Height-adjustable suspension fork

Abstract

Suspension fork (1) for a bicycle, in particular a recumbent tricycle, with - a fork head (2) and at least one shock absorber (3a,3b), wherein the shock absorber (3a,3b) has a stanchion (4a,4b) and a slider (5a,5b) guided telescopically relative to it, - a spring arrangement located in the strut (3a,3b) for damping relative movements between the stanchion tube (4a,4b) and the slider tube (5a,5b), and - a height adjustment device for setting a plurality of different length positions of the suspension fork (1), characterized by the fact that - the height adjustment device has an adjusting element (6) that is at least partially guided in or on the dip tube (5a, 5b), which is axially adjustable relative to the dip tube (5a, 5b) in an unlocked position and is axially locked relative to the dip tube (5a, 5b) in a locked position, and - a locking device is provided which, in the locking position, creates a positive engagement between a first profile element (7a,7b) formed on the immersion tube (5a,5b) and a second profile element (8a,8b) formed on the adjusting element (6) and, in the unlocking position, releases the positive engagement, - wherein the locking device can be switched between the locking position and the unlocking position by a relative rotation about the longitudinal axis between the immersion tube (5a, 5b) and the adjusting element (6), and - wherein an anti-rotation device is provided which is designed to prevent rotation of the adjusting element (6) relative to the standpipe (4a,4b) during adjustment.

Description

[0001] The invention relates to a suspension fork for a bicycle, in particular a recumbent tricycle, with a fork head and at least one shock absorber, wherein the shock absorber has a stanchion and a telescopically guided slider relative to it, a spring arrangement arranged in the shock absorber for damping relative movements between stanchion and slider, and a height adjustment device for setting a plurality of different length positions of the suspension fork.

[0002] Suspension forks for bicycles, and especially recumbent trikes, are subject to specific requirements regarding comfort, ergonomics, and flexibility. Particularly in rehabilitation settings or for bicycles designed for users with limited mobility, a low step-through height is crucial for easier mounting and dismounting. Conventional solutions often reduce the frame height by using smaller front wheels. However, this can necessitate a rigid front fork, as installing a conventional suspension fork may be structurally impossible or would result in significant disadvantages in terms of stability or comfort.

[0003] Furthermore, height-adjustable suspension forks currently available are mostly limited to sporty bicycles, especially mountain bikes, where adjustment typically involves a reduction in suspension travel and requires more effort to operate. This makes them less suitable for users with limited motor skills. Conventional systems also often lack the ability to quickly and easily switch between different wheel sizes without extensive modifications or adjustments. These drawbacks significantly impair the everyday usability, flexibility, and acceptance of recumbent trikes.

[0004] The invention is therefore based on the objective of providing a suspension fork of the type mentioned above that allows for ergonomic and flexible adjustment of the entry height to suit different user needs and application scenarios. The full suspension travel should be maintained regardless of the height, and switching between different front wheel sizes (in particular 16-inch and 20-inch) should be simplified. Furthermore, the operation of the fork should be intuitive, safe, and easily possible for all user groups.

[0005] The invention solves the problem, starting from a spring fork of the type mentioned above, in that the height adjustment device has an adjusting element guided in or on the dip tube, which is axially adjustable relative to the dip tube in an unlocked position and is axially locked relative to the dip tube in a locked position, and a locking device is provided which, in the locked position, establishes a positive engagement between a first profile element formed on the dip tube and a second profile element formed on the adjusting element, and in the unlocked position releases the positive engagement, wherein the locking device can be switched between the locked position and the unlocked position by a relative rotation about the longitudinal axis between the dip tube and the adjusting element, and wherein an anti-rotation device is provided.which prevents the adjusting element from rotating relative to the stanchion, at least during switching or adjusting.

[0006] This concept allows for a simple, quick, and safe adjustment of the suspension fork's overall length while maintaining full suspension function. The adjustment can be made effortlessly and with a high degree of safety and ease of use. The user can choose between a lower and a higher position as needed, for example, for easier mounting or a sportier riding experience; the suspension travel always remains unchanged. In practice, this allows for the use of different front wheel sizes without adversely affecting the frame geometry. The system is therefore also ideally suited for retrofitting existing bicycles.

[0007] An advantageous embodiment of the invention provides that the profile elements are designed as interlocking rib, tooth, or wedge profiles. This achieves a precise, positive-locking, and backlash-free locking mechanism that ensures consistently secure retention of the respective height setting, even with frequent use. Furthermore, the rib, tooth, or wedge profile design allows for a durable, low-wear mechanism that requires minimal maintenance.

[0008] According to a further embodiment, the rotation angle required for switching between the dip tube and the adjusting element is in the range of 80° to 100°, preferably around 90°. By defining this rotation angle, the user can operate the adjusting mechanism intuitively, with little effort and without risk of incorrect operation.

[0009] Advantageously, the adjustment element features an axially acting stop to limit the extension travel of the stanchion relative to the slider, with axial adjustment of the element resulting in a change to the overall extended length of the suspension fork. This axial adjustment allows for modification of the extended length, enabling precise adjustment of the ride height to individual user needs and different wheel sizes. This significantly increases comfort and flexibility in everyday use.

[0010] It is also advantageous that the adjustment mechanism has at least two discrete detents or locking positions along its longitudinal axis. This allows the user to quickly and reliably adjust the suspension fork to precisely defined positions, making it suitable for both everyday riding with a low entry point and a sportier riding position on longer tours. Incorrect positioning or unstable intermediate positions are effectively prevented by the clear detents.

[0011] It is particularly advantageous if the discrete detent or locking positions are specifically designed for use with two different front wheel sizes. This makes it possible, for example, to switch between 16-inch and 20-inch wheels and always adjust the suspension fork geometry to the correct size without having to modify any other components. This significantly simplifies handling in practical use.

[0012] One preferred design features two front wheel sizes: 16 inches and 20 inches. This configuration addresses the typical practical requirements in rehabilitation and for recumbent bicycles, significantly improving user-friendliness, flexibility, and adaptability.

[0013] Furthermore, an axial adjustment range of at least 50 mm, preferably 50 mm to 60 mm, and particularly preferably about 52 mm, ensures that the optimal fork setting can always be found, even under highly variable operating conditions. This large adjustment range expands the application range of the invention and increases comfort for a wide variety of user groups.

[0014] According to another embodiment, the anti-rotation device is designed as a guide with a connecting element guided relative to the standpipe in a precisely fitting opening. This reliably prevents unwanted rotation of the adjusting element and contributes to functional reliability even under intensive use. Furthermore, this design allows for easy assembly and maintenance of the mechanism.

[0015] The connecting element can be designed as a sheet metal piece that couples an upper stop element in the standpipe to a lower stop element. This solution results in a stable, lightweight, and material-saving construction that reliably transmits forces within the system and promotes cost-effective manufacturing.

[0016] The distance between the upper and lower stop elements defines the spring travel of the shock absorber. The advantage of this design lies in a precise and easily verifiable limitation of the spring travel, which further simplifies the damping adjustment and adaptation to different load conditions.

[0017] Furthermore, it is particularly advantageous if stops are provided on the dip tube to limit relative rotation in the circumferential direction or to give the user tactile feedback that the mechanism is fully locked or unlocked. This provides the user with clearly perceptible confirmation of the correct position, minimizing operating errors and increasing operational reliability.

[0018] A preferred embodiment provides that the spring assembly comprises at least one helical steel spring. This spring is characterized by its high reliability, durability, and good spring characteristic, and allows the use of conventional manufacturing technologies while requiring minimal maintenance.

[0019] In a further advantageous embodiment, the helical steel spring is combined with at least one additional, parallel-connected elastomer element, in particular a cellular polyurethane elastomer. This combination results in a progressive spring characteristic in the end range, which increases ride comfort and, above all, prevents bottoming out of the spring action during strong impacts.

[0020] Furthermore, the shock absorber can have at least one low-friction sliding bearing for guidance between the stanchion and slider tubes. This reduces the effort required during compression, minimizes wear, and significantly increases the service life of the entire system.

[0021] Maintenance and serviceability are further enhanced by the fact that the immersion tube is constructed from two half-shells connected by screw connections. This simplifies disassembly and repair as well as industrial manufacturing, reduces spare parts inventory, and facilitates removal and installation during maintenance work.

[0022] Finally, it is advantageous if the stanchion tube has an integrated nut or threaded element for attaching a thru-axle. This allows for quick, safe, and tool-free wheel changes, further increasing user comfort and supporting modern wheel mounting technologies.

[0023] Optionally, the dip tube can be further designed to increase the assembly strength and operational robustness of the two-piece dip tube design. For this purpose, an additional ring, particularly an aluminum ring, can be provided at the upper end of the dip tubes, which is fitted over them. Furthermore, a tongue-and-groove connection can be incorporated along an edge of the dip tube halves to reduce slippage between them. Additionally, the standpipe can be tapered in the area above a top rib or profile section to prevent or reduce impact at certain adjustment positions, especially at shorter lengths.

[0024] The invention will be explained in more detail below with reference to the drawings. The drawings show: Fig. 1: a schematic perspective overall view of a spring fork according to the invention in a first embodiment; Fig. 2: a schematic sectional view of a shock absorber made of Fig. 1; Fig. 3: a functional representation of the height adjustment in four states a to d according to the first embodiment; Fig. 4: a schematic exploded view of a shock absorber of a spring fork according to the invention in a second embodiment; Fig. 5: a schematic sectional view of the shock absorber made of Fig. 4; Fig. 6: a functional representation of the height adjustment in four states a to d according to the second embodiment.

[0025] Fig. Figure 1 shows a perspective overall view of a spring fork 1 according to the invention, comprising a fork head 2 and a steering tube 2a arranged on the fork head 2 in a first embodiment. Two spring struts 3a, 3b extend from the fork head 2, each comprising a stanchion 4a, 4b and a slider 5a, 5b guided telescopically relative to the stanchion. The stanchions 4a, 4b are guided axially displaceably within the slider 5a, 5b and enable the spring movement.

[0026] A height adjustment device is arranged in the area of ​​the shock absorbers 3a, 3b. This is explained in more detail with reference to the open view of shock absorber 3a. The height adjustment device comprises an adjustment element 6, which in this embodiment is designed as a stop unit. The stop unit comprises an upper stop element 6a, which is arranged inside the stanchion tube 4a, and a lower stop element 6b, which is arranged in the area of ​​the slider tube 5a. The upper stop element 6a and the lower stop element 6b are coupled to each other via a connecting element 6c, in particular a sheet metal plate. The distance between the stop elements 6a, 6b, or the effective length of the connecting element 6c, determines the available spring travel or limits the relative movement between the stanchion tube 4a and the slider tube 5a in the axial direction.

[0027] The adjusting element 6 further comprises a locking device by means of which the adjusting element 6 can be axially fixed in different positions on the immersion tube 5a. For this purpose, first profile elements 7a, 7b are provided on the immersion tube 5a and a second profile element 8a on the adjusting element 6, which in this embodiment are designed as ribs and, in a locking position, interlock positively, thereby preventing axial adjustment. In an unlocked position, the positive engagement is released, so that the length position can be changed by axial displacement. Switching between the locking position and the unlocked position is effected by a relative rotation about the longitudinal axis between the immersion tube 5a and the adjusting element 6.

[0028] Furthermore, an anti-rotation device is provided, by which the adjusting element 6 is secured against rotation relative to the standpipe 4a during adjustment. For this purpose, the connecting element 6c is guided axially in a form-fitting manner in a corresponding receptacle of the standpipe 4a.

[0029] Axle mounts 9a, 9b for receiving a wheel axle are provided at the lower end regions of the fork tubes 5a, 5b. A mudguard connection 10 is also shown. A brake adapter 11 for attaching a brake caliper is also provided on the fork tube 5b.

[0030] Fig. Figure 2 shows a sectional view of the individual shock absorber 3a of the spring fork 1. Fig. 1 with standpipe 4a and the telescopically guided immersion tube 5a. The adjusting element 6 is arranged partly inside the immersion tube 5a and partly inside the standpipe 4a. The adjusting element 6 comprises the upper stop element 6a, which is arranged in the standpipe 4a, the lower stop element 6b in the area of ​​the immersion tube 5a, and the connecting element 6c, in particular a sheet metal part, which mechanically couples the stop elements 6a and 6b.

[0031] The in Fig. The two dashed reference lines indicate the axial reference positions that are crucial for setting different length positions and for the spring travel. The double arrows illustrate that the adjusting element 6, or rather its effective position relative to the slide tube 5a, can be switched between at least two discrete axial positions. The left double arrow represents the axial adjustment travel A, over which the adjusting element 6 can be moved axially between the two discrete positions when unlocked. The right double arrow symbolizes the spring travel B, which is defined by the distance between the two stop elements 6a and 6b.

[0032] Fig. Figure 3 shows the functional sequence of the height adjustment on a shock absorber in four states a to d. The stanchion tube 4a, which is telescopically guided relative to the slider tube 5a, and the adjusting element 6, which is guided in the area of ​​the slider tube 5a, are shown. First profile elements 7a and 7b are provided on the slider tube 5a and are arranged at an axial distance from each other. A second profile element 8a is formed on the adjusting element 6, which can be selectively engaged with either the first profile element 7a or the first profile element 7b in a positive-locking manner.

[0033] Fig. 3a (locked, long): The adjusting element 6 is in a first axial position relative to the immersion tube 5a. The second profile element 8a is positively engaged with the first profile element 7a, so that the adjusting element 6 is axially locked relative to the immersion tube 5a and the corresponding length position is fixed.

[0034] Fig. 3b (unlocked, long): In the same axial position, the positive engagement between the second profile element 8a on the adjusting element 6 and the first profile element 7a on the immersion tube 5a is released. This is achieved by a relative rotation about the longitudinal axis between the immersion tube 5a and the adjusting element 6, so that the adjusting element 6 is axially adjustable relative to the immersion tube 5a in the unlocked position.

[0035] Fig. 3c (unlocked, short): With the positive locking engagement still released, the adjusting element 6 is moved axially relative to the immersion tube 5a into a second position. In this second position, the second profile element 8a is axially aligned with the first profile element 7b, so that a second length setting can be established after re-locking.

[0036] Fig. 3d (locked, short): By re-rotating the immersion tube 5a relative to the adjusting element 6, the positive engagement is restored, now between the second profile element 8a and the next first profile element 7b. The adjusting element 6 is thus axially locked relative to the immersion tube 5a in the second axial position, and the second length position is securely fixed.

[0037] The representation according Fig. Figure 3 illustrates the operating logic “unlock - axially reposition - lock” as well as the constructive advantage that the length positions are reproducibly determined via positively defined profile engagements, while the telescopic relative movement between standpipe 4a and immersion tube 5a is maintained for the spring function.

[0038] Fig. Figure 4 shows an exploded view of the shock absorber 3a in an alternative second embodiment. The stanchion tube 4a and the slider tube 5a are shown, the slider tube 5a being constructed from two half-shells in this embodiment. The half-shells can be connected to each other by means of fasteners 12, in particular screws, so that a closed slider tube 5a is formed in the assembled state.

[0039] The adjusting element 6 is arranged between the half-shells and, in this embodiment, is designed as an adjusting chamber 6d. In the assembled state, the adjusting chamber 6d surrounds the standpipe 4a at least partially and is guided in the interior of the immersion tube 5a formed by the half-shells.

[0040] The adjustment chamber 6d features second profile elements 8a, 8b, which, in the area shown, are designed as circumferentially extending ribs. Correspondingly, a first profile element is provided on the immersion tube 5a (not shown). The illustration thus clarifies the design principle that the locking mechanism is achieved via a positive engagement between the second profile elements 8a, 8b on the one hand and the first profile element on the other. The adjustment range A is essentially defined by the distance between the second profile elements 8a, 8b. The two-part design of the immersion tube 5a allows for easy integration of the adjustment chamber 6d. A further advantage of this arrangement is that the functional surfaces are protected inside the immersion tube 5a after the two halves are screwed together.In order for the immersion tube 5a to rotate relative to the adjustment chamber 6d, the adjustment chamber 6d must be axially secured against rotation to the standpipe 4a. This function can be achieved by a groove pattern associated with the standpipe 4a and corresponding guide rails on the adjustment chamber 6d.

[0041] Fig. Figure 5 shows a sectional view of the shock absorber 3a in its assembled state, with the stanchion tube 4a telescopically guided within the slider tube 5a. The adjusting element 6, in the form of the adjusting chamber 6d, is located inside the slider tube 5a. The illustration clarifies the position of the adjusting chamber 6d within the slider tube 5a and its coverage by the tube, thus enabling the height adjustment function to be integrated into the overall design and shielded from external influences.

[0042] Out of Fig. Figure 5 also shows that the adjustment chamber 6d is arranged as a separate component within the immersion tube 5a and can therefore assume a defined axial position that can be changed for different length positions. In the locked position, the axial position between the adjustment chamber 6d and the immersion tube 5a is secured by the positive engagement of the corresponding profile elements; in the unlocked position, the adjustment chamber 6d can be moved axially relative to the immersion tube 5a. The stanchion 4a can be moved along the spring travel B within the adjustment chamber 6d.

[0043] Fig. 6 shows analogous to Fig. 3 The functional sequence of the height adjustment is shown using four states a to d on the shock absorber 3a with stanchion tube 4a and slider tube 5a according to the second embodiment. The adjusting element 6 is designed as an adjusting chamber 6d and is arranged inside the slider tube 5a. The four partial figures illustrate the switching between two discrete length positions ("long" and "short") by unlocking, axially repositioning, and re-locking:

[0044] Fig. 6a (locked, long): The adjustment chamber 6d is in a first axial position. The first profile element on the immersion tube 5a (not visible) and the lower second profile element 8b on the adjustment chamber 6d are positively engaged, so that the adjustment chamber 6d is axially locked relative to the immersion tube 5a.

[0045] Fig. 6b (unlocked, long): By a relative rotation of 90° between immersion tube 5a and adjustment chamber 6d, the positive locking engagement is released; in this position, the adjustment chamber 6d is axially adjustable relative to the immersion tube 5a.

[0046] Fig. 6c (unlocked, short): In the unlocked position, the adjustment chamber 6d is axially moved into the second discrete position, thus preparing the second length position.

[0047] Fig. 6d (locked, short): By rotating again, the positive engagement is restored; the adjustment chamber 6d is locked in the second axial position, so that the short length position is securely fixed.

[0048] In this embodiment, the height adjustment is carried out according to the Fig. 1 and Fig. 2 analogous. In both embodiments, a steel spring may be provided, which is not shown for the sake of clarity.

[0049] Although the height adjustment device also takes the form of the adjustment chamber according to the Fig. 4-6 can be designed, an embodiment according to the Fig. 1-3 proved to be even more advantageous. In the case of the adjustable chamber, the additional chamber wall (in addition to the wall of the stanchion) leads to a constructive "doubling" of the side walls; this significantly increases the outer diameter of the stanchion compared to conventional suspension forks, which can complicate the integration of the suspension fork into existing frame designs.

[0050] In contrast, according to the Fig. 1-3 trained height adjustment devices result in a significantly more compact design because the adjustment chamber can be dispensed with; this eliminates the aforementioned wall doubling and the available installation space can be specifically reduced.

[0051] Furthermore, the adjustment mechanism can be designed so that (minus the profile sections) it has essentially the same diameter as the stanchion, thus reducing the diameter of the slider tube. Additionally, stops can be provided at the ends of the profile sections to prevent over-tightening and to give tactile feedback as to whether it is fully locked or unlocked; this also addresses the disadvantage observed in the chamber design of a lack of haptic feedback and potentially incomplete locking.

[0052] Finally, the basic functionality of the height adjustment (positive locking via profile areas and switching by relative rotation) remains unchanged; the design according to the Fig. 1-3 proves to be at least as functional as the principle with an adjustable chamber ( Fig.4-6), however, takes up significantly less installation space, which is why it is being pursued more favorably. Reference symbol list: 1 suspension fork 2 Fork head 2a Head tube 3a, 3b Shock absorbers 4a, 4b Standpipes 5a, 5b immersion tubes 6 Adjustment element 6a upper stop element 6b lower stop element 6c Connecting element 6d Adjustment chamber 7a, 7b first profile elements 8a, 8b second profile elements 9a, 9b axle mounts 10 Mudguard attachment 11 brake adapters 12 Fasteners Axial adjustment range (height adjustment) B Suspension travel

Claims

[1] Suspension fork (1) for a bicycle, in particular a recumbent tricycle, with - a fork head (2) and at least one shock absorber (3a,3b), wherein the shock absorber (3a,3b) has a stanchion (4a,4b) and a slider (5a,5b) guided telescopically relative to it, - a spring arrangement located in the strut (3a,3b) for damping relative movements between the stanchion tube (4a,4b) and the slider tube (5a,5b), and - a height adjustment device for setting a plurality of different length positions of the suspension fork (1), characterized by , that - the height adjustment device has an adjusting element (6) guided at least partially in or on the dip tube (5a, 5b), which is axially adjustable relative to the dip tube (5a, 5b) in an unlocked position and is axially locked relative to the dip tube (5a, 5b) in a locked position, and - a locking device is provided which, in the locking position, creates a positive engagement between a first profile element (7a,7b) formed on the immersion tube (5a,5b) and a second profile element (8a,8b) formed on the adjusting element (6) and, in the unlocking position, releases the positive engagement, - wherein the locking device can be switched between the locking position and the unlocking position by a relative rotation about the longitudinal axis between the immersion tube (5a, 5b) and the adjusting element (6), and - wherein an anti-rotation device is provided which is designed to prevent rotation of the adjusting element (6) relative to the standpipe (4a,4b) during adjustment. [2] Spring fork (1) according to claim 1, characterized by , that the profile elements (7a, 7b, 8a, 8b) are designed as interlocking rib, tooth or wedge profiles. [3] Suspension fork (1) according to claim 1 or 2, characterized by that the relative rotation has a rotation angle in the range of 80° to 100°, particularly preferably 90°. [4] Suspension fork (1) according to one of claims 1 to 3, characterized by , that the adjusting element (6) forms an axially effective stop to limit the extension travel of the stanchion (4a,4b) relative to the slider (5a,5b) and that the axial adjustment of the adjusting element (6) causes a change in the extended overall length of the suspension fork. [5] Suspension fork (1) according to any one of claims 1 to 4, characterized by , that the adjusting element (6) has at least two discrete detent / locking positions along the longitudinal axis. [6] Spring fork (1) according to claim 5, characterized by that the discrete detent / locking positions correspond to use with two different front wheel sizes. [7] Spring fork (1) according to claim 6, characterized bythat the two front wheel sizes are 16 inches and 20 inches. [8] Suspension fork (1) according to any one of claims 1 to 7, characterized by that an axial adjustment travel (A) of the height adjustment device is at least 50 mm, preferably 50 mm to 60 mm, particularly preferably 52 mm. [9] Suspension fork (1) according to any one of claims 1 to 8, characterized by , that the anti-rotation device includes a guide device which guides a connecting element (6c) guided relative to the standpipe (4a, 4b) in a precisely fitting opening. [10] Spring fork (1) according to claim 9, characterized by , that the connecting element (6c) is designed as a sheet metal which couples an upper stop element (6a) in the standpipe with a lower stop element (6b). [11] Spring fork (1) according to claim 10, characterized by , that a distance between the upper stop element (6a) and the lower stop element (6b) defines the spring travel (B) of the strut (3a,3b). [12] Suspension fork (1) according to any one of claims 1 to 11, characterized by , that stops are provided on the dip tube (5a,5b) which limit the relative rotation in the circumferential direction and / or provide haptic feedback on fully locked / unlocked. [13] Suspension fork (1) according to any one of claims 1 to 8, characterized by , that the adjusting element (6) is designed as an adjusting chamber (6d) which is arranged in the immersion tube (5a,5b) and is axially adjustable relative to the immersion tube (5a,5b). [14] Spring fork (1) according to claim 13, characterized by , that the anti-rotation device comprises a groove pattern arranged on the standpipe (4a,4b) and at least one guide rail formed on the adjustment chamber (6d), wherein the groove pattern is guided in the guide rail. [15] Suspension fork (1) according to any one of claims 1 to 14, characterized by that the spring assembly includes at least one helical steel spring. [16] Spring fork (1) according to claim 15, characterized by , that the helical steel spring is assigned at least one additional, parallel-connected elastomer element to form a progressive spring characteristic in the end region of the spring travel, preferably a cellular polyurethane elastomer. [17] Suspension fork (1) according to any one of claims 1 to 16, characterized by that the shock absorber (3a,3b) has at least one low-friction sliding bearing for guidance between the stanchion (4a,4b) and the slider (5a,5b). [18] Suspension fork (1) according to any one of claims 1 to 17, characterized by , that the immersion tube (5a,5b) is made up of two half-shells which are connected to each other by means of screw connections (12). [19] Suspension fork (1) according to any one of claims 1 to 18, characterized by , that the immersion tube (5a,5b) has an integrated nut or threaded element for attaching a thru-axle.

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