WO2020222012A1

WO2020222012A1 - Bicycle wheel system

Info

Publication number: WO2020222012A1
Application number: PCT/GB2020/051061
Authority: WO
Inventors: Daniel Alan CAIN
Original assignee: Streamline Cycling Limited
Priority date: 2019-04-30
Filing date: 2020-04-30
Publication date: 2020-11-05
Also published as: GB201906088D0; GB202115790D0; GB2583717A; GB202002802D0; GB2597175A; GB2597175B

Abstract

A bicycle wheel system is disclosed. The bicycle wheel system comprises a bicycle wheel and at least one wheel cover. The bicycle wheel comprises attachment means for removably attaching the wheel cover to the bicycle wheel. The wheel cover is interchangeable with wheel covers of different dimensions (e.g. rim depths, profiles and/or widths) such that the wheel cover fitted to the bicycle wheel is suited to the riding conditions. The wheel cover can be chosen to minimise the aerodynamic drag of the bicycle wheel and/or how readily the bicycle wheel might catch a cross-wind, which can be two competing considerations. The wheel cover is quick and simple to secure to the wheel and, in an embodiment of the present invention, can be interchanged with another wheel cover (or simply removed) without removing the bicycle wheel from the bicycle frame.

Description

Bicycle Wheel System

The present invention relates to bicycles. In particular, the present invention concerns improvements to bicycle wheels which enable the aerodynamic profile of a bicycle wheel to be quickly and easily changed.

Background to the Invention

A single wheel can be responsible for 15 to 20% of the total aerodynamic drag

experienced by a cyclist and his or her bicycle, and the spokes and internal geometry of the wheel can be responsible for up to 40% of this drag. This drag is known to reduce, significantly, as the depth of the rim of the wheel increases and/or conjunction with adoption of a more aerodynamic shape. A similar effect can be achieved by covering (at least partially) the spokes of the bicycle wheel with a smooth (or relatively smooth) surface. Some track wheels dispense with spokes entirely and instead comprise discs (so-called disc wheels). Similar wheels may also be used in triathlon and road time trials.

However, employing deep rims and/or covering the spokes is not always desirable. In riding conditions where there are cross-winds, a bicycle wheel with deep rims and/or covered spokes would more readily catch the cross-winds, affecting the lateral stability of the bike. As such, different rim depths are best suited to suit different riding conditions, with the actual selection of the best rim depth for particular riding conditions a matter of skill and experience, taking into account a host of environmental conditions.

It is understood that a particular wheel can be considered fast for a particular set or range of riding conditions, but no particular wheel can be fast for all riding conditions. In addition to different rim depths, different rim profiles or shapes behave differently in different riding conditions, as do different rim widths.

A competitive cyclist will typically need to purchase several different wheel sets each with different rim depths, profiles and/or widths to accommodate different riding conditions and/or cycling events. For example, disc wheels may be appropriate for track events or certain road events such as time trials and triathlons, whereas wheels with minimal rim depth may be more appropriate if there is expected to be high cross-winds or a very hilly course. Furthermore, the profile shape and/or width of the rim will have a significant impact on the aerodynamic performance of the wheel. For example, and as explained further below, a narrow profile with a sharp curve may be particularly suited to a fast rider in low or no crosswind whereas a wider profile with a blunter curve may be better suited to a slow rider in a high crosswind.

In addition to the inconvenience of transporting and storing multiple wheel sets, as well as the significant cost of purchasing them, interchanging between different wheel sets is undesirable as this can be time consuming, will require appropriate tools and the necessary knowledge and experience.

For example, a cyclist must be sufficiently knowledgeable and proficient to ensure the brakes are safely configured once the bicycle wheel has been replaced. In addition, if replacing a rear bicycle wheel, a cyclist will need to release the wheel from the chain set when removing the wheel and reengage the chain set when fitting a different wheel. It is unlikely that alignment will be perfectly preserved in the changeover, especially if the new wheel has a different cassette from the removed wheel. Furthermore, once a particular wheelset has been selected, there is little or no opportunity to change it during an event, and as noted above any changeover will be very time consuming and it is unlikely that the cyclist would in any case be carrying the replacement wheel.

Other problems include that if a disc wheel for example is subject to a foreign object strike or is otherwise damaged, the whole wheel needs to be replaced at significant cost. Even wheels without complete coverage but deep rims are more prone to damage than those with shallower rims.

A cyclist may have a power meter fitted in the hub on the rear wheel of their bicycle.

These power meters are very expensive and as such it is unrealistic to have several different wheelsets each with their own power meter. It is therefore usual to have to completely rebuild the wheel with the hub on a different rim if they wanted to have power readings on a different wheel.

It is also noted that bicycle wheels known in the art commonly have valves which attach to an inner tube within the tyre. These valves extend through the rim and project into the interior space of the wheel and also contribute non-trivially to the total aerodynamic drag produced by the wheel. There is also a minor contribution to the total aerodynamic drag from spoke nipples, although it is important to be able to access these for truing. While some aerowheels have internal nipples to reduce drag, they are extremely hard to access and maintenance on the wheel is much more difficult; it usually involves complete removal of the tyre and rim tape, and specialist tools are required.

As an alternative to deep rims, there exist covers which can cover the spokes of a bicycle wheel to reduce the aerodynamic drag. These covers typically cover the full surface area of the wheels, thereby effectively replicating disc wheels, and so are not suitable for all possible riding conditions or events.

It is therefore an object of an aspect of the present invention to provide a bicycle wheel system that obviates or at least mitigates one or more of the aforesaid disadvantages of bicycle wheels known in the art.

Summary of the Invention

According to a first aspect of the present invention there is provided a bicycle wheel system comprising,

a bicycle wheel; and

at least one wheel cover,

wherein the bicycle wheel comprises first attachment means; and

wherein the at least one wheel cover is removably attachable to the bicycle wheel via the first attachment means.

Optionally, the at least one wheel cover is removably attachable to the first attachment means.

Preferably, the wheel cover comprises a first cover portion and a second cover portion.

Preferably, the at least one wheel cover is shaped or dimensioned to partially or fully cover a plurality of spokes of the bicycle wheel. When attached the at least one wheel cover reduces the aerodynamic drag of the bicycle wheel. Preferably, the at least one wheel cover is circular or substantially circular. Alternatively, the at least one wheel cover is annular or substantially annular.

Most preferably, the first cover portion is dimensioned to partially or fully cover a first surface or side of the bicycle wheel. Most preferably, the second cover portion is dimensioned to partially or fully cover a second surface or side of the bicycle wheel.

Optionally, the first cover portion comprises two or more sub portions. Preferably, the second cover portion comprises two or more sub portions. The sub portions combine to make up the respective cover portions, and may permit attachment without requiring removal of the bicycle wheel from a bicycle.

Preferably, the first attachment means is/are located on/in a rim of the bicycle wheel. Optionally, the first attachment means comprises one or more brackets which are attached to the rim of the bicycle wheel. Optionally, the one or more brackets are wider than the rim, and preferably wider than a tyre located within the rim. Optionally, the brackets are removable. The one or more brackets may be attached to the rim, bonded to the rim or integrally formed with the rim.

Alternatively, or additionally, the first attachment means is/are located on a central hub of the bicycle wheel. Alternatively, or additionally, the first attachment means comprises spokes of the bicycle wheel, or spokes of the bicycle wheel may comprise first attachment means. The first attachment means may permit direct attachment of the wheel cover to the spokes. Alternatively the first attachment means may comprise clips or other fixings on the spokes.

Preferably, the first attachment means comprises one or more apertures. Optionally, the one or more apertures are located in one or more projections, which may comprise plates or pads. The one or more projections may be attached to the bicycle wheel, for example by bolting, welding, riveting or other suitable connection. Alternatively, the one or more projections may be integrally formed with the bicycle wheel, for example by extrusion or other forming methods. Further alternatively, the one or more projections may be comprised in one or more brackets which are attached to the bicycle wheel, bonded to the wheel or integrally formed with the wheel. The brackets may be removeably attached so as to be replaced with brackets of different widths. Accordingly, the bicycle wheel system may comprise a plurality of brackets

Most preferably, the at least one wheel cover comprises second attachment means configured, adapted or arranged to cooperate with the first attachment means of the bicycle wheel.

Optionally, the second attachment means can fix cover sections of the at least one wheel cover together independently of the first attachment means to allow safe storage of the covers when they are not in use.

Optionally, the second attachment means comprises one or more pins or bosses.

Optionally, the one or more pins or bosses are dimensioned to form an interference fit with one or more apertures of the first attachment means. Alternatively, the second attachment means comprises one or more clips. The clips may cooperate or otherwise attach to the first attachment means. Optionally, clips on the first cover portion attach to clips on the second cover portion.

Alternatively, the first cover portion comprises one or more male second attachment means and the second cover portion comprises one or more female second attachment means adapted to receive the one or more male second attachment means.

Preferably, one or more male attachment means is lockable to one or more female attachment means.

Optionally, the one or more male second attachment means is rotatable within and relative to the one or more female second attachment means to lock the one or more male second attachment means to the one or more female second attachment means. The male attachment means may lock upon a quarter turn or half turn relative to the female second attachment means, for example.

Alternatively, the first cover portion may comprise a combination of one or more female second attachment means and one or more male second attachment means. The second cover portion may comprise a combination of one or more female second attachment means and one or more male second attachment means.

Optionally, the one or more male second attachment means comprises a bayonet pin or similar.

Alternatively, the first attachment means may comprise a tongue and the second attachment means may comprise a groove. Alternatively, or additionally, the first attachment means may comprise a groove and the second attachment means may comprise a tongue. The tongue and the slot may be continuous.

Alternatively, the bicycle wheel system comprises a third attachment means which cooperates with the first and second attachment means.

Preferably, the first and second attachment means each comprise one or more apertures. Preferably, the third attachment means is configured to pass through corresponding apertures of the first and second attachment means. The third attachment means may comprise one or more bolts or screws or bayonet fittings or the like.

Optionally, an inner edge of the first and second cover portions is shaped to cooperate with the spokes of the wheel. Optionally, the shape of the inner edge of the first cover portion corresponds with the shape of the inner edge of the second cover portion.

Optionally, the inner edge of the first cover portion comprises one or more clips to attach to the inner edge of the second cover portion, and vice versa.

Optionally, the at least one wheel cover is wider than a tyre located within the rim of the wheel. Optionally, an outer edge of the at least one wheel cover is configured to be received in a gap between the rim and the tyre. Alternatively, the at least one wheel cover is configured to cover the gap between the rim and the tyre. Preferably, an outer edge of the at least one wheel cover is configured to contact the tyre. Optionally, an outer edge of the at least one wheel cover is configured to cooperate with an outer surface of the tyre (and/or vice versa).

Optionally, the width of the at least one wheel cover is defined by the length of the second attachment means. The second attachment means may vary in length to allow different cover widths.

Optionally, the wheel cover is resilient. Optionally, the wheel cover or at least an edge of the wheel cover comprises a flexible material. The wheel cover or at least an edge of the wheel cover may comprise carbon fibre, plastic, foam and/or rubber.

Optionally, the wheel cover comprises varying thicknesses to provide regions of varying rigidity or flexibility. For example, thicker towards the centre of the wheel, and thinner towards the tyre where the cover overlaps.

Most preferably, the bicycle wheel system comprises a plurality of covers. Preferably, the plurality of covers are interchangeable.

Most preferably, the plurality of covers comprise covers of different sizes and/or shapes, including for example different depths, profile shapes and widths. Optionally, the first, second and/or third attachment means comprise one or more of screws, clips, magnets, or the like.

According to a second aspect of the present invention there is provided a method comprising:

providing a bicycle wheel with first attachment means; and

providing at least one wheel cover,

removably attaching the at least one wheel cover to the bicycle wheel via the first attachment means.

Most preferably, the bicycle wheel and the at least one wheel cover are comprised in the bicycle wheel system according to the first aspect.

Most preferably, the at least one wheel cover comprises second attachment means, which cooperates with the first attachment means of the bicycle wheel.

Embodiments of the second aspect of the invention may comprise features to implement preferred or optional features of the first aspect of the invention or vice versa.

According to a third aspect of the invention there is provided a bicycle wheel comprising first attachment means.

According to a fourth aspect of the invention there is provided a bicycle wheel cover which is removably attachable to a bicycle wheel comprising first attachment means.

Embodiments of the third and fourth aspects of the invention may comprise features to implement preferred or optional features of the first aspect of the invention or vice versa.

It is also foreseen that first and second cover portions of the first aspect may connect to one another directly to attach the wheel cover to the bicycle wheel. Accordingly, in a fifth aspect of the invention there is provided a bicycle wheel cover comprising a first cover portion and a second cover portion, wherein the first and second cover portions each comprise corresponding attachment means such that the bicycle wheel cover is removably attachable to a bicycle wheel by attaching the first cover portion to the second cover portion. Embodiments of the fifth aspect of the invention may comprise features corresponding to preferred or optional features of the first aspect of the invention or vice versa. For example, the attachment means may comprise one or more of screws, clips, magnets, bayonet fittings, quarter turn fittings or the like.

Brief Description of Drawings

There will now be described, by way of example only, various embodiments of the invention with reference to the drawings (like reference numerals being used to denote like features, whether expressly mentioned in the detailed description below or not), of which:

Figure 1 illustrates a bicycle wheel system in accordance with the present invention, showing a bicycle wheel and a wheel cover;

Figure 2 is a perspective view of the bicycle wheel system shown in Figure 1 with one cover portion attached;

Figure 3 is a perspective view of the bicycle wheel of the bicycle wheel system shown in Figure 1 with both covers omitted;

Figure 4 is a perspective view of the cover of the bicycle wheel system shown in Figure 1 with the wheel omitted;

Figure 5 is a close-up perspective view of the wheel of the bicycle wheel system shown in Figure 1 showing detail of the rim;

Figure 6 illustrates an alternative embodiment of the bicycle wheel system shown in Figure 1 , showing a close-up perspective view of the rim with one cover portion attached;

Figure 7 is a close-up view of the bicycle wheel system shown in Figure 6 showing detail of the attachment between cover portions and the rim;

Figure 8 illustrates an alternative embodiment of one cover portion of the wheel system shown in Figure 1 in which the cover portion comprises two sub portions;

Figure 9 illustrates a further alternative embodiment of the bicycle wheel system shown in Figure 1 , showing a full wheel cover;

Figure 10 illustrates in perspective view the bicycle wheel system of Figure 9; Figure 11 illustrates a close up view of an alternative embodiment of the bicycle wheel system shown in Figures 6 and 7 showing detail of an alternative attachment between cover portions and the rim;

Figure 12 illustrates a section of one cover portion of another alternative embodiment of the wheel system shown in Figure 1 , and specifically detail of the inner edge of the cover portion;

Figure 13 shows a cross section through three wheel covers which increase the overall width of a wheel when applied;

Figure 14 shows a cross section through three similar wheel covers to those illustrated in Figure 13 and which also significantly reduce drag;

Figure 15 illustrates an alternative bracket;

Figure 16 illustrates another alternative bracket; and

Figure 17 illustrates a further alternative bracket.

Detailed Description of the Preferred Embodiments

In the description which follows, like parts are marked throughout the specification and drawings (whether explicitly described or not) with like reference numerals. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of embodiments of the invention.

An explanation of the present invention will now be described with reference to Figures 1 to 10.

Figures 1 and 2 depicts a bicycle wheel system 101 comprising a bicycle wheel 102, having a rotational axis 103, and a wheel cover 104. The bicycle wheel 102 comprises a central hub 105 located along the rotational axis 103, and a circular rim 106 connected to the central hub 105 by a plurality of spokes 107, as can also be seen in Figure 3.

The bicycle wheel 102 further comprises a first surface or side 108 substantially opposing a second surface or side 109. The first and second surfaces or sides 108, 109 are centred about the rotational axis 103.

The wheel cover 104 is removably attached to the rim 106 and partially covers the spokes on first and second surfaces or sides 108, 109 of the bicycle wheel 102. As can be seen in Figure 4 the wheel cover 104 comprises a first cover portion 110, dimensioned to partially cover the spokes 107 on first surface or side 108 of the bicycle wheel 102, and a second cover portion 111 , dimensioned to partially cover the spokes 107 on second surface or side 109 of the bicycle wheel 102. When attached, the wheel cover 104 thereby reduces the aerodynamic drag of the bicycle wheel 102.

The first and second cover portions 110, 111 are substantially annular in shape. In this embodiment the inner edge 150 of each cover portion, that is the edge closest to the central hub 105, is shaped to cooperate with the spokes 107; for example comprising projecting portions 151 where the spokes 107 extends to the opposite surface or side 108, 109 of the bicycle wheel 102, and inset portions 152 where the spokes 107 extend to the same surface or side 108, 109 of the bicycle wheel 102. Projecting portions 151 and inset portions 152 on the first and second cover portions 110, 111 , respectively, correspond such that complete coverage is achieved. There may be provided further attachment means to attach respective inner edges 150 of the first and second cover portions 110,

111. This could be a simple click or interference fit (or just a guidance hole). Figure 12 illustrates a section of one such cover portion 510 of alternative embodiment in which a projecting portion 551 of an inner edge 550 of the cover portion 510 is provided with a clip 553 which attaches to a corresponding inset portion of a cooperating cover portion (not shown). It will be evident that the inset portions of the illustrated section (either side of the projecting portion) can attach to clips provided on corresponding projecting portions on the cooperating cover portion (not shown).

The wheel cover 104 is removeable and interchangeable such that, for example, a wheel cover 104 dimensioned to cover 30% of the spokes 107 on the first and second surfaces or sides 108, 109 of the bicycle wheel 102 can be replaced with a wheel cover

dimensioned to cover 80% or even 100% (such as illustrated in and described below in relation to Figures 9 and 10). The dimensions of the wheel cover 104 chosen to be fitted to the bicycle wheel 102 are dependent on the riding conditions. More specifically, it is a balance between minimising the aerodynamic drag of bicycle wheel 102 and how readily the bicycle wheel 102 might catch a cross-wind, and may take into account other factors such as the nature of the event and/or the skill of the rider.

The bicycle wheel 102 comprises first attachment means for attaching the wheel cover 104 to the bicycle wheel 102. As particularly shown in Figures 3 and 5, the first attachment means takes the form of a plurality of apertures 112 (in this case five on each side) each provided in a protrusion 113 (which may be a plate or pad for example). Each protrusion 113 is integral to the rim 106 of the bicycle wheel 102 and projects or extends from the rim 106 towards the central hub 105 of the bicycle wheel 102. Figure 5 depicts a set of corresponding protrusions 114 comprising a first protrusion 113a on the first surface or side 108 of the bicycle wheel 102 and a second protrusion 113b on the second surface or side 109 of the bicycle wheel 102. The first and second protrusions 113a, 113b are circumferentially aligned; in other words, at the same circumferential location about the wheel 102 such that the apertures 112 in the respective protrusions 113a, 113b are also aligned. As noted above, the bicycle wheel 102 comprises five sets of corresponding protrusions 114 distributed equally about the circumference of the bicycle wheel 102. As described in relation to the embodiments of Figures 13, 14, 15 and 16 below, it is also foreseen that the protrusions may be comprised in brackets which are attached to the bicycle wheel.

The wheel cover 104 comprises second attachment means for attaching the wheel cover 104 to the rim of the bicycle wheel 102. As can be seen in Figure 4, the second attachment means takes the form of a plurality of pins or bosses 115. The pins or bosses 115 are dimensioned to form an interference fit with a corresponding aperture 112 in the bicycle wheel 102. In this embodiment, the first 110 and second 111 cover portions each comprise five pins or bosses 115 distributed equally about the circumference of the cover portions 110, 111 where the pins or bosses 115 are orientated to engage and form an interference fit with the apertures 112 in the respective five sets of protrusions 114 on the bicycle wheel 102.

As will be appreciated by a person skilled in the art, the bicycle wheel 102 could comprise more or fewer than five sets of protrusions 114. Furthermore, instead of one or more sets of protrusions 114, there may be more or fewer protrusions 113 upon the first surface or side 108 than the second surface or side 109. Also, the protrusions 113 upon the first surface 108 may not be circumferentially aligned with the protrusions on the second surface 109. The number, location and arrangement of the pins 115 of the wheel cover 104 may be varied in order to correspond to the apertures 112 of the bicycle wheel 102. It is foreseen that a single protrusions (e.g. plates or pads) may be provided, perhaps centrally in the rim, instead of pairs of protrusions on both surfaces or sides.

It is also foreseen that the apertures may be provided in the rim itself, i.e. without the need to form, attach or otherwise provide protrusions in which the apertures are provided (as described above). This may have the advantage that when wheel covers are not fitted the aerodynamic drag is not increased undesirably.

Conveniently, the second attachment means may also permit cover portions to be attached together separately from the first attachment means, so as to store them together for example.

In an alternative, preferred embodiment, the second attachment means takes the form of one or more bayonet fittings 216. More specifically, the first cover portion 210 comprises a plurality of female bayonet pins 217 and the second cover portion 211 comprises a corresponding plurality of male bayonet pins 218. The female 217 and male 218 bayonet pins are dimensioned to pass through the apertures 212 on the first 208 and second 209 surfaces of the bicycle wheel 202 respectively. As shown in Figures 6 and 7, the female 217 and male 218 bayonet pins meet between a set of plates 214. The female bayonet pin 217 is dimensioned to receive the male bayonet pin 218 which can be rotated to lock the male bayonet pin 218 to the female bayonet pin 217, and/or vice versa, securing the wheel cover 204 to the bicycle wheel 202.

Note that the respective cover portions 210, 211 may comprise locking or retaining means to hold the male bayonet pin 218 and/or the female bayonet pin 217 (or equivalent second attachment means) in locked and/or unlocked positions. This would permit a user to set all the bayonet pins (for example) to a position in which they are able to interlock when the covers are aligned rather than require the user to align each in turn when joining the cover portions together. For example, a simple spring loaded ball bearing arrangement (or the like) with corresponding indentations in the cover would permit indexing or self-alignment of the rotatable pins in said locked and/or unlocked positions.

As will be appreciated by a person skilled in the art, the first cover portion 210 could comprise a combination of female 217 and male 218 bayonet pins and the second cover portion 211 would comprise the opposing combination of male 218 and female 217 bayonet pins. It will also be appreciated that the bayonet pins 216 may additionally form an interference fit with the apertures 212 as well as the locking functionality. This would prevent unwanted rattling for example, which in addition to an audible annoyance may cause the attachment to loosen over time.

In an alternative embodiment shown in Figures 9 and 10, there is shown a full wheel cover 404. Although described as an alternative embodiment, wheel cover 404 could

also/instead be comprised in a bicycle wheel system comprising a wheel 102/402 and wheel cover 104, providing a rider with three different wheel configurations; no cover, partial cover and full cover. The full cover comprises a first cover portion 410 and a second cover portion 411 ; the second cover portion 411 is not as deep as the first cover portion 410 in order to accommodate the cassette and chainset (not shown) as the wheel 402 is a rear wheel. As shown in Figure 10 in particular, when attached to the wheel 402 the cover 404 completely covers the spokes 407 of the wheel 402. In this embodiment, further detail of which is shown in Figure 11 , the male pin 418 comprises two projections which are aligned with and received in corresponding slots in the female pin 417. The end of the male pin 418 is thus inserted in the end of the female pin 417, whereupon a turn of the male pin 418 (in this case a quarter turn) locks the male pin 418 to the female pin 417. There may be provided a cam surface within the female pin which engages the protrusions such that the male pin 418 and female pin 417 are drawn together as the male pin 418 is rotated. There may also be provided a latching feature, such as a leaf, which prevents or restricts rotation of the male pin 418 in the opposite direction once locked.

In a further alternative embodiment (not shown), the first and second attachment means may take the form of a tongue and groove. The tongue may be provided on the rim and the groove on the wheel cover (or portions of the wheel cover) or vice versa, and the tongue and groove may be continuous around the rim of the bicycle wheel and the wheel cover, or may be discontinuous.

It is envisaged that any attachment means suitable for connecting the first cover portion to the second cover portion and/or to the bicycle wheel may be employed. By way of (non limiting) example it is foreseen that one or more of screws, clips, magnets or the like may be used.

As an additional alternative, like the first attachment means in embodiments described above, the second attachment means could also take the form of a plurality of apertures (in the cover portions). In such an embodiment, the bicycle wheel system may comprise a third attachment means which takes the form of a bolt or screw or other through-connector which passes through the aperture or apertures of the bicycle wheel and the

corresponding apertures of the cover portions, thereby securing the wheel cover to the bicycle wheel. Alternatively, instead of a bolt or screw, an fixing comprising an attachment or locking arrangement such as shown in Figure 6 or Figure 11 could be used to attach the cover portions to one another.

In a further alternative embodiment, Figure 8 shows a first cover portion 310 comprising two sub portions 319; this arrangement enables the first cover portion 310 to be attached to a bicycle wheel (not shown) without removing it from the bicycle frame (and associated chainset - also not shown). Of course, both the first 310 and 311 second cover portions may comprise two or more such sub portions 319 such that the bicycle wheel 302 does not have to be disconnected from the bicycle frame to fit the first 310 and 311 second cover portions. The wheel covers of any of the embodiments described above may be provided with sub portions in this way to enable attachment to the bicycle wheel without removal from the bicycle frame.

It is also envisaged that instead of the various first attachment means described above being located on or in the rim of the bicycle wheel, first attachment means could alternatively (or additionally) be located at, on or in the central hub of the bicycle wheel.

For example, if the wheel cover is dimensioned to cover 100% of the spokes on the first and second surfaces or sides, the central hub may comprise one or more plates or pads with corresponding apertures or simply apertures within the hub itself. If employed in addition to first attachment means provided on or in the rim this arrangement provides additional means for securing the wheel cover to the bicycle wheel. First attachment means could further alternatively (or additionally) be located on one or more of the bicycle spokes, or indeed comprise the bicycle spokes themselves. The spokes may be provided with clips and/or the wheel cover may be provided with clips with attach to those clips or to the spokes themselves as appropriate.

A key advantage of the bicycle wheel system of the present invention (and described herein in various exemplary embodiments) is that a cyclist would only need to purchase one bicycle wheel to which different dimensioned wheel covers could be interchangeably fitted. Another key advantage is that the first and second attachment means provide a quick and simple means to secure one or more wheel covers to the bicycle wheel. A wheel cover where the first and second cover portions comprise sub portions has the advantage that the bicycle wheel does not have to be detached from a bicycle frame to fit the wheel cover. This reduces the time, effort, skills and tools required to secure the wheel cover.

An experienced cyclist might even purchase covers of the same depth but different aerodynamic sections (for example one for crosswinds when it’s a windy day and one for low yaw angles when it’s a calm day). These will be much cheaper than buying multiple wheelsets as the cyclist won’t need to purchase additional spokes/hubs for each setup. Furthermore, if there is a foreign object strike on the aerodynamic cover section of the wheel, the cover can be replaced without having to replace the whole wheel.

Power meters are sometimes provided in the hub on the rear wheel of a bicycle.

Commonly, and because power meters are expensive pieces of kit, cyclists would need to completely rebuild the wheel with the hub on a different rim if they wanted to have power readings on separate wheels. The present invention means that a cyclist can have power readings at all times with different covers fitting over the same spokes/hubs/base rim.

It is also noted that the aerodynamic drag caused by protruding valves (which attach to the inner tube within the tyre) can be eliminated by selecting a cover which fits over the valve and covers it. As noted above there is also a minor contribution to the total aerodynamic drag from spoke nipples, which can be eliminated using the covers of the invention while maintaining relative ease of access to true the wheel if necessary (by simply removing the covers). As such there is no need to adopt internal nipples of the kind seen in some aerowheels.

Further advantages become apparent in the context of further embodiments as described below and with reference to the drawings.

Figure 13 shows a cross section through a wheel 602 having (a) a 50 mm depth cover 610a,611a, (b) a 80 mm depth cover 610b, 611b and (c) a full wheel cover 610c, 611c (view truncated) according to another embodiment of the invention. It will of course be understood that these dimensions are provided for example and for comparison only; any required size of cover can be provided without departing from the scope of invention. Note that the cover portions 610a/b/c, 611a/b/c are shown as a continuous cover although as described below (and consistent with the description above) they are separate but connected parts.

In this embodiment, the effective width of the wheel 602 is increased by the covers such that it is greater than the width of the tyre 621. This is partly facilitated by use of a bracket 613 which is attached to the inner surface of the rim 606 and which is itself wider than the rim 606 and the tyre 621. A similar effect could of course be achieved in an alternative embodiment using a bracket of similar width to the rim and the tyre but a cover comprising a thicker material or at least an internal projection in the region of the bracket, or alternatively the width of the covers could be determined by the length of the second attachment means; however this arrangement (wider bracket) allows the extra wheel width to be achieved without significant weight increase or complicating the internal configuration of the cover. Alternatively, the length of the protrusions 617,618 which provide the second attachment means may be increased or decreased to increase or decrease the effective width of the wheel.

A plurality of the brackets are disposed around the circumference of the wheel, ideally evenly spaced so as to distribute weight evenly. Clearly fewer brackets will contribute less weight. Note that the brackets may be removable so that they may be replaced with brackets of different widths to support covers providing the wheel with different effective widths.

The benefit of increasing the width of the wheel is that it increases the stall angle of the wheel. This is extremely important when cycling because the wind tends to change direction quickly with yaw angles ranging from 0-45 degrees depending on wind strength, cyclist speed and terrain. Increasing wheel width would conventionally require the rim to be widened, which has an inevitable effect on the weight of the wheel. As noted above, this embodiment allows the wheel width to be increased without unduly increasing the overall weight of the wheel.

As in previous embodiments, the actual profile of the cover as well as the depth can be varied according to a rider’s requirement. For example, the profile of one cover could be slightly narrower with a sharp curve in the profile, which is excellent for riders travelling at high speed and/or low crosswinds as the flow will stay attached to the wheel due to the reduced rate of change of curvature, therefore reducing drag. A wider profile with a blunter curve will perform better for slower riders and/or greater crosswinds as the airflow will stay attached to the surface that extends outwards beyond the tyre reducing drag and creating a more predictable stall. Also a wide profile with a sharp trailing edge and a narrow profile with a blunt trailing edge will provide other, different properties, suitable for certain conditions and disciplines. Any combination of widths and curve shapes can be used to predict the characteristics of the wheel and be used to the advantage of the rider when selecting their covers for the conditions on the day. Taking the embodiment shown in Figure 13(a), cover portions 610a and 611a are provided with corresponding protrusions 617,618 which engage one another and the bracket 613a to hold the cover in place. These protrusions 617,618 might comprise pins and bosses, male and female bayonet pins, magnets, threaded or adhesive interfaces, or any other suitable attachment arrangement.

Illustrating a similar embodiment, Figure 14 also shows a cross section through a wheel 702 having (a) a 50 mm depth cover 710a, 711a, (b) a 80 mm depth cover 710b, 711b and (c) a full wheel cover 710c,711 c (view truncated) according to another embodiment of the invention. Again, it will be understood that these dimensions are provided for example and for comparison only; any required size of cover can be provided without departing from the scope of invention.

In the embodiment shown in Figure 13 it will be noted that the edge of the cover closest to the tyre 621 curves inwards towards the tyre 621 and rim 606. In the embodiment shown in Figure 14 the effective width of the wheel 702 is also greater than that of the tyre 721 , but in addition the edge of the cover closest to the tyre 721 actually extends beyond the rim 706 so as to cover the gap 725 that occurs between the tyre 721 and the rim 706.

Covering the gap 725 between the tyre 721 and the rim 706 results in a significant aerodynamic benefit as it helps reduce turbulence and keeps the airflow attached as it rounds the tyre. It is known that a stall (high drag, low lift) occurs when the airflow separates from an object. This occurs when the rate of change of curvature of the surface of an object is too high (a tyre being a perfect example of this). By reducing this rate of change of curvature, the airflow can be kept attached to the wheel longer giving improved aerodynamic performance (e.g. reduced drag), especially at higher yaw angles.

The material used for the portions of the cover which meet the tyre might include carbon fibre, plastic, foam, rubber or similar, although the cover might be comprised entirely of such material of varying thicknesses (for example thicker towards the centre of the wheel where it is more important for the cover to be rigid, and thinner towards the tyre where it is more important - in this embodiment - for the cover to be flexible. It is preferred that this material, and/or the cover as a while, is resilient to as to urge the edge of the cover towards the tyre and also permit the cover to flex with the movement of the rubber tyre as the wheel rotates and also in the instance of a puncture where the tyre deflects. In addition to the configuration and/or arrangement of the cover itself, it is foreseen that the tyre could be shaped, configured or modified, for example by a small extrude, to cooperate with the edges of the covers. A smooth transition between the curve in the tyre and the curve of the wheel cover would help with the interface between the tyre and the covers on the rims with full coverage that meet with the tyre, and minimise turbulence and the possibility of breaking the airflow.

Note that the embodiments shown in Figures 13 and 14 are particularly applicable to disc brake wheels, because the braking surface (e.g. for caliper-style brakes) on the rim 606,706 is covered. However, it is envisaged that the cover might provide a braking surface for caliper-style brakes.

Figure 15 shows some additional detail of an exemplary bracket 813 which can be removably attached to the inner surface of a wheel rim 806. As can be seen from the drawing of the bracket itself in (a), the apertures in the protrusions do not comprise completely enclosed holes or through bores but instead comprise analogous recesses 813a which accommodate the attachment means 817,818. An indentation 813b is provided to help seat the attachment means 817,818. It will be realised that if a plurality of such brackets 813 are provided around the circumference of the wheel it is not necessary to have completely enclosed holes or through bores and the recesses 813a will suffice.

Figure 16 shows some detail of an alternative bracket 913 which dispenses with the protrusions altogether, although the indentation 913b is retained to aid in locating the attachment means 917,918 (here, and in the Figure 15 embodiment, the first attachment means or bracket might be interchangeably described as a locating means). As shown in (b) the male attachment means 917 comprises an extrusion 917a (female attachment means 918 is also provided with such an extrusion) which abuts the side of the bracket 913 and thus aids in securing the cover and preventing rattling. The extrusion 917a can completely bridge the gap between the bracket 913 and the cover, although this is not a requirement; as mentioned above it is possible to solely define the width of the cover by appropriate selection of the length of the attachment means 917/918. As shown, the extrusion 917a can extend partially around the circumference of the attachment means 917; this is possible because of the limited range of rotation of the attachment means 917 (which in this embodiment is a quarter-turn bayonet fitting), but it may extend fully around the circumference of the attachment means 917. It will be understood that a similar feature and function might be provided with a snap ring, washer, o-ring or other similar member instead of an extrusion.

Although in the foregoing embodiments the wheel cover is attached to the bicycle wheel via or using first attachment means provided on the wheel itself, it is foreseen that first and second cover portions of the wheel cover may instead connect to one another directly to attach the wheel cover to the bicycle wheel. In such an embodiment the first and second cover portions may each comprise corresponding attachment means such that the bicycle wheel cover is removably attached to a bicycle wheel simply by attaching the first cover portion to the second cover portion. The attachment means may comprise one or more of screws, clips, magnets, bayonet fittings, quarter turn fittings or the like. Alternatively, the cover portions may comprise apertures through which fittings may be inserted to attach and/or lock the cover portions together.

Note that, as intimated above, in any of the embodiments of the invention the width of the covers may be determined by the length of the second attachment means (or, in the absence of first attachment means on the bicycle rim, the length of the attachment means). The embodiment illustrated in Figure 17 helps to explain this feature. Figure 17 shows some additional detail of an exemplary bracket 1013 which can be removably attached to the inner surface of a wheel rim 1006. As can be seen from the bracket itself in (a), an indentation 1013b is provided to help seat the attachment means 1017,1018. It will be realised that the indentation 1013b aids in locating the attachment means

1017,1018. As shown in (c) and (d) the length of the attachment means 1017,1018 (and 1017’, 1018’) define the width of the cover. The shape or profile of the indentation 1013b matches the shape or profile of the attachment means 1017,1018 including, as shown in (b), the provision of corresponding shoulders. If an interference fit or push fit is formed (which is possible where there are a plurality of brackets and corresponding attachment means distributed around the wheel) it can assist when attaching the cover portions to the wheel as they will not fall off prior to applying the second attachment means, as well as ensuring no rattle between the second attachment means and the bracket and this would be true of all embodiments of the invention which employ an interference or push fit.

A bicycle wheel system is disclosed. The bicycle wheel system comprises a bicycle wheel and at least one wheel cover. The bicycle wheel comprises attachment means for removably attaching the wheel cover to the bicycle wheel. The wheel cover is

interchangeable with wheel covers of different dimensions (e.g. rim depths, profiles and/or widths) such that the wheel cover fitted to the bicycle wheel is suited to the riding conditions. The wheel cover can be chosen to minimise the aerodynamic drag of the bicycle wheel and/or how readily the bicycle wheel might catch a cross-wind, which can be two competing considerations. The wheel cover is quick and simple to secure to the wheel and, in an embodiment of the present invention, can be interchanged with another wheel cover (or simply removed) without removing the bicycle wheel from the bicycle frame.

Throughout the specification, unless the context demands otherwise, the terms“comprise” or“include”, or variations such as“comprises” or“comprising”,“includes” or“including” will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers. Furthermore, unless the context clearly demands otherwise, the term“or” will be interpreted as being inclusive not exclusive.

The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise form disclosed. The described embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilise the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Therefore, further modifications or improvements may be incorporated without departing from the scope of the invention.

Claims

1. A bicycle wheel system comprising,

a bicycle wheel; and

at least one wheel cover,

wherein the bicycle wheel comprises first attachment means located on or in a rim of the bicycle wheel; and

wherein the at least one wheel cover comprises second attachment means which cooperates with the first attachment means;

whereby the at least one wheel cover is removably attachable to the rim of the bicycle wheel.

2. The bicycle wheel system of claim 1 , wherein the at least one wheel cover is

removably attachable to the first attachment means.

3. The bicycle wheel system of claim 1 or claim 2, wherein the at least one wheel cover is shaped or dimensioned to partially or fully cover a plurality of spokes of the bicycle wheel.

4. The bicycle wheel system of any preceding claim, wherein the at least one wheel cover is circular or substantially circular.

5. The bicycle wheel system of any of claims 1 to 3, wherein the at least one wheel cover is annular or substantially annular.

6. The bicycle wheel system of any preceding claim, wherein the wheel cover

comprises a first cover portion and a second cover portion.

7. The bicycle wheel system of claim 6, wherein the first cover portion is dimensioned to partially or fully cover a first surface or side of the bicycle wheel.

8. The bicycle wheel system of claim 6 or claim 7, wherein the second cover portion is dimensioned to partially or fully cover a second surface or side of the bicycle wheel.

9. The bicycle wheel system of any preceding claim, wherein the first cover portion and/or the second cover portion comprises two or more sub portions.

10. The bicycle wheel system of any preceding claim, wherein the first attachment means comprises one or more brackets which are attached to the rim of the bicycle wheel.

11. The bicycle wheel system of claim 10, wherein the one or more brackets are wider than the rim, and preferably wider than a tyre located within the rim.

12. The bicycle wheel system of claim 10 or claim 11 , wherein the one or more brackets are removable.

13. The bicycle wheel system of any preceding claim, wherein the first attachment means comprises one or more apertures or recesses which receive the second attachment means.

14. The bicycle wheel system of claim 13, wherein the one or more apertures or

recesses are located in one or more projections.

15. The bicycle wheel system of claim 14, wherein the one or more projections are attached to the bicycle wheel, integrally formed with the bicycle wheel, or comprised in one or more brackets which are attached to the bicycle wheel.

16. The bicycle wheel system of any preceding claim, wherein the first attachment means comprises an indentation to locate the second attachment means.

17. The bicycle wheel system of any preceding claim, wherein the second attachment means comprises one or more pins or bosses.

18. The bicycle wheel system of claim 17, wherein the one or more pins or bosses are dimensioned to form an interference fit with one or more apertures of the first attachment means.

19. The bicycle wheel system of any preceding claim, wherein the second attachment means comprises one or more clips, and wherein optionally clips on the first cover portion attach to clips on the second cover portion.

20. The bicycle wheel system of any preceding claim, wherein the first cover portion comprises one or more male second attachment means and the second cover portion comprises one or more female second attachment means adapted to receive the one or more male second attachment means.

21. The bicycle wheel system of any preceding claim, wherein the one or more male second attachment means is lockable to the one or more female second attachment means.

22. The bicycle wheel system of any preceding claim, wherein the bicycle wheel system comprises a third attachment means which cooperates with the first and second attachment means.

23. The bicycle wheel system of claim 22, wherein the first and second attachment means each comprise one or more apertures and the third attachment means is configured to pass through corresponding apertures of the first and second attachment means.

24. The bicycle wheel system of any preceding claim, wherein the at least one wheel cover is wider than a tyre located within the rim of the wheel.

25. The bicycle wheel system of any preceding claim, wherein an outer edge of the at least one wheel cover is configured to be received in a gap between the rim and the tyre.

26. The bicycle wheel system of any preceding claim, wherein the at least one wheel cover is configured to cover the gap between the rim and the tyre.

27. The bicycle wheel system of any preceding claim, wherein an outer edge of the at least one wheel cover is configured to contact the tyre.

28. The bicycle wheel system of any preceding claim, wherein an outer edge of the at least one wheel cover is configured to cooperate with an outer surface of the tyre (and/or vice versa).

29. The bicycle wheel system of any preceding claim, wherein the wheel cover is resilient.

30. The bicycle wheel system of any preceding claim, wherein the wheel cover or at least an edge of the wheel cover comprises a flexible material.

31. The bicycle wheel system of any preceding claim, wherein the wheel cover or at least an edge of the wheel cover comprises carbon fibre, plastic, foam and/or rubber.

32. The bicycle wheel system of any preceding claim, wherein the wheel cover

comprises varying thicknesses to provide regions of varying rigidity or flexibility.

33. The bicycle wheel system of any preceding claim, wherein the bicycle wheel system comprises a plurality of wheel covers of different sizes and/or shapes, including for example different depths, profile shapes and widths.

34. The bicycle wheel system of claim 33, wherein the plurality of wheel covers are

interchangeable.

35. The bicycle wheel system of any preceding claim, wherein first, second and/or third attachment means comprise one or more of screws, clips, magnets, bayonet fittings or the like.

36. A method comprising:

providing a bicycle wheel with first attachment means;

providing at least one wheel cover with second attachment means; and

removably attaching the at least one wheel cover to the bicycle wheel;

wherein the bicycle wheel and the at least one wheel cover are comprised in a bicycle wheel system of any preceding claim.