Skateboard tail truck

Abstract

A skateboard truck comprising a tail body with an elongated structure and a distal tail body bore, configured to twist along a defined twist axis. This twist axis is aligned with the elongation of the tail body. The tail body includes a first flexible rib designed to deflect in response to twisting along the twist axis. Additionally, the truck features a bushing that supports the tail body at the tail body bore and also supports an axle. This innovative design enhances the skateboard's maneuverability and responsiveness by allowing controlled flexibility and torsional movement, improving overall ride performance and stability.

Description

[0001]SKATEBOARD TAIL TRUCK BACKGROUND The present technology is directed to skateboard truck apparatuses. Skateboarding has evolved into several different disciplines such as trick, to vert, to high-speed downhill skating and as a form of exercise and transportation. Over long distance riding an operator typically employs a propulsion method known as “pumping”. Pumping involves turning back and forth across a generally straight direction. It’s been found that turning causes the operator to put more energy into the skateboard and causes it to accelerate. The applicant has found that by restricting the trailing or “tail” truck pumping is more efficient. Some of the embodiments include a skateboard with a truck like prior art for steering. This truck will be referred to as a conventional truck, another truck which is constrained to two degrees of freedom and is referred to as a tail truck. The conventional truck has an offset axis which allows the skateboard to turn. The tail truck restricts the axle compliance to vertical displacement of each wheel independently and rotationally about an axis perpendicular to this vertical displacement. The combination of the tail truck with the conventional truck mentioned above, uniquely allows for propulsion and stability at higher speeds. SUMMARY According to some examples, the present technology is directed to a skateboard truck that allows pivoting about the direction of travel and vertical compliance. In other examples, the present technology is directed to a skateboard truck that allows pivoting about a set direction and vertical compliance. In other examples, the skateboard truck is an integral part of the board of a skateboard. Groenenboom US9555314 discloses a skateboard truck which provides for vertical and tilting compliance. This device has a tilting compliance that is essentially linear. As the compliance is deflected (as in a turn) the torsion resistance increases linearly. The ability to adjust the tilting compliance would further enhance a skateboard truck. In general, a skateboard truck comprising a tail body having an elongated body a tail body bore on the distal end and configured to twist about a twist axis the twist axis oriented along the elongated body of the tail body the tail body further having a first flexible rib configured to deflect in response to a twist about the twist axis, and a bushing configured to support the tail body at the tail body bore and configured to support an axle. Some embodiments include a skateboard truck wherein the bushing is rigid. Some embodiments include a skateboard truck wherein the tail body includes a second flexible rib adjacent to the first flexible rib and the skateboard truck includes a first insert configured to transfer load from the first flexible rib to the second flexible rib in response to a twist about the twist axis. Some embodiments include a skateboard truck wherein the tail body includes a third flexible rib adjacent to the first flexible rib opposite the second flexible rib, and the skateboard truck includes a second insert configured to transfer load from the first flexible rib to the third flexible rib in response to a twist about the twist axis. Some embodiments include a skateboard truck wherein the bushing is flexible. Some embodiments include a skateboard truck wherein the bushing includes a hollow volume configured to determine a desired stiffness. Some embodiments include a skateboard truck wherein the insert includes a hole configured to determine a desired stiffness. Some embodiments include a skateboard truck wherein the tail body includes a second flexible rib adjacent to the first flexible rib and a third flexible rib adjacent the first flexible rib further the second and third flexible ribs are configured to support the first flexible rib. Some embodiments include a skateboard truck wherein the skateboard truck is removable from a board. Some embodiments include a skateboard truck wherein the tail body includes a twist axis and is configured to twist about the twist axis. Some embodiments include a skateboard truck wherein the tail body is configured to resist flexibility in any axis except the twist axis. Some embodiments include a skateboard truck wherein the first insert is square. Some embodiments include a skateboard truck wherein the first insert is cylindrical. Some embodiments include a skateboard truck wherein the first insert includes a hole, the hole configured to receive a third insert, and a third insert configured to fit into the hole. Some embodiments include a skateboard truck wherein the third insert is configured to be stiffer than the first insert. Some embodiments include a skateboard truck wherein the bushing is a bushing feature and is an integral feature of the tail body. Some embodiments include a skateboard truck wherein the bushing includes a hollow volume. A method comprising; riding a skateboard having the skateboard truck without the inserts installed, determining the flexibility of the skateboard truck, installing the inserts configured to transfer load from the first flexible rib to the second flexible rib, riding the skateboard having the skateboard truck with inserts installed, determining the flexibility of the skateboard truck, changing the flexibility of the insert, and riding the skateboard having the changed flexibility insert installed. A method of adjusting the stiffness of a skateboard truck comprising; riding a skateboard having the skateboard truck with the bushing having a hollow volume, determining the flexibility of the skateboard truck, removing the hollow volume from the bushing, riding the skateboard having the skateboard truck with the hollow volume removed installed, determining the flexibility of the skateboard truck, changing the material of the bushing, and riding the skateboard having the changed bushing material. Conventional trucks tend to squeak during use. The present device eliminates this squeaking. Since squeaking is generally caused by sliding compliant interfaces between bushings, eliminating this type of contact results in less squeaking. Due to the geometry of the present device sliding contacts are reduced. Conventional trucks include a cantilevered bolt supported at an angle for allowing turning. This turning function is a result of bending the cantilevered bolt and overcoming friction between the truck and bushings to slide the truck into a turning position. As a result of this conventional truck geometry, the cantilevered bolt, AKA kingpin is highly stressed. Additionally, the truck overall has a sloppy feel as the kingpin and bushings must move (or slide) to accommodate turning. The present device addresses these and other shortcomings of the conventional truck. A tail truck that eliminates a cantilevered kingpin and sliding bushing is disclosed. BRIEF DESCRIPTION OF THE DRAWINGS Fig.1 depicts an isometric view of a skateboard with a tail truck. Fig.2 depicts a broken top view of a skateboard with a tail truck. Fig.3 depicts a front view of a skateboard with a tail truck. Fig.4 depicts a broken side view of a skateboard with a tail truck. Fig.5 depicts a top view of a tilted turning skateboard with a tail truck. Fig.6 depicts a partial top view of a skateboard with a conventional truck tilting during a turn. Fig. 7 depicts a partial front view of a skateboard with a conventional truck tilting during a turn. Fig. 8 depicts a partial top view of a lilted skateboard with a tail truck tilting during a turn. Fig.9 depicts the top view of a skateboard tail truck. Fig.10 depicts a cross-section view indicated in Fig.9. Fig.11 depicts a front view of a bushing. Fig.12 depicts a side view of a bushing. Fig.13 depicts an isometric view of a bushing. Fig. 14 depicts a top view of a tail body indicating support and force locations for a finite elements analysis. Fig. 15 depicts a side view of a tail body indicating support and force locations for a finite elements analysis. Fig. 16 depicts an isometric view of a tail body indicating support and force locations for a finite elements analysis. Fig. 17 depicts a top view of a tail body approximately depicting deformation of the tail body as a result of a finite elements analysis in reaction to the supports and forces indicated in Figs.14-16. Fig.18 depicts a top view of a skateboard tail truck. Fig.19 depicts a cross-sectional view indicated in Fig.18. Fig.20 depicts an enlarged detail indicated in Fig.19. Fig.21 depicts side view of an insert. Fig.22 depicts a front view of an insert. Fig.23 depicts a bottom view of an insert. Fig.24 depicts a cross-sectional view indicated in Fig.21. Fig.25 depicts an isometric view of an insert. Fig. 26 depicts a flow chart for a method of adjusting the flexibility of a skateboard having a tail truck. Fig.27 depicts a broken top view of a skateboard with a flexible tail truck. Fig.28 depicts a front view of a skateboard with a flexible tail truck. Fig. 29 depicts a broken side view of a skateboard with a flexible tail truck. Fig.30 depicts a top view of a tilted turning skateboard with a flexible tail truck. Fig. 31 depicts a partial top view of a skateboard with a conventional truck tilting during a turn. Fig. 32 depicts a partial front view of a skateboard with a conventional truck tilting during a turn. Fig.33 depicts a partial top view of a tilted skateboard with a flexible tail truck tilting during a turn. Fig.34 depicts a top view of a flexible tail truck. Fig.35 depicts a cross-sectional view indicated in Fig.34. Fig.36 depicts a side view of a flexible bushing. Fig.37 depicts a front view of a flexible bushing. Fig.38 depicts an isometric view of a flexible bushing. Fig. 39 depicts a flow chart for a method of adjusting the flexibility of a skateboard having a flexible tail truck. Fig. 40 depicts an isometric view of a skateboard having an integrated tail truck. Fig.41 depicts a broken top view of a skateboard having an integrated tail truck. Fig. 42 depicts a front view of a skateboard having an integrated tail truck. Fig.43 depicts a broken side view of a skateboard having an integrated tail truck. Fig.44 depicts a partial top view of an integrated tail truck. Fig.45 depicts a cross-sectional view indicated in Fig.44. Fig.46 depicts a top view of a tail truck. Fig.47 depicts a cross-sectional view indicated in Fig.46. Fig.48 depicts a cross-section view indicated in Fig.46. Fig.49 depicts a top view of a tail truck. Fig.50 depicts a cross-sectional view indicated in Fig.49. DETAILED DESCRIPTION Various aspects and examples of a skateboard truck, as well as related methods, are described below and illustrated in the associated drawings. Unless otherwise specified, a skateboard truck in accordance with the present teachings, and / or its various components, may contain at least one of the structures, components, functionalities, and / or variations described, illustrated, and / or incorporated herein in connections with the present teachings may be included in other similar devices and methods, include being interchangeable between disclosed examples. The following description of various examples is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. Additionally, the advantages provided by the examples and examples described below are illustrative in nature and not all examples and examples provide the same advantages or the same degree of advantages. This Detailed Description includes the following section, which follows immediately below: (1) Definitions; (2) Overview; (3) Examples; (4) Advantages, Features, and Benefits; and (5) Conclusion . Definitions The following definitions apply herein, unless otherwise indicated. “Comprising,” “including,” and “having” (and conjugations thereof) are used interchangeably to mean including but not necessarily limited to, and are open-ended terms not intended to exclude additional unrecited elements, or method steps. Terms such as “first,” “second,” and “third” are used to distinguish or identify various members of a group, or the like, and are not intended to show serial or numerical limitations. “AKA” means “also known as,” and may be used to indicate an alternative or corresponding term for a given element or elements. The terms “inboard,” “outboard,” “forward,” “rearward,” and the like are intended to be understood in the context of a host vehicle on which systems described herein may be mounted or otherwise attached. For example, “outboard” may indicate a relative position that is laterally farther from the centerline of the vehicle, or a direction that is away from the vehicle centerline. Conversely, “inboard” may indicate a direction toward the centerline, or a relative position that is closer to the centerline. Similarly, “forward” means toward the front portion of the vehicle, and “rearward” means toward the rear of the vehicle. In the absence of a host vehicle, the same directional terms may be used as if the vehicle were present. For example, even when viewed in isolation, a device may have a “forward” edge, based on the fact that the device would be installed with the edge in question facing in the direction of the front portion of the host vehicle. “Coupled” means connected, either permanently or releasably, whether directly or indirectly through intervening components. “Resilient” describes a material or structure configured to respond to normal operation loads (e.g. when compressed) by deforming elastically and returning to an original shape or position when unloaded. “Rigid” describes a material or structure configured to be stiff, non- deformable, or substantially lacking in flexibility under normal operation conditions. “Flexible” describes a material or structure configured to spontaneously resume is former shape after being stretched and / or compressed. “Providing,” in the context of a method, may include receiving, obtaining, purchasing, manufacturing, generating, processing, preprocessing, and / or the like, such that the object or material provided is in a state and configuration for other steps to be carried out. “Operatively,” describes a connection between two devices or entities such that a function is provided from one entity to another. For example, a first entity may be operatively connected to a second entity for transferring force. In this example, a connection between first and second entity may be by gears, a belt, solder, or weld such that force (or torque) is transferred from first entity to second entity. “Force,” and “torque,” in this disclosure includes positive and negative values. For instance, force provided to object one from object two means, object one pushes or pulls on object two and / or object two pushes or pulls on object one. “Stress,” in this disclosure refers to force acting on any infinitesimal area located inside a load carrying member divided by the infinitesimal area. The direction of force relative each infinitesimal area determines the type of stress. “Tensile stress” refers to the stress acting perpendicular away from the infinitesimal area. “Compressive stress” refers to the stress acting perpendicular and into the infinitesimal area. “Shear stress” refers to the stress acting parallel to the infinitesimal area. Tensile stress in a negative direction is compressive stress. “Normal stress” refers to both tensile stress and compressive stress, for example a member may carry tensile stress or compressive stress depending on external loads. In this case the member carries normal stresses. “Pitch” within this disclosure refers to an axis of rotation which is generally perpendicular to the vertical direction and the direction of travel. Pitch angle describes a front up or a front down orientation of a component. In this disclosure, one or more publication, patents, and / or patent application may be incorporated by reference. However, such material is only incorporated to the extent that no conflict exists between the incorporated material and the statements and drawings set forth herein. In the event of any such conflict, including any conflict in terminology, the present disclosure is controlling. Overview Generally, the present disclosure pertains to devices and methods for a skateboard truck. A skateboard truck is used to support a skateboard on which an operator is positioned. Disclosed is a skateboard truck having a following or tail truck which allows vertical and twist compliance. The tail truck may include a tail body having ribs, inserts which support the ribs, a pair of wheels, and a torsion transfer device which transfers force from the wheels to the tail body. The inserts may be of differing material and geometry allowing adjustment of the tail truck characteristics. The torsion transfer device may include compliant material and geometry. The insert periphery may be in contact with the tail body ribs or may be removed. The torsion transfer device may be supported in a bore hole of the tail body and support a wheel axle. The hanger may be supported by the pivot member such that the hanger may tilt. Examples I: Stiff Tail Truck Fig. 1 depicts a skateboard 1 which includes board 2, stiff tail truck 3, conventional truck 4. During operation the skateboard 1 supports a user on the top surface 2A and the skateboard 1 is supported by wheels 5, 6, 7, and 8. Wheels 5, and 6 are attached to tail truck 3, and wheels 7 and 8 are attached to conventional truck 4. Conventional truck 4 connects to board 2 on one end and tail truck 3 is attached to board 2 on the other end. In some examples, conventional truck 4 and tail truck are attached to board 2 using bolt mount assemblies 20. In some examples, the tail truck 3 may be attached at both ends and / or may be an integral part of board 2. Figs. 2, 3, and 4 depict orthograph views of skateboard 1. Fig. 2 establishes a general direction of travel indicated by arrow 9. A tilt axis 10 is also shown and Fig. 2. Tilt axis 10 is located midway between wheels 5 and 6 and midway between wheels 7 and 8. Figs. 5, 6, 7, and 8 depict various views of skateboard 1 as it is tilted about tilt axis 10 at tilt angle 13A relative to ground 14. Conventional truck 4 includes the required mechanisms to cause wheels 7 and 8 to be directed to roll in a direction indicated by arrow 11. Wheel axis 12 and tilt axis 10 are oriented at turn angle 13B causing the wheels 7 and 8 to roll in direction 11. Fig.8 depicts tail truck 3 with wheels 5 and 6 rolling along ground 14. Understanding that the wheels are contacting ground 14 and board 2 is oriented at angle 13A, the tail 100 must flex to allow tilting at angle 13A. Tail truck 100 is depicted in Figs.9, and 10. Tail body 101 is a continuous member and may include mounting holes 101B to mount tail body 101 to board 2 on board under surface 2B (shown best in Fig. 2). In some embodiments, bolt mount assemblies 20 are used to clamp the tail body to board under surface 2B. How the tail body is attached to board 2 is not critical to the function of the tail 100 except that a portion of the tail assembly is able to flex such that board 2 is able to tilt. In some embodiments, the tail body may be attached to the topside 2A of board 2. Tail body 101 may flexible ribs 101D, 101J, 101K, 101L, 101M, 101N, 101O, and 101P (best shown in Fig. 14). Flexible ribs allow tail body 101 to twist about twist axis 101I and comply vertically while resisting compliance and twisting in other axes. In some embodiments, tail 100 may include structurally ridged components. Fig.10 depicts a cross-sectional view of tail 100. Tail body 101 supports bushings 105 (shown in detail in Figs.11, 12, and13) in tail body bores 101A on bushing periphery 105D. Bushings 105 support axle 102 at bushing bore 105A. Axle 102 rotationally supports wheels 5 and 6 by supporting wheel bearings 106. In some embodiments, bearings 106 are restricted from moving along the length of axle 102 by clamping on each side of each bearing. Axle 102 may include an axial support 102A which may be positioned against the outside surface of a bearing 106. A bearing spacer 104 may be positioned against the other side of bearing 106. Bearing spacer 104 may be positioned against first bushing shoulder 105B and second bushing shoulder 105C may be positioned against tail body bore step 101B located in tail body bore 101A. Further, axle 102 may also include a threaded portion 102B. Threaded portion 102B may be used to thread nut 107 against a similar bearing 106, bushing 105, spacer 104, and tail body 101 assembly and clamping the wheels restricting movement along axle 102. In some embodiments, bushings 105 may be rigid in these embodiments flexing is limited to tail body 101. Figs. 14, 15, and 16 depict the loads and supporting constraints of tail body 101 during tilting of board 2 about tilt axis 10 during a turn. Tail mounting surfaces 101C are held rigidly against board under surface 2B. Bushing bores 101A support bushings 105 responding with force 200A. Twisting about twisting axis 101I is caused by this load and supporting constraints. Fig. 17 shows deflection results after running an FEA (finite element analysis) analysis using an Autodesk TM component with the loading constraints and forces shown in Figs.14-16. Middle rib 101D is severely twisted however all the flexible ribs 101D, 101J, 101K, 101L, 101M, 101N, 101O, and 101P are flex and move relative to each other. This twisting is indicative of a less stiff area included in tail body 101. In some embodiments, an operator may want a very soft tail body. However, in others and operator may want more stiffness. Figs.18, 19, and 20 depict a tail truck with additional stiffening. Inserts 300 and 31 are placed along the sides of middle rib 101D. Inserts 300 and 301 contact middle rib sides 101E and 101F and auxiliary rib sides 101G and 101H (best seen in Fig.20). The applicant has found that adding inserts 300 and 301 the stiffness of tail body 101 is increased. This additional stiffness provides an operator with more options regarding tail truck 3 stiffness. Figs.21-25 depict an example of insert 300. Insert 300 includes a hole 300B partially through insert 300. Features such as this may be used to determine the stiffness desired. The desired stiffness being a stiffness an operator may desire. Although insert 300 and tail body 101 have a specific geometry any geometry that transfers load from middle rib 101D to other tilt body ribs is well within the scope of the disclosure. II: Method of adjusting the stiffness of Stiff Tail Truck Fig.26 depicts a method of adjusting the stiffness of a stiff tail truck. Step 1351 may include an operator riding skateboard 1 without inserts 300 and 301 installed. The method may continue to Step 2352. Step 2352 may include an operator determining the desirability of the skateboard stiffness. If skateboard 1 has the desired stiffness the method is ended. If not, the method may continue to Step 3354. Step 3354 may include installing inserts 300 and 301. The method may continue to Step 4355. Step 4355 may include an operator riding skateboard 1 with the inserts 300 and 301 installed. Step 5356 may include an operator determining the desirability of the skateboard stiffness. If skateboard 1 has the desired stiffness the method is ended. If not, the method may continue to Step 6357. Step 6357 may include changing the material of inserts 300 and 301 to a material with a different stiffness. The method may continue to Step 7358. Step 7358 may include riding skateboard 1 with inserts 300 and 301 made of material having a new material installed. The method may continue to Step 8359. Step 8359 may include an operator determining the desirability of the skateboard stiffness. If skateboard 1 has the desired stiffness the method is ended. If not, the method may repeat steps 6357, 7358, and 8359 until skateboard 1 has the desired stiffness and the method may end. III: Flexible Tail Truck Fig.27, 28, and 29 depict a skateboard 401 which includes board 402, tail truck 403, and conventional truck 4. During operation the skateboard 401 supports a user on the top surface 402A and the skateboard 401 is supported by wheels 405, 406, 407, and 408. Wheels 405, and 406 are attached to tail truck 403, and wheels 407 and 408 are attached to conventional truck 404. Conventional truck 404 attaches to board 402 on one end and flexible tail truck 403 attaches to board 402 on the other end. In some examples, conventional truck 4 and tail truck are attached to board 402 using bolt mount assemblies 420. In some examples, the tail truck 403 may be attached at both ends and / or may be an integral part of board 2. Fig.27 and 29 establishes a general direction of travel indicated by arrow 409. A tilt axis 410 is also shown and Fig.27. Tilt axis 410 remains midway between wheels 405 and 406 and midway between wheels 407 and 408. Figs.30, 31, 32, and 33 depict various views of skateboard 401 as it is tilted about tilt axis 410 at tilt angle 413A relative to ground 414. Conventional truck 404 includes the required mechanisms to cause wheels 407 and 408 to be directed to roll in a direction indicated by arrow 411. Wheel axis 412 and tilt axis 410 are oriented at turn angle 413B causing the wheels 407 and 408 to roll in direction 411. Fig. 29 depicts tail truck 403 with wheels 405 and 406 rolling along ground 414. Understanding that the wheels are contacting ground 414 and board 402 are oriented at angle 413A, the tail 500 must flex to allow tilting at angle 413A. Tail 500 is depicted in Figs. 34, and 35. Tail body 501 is a continuous member and may include mounting holes 501C to mount tail body 501 to board 402 on board under surface 402B (shown best in Fig.29). In some embodiments, bolt mount assemblies 420 and 420A are used to clamp the tail body 501 to board top surface 402A. How the tail body 501 is attached to board 402 is not critical to the function of the tail 500 except that a portion of the tail 500 is able to flex such that board 402 is able to tilt. In some embodiments, the tail body 501 may be attached to the top or side of board 402. In some embodiments, tail 500 may include structurally ridged components. Fig.35 depicts a cross-sectional view of tail 500. Tail body 501 supports flex bushings 505 in tail body bores 501A on flex bushing periphery 505D. Flex bushings 505 support axle 502 at bushing bore 505A. Axle 502 rotationally supports wheels 405 and 406 by supporting wheel bearings 506. In some embodiments, bearings 606 are restricted from moving along the length of axle 502 by clamping on each side of each bearing 506. Axle 502 may include an axial support 502A which may be positioned against the outside surface of a bearing 506. Figs. 36, 37, and 38 depicts flex bushings 505 that may include a cone shaped feature 505E. Cone shaped feature 505E may be shaped to provide flexibility of bushing 505. Flex bushings 505 may additionally include hollow volumes 505F to allow additional flexing of flex bushings 505. Flexing bushing 505 may be constructed of flexible material such as urethane, rubber, plastic, or metal. Bearing 406 may be positioned against first bushing shoulder 105B and second bushing shoulder 505C may be positioned against tail body bore step 501B located in tail body bore 501A. Further, axle 502 may also include a threaded portion 502B. Threaded portion 502B may be used to thread nut 507 against a similar bearing 506, bushing 505, and tail body 501 assembly and clamping the wheels 406 and 405, restricting movement along axle 502. In some embodiments, bushings 505 may be rigid in these embodiments flexing is limited to tail body 501. Tail body 501 may include flexible ribs similar to flexible ribs 101D, 101J, 101K, 101L, 101M, 101N, 101O, and 101P of tail body 101. These flexible ribs of tail body 501 may flex during a turn as the similar ribs 101D, 101J, 101K, 101L, 101M, 101N, 101O, and 101P of tail body 101. Tail body 501 may include inserts 300 and 301. As in the stiff tail truck 3, inserts 300 and 301 are located adjacent to tail flex rib 501D. Inserts 300 and 301 provide support to tail flex rib 501A like the stiff tail truck 100. IV: Method of adjusting the stiffness of Flexible Tail Truck Fig.39 depicts a method of adjusting the stiffness of a flexible tail truck. Step 1651 may include an operator riding skateboard 401 with flexible bushings 505. Step 2652 may include an operator determining the desirability of the skateboard stiffness. If skateboard 401 has the desired stiffness the method is ended. If not, the method may continue to Step 3654. Step 3654 may include removing hollow volumes 505F from bushings 505. The method may continue to Step 4655. Step 4655 may include an operator riding skateboard 401 with bushings 505 with hollow volumes 505F removed. The method may continue to Step 5656 Step 5656 may include an operator determining the desirability of the skateboard stiffness. If skateboard 401 has the desired stiffness the method is ended. If not, the method may continue to Step 6657. Step 6657 may include changing the material of bushings 505 to a stiffer material. The method may continue to Step 7658. Step 7658 may include riding skateboard 401 bushings 505 made of stiffer material installed. The method may continue to Step 8659. Step 8659 may include an operator determining the desirability of the skateboard stiffness. If skateboard 401 has the desired stiffness the method is ended. If not, the method may repeat steps 6657, 7658, and 8659 until skateboard 401 has the desired stiffness and the method may end. IV: Integrated Tail Truck In some embodiments, the board and tail body may be combined into a single integral part. Figs.40-43 depict a skateboard 700 in which board 701 and the tail body 702 are a single integral part. The tail body 702 may support wheels 5 and 6 and allows only vertical compliance and tilt about the tilt axis 10. Figs 40- 43 includes a conventional truck 4 which allows for turning the skateboard 700 during operation. During operation the skateboard 701 supports a user on the top surface 701A and the skateboard 701 is supported by wheels 5, 6, 7, and 8. Wheels 5, and 6 are attached to tail body 702, and wheels 7 and 8 are attached to conventional truck 4. Conventional truck 4 connects to board 701 on one end and tail body 702 is located on the other end. In some examples, the tail body 701 may be located at both ends. Figs.41, 42, and 43 depict orthograph views of skateboard 701. Fig.41 establishes a general direction of travel indicated by arrow 9. A tilt axis 710 is also shown and Fig. 41. Tilt axis 710 remains midway between wheels 5 and 6 and midway between wheels 7 and 8. During operation, skateboard 700 responses to tilting about tilt axis 10 as described in other examples. Specifically, conventional truck 4 turns the direction of wheels 7 and 8 while the tail body 702 is compliant vertically and twists about tilt axis 10. As tail body 702 twists wheels 5 and 6 remain in contact with ground 14. In some embodiments, tail body 702 may include structurally ridged components. Figs. 44 and 45 depict inserts 703. Inserts 703 may interface with features of tail body 702 as described in examples “Stiff Tail Truck” and “Flexible Tail Truck”. IV: Bushing, Insert, and Flexible Rib Variations Figs.46 – 50 depict variations of bushings, inserts, and ribs that may be additional embodiments of a skateboard having a tail body 801. Fig.46 depicts a tail body 801. Tail body 801 may be attached to a skateboard board at mounting features 801A. Tail body 801 rotationally supports wheels 5 and 6. Inserts 802 and 803 may reside within tail body pockets 804 and 805. Tail body pocket 804 form flexible ribs 806 and tail body pocket 805 form flexible ribs 807. Inserts 802 and 803 along with tail body pockets 804 and 805, and flexible ribs 806 and 807 are best shown in Fig.47. During operation an operator may tilt the skateboard about the tilt axis 10 this may cause the flexible ribs 806 and 807 to deflect. Inserts 802 and 803 fit into tail body pockets 804 and 805 and support flexible ribs 806 and 807. Inserts 802 and 803 support flexible ribs 806 and 807 as the flexible ribs 806 and 807 deflect and this support causes the combined structure of tail body 801 and inserts 802 and 803 to be stiff. Fig.48 depicts bushing feature 810 as an integral feature of tail body 801. Axle 102 is supported by bushing feature 810 and rotationally supports wheels 5 and 6. Bushing feature 810 may be in contact with bearings 106. Bushing feature 810 may increase stiffness while allowing vertical compliance and twist compliance as well as restrict other directions of compliance. Figs. 49 – 50 depict variations of inserts that may be additional embodiments of a skateboard having a tail body. Figs.49 and 50 depict a tail body 901. Tail body 901 may be attached to a skateboard board at mounting features 901A. Tail body 901 rotationally supports wheels 5 and 6. Inserts 902 may reside within tail body pockets 904. Tail body pockets 904 form flexible ribs 906 and 907. Inserts 902 may include hole 902A which may be left empty or stiffening inserts 903 may be in hole 902A. In some embodiments, inserts 903 may be insert protrusions that are an integral part of the tail body. In some embodiments, inserts 902 may be configured to be used as bushings 4A in a conventional truck 4 (best shown in Fig.7). This configuration of bushings 4A being used as an insert 902, allows an operator to reduce the number of replacement parts needed during use. During operation an operator may tilt the skateboard about the tilt axis 10 this may cause the flexible ribs 906 and 907 to deflect. Inserts 902 and 903 fit into tail body pockets 904 and support flexible ribs 906 and 907. Inserts 902 and 903 support flexible ribs 906 and 907 as the flexible ribs 906 and 907 deflect and this support causes the combined structure of tail body 901 and inserts 902 and 903 to be stiff. Advantages, Features, and Benefits The examples of the skateboard truck described herein provide several advantages over known skateboard trucks. For example, illustrative examples described herein provide easily adjusted skateboard twist and vertical compliance while resisting twist and compliance in other directions. Additionally, the stiffness may be adjusted by the operator. This stiffness adjustment may be used to increase or decrease the amount of “turning” the truck will allow given a specific amount of twisting force exerted by an operator. This can be very helpful when traveling at high speeds or long distances. Additionally, in the tail truck slop within the device is eliminated by preloading and fully supported components. A conventional truck typically supports the kingpin by an axial load only. A large clearance hole on the conventional hanger allows movement of the hanger relative to the kingpin. However, to increase the resistance to the hanger movement more friction is required between the conventional bushings and the conventional hanger. To increase this friction more axial force on the kingpin is required, thus increasing the stress on the kingpin. Additionally, sliding components are eliminated. This prevents squeaking caused by sliding components in a conventional skateboard truck. Conclusion The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present technology has been presented for purposes of illustration and description but is not intended to be exhaustive or limited to the present technology in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the present technology. Exemplary examples were chosen and described in order to best explain the principles of the present technology and its practical application, and to enable others of ordinary skill in the art to understand the present technology for various examples with various modifications as are suited to the particular use contemplated. In the above description, for purposes of explanation and not limitation, specific details are set forth, such as particular examples, procedures, techniques, etc. in order to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced in other examples that depart from these specific details. Reference throughout this specification to "one example" or "an example" means that a particular feature, structure, or characteristic described in connection with the examples is included in at least one example of the present invention. Thus, the appearances of the phrases "in one example" or "in an example" or "according to one example" (or other phrases having similar import) at various places throughout this specification are not necessarily all referring to the same examples. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more examples. Furthermore, depending on the context of discussion herein, a singular term may include its plural forms and a plural term may include its singular form. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. If any disclosures are incorporated herein by reference and such incorporated disclosures conflict in part and / or in whole with the present disclosure, then to the extent of conflict, and / or broader disclosure, and / or broader definition of terms, the present disclosure controls. If such incorporated disclosures conflict in part and / or in whole with one another, then to the extent of conflict, the later- dated disclosure controls. While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. The descriptions are not intended to limit the scope of the invention to the particular forms set forth herein. To the contrary, the present descriptions are intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims and otherwise appreciated by one of ordinary skill in the art. Thus, the breadth and scope of a preferred embodiment should not be limited by any of the above-described exemplary embodiments.

Claims

CLAIMS I claim:

1. A skateboard truck comprising; a tail body having an elongated body a tail body bore on the distal end and configured to twist about a twist axis the twist axis oriented along the elongated body of the tail body the tail body further having a first flexible rib configured to deflect in response to a twist about the twist axis, and a bushing configured to support the tail body at the tail body bore and configured to support an axle.

2. The skateboard truck of claim 1 wherein the bushing is rigid.

3. The skateboard truck of claim 1 wherein the tail body includes a second flexible rib adjacent to the first flexible rib and the skateboard truck includes a first insert configured to transfer load from the first flexible rib to the second flexible rib in response to a twist about the twist axis.

4. The skateboard truck of claim 3 wherein the tail body includes a third flexible rib adjacent to the first flexible rib opposite the second flexible rib, and the skateboard truck includes a second insert configured to transfer load from the first flexible rib to the third flexible rib in response to a twist about the twist axis.

5. The skateboard truck of claim 1 wherein the bushing is flexible.

6. The skateboard truck of claim 5 wherein the bushing includes a hollow volume configured to determine a desired stiffness.

7. The skateboard truck of claim 3 wherein the insert includes a hole configured to determine a desired stiffness.8.The skateboard truck of claim 1 wherein the tail body includes a second flexible rib adjacent to the first flexible rib and a third flexible rib adjacent the first flexible rib further the second and third flexible ribs are configured to support the first flexible rib.

9. The skateboard truck of claim 1 wherein the skateboard truck is removable from a board.

10. The skateboard truck of claim 1 wherein the tail body includes a twist axis and is configured to twist about the twist axis.

11. The skateboard truck of claim 10 wherein the tail body is configured to resist flexibility in any axis except the twist axis.

12. The skateboard truck of claim 3 wherein the first insert is square.

13. The skateboard truck of claim 3 wherein the first insert is cylindrical.

14. The skateboard truck of claim 3 wherein the first insert includes a hole, the hole configured to receive a third insert, and a third insert configured to fit into the hole.

15. The skateboard truck of claim 3 wherein the tail body includes an insert protrusion, the first insert includes a hole configured to receive the insert protrusion.

16. The skateboard truck of claim 14 wherein the third insert is configured to be stiffer than the first insert.

17. The skateboard truck of claim 1 wherein the bushing is a bushing feature and is an integral feature of the tail body.

18. The skateboard truck of claim 1 wherein the bushing includes a hollow volume.19.The skateboard of claim 3 wherein the first insert is a conventional truck bushing.

20. A method of adjusting the stiffness of a skateboard truck comprising; a tail body having an elongated body having a tail body bore on the distal end and configured to twist about a twist axis the twist axis oriented along the elongated body of the tail body the tail body further having a first flexible rib configured to deflect in response to a twist about the twist axis and a second flexible rib adjacent to the first flexible rib, an insert configured to transfer load from the first flexible rib to the second flexible rib, and a bushing configured to support the tail body at the tail body bore and configured to support an axle, the method comprising; riding a skateboard having the skateboard truck without the inserts installed, determining the flexibility of the skateboard truck, installing the inserts configured to transfer load from the first flexible rib to the second flexible rib, riding the skateboard having the skateboard truck with inserts installed, determining the flexibility of the skateboard truck, changing the flexibility of the insert, and riding the skateboard having the changed flexibility insert installed.

21. A method of adjusting the stiffness of a skateboard truck comprising; a tail body having an elongated body and a tail body bore on the distal end and configured to twist about a twist axis the twist axis oriented along the elongated body of the tail body the tail body further having a first flexible ribconfigured to deflect in response to a twist about the twist axis and a second flexible rib adjacent to the first flexible rib, and a bushing having a hollow volume and configured to support the tail body at the tail body bore and configured to support an axle, the method comprising; riding a skateboard having the skateboard truck with the bushing having a hollow volume, determining the flexibility of the skateboard truck, removing the hollow volume from the bushing, riding the skateboard having the skateboard truck with the hollow volume removed installed, determining the flexibility of the skateboard truck, changing the material of the bushing, and riding the skateboard having the changed bushing material.

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