome or ameliorate at least one of the disadvantages of the prior art, or at least provide alternative processes and structures that are more effective than the prior art. At any rate it is at the very least aimed to offering a useful choice and contribution to the existing art.

According to an aspect, a hub assembly for a bicycle is provided, comprising a hub shell for a driven wheel of the bicycle; a cylindrical driver body arranged for being coupled to a cassette or set of sprockets; and a transmission selectively operable according to two different transmission ratios. The transmission is housed under the hub shell and/or under the driver body. The transmission is operatively arranged between the cylindrical driver body and the hub shell. The driver body being cylindrical allows for mounting industry standard cassettes of sprockets thereon. Standard cassettes of sprockets have a cylindrical bore for being rotationally coupled to a driver body. Hence, a hub assembly can be provided having a hub transmission in addition to a cassette of sprockets and associated derailleur, wherein the cylindrical driver body can be compatible with standard cylindrical bore cassettes. The cylindrical driver may for example be provided with an external axial spline for cooperating with a complementary spline of the, e.g. standard, cassette of sprockets. The cylindrical driver body having splines on the cylindrical surface of the driver body is herein also referred to as a cylindrical driver body. It will be appreciated that the cylindrical driver body has a cylindrically shaped perimeter. It will be appreciated that the cylindrical driver body may be tubular shaped, i.e. defining a hollow space therein, e.g. to allow an axle to be provided there through, and to minimize weight. The cylindrical driver body preferably has a substantially constant, e.g. circular, cross sectional perimeter in a plane transverse to a rotation axis of the assembly. A diameter of the cylindrical driver body may for example be approximately between 30 and 40 millimeter, for example approximately 35 millimeter.

The cylindrical driver body and the hub shell may rotate about an axis, e.g. a wheel axis. Torque can be transmitted from the cylindrical driver body, via the transmission, to the hub shell. The cylindrical driver body may be connected to an input of the transmission, whereas the hub shell may be connected to an output of the transmission. The transmission may be configured to be selectively operable according to a plurality of transmission ratios. The transmission may particularly be configured to be selectively operable according to two transmission ratios or more.

Optionally, the hub assembly comprises an intermediate drive body having an input connected to the cylindrical driver body by a first coupling mechanism and an output connected to an input of the transmission by a second coupling mechanism. The intermediate drive body interconnects the cylindrical driver body to the transmission. The first coupling mechanism may be arranged to couple the intermediate drive body detachably to the driver body, to allow replacement of the driver body, for example for maintenance of the driver body and associated parts such as bearings, or to replace it with another cylindrical driver body having a different mounting arrangement, e.g. a spline, for a different type of cassette.

Optionally, the hub assembly comprises a, e.g. sealed, hub chamber formed by the hub shell, wherein the transmission is housed within the hub chamber, and wherein the intermediate drive body extends between an intermediate drive body output being internal to the hub chamber and an intermediate drive body input being external to the hub chamber. The transmission can accordingly be protected from environment. The sealed hub chamber may for example be substantially water tight, to prevent water and/or debris from entering the sealed hub chamber. The first coupling mechanism may be arranged at the intermediated drive body input. Optionally, the first coupling mechanism is arranged external to the, e.g. sealed, hub chamber. This allows for easy removal of the driver body from hub assembly, e.g. for maintenance or replacement, particularly while the transmission can remain, e.g. sealedly, housed in the hub chamber. If the first coupling mechanism is arranged external to the hub chamber, the driver body does not need to extend into the hub chamber. Hence, the driver body may be entirely external to the hub chamber. The cylindrical driver body may for example extend, e.g. parallel to a rotation axis, between two opposite axial ends, wherein both axial ends are external to the hub chamber. The driver body may extend at one axial end, via the first coupling mechanism, with the intermediate drive body.

Optionally, the hub shell is bearing mounted to an axle of the hub assembly by a first bearing and a second bearing, the first bearing being arranged at a larger radius from the axle than the second bearing. The first bearing and the second bearing can be arranged axially overlapping with respect to the axle. The first bearing and the second bearing are for example concentrically arranged with respect to the axle. The first bearing and the second bearing are hence arranged between the hub shell and the axle.

Optionally, the intermediate drive body extends from its intermediate drive body output internal to the sealed hub chamber to its intermediate drive body input external to the sealed hub chamber between the first bearing and the second bearing. The first bearing and the second bearing may form a boundary of the hub chamber.

Optionally, the hub shell is further bearing mounted to the axle by a third bearing, axially spaced from the first and second bearings.

Optionally, the cylindrical driver body extends, e.g. parallel to a rotation axis, between two opposite axial ends, one of the axial ends being internal to the sealed hub chamber and another one of the axials ends being external to the hub chamber. Hence, the cylindrical driver body may connect to the transmission, e.g. via the intermediate drive body, in the hub chamber. Optionally, the intermediate drive body input and the intermediate drive body output are both internal to the hub chamber.

Optionally, the first coupling mechanism is arranged internal to the, e.g. sealed, hub chamber. Hence, the first coupling mechanism may be protected from the environment.

Optionally, the cylindrical driver body is bearing mounted to the axle by the first bearing and/or second bearing.

Optionally, the cylindrical driver body is bearing mounted to the axle by a fourth bearing, axially spaced from the first and second bearings. For example, if the cylindrical driver body extends into the hub chamber, the cylindrical driver body may extend between the, e.g. concentric, first and second bearing. Hence, the cylindrical driver body may for example be bearing mounted to the axle, e.g. only, by the fourth bearing and one of the first and second bearings.

Optionally, the cylindrical driver body is further bearing mounted to the axle by a fifth bearing, axially spaced from the first and second bearings. For example, if the cylindrical driver body is entirely external to the, e.g. sealed, hub chamber, the cylindrical driver body may be bearing mounted to the axle, e.g. only, by the fourth bearing and the fifth bearing. The cylindrical driver body and the hub shell may hence be individually bearing mounted to the axle by respective sets of bearings.

Optionally, the first coupling mechanism is arranged for detachably coupling the cylindrical driver body to the intermediate drive body input.

Optionally, the first coupling mechanism comprises a bidirectional first coupling, such as a splined coupling, arranged for transferring torque between the cylindrical driver body and the intermediate drive body in two opposing rotation directions.

Optionally, the first coupling mechanism comprises a unidirectional first clutch, arranged for transferring torque between the cylindrical driver body and the intermediate drive body input in only one rotation direction. The unidirectional first clutch may hence be a one-way clutch, or freewheel clutch.

Optionally, the unidirectional first clutch is of a ratchet-type, having ratchet teeth associated with the cylindrical driver body and a ratchet pawl associated with the intermediate drive body input or vice versa.

Optionally, the ratchet-type unidirectional first clutch includes an axial ratchet mechanism, in which the ratchet teeth and the ratchet pawl conjoin in axial direction.

Optionally, the ratchet-type unidirectional first clutch includes a radial ratchet mechanism, in which the ratchet teeth and the ratchet pawl conjoin in radial direction.

Optionally, the transmission comprises a planetary gear set including a ring gear, a planet carrier carrying a planet gear and a sun gear.

Optionally, the second coupling mechanism connects the intermediate drive body to a first one of the ring gear, planet carrier or sun gear..

Optionally, the transmission comprises an actuatable clutch, particularly a load-shifting clutch arranged for being coupled and/or decoupled under load.

Optionally, the actuatable clutch is arranged between on the one hand a second one of the ring gear, planet carrier or sun gear and on the other hand the intermediate drive body output or the first one of the ring gear, planet carrier or sun gear. The actuatable clutch allows to switch between different transmission ratios of the transmission. For example, in a coupled state the actuatable clutch may clutch the first one to the second one of the sun gear, the planet carrier and the ring gear for operating the transmission according to unitary transmission ratio, whereas in a decoupled state the actuatable clutch may decouple the first one and the second one of the sun gear, the planet carrier and the ring gear for operating the transmission according to a nonunitary transmission ratio. Also, for example, in a coupled state the actuatable clutch may couple the first one and the second one of the sun gear, the planet carrier and the ring gear to each other via the intermediate drive body, for operating the transmission according to unitary transmission ratio, whereas in a decoupled state the actuatable clutch may decouple the first one from the second one of the sun gear, the planet carrier and the ring gear for operating the transmission according to a nonunitary transmission ratio. The actuatable clutch may actuatable upon a user request, e.g. using a shifter at a handlebar of the bicycle. The first one of the ring gear, planet carrier or sun gear can be the ring gear, while the second one of the ring gear, planet carrier or sun gear can be the planet carrier. The sun gear can be mounted to the axle via a unidirectional clutch to allow the sun gear to rotate in one direction only with respect to the axle. The axle can be stationary, i.e. non-rotatable, relative to a frame of the bicycle to allow the sun gear to transmit torque to the axle in the non-rotating direction of the sun gear.

The intermediate drive body may be coupled to the first one of the sun gear, planet carrier or ring gear by a bidirectional coupling, such as a splined coupling, arranged for transferring torque between the intermediate drive body output and the first one of the sun gear, planet carrier or ring gear in two opposing rotation directions. If the intermediate drive body is coupled to the first one of the sun gear, planet carrier or ring gear by a bidirectional coupling, it may be desired that the first coupling mechanism includes a unidirectional coupling.

Optionally, the hub assembly comprises a second unidirectional clutch connecting the intermediate drive body output and the first one of the ring gear, planet carrier or sun gear. The intermediate drive body may hence be coupled to the first one of the sun gear, planet carrier or ring gear by a unidirectional clutch, such as a freewheel, arranged for transferring torque between the intermediate drive body output and the first one of the sun gear, planet carrier or ring gear in only one rotation direction. Hence, the second unidirectional clutch can be overrun.

Optionally, the hub assembly comprises a third unidirectional clutch connecting the intermediate drive body output and the second one of the ring gear, planet carrier or sun gear. The intermediate drive body may hence be coupled to the second one of the sun gear, planet carrier or ring gear by a unidirectional clutch, e.g. a one-way clutch, arranged for transferring torque between the intermediate drive body output and the second one of the sun gear, planet carrier or ring gear only one rotation direction. If the intermediate drive body is coupled to the first one of the sun gear, planet carrier or ring gear by a unidirectional clutch, and the intermediate drive body is coupled to the second one of the sun gear, planet carrier or ring gear by a unidirectional clutch, the first coupling mechanism may include either a bidirectional coupling or a unidirectional clutch.

Optionally, the hub shell has a non-uniform cross section in axial direction thereof, e.g. for housing the transmission at a drive side of the hub shell near the cylindrical driver body.

Optionally, the hub shell is substantially conically shaped. At a drive side of the hub shell, i.e. proximal to the cylindrical driver body, the hub shell may have a larger diameter than at the non-drive side of the hub shell, i.e. distal to the cylindrical driver body. From the drive side to the non-drive side, the hub shell diameter may decrease, e.g. gradually.

Optionally, the hub shell is provided with a first spoke flange, for attaching a wheel spoke thereto, at a drive side of the hub shell near the cylindrical driver body and second spoke flange, for attaching a wheel spoke thereto, at non-drive side of the hub shell opposite the drive side. The first spoke flange can be at a larger radius from a rotation axis of the hub shell than the second spoke flange. Optionally, the hub shell includes an inner hub shell and an outer hub shell. The outer hub shell is detachably mounted to the inner hub shell. Hence, the inner hub shell may e.g. house the transmission. The outer hub shell, and e.g. spokes, a rim and/or a tire connected thereto may be dismounted from the inner hub shell, e.g. to be replaced by another outer hub shell and optionally spokes, rim and/or tire connected thereto, the spoke flanges may hence mounted to, or part of, the outer hub shell.

Optionally, the hub shell, e.g. the inner hub shell may house an electrical actuator of the transmission and/or a wireless transceiver and/or an antenna and/or processor and/or a battery and/or an electrical generator and/or a pairing button. The electrical actuator may be configured to operate the transmission for switching from one transmission ratio to another. The wireless transceiver may be configured to receive and process a switching instruction, and e.g. relay it to the electrical actuator. The antenna may be configured to receive the switching instruction. The processor may be arranged for processing the switching instruction. The battery may be configured to provide electrical energy to the transceiver and/or actuator. The electrical generator may be configured to provide electrical energy to the transceiver and/or actuator and/or battery. The pairing button may be configured to bring the processor and/or transceiver into a pairing mode, such as for pairing with a controller, e.g. a shifter device, e.g. at the handlebar. The electrical actuator of the transmission and/or the wireless transceiver and/or the antenna and/or the processor and/or the battery and/or the electrical generator and/or the pairing button, may be connected to the hub shell, such as to the inner hub shell.

According to a further aspect, a wheel for a bicycle is provided, comprising a hub assembly as described herein.

According to another aspect, a bicycle is provided, comprising a wheel as described herein, particularly a rear wheel, or a hub assembly as described herein. It will be appreciated that any of the aspects, features and options described herein can be combined. It will particularly be appreciated that any of the aspects, features and options described in view of the hub assembly apply equally to the wheel and the bicycle, and vice versa.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings in which:

Figures 1-5 show schematic examples of a hub assembly; and Figure 6 shows a schematic example of a bicycle.

DETAILED DESCRIPTION

Figures 1-5 show schematic examples of a hub assembly 100. Figure IB shows a functional schematic of the hub assembly 100 of figure 1A; figure 2B shows a functional schematic of the hub assembly 100 of figure 2A; and figure 3B shows a functional schematic of the hub assembly 100 of figure 3A.

The hub assembly 100 comprises a hub shell 10, and a cylindrical driver body 30. The hub shell 10 and the driver body 30 are rotatable about an axle 11, which extends along a rotation axis A. The cylindrical driver body 30 is arranged for receiving a cassette of sprockets 70 thereon. An axial spline may be provided on a perimeter of the cylindrical driver body 30 for engaging a complementary spline of the cassette of sprockets, such as to transfer torque from the cassette to the driver body 30. The cylindrical driver body 30 may particularly have an industry standard diameter, for being compatible with industry standard cassettes. The cylindrical driver body 30 may also be provided with a standard axial spline for cooperating with standard cassettes. The cylindrical driver body 30 may for example be provided with nine axial splines. The cylindrical driver body can e.g. be configured to be compatible with Uniglide, Hyperglide, Hyperglide+, XD, or Exa-Drive.

The hub assembly 100 comprises a transmission 40. The transmission 40 is selectively operable according to two or more transmission mission ratios. The transmission 40 acts between the cylindrical driver body 30 and the hub shell 10. Hence, the cylindrical driver body 30 is connectable to an input of the transmission, whereas an output of the transmission is connectable to the hub shell 10.

Here, the transmission 40 includes a planetary gear set including a sun gear 41, a planet carrier 42 carrying a planet gear 44, and a ring gear 43. The sun gear 41, planet carrier 42 and ring gear 43 are rotatable about the axis A. The hub shell 10 is in these examples coupled to the planet carrier 42, but it will be appreciated that the hub shell 10 may also be coupled or couplable to the sun gear 41 and/or ring gear 43. Hence, in these examples, the planet carrier 42 forms an output of the transmission 40. The sun gear 41 is connected to the axle 11 via unidirectional fourth clutch 64.

The transmission 40 includes an actuatable clutch 45 for changing a transmission ratio of the transmission 40. Here, the actuatable clutch 45 in a coupled state effectively couples the ring gear 43 to the planet carrier 42, such that the ring gear 43 and the planet carrier 42 are rotatably fixed to each other. In the decoupled state, the actuatable clutch 45 decouples the ring gear 43 from the planet carrier 42, for allowing the ring gear 43 and the planet carrier 42 to rotate at different rotational speeds. Hence, in these examples, an input of the transmission may be considered to be formed by the ring gear 43 and/or the planet carrier 42. For example, in the decoupled state of the actuatable clutch 45, the input may be considered to be formed by the ring gear 43, whereas in the coupled state of the actuatable clutch 45, the input may be considered to be formed by both the ring gear 43 and the planet carrier 42. A clutch actuator 46 is here provided for actuating the actuatable clutch 45. The clutch actuator 46 may be controlled by a user, e.g. using shifter device, e.g. at a handlebar of the bicycle.

The transmission 40 is in this example housed within a hub chamber 18. In this example, the hub chamber 18 is a sealed hub chamber. Here, the hub shell 10 defines the sealed hub chamber 18. Hence, in this example, the transmission 40 is entirely housed by the hub shell 10. It will be appreciated that the transmission 40 may also, e.g. partly, be housed by the cylindrical driver body 30. The sealed hub chamber 18 is substantially conically shaped in these examples. A radius of the hub shell 10 from the axis A at the drive side is larger than a radius of the hub shell 10 at the non-drive side of the hub shell 10. The hub shell 10 is provided with a first spoke flange 71 at the drive side of the hub shell 10 and a second spoke flange 72 at the non-drive side of the hub shell 10. The first and second spoke flanges 71, 72 are arranged for attaching spokes of a wheel thereto. The first spoke flange 71 is in these examples at a larger radius from the axis A than the second spoke flange 72.

The assembly 100 here comprises an intermediate drive body 20. The intermediate drive body 20 operatively interconnects the cylindrical driver body 30 and the transmission 40. The intermediate drive body 20 includes an input 21 for connection to the cylindrical driver body 30 and an output 22 for connection to the transmission 40. The intermediate drive body output 22 is internal to the sealed hub chamber 18. The intermediate drive body input 21 may be internal to the sealed hub chamber 18 or external to the sealed hub chamber 18. Torque is transferred from the cylindrical driver body 30 to the transmission 40 by the intermediate drive body 20. Here, the assembly 100 includes a first coupling mechanism 50 for coupling the cylindrical driver body 30 to the intermediate drive body 20, and a second coupling mechanism 60 for coupling the transmission 40 to the intermediate drive body 20. The second coupling mechanism is internal to the sealed hub chamber 18. The first coupling mechanism 50 may be internal to the sealed hub chamber 18 or external to the sealed hub chamber 18.

The hub shell 10 is bearing mounted to the axle 11 by a first bearing 12 and a second bearing 13. In this example, the first bearing 12 and the second bearing 13 are arranged axially overlapping, here concentrically, with respect to the axis A. The first bearing 12 is provided at a smaller radius from the axis A than the second bearing 13. The intermediate drive body 20 or the cylindrical driver body 30 may extend between the first bearing 12 and the second bearing 13, to reach from internal to the sealed hub chamber 18 to external to the sealed hub chamber 18 or vice versa. The hub shell is further bearing mounted to the axle by a third bearing 14. The third bearing 14 is axially spaced from the concentric first and second bearings 12, 13, at a non-drive side of the hub assembly 100. The cylindrical driver body 30 can be bearing mounted to the axle 11 by the first bearing 12 and an additional fourth bearing 15 axially spaced from the concentric first and second bearings 12, 13. This minimizes the number of bearings of the assembly 100, and thus the overall weight. Alternatively, the cylindrical driver body 30 can be bearing mounted to the axle 11 by the fourth bearing 15 and an additional fifth bearing 16, both being axially spaced from the concentric first and second bearings 12, 13. This allows for easy replacement of the cylindrical driver body 30. The bearings described herein may be roller bearings.

In the example of figures 1A and IB, the first coupling mechanism 50 is external to the sealed hub chamber 18. The first coupling mechanism here includes a first coupling 51, arranged at the input 21 of the intermediate drive body 20. The first coupling 51 is in this example a unidirectional first clutch 51, such as a freewheel. The unidirectional first clutch 51 is arranged for transferring torque between the cylindrical driver body 30 to the intermediate drive body 20 in only one rotation direction about the axis A, more specifically the forward drive direction. Hence, for example, the unidirectional first clutch 51 enables cylindrical driver body 30 to drive the intermediate drive body 20 in a forward rotation direction about the axis A, but not in a backward rotation direction about the axis A. The unidirectional first clutch 51 hence also allows the intermediate drive body 20 to rotate in the forward direction at a larger rotational speed than the driver body 30, i.e. overrunning the unidirectional first clutch 51. The first coupling 51 may be detachable for allowing the cylindrical driver body to be detached from the hub shell 10, e.g. for replacement or service. Thereto the first coupling may e.g. also include a splined connection to the intermediate drive body 20.

In the example of figures 1A and IB, the second coupling mechanism 60, at the output 22 of the intermediate drive body 20, includes a second coupling 62. The second coupling 62 is here a bidirectional second coupling 62, e.g. a detachable coupling such as a splined coupling or a fixed direct connection, coupling the intermediate drive body output 22 to the ring gear 43 of the transmission. Hence, here, the ring gear 43 is drivable in rotation about the axis A by the cylindrical driver body 30, via the intermediate drive body 20. In a decoupled state of the actuatable clutch 45, the ring gear 43 in turn drives the planet carrier 42 in rotation about the axis A at a reduced rotation speed compared to the ring gear 43. In a coupled state of the actuatable clutch 45, the ring gear 43 and the planet carrier 42 corotate about the axis A at an equal rotation speed.

The second coupling mechanism 60, at the output 22 of the intermediate drive body 20, in this example includes a third coupling 63. The third coupling 63 is, here, arranged to couple the intermediate drive part 20 to an input of the actuatable clutch 45. Here, the third coupling 63 is a unidirectional third clutch 63, e.g. a freewheel clutch. The unidirectional third clutch 63 prevents lockup of the transmission 60 if the hub shell 10 is rotated in the backward rotation direction, e.g. when the bicycle is rolled rearwards, and the actuatable clutch 45 is in the coupled state, since the ring gear 43 is enabled to rotate faster backwards about the axis A than the planet carrier 42. The third unidirectional clutch 63 is accordingly overrun if the bicycle is rolled backwards, and the actuatable clutch is in the coupled state.

Figures 2A and 2B show an example of a hub assembly 100 similar to the example of figures 1A and IB. In the example of figures 2A and 2B, however, the first coupling mechanism 50 includes a bidirectional first coupling 51, and the second coupling mechanism 60 includes a unidirectional second clutch 62. The first coupling mechanism 50 is arranged external to the sealed hub chamber 18. The first coupling mechanism 50 is, here, particularly arranged for allowing the cylindrical driver body 30 to be easily detached from the intermediate drive body 20. The bidirectional first coupling 51 may for example provide a splined connection between the cylindrical driver body 30 and the intermediate drive body 20. The unidirectional second clutch 62 allows for freewheeling when the actuatable clutch 45 is in the coupled state or uncoupled state. Hence, in this example, the second unidirectional clutch 62 couples the intermediated drive body 20 to the ring gear 43 in only one rotation direction, particularly the forward drive direction.

Figures 3A and 3B shows an example similar to the example of figure 2. In the example of figures 3A and 3B, however, the first coupling mechanism 50 is located internal to the, in this example sealed, hub chamber 18. Hereto, in this example, the cylindrical driver body 30 extends with one end thereof into the sealed hub chamber 18. The first coupling mechanism 50, here, comprises a bidirectional first coupling 51. The bidirectional first coupling 51 can be a fixed direct connection. Alternatively, the bidirectional first coupling can be a detachable connection, such as a splined connection. The intermediate drive body 20 thus is located, in this example, entirely within the sealed hub chamber 18. Figure 4 shows an example of a hub assembly 100 similar to the example of figure 1. In the example of figure 4, however, the actuatable clutch 45 is arranged on a non-drive side of the transmission 40, i.e. opposite the cylindrical driver body 30 relative to the transmission 40. In the example of figure 1, the actuatable clutch 45 is arranged on a drive side of the transmission 40. Also, the clutch actuator 46 is arranged on the nondrive side of the transmission 40. In particular, here the clutch actuator 46 is arranged to the non-drive side of the actuatable clutch 45. In this arrangement, the clutch actuator can be easily connected to an external electronic device, such as shifter device, external battery, and/or external controller. Here, the shift actuator 46 is connectable to the external electronic device by a wire 70. The wire 70 extends from the shift actuator 46 to an external terminal 73, external to the sealed hub chamber 18, between the axle 11 and a bearing 14 by which the hub shell 10 is bearing mounted to the axle 1. Alternatively, the wire 70 may extend between the bearing and the hub shell 10. It is also possible that the shift actuator 46 is wirelessly connectable to the external electronic device. Thereto, the hub assembly 100 may include a receiver and/or transmitter, e.g. in the sealed hub chamber 18. It will be appreciated that the actuatable clutch 45 can be arranged on a non-drive side of the transmission 40, and optionally the clutch actuator 46 can be arranged to the non-drive side of the actuatable clutch 45, in the examples of figures 2A, 2B, 3A and 3B as well. It will be appreciated that the wire 70 and/or receiver/transmitter can also be included in the examples of figures 2A, 2B, 3A, 3B and 6.

Figure 5 shows an example of the hub assembly 100 similar to the example of figure 4. The example of figure 5 includes a cassette of sprockets 74, here having eleven sprockets. In this example it can be seen that the bearings 12 and 13 are arranged axially overlapping. In the example of figure 5, the hub shell 10 includes an inner hub shell 10A and an outer hub shell 10B. Here, the outer hub shell 10B is detachably mounted to the inner hub shell 10A. Here, the spoke flanges 71, 72 are part of the outer hub shell 10B. This provides the advantage that the outer hub shell 10B can remain with the spokes, rim and optionally tire, while the inner hub shell 10A can remain with the transmission. This can facilitate exchanging tires relative to the transmission.

Optionally, the hub shell 10, e.g. the inner hub shell 10A may house an electrical actuator of the transmission and/or a wireless transceiver and/or an antenna and/or processor and/or a battery and/or an electrical generator and/or a pairing button. The electrical actuator may be configured to operate the transmission for switching from one transmission ratio to another. The wireless transceiver may be configured to receive and process a switching instruction, and e.g. relay it to the electrical actuator. The antenna may be configured to receive the switching instruction. The processor may be arranged for processing the switching instruction. The battery may be configured to provide electrical energy to the transceiver and/or actuator. The electrical generator may be configured to provide electrical energy to the transceiver and/or actuator and/or battery. The pairing button may be configured to bring the processor and/or transceiver into a pairing mode, such as for pairing with a controller, e.g. a shifter device, e.g. at the handlebar. The electrical actuator of the transmission and/or the wireless transceiver and/or the antenna and/or the processor and/or the battery and/or the electrical generator and/or the pairing button, may be connected to the hub shell, such as to the inner hub shell.

Figure 6 shows a bicycle 1000, comprising a hub assembly 100 as described herein. The bicycle 1000 comprises a frame 1024 with a front fork 1005 and a rear fork having a chain stay 1007, as well as a front wheel 1011 and a rear wheel 1013 located in the front and rear fork respectively. The bicycle 1000 further comprises a crank 1050, coupled to a front chain wheel 1019, wherein a chain 1023 threads over the front chain wheel 1019 and one of the sprockets of the cassette 74. A derailleur 1020 is provided for shifting the chain 1023 from one sprocket of the cassette 74 to another.

Herein, the invention is described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein, without departing from the essence of the invention. For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, alternative embodiments having combinations of all or some of the features described in these separate embodiments are also envisaged.

However, other modifications, variations, and alternatives are also possible. The specifications, drawings and examples are, accordingly, to be regarded in an illustrative sense rather than in a restrictive sense.

For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word ‘comprising’ does not exclude the presence of other features or steps than those listed in a claim. Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to ‘only one’, but instead are used to mean ‘at least one’, and do not exclude a plurality. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to an advantage.