Fork steerer tube arrangement and bicycle

Abstract

Fork steerer assembly (1) for a bicycle (100), comprising a lower fork steerer (2), an upper fork steerer (3), an outer clamping element (5), wherein the upper fork steerer (3) at least partially surrounds the lower fork steerer (2) in an overlap area (6), wherein the outer clamping element (5) rests against the outside of the upper fork steerer (3) in the overlap area (6) and is designed to exert an inward force on the outside of the upper fork steerer (3), wherein an inner clamping element (4) is provided, which is arranged with a lower part (4.1) against the inside of the lower fork steerer (2) and with an upper part (4.2) against the inside of the upper fork steerer (3) and is designed to exert an outward force on the inside of the lower fork steerer (2) and the inside of the upper fork steerer (3).

Description

[0001] The invention relates to a fork stem arrangement for a bicycle and a bicycle.

[0002] Highly flexible handlebar height adjustment is a common request for bicycles. Often, the desire is to set the handlebar height higher than originally intended. In such cases, the length of the steerer tube typically limits the upward adjustment range. To enable adjustment beyond the intended maximum height, so-called Ahead adapters are known from the prior art. These are clamped onto the steerer tube and extend it. A disadvantage of these adapters is that they can only be used with steel steerer tubes.

[0003] Such a fork stem arrangement is known, for example, from DE 603 ​​05 039 T2 or DE 10 2015 103 741 A1.

[0004] Besides the desired upward adjustability, there's also the need to position bicycle cockpits and classic stems with handlebars lower than intended. Cyclists typically achieve this by using spacers mounted above the cockpit or simply shortening the steerer tube with a saw. Both methods compromise safety. Cutting the steerer tube, in particular, negatively impacts the bicycle's resale value.

[0005] The invention is based on the objective of providing a fork stem arrangement that offers a high degree of safety while simultaneously allowing maximum flexibility with regard to height adjustability.

[0006] This problem is solved by the fork stem arrangement shown in claim 1. Advantageous embodiments and further developments of the invention can be found in the dependent claims and the description with reference to the drawings.

[0007] According to the invention, the fork stem arrangement comprises a lower fork stem, an upper fork stem, an inner clamping element and an outer clamping element.

[0008] The upper steerer tube is preferably a standard industrial steerer tube with an outer diameter of 28.6 mm. The upper steerer tube preferably has an inner diameter of 24.2 mm. The upper steerer tube at least partially surrounds the lower steerer tube in an overlap area. For this purpose, the lower steerer tube has an outer diameter in the overlap area that is at most equal to the inner diameter of the upper steerer tube. It is conceivable that the lower steerer tube has an outer diameter of 24 mm in the overlap area. It is conceivable that the lower steerer tube has an inner diameter of 20 mm in the overlap area. Preferably, the lower steerer tube has a smaller outer diameter within the overlap area than below the overlap area.It is therefore conceivable that the lower fork steerer tube has a first section with a large diameter and a second section with a small diameter. It is also conceivable that the transition area between the first and second sections is conical. The overlapping area of ​​the fork steerer tubes achieves a high degree of stability and thus safety.

[0009] Alternatively, the lower steerer tube could be a standard industrial-sized steerer tube with an outer diameter of 28.6 mm. The upper steerer tube at least partially surrounds the lower steerer tube in an overlap area. For this purpose, the upper steerer tube has an inner diameter in the overlap area that is at least equal to the outer diameter of the lower steerer tube. Preferably, the upper steerer tube has a smaller outer diameter above the overlap area than within the overlap area. It is further preferred that the upper steerer tube has a smaller inner diameter above the overlap area than within the overlap area. Particularly preferred is the upper steerer tube having an outer diameter of 28.6 mm above the overlap area and an inner diameter of 28.8 mm within the overlap area.Furthermore, it is preferably provided that the upper fork steerer tube has an outer diameter of 33 mm in the overlap area. It is therefore conceivable that the upper fork steerer tube has a first section with a large diameter and a second section with a small diameter. For this purpose, it is conceivable that a transition area between the first and second sections is conically shaped. The overlap in the overlap area of ​​the fork steerer tubes achieves a high degree of stability and thus safety.

[0010] The outer clamping element is arranged such that it rests against the outside of the upper fork steerer tube in the overlap area. According to the invention, the outer clamping element exerts an inward force on the outside of the upper fork steerer tube. This significantly increases the strength of the fixation between the upper and lower fork steerer tubes.

[0011] According to the invention, the fork steerer assembly has an inner clamping element, wherein the inner clamping element is arranged with a lower part against the inside of the lower fork steerer and with an upper part against the inside of the upper fork steerer, wherein the inner clamping element is designed to exert an outward force on the inside of the lower fork steerer and an outward force on the inside of the upper fork steerer. This clamps the inner and outer fork steerer and fixes them relative to each other.

[0012] By loosening the inner and outer clamping elements so that they exert little or no force on the inner and outer sides of the fork steerer tubes, the position of the upper steerer tube can be adjusted. For example, the upper steerer tube can be moved further up or down. It is also possible to replace the existing upper steerer tube with one that is longer or shorter after loosening the inner and outer clamping elements. This allows for a high degree of flexibility in adjusting the head tube height. Furthermore, it offers the advantage of being able to interchange differently configured upper steerer tubes to meet various requirements. This makes it possible, for example, to achieve significant height adjustments.

[0013] According to a preferred embodiment of the invention, the outer clamping element is designed to exert the inward force on the outside of the upper fork steerer tube in such a way that the inside of the lower fork steerer tube is pressed onto the lower part of the inner clamping element. This advantageously increases the stability of the fixation between the upper and lower fork steerer tubes.

[0014] Preferably, the inner clamping element is an expander, wherein the outer diameter of the lower part of the inner clamping element is adapted to the inner diameter of the lower fork steerer tube, and the outer diameter of the upper part of the inner clamping element is adapted to the inner diameter of the upper fork steerer tube. This enables advantageous force transmission from the expander to the lower and upper fork steerer tubes. An outer diameter and an inner diameter within the meaning of the present invention are not necessarily limited to a circular outer or inner contour, but merely describe the geometric design of the outer or inner contour of the upper or lower fork steerer tube with respect to a plane that is orthogonal to the main extension direction of the upper or lower fork steerer tube.In the context of the present invention, "adapted" means that the outer contour of the inner clamping element is at least partially flush with the inner surface of the upper or lower fork steerer tube. In particular, it is provided, for example, that the inner diameter of the upper fork steerer tube is oval and that the outer diameter of the upper part of the inner clamping element is at least partially oval. Likewise, it is provided, in particular, that the inner diameter of the lower fork steerer tube is oval and that the outer diameter of the lower part of the inner clamping element is at least partially oval.

[0015] According to a further preferred embodiment of the present invention, the lower part and the upper part of the inner clamping element are arranged side by side along a vertical direction, the lower part of the inner clamping element having a smaller extent in a transverse direction orthogonal to the vertical direction than the upper part of the inner clamping element. The resulting shape of the inner clamping element ensures excellent contact between the inner clamping element and the inner surfaces of the upper and lower fork steerer tubes. The vertical direction, as defined in the present invention, corresponds to the main extension direction of the lower and upper fork steerer tubes.

[0016] Preferably, the outer clamping element is a clamping spacer. A clamping spacer, as defined in the present invention, is an element encompassing the upper fork steerer tube, which is provided for spacing elements along the vertical direction above and below the clamping spacer. The clamping spacer preferably has a screw with which the inward force can be applied by turning the screw.

[0017] According to a further preferred embodiment of the present invention, the outer surface of the lower fork steerer tube has an oval cross-section, at least in the overlapping area, and the inner surface of the upper fork steerer tube also has an oval cross-section, at least in the overlapping area. This advantageously secures the upper and lower fork steerer tubes against rotation relative to each other. It is conceivable that the outer surface of the lower fork steerer tube has an oval cross-section along its entire length and that the inner surface of the upper fork steerer tube has an oval cross-section along its entire length.It is also conceivable that the outer surface of the lower fork steerer tube has a non-circular cross-section, for example a square cross-section, at least in the overlap area, and that the inner surface of the upper fork steerer tube has a non-circular cross-section, for example a square cross-section, at least in the overlap area. Preferably, the outer surface of the upper fork steerer tube has a circular cross-section. Furthermore, it is preferably the inner surface of the lower fork steerer tube has a circular cross-section.

[0018] Furthermore, it is preferably provided that the outer surface of the lower fork steerer tube has at least one flattened area, at least in the overlap area. Furthermore, the inner surface of the upper fork steerer tube preferably has at least one flattened area, at least in the overlap area. The flattened area of ​​the upper fork steerer tube is arranged to abut the flattened area of ​​the lower fork steerer tube.

[0019] It is conceivable that the outer clamping element is adapted to the outer diameter of the upper fork steerer tube. In particular, it is intended that an inner diameter of the outer clamping element is at least partially adapted to the outer diameter of the upper fork steerer tube.

[0020] Preferably, the upper fork steerer tube has a lateral slot. This ensures significantly better power transmission.

[0021] Furthermore, it is preferably provided that a clamping element of the inner clamping element is arranged such that the clamping element can be actuated from an interior space of the upper fork steerer tube, wherein the clamping element is designed to effect and / or mediate the application of the outward force to the inside of the lower fork steerer tube and the inside of the upper fork steerer tube. In other words, it is provided that the clamping element is operated from above. However, it is also conceivable that the clamping element can be operated through the lateral slot or through another lateral slot of the upper and / or lower fork steerer tube.

[0022] It is conceivable that the clamping element has a screw for screwing into the inner clamping element, whereby screwing in causes the clamping element to expand against the insides of the upper fork steerer tube and the lower fork steerer tube.

[0023] To improve the installation of cables along the steerer tube, it is preferably provided that the inner clamping element has a cable guide. This advantageously allows cables, such as brake lines or electrical cables, to be routed from the bicycle cockpit through the interior of the upper and lower steerer tubes. Besides a visually appealing arrangement, this saves installation space and protects the cables from mechanical damage. Furthermore, it is particularly advantageous that the currently common, complex routing of the cables through an enlarged bearing is eliminated.

[0024] Preferably, the lower steerer tube and the upper steerer tube are both made of carbon material. According to an alternative and preferred embodiment of the present invention, the lower steerer tube is made of carbon material, while the upper steerer tube is made of a metal, preferably aluminum. This advantageously combines the benefits of a carbon steerer tube, particularly its low weight, with those of a metal steerer tube. The metal construction of the upper steerer tube provides an additional safety advantage and allows for greater extension of the upper steerer tube. Furthermore, the combination of carbon and metal materials allows for adjustment of the steerer tube's elasticity.Thus, the fork steerer assembly allows for greater suspension travel when the upper steerer tube is extended further. When the upper steerer tube is pushed further onto the lower steerer tube, the fork steerer assembly becomes stiffer. It is also conceivable that the upper steerer tube is made of a carbon material and the lower steerer tube of a metal, preferably aluminum. For the purposes of this invention, aluminum includes not only aluminum but also any aluminum alloy.

[0025] Another object for solving the problem posed at the outset is a bicycle having a fork stem arrangement according to the invention.

[0026] Preferably, the upper fork steerer tube is mounted to the bicycle's head tube by means of a bearing, with the outer clamping element forming an upper bearing cover. This advantageously ensures that the bearing play remains fixed even when the bicycle cockpit is removed.

[0027] All details, features and advantages previously disclosed in connection with the fork stem arrangement according to the invention also relate to the bicycle according to the invention.

[0028] Further details, features, and advantages of the invention will become apparent from the drawings and from the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the inventive concept.

[0029] They show: Fig. 1: A first sectional view of a fork stem arrangement for a bicycle according to an exemplary embodiment of the present invention, Fig. 2: a second sectional view of a fork stem assembly for a bicycle according to an exemplary embodiment of the present invention, Fig. 3: Another view of a fork stem arrangement for a bicycle according to an exemplary embodiment of the present invention, Fig. 4: a schematic representation of an inner clamping element of a fork stem assembly according to an exemplary embodiment of the present invention, Fig. 5: a cross-sectional view of the overlap area of ​​a fork stem arrangement according to an exemplary embodiment of the present invention along the vertical axis and Fig. 6: a third sectional view of a fork stem arrangement for a bicycle according to an exemplary embodiment of the present invention.

[0030] In the figures described below, identical elements are always designated with the same numbers or letters and are therefore not necessarily described multiple times.

[0031] Fig. 1, Fig. 2 and Fig. Figures 6 each show a cross-sectional, schematic representation of a fork stem arrangement 1 according to an exemplary embodiment of the present invention for a bicycle 100 according to an exemplary embodiment of the present invention.

[0032] The fork steerer assembly 1 comprises a lower fork steerer 2, which is at least partially enclosed by an upper fork steerer 3 in an overlap area 6. Preferably, the upper fork steerer 3 is an industry-standard steerer, i.e., its outer diameter is 28.6 mm. The upper fork steerer 3 can be made, for example, of a carbon material or a metal, such as aluminum. The lower fork steerer 2 has an outer diameter, at least in the overlap area 6, that allows the upper fork steerer 3 to slide over the lower fork steerer 2. The lower fork steerer 2 can be made of the same material as the upper fork steerer 3. However, it is also conceivable that the upper fork steerer 3 is made of a different material, for example, a metal such as aluminum.

[0033] To adjust the steering height, the upper fork steerer tube 3 is moved along the vertical direction H relative to the lower fork steerer tube 2. Once the steering height is set, the upper fork steerer tube 3 and the lower fork steerer tube 2 must be fixed relative to each other. Two clamping elements 4, 5 are provided for this purpose. An inner clamping element 4 rests with a lower part 4.1 against the inside of the lower fork steerer tube 2. An upper part 4.2 of the inner clamping element 4 rests against the inside of the upper fork steerer tube 3. By means of a tensioning element 4.3 of the inner clamping element 4, an outward force can be exerted on the inside of the lower fork steerer tube 2 and the upper fork steerer tube 3. The tensioning element 4.3 is either inserted from above through the upper fork steerer tube 3 ( Fig. 4(a)) or laterally ( Fig. 4(b)) is accessible through a slot 3.1 in the upper fork steerer tube 3. An outer clamping element 5, designed as a clamping spacer, rests against the outside of the upper fork steerer tube 3 in the overlap area 6. The outer clamping element 5 is designed to exert an inward force on the upper fork steerer tube 3 and through the upper fork steerer tube 3 onto the inner fork steerer tube 2 and finally onto the inner clamping element 4. The outer clamping element 5 is adapted to the outer contour of the upper fork steerer tube 3 such that the outer clamping element 5 rests against the outside of the upper fork steerer tube 3 over as large an area as possible.

[0034] The inner clamping element 4 is designed as an expander. The outer diameter of the lower part 4.1 of the inner clamping element 4 is adapted to the inner diameter of the lower fork steerer tube 2 such that the lower part 4.1 is at least partially in contact with the inside of the lower fork steerer tube 2. For this purpose, the outer contour of the lower part 4.1 of the inner clamping element 4 is adapted to the inner contour of the lower fork steerer tube 2 in the overlap area 6. Likewise, the outer diameter of the upper part 4.2 of the inner clamping element 4 is adapted to the inner diameter of the upper fork steerer tube 3. The upper part 4.2 is at least partially in contact with the inside of the upper fork steerer tube 3. For this purpose, the outer contour of the upper part 4.2 of the inner clamping element 4 is also adapted to the inner contour of the upper fork steerer tube 3 in the overlap area 6.The inner clamping element 4 therefore has different extensions along the vertical direction H and along a transverse direction Q, which is orthogonal to the vertical direction H.

[0035] To prevent twisting of the lower fork steerer tube 2 and the upper fork steerer tube 3, it can be provided that, at least in the overlap area 6, the lower fork steerer tube 2 and the upper fork steerer tube 3 are not round. For example, the fork steerer tubes 2 and 3 could be oval or have flattened areas 10.

[0036] A good force transmission is achieved by the fact that the upper fork steerer tube 3 can have the lateral slot 3.1. This allows the upper fork steerer tube 3 to be clamped onto the lower fork steerer tube 2 over a large area.

[0037] If the fork steerer assembly 1 is installed in a bicycle 100, the fork steerer assembly 1 is rotatably mounted in a head tube 8 of the bicycle 100 with at least one bearing 7 of a headset of the bicycle 100. The outer clamping element 5 can form an upper bearing cover for the bearing 7. A stem 12 of the bicycle 100 is arranged on the upper fork steerer 3 and spaced from the outer clamping element 5 by spacers 9. An Ahead cap 13, which is secured with an Ahead cap screw 13.1, forms the top end. The Ahead cap screw 13.1 engages in a thread in the clamping element 4.3 of the inner clamping element 4, so that by turning the Ahead cap screw 13.1 it can be screwed onto and fastened to the inner clamping element 4.

[0038] To adjust the steering height, simply loosen the Ahead cap screw 13.1 and remove the Ahead cap 13. The stem 12 can then be loosened and also removed. Because the outer clamping element 5 remains attached to the bearing 7 even with the cockpit removed, the headset bearing play remains fixed in this situation as well. Depending on the design, the inner clamping element 4 can be adjusted laterally ( Fig. 4(b)) or from above ( Fig. 4(a)), relaxes, thus releasing the outward force of the inner clamping element 4. With the additional relaxation of the outer clamping element 5, the inward force and thus the fixation of the upper fork steerer tube 3 and the lower fork steerer tube 2 is released, and they become movable relative to each other. This allows for a new steering height adjustment.

[0039] The inner clamping element 4 has a cable gland 4.4. Cables 11, such as brake cables, brake lines, or electrical cables, are routed through this cable gland 4.4. This allows the cables 11 to be routed through the interior 3.2 of the upper fork steerer tube 3 and the lower fork steerer tube 2. A complex routing through the bearings 7 of the headset of the bicycle 100 is therefore unnecessary.

[0040] The fork stem assembly 1 according to the invention enables a steering height adjustment with a large adjustment range. Visually, the fork stem assembly 1 is hardly distinguishable from a conventional fork stem assembly. Reference symbol list: 1 Fork steerer assembly 2 lower fork steerer 2.1 side slot 3 upper fork steerer 3.1 side slot 3.2 Interior 4 inner clamping element 4.1 lower part 4.2 upper part 4.3 Tensioning element 4.4 Cable routing 5 outer clamping element 6 Coverage area 7 warehouses 8" head tube 9 Spacers 10 flattened area 11 Management 12 Extension 13 Ahead cap 13.1 Ahead cap screw 100 bicycles H Upward direction Q transverse direction

Claims

[1] Fork steerer assembly (1) for a bicycle (100), comprising a lower fork steerer (2), an upper fork steerer (3), an outer clamping element (5), wherein the upper fork steerer (3) at least partially surrounds the lower fork steerer (2) in an overlap area (6), wherein the outer clamping element (5) rests against the outside of the upper fork steerer (3) in the overlap area (6) and is designed to exert an inward force on the outside of the upper fork steerer (3), wherein an inner clamping element (4) is provided, which is arranged with a lower part (4.1) against the inside of the lower fork steerer (2) and with an upper part (4.2) against the inside of the upper fork steerer (3) and is designed to exert an outward force on the inside of the lower fork steerer (2) and the inside of the upper fork steerer (3). [2] Fork shank arrangement (1) according to claim 1, characterized by, that the outer clamping element (5) is designed to exert the inward force on the outside of the upper fork steerer tube (3) in such a way that the inside of the lower fork steerer tube (2) is pressed onto the lower part (4.1) of the inner clamping element (4). [3] Fork stem arrangement (1) according to one of claims 1 or 2, characterized by , that the inner clamping element (4) is an expander, wherein the outer diameter of the lower part (4.1) of the inner clamping element (4) is adapted to the inner diameter of the lower fork steerer tube (2) and the outer diameter of the upper part (4.2) of the inner clamping element (4) is adapted to the inner diameter of the upper fork steerer tube (3). [4] Fork stem arrangement (1) according to one of the preceding claims, characterized by, that the lower part (4.1) of the inner clamping element (4) and the upper part (4.2) of the inner clamping element (4) are arranged side by side along a vertical direction (H), wherein the lower part (4.1) of the inner clamping element (4) is smaller than the upper part (4.2) of the inner clamping element (4) in a transverse direction (Q) arranged orthogonally to the vertical direction (H). [5] Fork stem arrangement (1) according to one of the preceding claims, characterized by , that the outer clamping element (5) is a clamping spacer. [6] Fork stem arrangement (1) according to one of the preceding claims, characterized by , that the outside of the lower fork steerer tube (2) has an oval cross-section at least in the overlap area (6) and that the inside of the upper fork steerer tube (3) has an oval cross-section at least in the overlap area (6). [7] Fork stem arrangement (1) according to one of the preceding claims, characterized by, that the outside of the lower fork shank (2) has at least one flattened area (10) at least in the overlap area (6) and that the inside of the upper fork shank (2) has at least one flattened area (10) at least in the overlap area (6), wherein the flattened area (10) of the upper fork shank (3) is arranged in abutting the flattened area (10) of the lower fork shank (2). [8] Fork stem arrangement (1) according to one of the preceding claims, characterized by , that the upper fork steerer tube (3) has a lateral slot (3.1). [9] Fork stem arrangement (1) according to any one of the preceding claims, characterized by, that a clamping element (4.3) of the inner clamping element (4) is arranged such that the clamping element (4.3) can be actuated from an interior (3.2) of the upper fork shank (3), wherein the clamping element (4.3) is provided to effect and / or mediate the application of the outwardly directed force to the inside of the lower fork shank (2) and the inside of the upper fork shank (3). [10] Fork shaft arrangement (1) according to claim 9, characterized by , that the clamping element (4.3) has a screw for screwing into the inner clamping element (4), whereby screwing in causes the clamping element (4) to expand against the insides of the upper fork steerer tube (3) and the lower fork steerer tube (2). [11] Fork stem arrangement (1) according to any one of the preceding claims, characterized by , that the inner clamping element (4) has a cable entry (4.4). [12] Fork stem arrangement (1) according to any one of the preceding claims, characterized by , that the lower fork steerer tube (2) is made of a carbon material and that the upper fork steerer tube (3) is made of a metal, preferably aluminium. [13] Bicycle (100) comprising a fork stem arrangement (1) according to one of the preceding claims. [14] Bicycle (100) according to claim 13, characterized by , that the upper fork shank (3) is supported by a bearing (7) on a head tube (8) of the bicycle (100), wherein an upper bearing cover of the bearing (7) is formed by the outer clamping element (5).

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