Wheel and Bicycle

Abstract

An injection molded, one-sided mountable wheel for a bicycle, the wheel comprising a rim, a central hub, and a plurality of hollow spokes connecting the rim to the central hub.

Description

Technical Field

[0001] The present invention generally relates to a bicycle wheel, and more particularly to a one-sided mounted bicycle wheel.

Background Art

[0002] Most wheels of currently state-of-the-art bicycles are attached to the bicycle frame at two fixed points. Conventional bicycle wheels are attached at these two points, which are generally on both sides of the wheel center plane and usually involve fasteners that firmly connect the axle of the wheel hub to the rear or front fork frame members.

[0003] Such conventional two-sided mounted bicycle wheels have many advantages such as low manufacturing cost, light weight, robust structure, standardized manufacturing and maintenance, etc., but also have major drawbacks. To effectively access the tire and tube or to replace the tire and tube (such as when repairing a flat), it is necessary to completely remove the wheel from the bicycle frame and chain. Removing the front wheel of a conventional two-sided mounted wheel from the bicycle frame is relatively easy when using a so-called Quick release skewer and usually does not get grease on the user's hands.

[0004] However, removing the rear wheel of a conventional two-sided mounted wheel from a bicycle is usually a much more complex, cumbersome and troublesome operation, resulting in the user's hands or clothes being soiled with oil or dirt from the rear derailleur gear and chain system. There is also the complexity of ensuring that the brake system is released before removing the wheel and then safely readjusting it after reattaching the wheel to the frame. In the case of a bicycle frame with a conventional two-sided mounted wheel that employs a rear wheel planetary multi-stage gear hub, there is also the complexity that the user usually has to adjust the chain or belt tension using a so-called "horizontal rear dropout" or eccentric bottom bracket adjustment structure.

[0005] There are further drawbacks in the configuration of the frame of the two-sided mounted wheels, which become apparent when attached to a folding bicycle having a folding hinge mechanism for positioning the front and rear wheels in a coaxial configuration when folded. The frame of the two-sided mounted wheels causes the width of the folded bicycle to increase by the amount of the folded wheel axle, making the folded bicycle larger and bulkier, which is undesirable.

[0006] A few special bicycles such as Strida (trademark), Gocycle (trademark), IF Move (trademark), Mando Footloose (trademark), etc. are pioneers in the use of single-sided mounted wheels. The design of these single-sided mounted wheel bicycles has the unique advantage that the rider does not need to remove the wheel from the bicycle when removing the tire from the wheel.

[0007] The design of single-sided mounted wheels varies greatly depending on the current state-of-the-art single-sided mounted wheel bicycles. The differences relate to the selection of materials, the combination of materials in manufacturing, shape, and structure.

[0008] For example, in the design of the wheels of some single-sided mounted bicycles, since conventional bicycle technologies such as triangular wire spokes that connect a metal rim to a central hub with tension are adopted, the central hub is attached to a sufficiently large axle that fits into the bicycle frame on one side with bearings and in a cantilever arrangement.

[0009] The drawback of this design is that the structure of the wire spokes becomes relatively wide because it is necessary to form the spokes into a triangle and provide equal tension on each side of the center plane of the rim. This width is not desirable in the design of a folding bicycle or a design using disc brakes, because the disc brake caliper needs to be attached at the location where the wire spoke wheel is widest, i.e., close to the center rotation axis of the wheel. Since the disc brake caliper needs to have sufficient clearance from the rotating spokes, it is necessary to additionally widen the width of the entire structure of the wheel mounting of the disc brake caliper.

[0010] A further disadvantage of designs using single-sided mounted wire spoke wheels is that the spokes, due to their complex nature and the large number of spokes, are difficult to keep clean as they pick up dirt and grease during riding. Wire spoke wheels also sometimes require regular maintenance to keep the spoke tension constant and ensure proper wheel operation.

[0011] In other single-sided mounted wheel designs, the single-sided mounted wheels are made by subjecting materials such as fiber-reinforced plastics, or resins and glass or carbon matrices, or aluminum or magnesium to injection molding or casting, or forging or vacuum or pressure forming composite material manufacturing processes. In these designs, generally, the spokes are formed to curve, or the spokes are connected to the rim and hub such that the hub or area connecting the wheel to the bicycle is offset to one side of the central plane of the wheel.

[0012] The fixing structures of these single-sided mounted wheels are similar to those of automobiles and usually take the form of several hub mounting bolts for connecting the wheel to a rotatable hub, a disc brake, and a stub axle assembly. The advantage of the curved spokes offset from these wheel centerlines is that there is space to accommodate the disc brake caliper due to the offset of the spokes, and the mounting structure of the wheel and hub becomes more compact. Also, in these cantilevered single-sided mounted wheels, compared to wire spoke wheels, the aerodynamic performance is improved, and their smooth shape and fewer spokes make them easier to clean than wire spoke wheels.

[0013] However, current state-of-the-art cantilevered single-sided wheels have several disadvantages. Generally, the materials and processes used to create the above shapes can result in wheels that are either heavy, or expensive, or lack sufficient strength or rigidity for safety and performance.

[0014] In the case of the design and structure by casting or forging of magnesium or aluminum, since the metal requires painting, the weight and cost further increase, and when the base metal is porous, problems may occur in the surface finish.

[0015] In the case of plastic injection molded wheels, the wheels do not require paint and the manufacturing process can be very low cost. However, the materials used lack sufficient rigidity and strength for the required weight, and when trying to give enough strength to meet safety requirements, the wheels tend to become too heavy.

[0016] For injection molded rims made of glass-reinforced plastic materials, there are significant problems especially when high-pressure tires are mounted, or when the user inflates the tires at a pressure higher than the rim rating. If these rims are not properly designed, they can cause catastrophic failures, and generally, additional materials are required for substantial reinforcement, increasing the weight.

[0017] In some designs, attempts have been made to overcome the problems of high-pressure tires mounted on injection molded plastic rims by using a conventional metal extruded rim that is bolted or glued or joined to a sub-assembly consisting of injection molded plastic spokes and hubs. The disadvantages of this approach generally include increased cost, increased weight, as well as the complexity and durability of joining different materials, and long-term reliability.

[0018] All of these material and manufacturing process designs are subject to the limitation that a hollow box cross-section cannot be adopted. If this were adopted, the stress of the material could be reduced without increasing the weight, and the rigidity could be increased. In generally available manufacturing processes such as auto-injection molding, forging, or casting, only designs that adopt a "U" channel or "I-beam" channel cross-section (for example, a hollow cross-section is impossible) are possible, but they are substantially inferior in terms of specific strength and rigidity compared to the hollow box cross-section structure.

[0019] Wheels made of carbon or glass composite materials can adopt a box cross-section structure, and the internal core is filled with a core of air, foam, or metal matrix that is bonded to the outer carbon fiber or glass fiber wall. This design provides a very strong, rigid, and lightweight wheel, but the price is significantly higher. This high price is due to the complex manufacturing method, the high material cost of the composite material fibers, and the multi-piece structure.

[0020] When a bicycle wheel fails, it can lead to serious injury or death. Therefore, bicycle wheels need to be constructed to withstand extreme conditions such as over-inflation of pneumatic tires or being stored in very hot or very cold conditions (e.g., inside a car on a hot day or in the snow outdoors). Since the wheel forming process and specific geometries can change the properties of the wheel materials such as strength and rigidity, manufacturers have chosen a trial-and-error method to reduce the risk of failure.

Summary of the Invention

[0021] A first aspect of the present invention is a wheel for a bicycle that can be cantilever-mounted on one side by injection molding, comprising a rim, a central hub, and a plurality of hollow spokes connecting the outer rim to the central hub.

[0022] A wheel that can be mounted on one side is a wheel that can be attached only from one side.

[0023] Preferably, the central hub is offset from the plane defined by the center line of the outer rim.

[0024] Conventional injection molding techniques cannot be used to create hollow structures such as hollow spokes, so such a design is contrary to conventional injection molding designs.

[0025] There exists a relatively new manufacturing process known as the "lost core" or "soluble core" process. This process is based on low-cost and high-efficiency injection molding, but can adopt an internal hollow structure such as a hollow spoke. The central solid "lost core" is usually made of metal and is usually removed by dissolving it in a liquid and discharging it from the part after the injection molding process.

[0026] Since the final part has a hollow "box" cross-sectional structure, compared with the one-sided mounted wheels of conventional injection molding, this wheel is substantially improved in terms of specific strength and rigidity, and can achieve a lightweight structure commensurate with the manufacturing cost.

[0027] Manufacturing a one-sided mounted wheel using the lost core process is particularly difficult because the central hub is displaced from the plane defined by the center line of the rim (i.e., the location where the spoke connects to the central hub is displaced from the plane where the center line of the wheel's rim is located), so the wheel becomes asymmetric, and due to temperature changes during the molding process, there is a risk that the wheel will shrink asymmetrically and / or deform and / or bend. Therefore, using the lost core process for a cantilevered one-sided mounted wheel with an asymmetric geometry and shape has not been considered before. Such a wheel design is typically used when a disc brake is used instead of a caliper brake. Using a caliper brake that contacts the rim of the wheel to provide braking force is often avoided for previous forms of injection molded wheels because the caliper brake mainly has a harmful effect on the material of the rim that forms the wheel due to heating during braking.

[0028] This wheel can also be used in other vehicles such as scooters, tricycles or quadricycles, and can also be used with wheels commonly used or usable in bicycles.

[0029] Preferably, the rim includes a hollow cross-section. The term "rim" is intended to mean a wheel rim typically supported by spokes. It may have additional features that extend further outward from the hub than the outer rim, such as a wheel frame and / or a tire. Thus, the rim is also referred to as the outer rim or the wheel rim.

[0030] Preferably, the wheel is configured to receive a pneumatic tire.

[0031] The wheel may have a hub at its radial center, and the hub may be attachable to an axle or may provide an axle. The hub may have a surface that provides an inner wheel hub surface. The inner wheel hub surface may provide a ring, such as a ring, arranged to engage with the axle during use. Preferably, the inner wheel hub surface of the wheel includes a plurality of inner discharge holes. More preferably, each inner discharge hole of the plurality of inner discharge holes is substantially aligned with one innermost end of each of the plurality of hollow spokes.

[0032] Preferably, the outer surface of the rim includes a plurality of outer discharge holes. More preferably, each outer discharge hole of the plurality of outer discharge holes is substantially aligned with one outermost end of each of the plurality of hollow spokes.

[0033] The outer surface of the rim may be a wheel rim tube contact surface. Strategically positioned and shaped holes (such as inner discharge holes and / or outer discharge holes) allow the "lost core" to be melted and discharged from the wheel after injection molding.

[0034] Preferably, each outer discharge hole of the plurality of outer discharge holes includes a surrounding reinforcement area.

[0035] Preferably, the linear size of the reinforcement area is between 2.0 times and 4.0 times, preferably between 2.0 times and 3.0 times, and most preferably 2.5 times larger than the linear size of each respective outer discharge hole.

[0036] The linear size refers to the width and length of the outer discharge hole. For example, the length and width of each reinforcing region are preferably between 2.0 times and 3.0 times, and most preferably 2.5 times larger than the length and width of the outer discharge hole, respectively.

[0037] Preferably, the outer discharge hole is (substantially) elliptical, and the width of each outer discharge hole is between 6 millimeters and 10 millimeters, preferably between 7 millimeters and 9 millimeters, and most preferably 8 millimeters. The length of each outer discharge hole is between 16 millimeters and 24 millimeters, preferably between 18 millimeters and 22 millimeters, and most preferably 20 millimeters.

[0038] Optionally, the width of each outer discharge hole is about 8 millimeters, and the length of each outer discharge hole is about 20 millimeters.

[0039] The relatively high air pressure of the pneumatic tire causes extreme stress on the outer surface of the rim. The reinforcing material around the discharge hole and the valve stem hole distributes the stress evenly, enabling the use of low-cost materials such as 15% glass-filled nylon 66. For non-pneumatic tires such as solid rubber tires, the stress generated by the tire is much lower and there are fewer fluctuations (such as overfilling of pneumatic tires by the user or changes in tire pressure due to temperature or altitude), so such problems are not considered.

[0040] Preferably, the wheel further comprises a tire valve stem hole on the outer surface of the rim configured to receive the tire valve stem.

[0041] Preferably, the tire valve stem hole includes a surrounding reinforcing region.

[0042] Preferably, each reinforcing region has a thickness between 1.5 times and 3 times, preferably between 2.0 times and 3.0 times, and most preferably 2.5 times the nominal thickness of the outer surface.

[0043] Preferably, the nominal thickness of the outer surface is between 1.5 millimeters and 3.5 millimeters, preferably between 1.9 millimeters and 3.1 millimeters, more preferably between 1.9 millimeters and 2.1 millimeters, and most preferably 2.0 millimeters. The term "nominal thickness" is intended to mean the typical thickness of the material from which the wheel is made to which thickening does not apply, where thickening refers to intentional thickening or corners or locations with increased curvature where the thickness may increase, and such locations where no thickening is performed may be present on the side of the rim and the central portion of each spoke.

[0044] Optionally, the wheel includes a hub connection surface arranged to abut the bicycle when the wheel is attached to the bicycle, and the abutment surface is offset from the plane defined by the centerline of the rim.

[0045] Optionally, the axis of each hollow spoke extending along the longitudinal direction of each spoke is curved. This axis may be a radial axis with respect to the wheel (however, it may be oriented at an angle with respect to the plane in which the rim is located).

[0046] The offset hub connection surface and the curved spokes can provide more space for the disc brake.

[0047] Optionally, the cross-sectional area of each hollow spoke smoothly decreases radially outward from the center of the wheel.

[0048] Optionally, the wheel further comprises a central spar web structure that extends symmetrically within each hollow spoke and is perpendicular to the plane defined by the centerline of the rim. Such a spar serves to stabilize the spoke during cooling in the forming process and helps to stabilize the outer shape of the spoke to increase the lateral rigidity of the wheel.

[0049] Optionally, the wheel further comprises a conical central wheel hub coaxial with the center of rotation of the wheel.

[0050] Preferably, the diameter of the wheel is less than 500 millimeters.

[0051] Preferably, the diameter of the wheel is greater than 300 millimeters.

[0052] Preferably, the hub of the wheel includes a plurality of through holes parallel to the central rotation axis of the wheel, arranged to receive the respective plurality of bolts.

[0053] Preferably, the wheel is a lost-core injection molded single-sided mounted wheel or a soluble-core injection molded single-sided mounted wheel.

[0054] Preferably, the wheel is made of glass-filled nylon. For example, the wheel can be made of (about) 15% glass-filled nylon 66. Of course, other glass filling rates (%) and other types of nylon can also be used.

[0055] Preferably, the wheel is formed of a homogeneous material.

[0056] Optionally, the wheel may include five hollow spokes, six hollow spokes, or seven or more hollow spokes.

[0057] As a second aspect of the present invention, there is a bicycle including the wheel of the first aspect.

[0058] Preferably, the wheel is attached to the bicycle with a plurality of bolts and a wheel hub collar. Further, the wheel hub collar may be used as an axle.

[0059] The wheel hub collar reduces the stress of the material by evenly spreading the pressing load from the bolts over the entire wheel.

[0060] Preferably, the bicycle further includes a pneumatic tire attached to the wheel.

Brief Description of the Drawings

[0061] Examples of the present invention will now be described in detail with reference to the accompanying drawings.

[0062]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

DETAILED DESCRIPTION OF THE INVENTION

[0063] FIG. 1 shows a bicycle with a cantilever single-sided mounted wheel.

[0064] As shown in FIG. 2, on the rear side of the bicycle, a disc brake rotor 7 is firmly attached to a rotatable wheel hub 23 and is interlocked with a brake caliper 3 firmly attached to the bicycle 1. In order to attach the cantilever single-sided mounted wheel 2 to which the tire 4 is attached to the rotatable wheel hub 23 on the rear side, a plurality of wheel hub collar attachment bolts 6 are used to press the wheel hub collar 5 against the cantilever single-sided mounted wheel 2, thereby firmly attaching it to the rotatable wheel hub 23 on the rear side.

[0065] A perspective view of the cantilever single-sided mounted wheel 2 is shown in FIG. 3, and FIG. 3 shows a cut-away cross-section through the curved wheel spokes 11, the central wheel hub 21, and the inner shape 22 of the wheel rim, and the wheel rim tube contact surface 8. The cantilever single-sided mounted wheel 2 has a uniform structure and is made of a homogeneous material throughout.

[0066] The material properties of the cantilevered single-sided mounted wheel 2 are ideally fiber-reinforced plastics that can be injected into a mold in a heated, liquid state and then cooled and solidified. The manufacturing process of the cantilevered single-sided mounted wheel 2 is a so-called "lost core" or "soluble core" injection molding process, whereby an individual, usually metallic core is used to form an internal hollow structure during the injection molding stage and is then removed from the part by dissolving the core and washing or discharging it.

[0067] The cantilevered single-sided mounted wheel 2 is generally circular and conical and is formed by a central wheel hub 21 that is coaxial with the rotation center of the cantilevered single-sided mounted wheel 2, and further has a planar wheel hub connection surface 19 that is substantially orthogonal, and ideally this surface is parallel to the vertical plane of the cantilevered single-sided mounted wheel 2. As an alternative, the central wheel hub 21 and the wheel hub connection surface 19 may be combined to form a conical taper shape.

[0068] Through the wheel hub connection surface 19, there are a plurality of wheel hub attachment bolt holes 9 for attaching the cantilevered single-sided mounted wheel 2 to the bicycle 1. Inside the central wheel hub 21, there are a plurality of inner spoke discharge holes 10 that are generally aligned with each curved wheel spoke 11.

[0069] The function of the inner spoke discharge holes 10 is to make the inner core of the "lost core" manufacturing process removable after the material of the cantilevered single-sided mounted wheel 2 has solidified. The shape of each inner spoke discharge hole 10 is approximately round (e.g., circular) or elliptical and has a smooth and uniform geometric shape with minimal sharp edges or corners.

[0070] Each curved wheel spoke 11 generally has a hollow "box cross-section" design and a uniform thickness. Ideally, five curved wheel spokes 11 are provided to reduce the material stress applied from the curved wheel spokes 11 to the inner shape of the wheel rim 22, but wheels with other numbers of spokes are also envisioned and may have three or more spokes.

[0071] The wheel rim inner shape 22 and the wheel rim tube contact surface 8 are integrally connected to the curved wheel spoke 11 by a continuous and smooth transition of the shape, and these are made in a generally hollow "box section" configuration that can receive the bicycle tire and tube. The wheel rim inner shape 22 and the wheel rim tube contact surface 8 have a tire valve stem hole 13 that can receive the valve stem of the bicycle tube in order to inflate the tube and tire with air.

[0072] The wheel rim tube contact surface 8 has a plurality of outer spoke discharge holes 12 that are substantially aligned with each curved wheel spoke 11. The function of the outer spoke discharge holes 12 is the same as that of the inner spoke discharge holes 10, which is to make the inner core of the "lost core" manufacturing process removable after the solidification of the material of the cantilevered single-sided mounted wheel 2. The shape of the inner spoke discharge holes 10 is substantially circular or elliptical, with a smooth and uniform geometry having minimal sharp edges or corners.

[0073] The discharge holes 10, 12 are depicted as being aligned with the spokes 11, but other discharge holes may be added and positioned in other locations, for example, in the regions between the spokes.

[0074] Figure 4 is a vertical cross-sectional view showing the cantilevered single-sided mounted wheel 2 attached to the front-side rotatable wheel hub 14 in the central wheel hub 21, and the front wheel hub bearing 15 having a plurality of wheel hub collar mounting bolts 6 and a wheel hub collar 5. The function of the wheel hub collar 5 is to evenly distribute the pressing load from each wheel hub collar mounting bolt 6 across the cantilevered single-sided mounted wheel 2 in order to reduce material stress.

[0075] The front-side rotatable wheel hub 14 is rotatably attached to the front-side fork shaft assembly 18, and a brake caliper 3 that interlocks with a disc brake rotor 7 firmly attached to the front-side rotatable wheel hub 14 is mounted thereon.

[0076] Each curved wheel spoke 11 is generally curved and offset from the center line plane of 2 so as to secure a space for the brake caliper 3. Similarly, the wheel hub connection surface 19 is substantially offset to one side with reference to the center line plane of the cantilever single-sided mounted wheel 2 so as to secure a space for the brake caliper 3.

[0077] Each outer spoke discharge hole 12 is surrounded by a reinforcing area 16 of the discharge hole of the outer spoke, and this area is generally twice the thickness of the nominal thickness of the wheel rim tube contact surface 8. The function of the outer spoke discharge hole reinforcing area 16 is to reduce the material stress around the front fork shaft assembly 18.

[0078] The size and shape of the reinforcing area 16 of the discharge hole of the outer spoke are generally larger than twice the outer spoke discharge hole 12 and smoothly connect to the wheel rim tube contact surface 8.

[0079] Similarly, the tire valve stem hole 13 is surrounded by a tire valve stem hole reinforcing area 20, and this area is generally thicker than twice the nominal thickness of the wheel rim tube contact surface 8 and the inner shape 22 of the wheel rim. The function of the tire valve stem hole reinforcing area 20 is to reduce the material stress around the tire valve stem hole 13.

[0080] The size and shape of the tire valve stem hole reinforcing area 20 are generally larger than twice the tire valve stem hole 13 and smoothly blend into the wheel rim tube contact surface 8.

[0081] The cantilever single-sided mounted wheel 2 is formed with a rim tire profile 17 that can accept standard bicycle tires and tubes.

[0082] FIG. 5 shows a cross-section of a spoke 11 having an optional central web structure 24. The central web 24 may extend over all or a part of the length of the spoke 11 and symmetrically extends within the spoke 11 in a plane perpendicular to the plane defined by the centerline of the outer rim of the wheel 2. The central web 24 stabilizes the spoke 11 during cooling in the forming process and stabilizes the outer shape of the spoke 11 to increase the lateral rigidity of the wheel 2.

Claims

1. A cantilever - type one - side - mountable wheel for a bicycle by injection molding, a rim including an inner shape and a tube contact surface, a central hub, a plurality of hollow spokes connecting the rim to the central hub, and a central spar symmetrically extending within each hollow spoke and forming a plane perpendicular to the plane defined by the center line of the rim, comprising: The cantilever - type one - side - mountable wheel has a uniform structure and is made of a homogeneous material throughout.

2. The wheel according to claim 1, wherein the central hub is offset from the plane defined by the center line of the rim.

3. The wheel according to any one of claims 1 - 2, wherein the rim includes a hollow cross - section.

4. The wheel according to any one of claims 1 - 3, wherein the wheel is configured to receive a pneumatic tire.

5. The wheel according to any one of claims 1 - 4, wherein the inner hub surface of the wheel has a plurality of inner discharge holes.

6. The wheel according to claim 5, wherein each of the plurality of inner discharge holes is aligned with the innermost end of each of the plurality of hollow spokes.

7. The wheel according to any one of claims 1 - 6, wherein the outer surface of the rim has a plurality of outer discharge holes.

8. The wheel according to claim 7, wherein each of the plurality of outer discharge holes is aligned with the outermost end of each of the plurality of hollow spokes.

9. The wheel according to claim 7 or claim 8, wherein each of the plurality of outer discharge holes includes a surrounding reinforcement region.

10. The wheel according to claim 9, wherein the linear size of the reinforcement region is 2.0 - 4.0 times larger than the linear size of each of the respective outer discharge holes.

11. The outer discharge holes are substantially elliptical, the width of each outer discharge hole is 6 millimeters to 10 millimeters, the length of each outer discharge hole is 16 millimeters to 24 millimeters. The wheel according to any one of claims 7 - 10.

12. The wheel according to claim 11, wherein the width of each outer discharge hole is about 8 millimeters and the length of each outer discharge hole is about 20 millimeters.

13. The wheel according to any one of claims 7 - 12, further having a tire valve stem hole on the outer surface of the rim configured to receive a tire valve stem, and the tire valve stem hole includes a surrounding reinforcement region.

14. The wheel according to any one of claims 8 to 13, wherein each reinforcing region is 1.5 to 3.0 times thicker than the nominal thickness of the outer surface.

15. The wheel according to claim 14, wherein the nominal thickness of the outer surface is 1.5 millimeters to 3.5 millimeters.

16. When the wheel is attached to a bicycle, the wheel includes a contact surface arranged to contact the bicycle, and the contact surface is offset from the plane defined by the center line of the rim. The wheel according to any one of claims 1 to 15.

17. The wheel according to claim 16, wherein the axis of each hollow spoke extending along the longitudinal direction of each spoke is curved.

18. The wheel according to any one of claims 1 to 17, wherein the cross-sectional area of each hollow spoke smoothly decreases radially outward from the center of the wheel.

19. The wheel according to any one of claims 1 to 18, wherein the diameter of the wheel is less than 500 millimeters.

20. The wheel according to any one of claims 1 to 19, wherein the diameter of the wheel is greater than 300 millimeters.

21. The wheel according to any one of claims 1 to 20, wherein the hub of the wheel includes a plurality of through holes parallel to the central rotation axis of the wheel, configured to receive respective plurality of bolts.

22. The wheel according to any one of claims 1 to 21, wherein the wheel is a one-sided mountable wheel by lost-core injection molding or a one-sided mountable wheel by soluble-core injection molding.

23. The wheel according to any one of claims 1 to 22, including five hollow spokes, six hollow spokes, or seven or more hollow spokes.

24. A bicycle comprising the wheel according to any one of claims 1 to 23.

25. The bicycle according to claim 24, wherein the wheel is attached to the bicycle using a plurality of bolts and a wheel hub collar.

26. The bicycle according to claim 24 or claim 25, further comprising a pneumatic tire attached to the wheel.

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