STEM FOR A BICYCLE

Description

Technical field

[0001] The invention relates to a stem for a bicycle and a bicycle with such a stem. State of the art

[0002] A stem for a bicycle is known in the prior art, which enables rotation of the bicycle handlebar with respect to a bicycle fork. For example, document CN202541746U discloses a stem for a bicycle, comprising a handlebar coupling portion and a fork stem coupling portion provided at a distance therefrom, wherein the fork stem coupling portion has a fork stem support portion and a fork stem holder rotatably received in the fork stem support portion. The stem further comprises a locking mechanism for locking the rotational mobility of the fork stem holder in at least one rotational direction. The locking mechanism is configured to lock the rotational mobility of the fork stem holder by means of a force-fitting clamping connection with a holder portion of the fork stem holder located in the axial direction within the fork stem support portion. Description of the invention

[0003] In one aspect, the invention relates to an improved stem which enables a bicycle handlebar to be rotated relative to a bicycle fork and has a particularly low overall height with improved safety for the user.

[0004] The stem can be reversible, allowing it to be used for two different handlebar height positions. The stem can have a stem angle. Furthermore, the stem can also be a zero-degree stem.

[0005] The stem may have a handlebar coupling portion and a fork stem coupling portion provided at a distance therefrom. The handlebar coupling portion is configured to receive a handlebar stem. The handlebar coupling portion may have a pipe clamp-like structure for receiving and clamping a handlebar stem. The fork stem coupling portion is configured to receive a fork stem.

[0006] The steerer tube coupling section has a steerer tube support section and a steerer tube holder rotatably received in the steerer tube support section. The steerer tube holder is accordingly received in the steerer tube support section such that it can be rotated therein or pivoted relative to it. The steerer tube holder is configured to receive a section of the steerer tube of a bicycle fork. For example, the steerer tube can be secured in the steerer tube holder by clamping. In particular, the steerer tube holder can be firmly fastened to the steerer tube. With the fork holder attached to a steerer tube, the steerer tube support section and thus a handlebar attached to the stem can be pivoted around the steerer tube.

[0007] The stem further comprises a locking mechanism for locking the rotational mobility of the fork stem mount in at least one rotational direction. The locking mechanism can be configured to lock the rotational mobility of the fork stem mount by positive engagement with a holder portion of the fork stem mount located axially within the fork stem support portion. The locking mechanism is suitable for locking the fork stem mount and a fork stem attached to the fork stem mount in at least one use position. The use position is a position in which the handlebar extends transversely to the extension direction of a front wheel accommodated in the bicycle fork.In the use position, the stem is also in a position where the fork mount can be additionally clamped into the fork stem support section to achieve a particularly secure, play-free, and rotationally fixed connection between the handlebar and fork. The locking mechanism can therefore be used as a type of pre-adjustment to reliably achieve and maintain the use position in preparation for a final tightening operation to clamp the fork stem. At the same time, the locking mechanism acts as an additional safety device to prevent unintentional twisting of the handlebar relative to the bicycle fork in the event of a failure or unintentional release of the clamp connection between the fork mount and the fork stem support section.

[0008] In the described stem, the rotational mobility of the fork stem mount can thus be achieved by engagement with an element located in the fork stem support section. The engagement thus occurs inside the fork stem support section. This creates a stem with an integrated pivot mechanism and an integrated locking mechanism.

[0009] According to a preferred embodiment, the locking mechanism is provided substantially entirely within the fork stem support portion. In the context of the present invention, "provided substantially entirely within the fork stem support portion" can be understood to mean a provision in which almost all essential components, in particular the components that effect the positive engagement, are provided entirely within the fork stem support portion, and only, for example, an actuating component or an actuating portion of the locking mechanism can protrude from the fork stem support portion.

[0010] According to a preferred embodiment, the locking mechanism can have a locking element. The locking element can be a plate-like element. The locking element can be made of metal. The locking element can be provided to create the positive engagement. For this purpose, the locking element can be arranged to be movable between a locking position and a release position. In the locking position, rotation of the fork stem holder relative to the fork stem support section is locked. In the release position, rotation or pivoting of the fork stem holder relative to the fork stem support section is permitted. The locking element can have a contact section which, in the locking position, can come into contact with a locking section of the fork stem holder. The locking section can be provided on the holder section. The contact section can be formed on the locking element as a contact surface.The contact surface can in particular be a longitudinal end surface of the locking element that limits the longitudinal extent of the locking element, for example an end surface.

[0011] According to one embodiment, the contact portion of the locking element can be arranged to be movable back and forth in the direction of a fork stem holder rotation axis of the fork holder. For example, the contact portion can be movable radially toward and away from the fork stem holder rotation axis. Additionally, however, the contact portion can be movable along a path that extends such that, upon movement of the contact portion along the path, the distance from the fork stem holder rotation axis is reduced or increased.

[0012] According to a further embodiment, the locking element can be pivotally supported on a support section of the fork shaft support section. For this purpose, the locking element can have a rounded end which is supported in a rounded recess. If the locking element is plate-like, one end of the plate-like locking element can be designed in the shape of a half-cylinder. A central axis of the half-cylinder can then define a pivot axis of the locking element around the support section. The locking element can thus form a hinge-like joint together with the support section. The contact section described above can be formed at an end of the locking element which is opposite the end of the locking element at which the locking element is supported on the support section. The locking element can be pivotable about a pivot axis parallel to the fork shaft holder rotation axis.The pivot axis of the locking element can therefore run parallel to the fork stem holder rotation axis.

[0013] According to a preferred embodiment, the locking mechanism can comprise a urging component that biases the locking element toward the locking position. In this way, the locking mechanism can be designed to be self-acting, so that the positive engagement is automatically achieved upon appropriate alignment of the components involved.

[0014] According to a preferred embodiment, the urging component can comprise a leaf spring. The leaf spring can be attached to the fork stem support section on one side. Preferably, the leaf spring can be curved at least in sections around the fork stem support rotation axis.

[0015] According to a preferred embodiment, the urging component can be fixed on one side to the fork shaft support section by means of a fixing section and, in addition to the fixing section, can have an actuating section that can be handled by a user for adjusting the urging component in the direction of the release position and a fastening section that is preferably provided in the direction of extension of the urging component between the fixing section and the actuating section, on which fastening section the locking element is mounted.

[0016] According to one embodiment, the actuating portion can protrude laterally from the fork stem support portion, in particular from a portion of the fork stem support portion that forms a housing. In this way, a user can grasp the actuating portion and easily actuate the locking mechanism toward the release position.

[0017] According to a further embodiment, the fork stem mount can have an asymmetrically shaped, pipe clamp-like clamping body. The clamping body preferably forms the holder section of the fork stem mount. A sleeve can be provided in the clamping body, which is designed to receive the fork stem and can be clamped in the fork stem support section for the final, torsion-proof clamping of the fork holder.

[0018] The clamping body can have two leg sections, which have a receiving area between them for receiving the sleeve and / or a fork stem section of the bicycle fork. To generate a clamping force, a distance between free ends of the leg sections can be reduced in order to reduce a dimension of the receiving area. At one free end of the two free ends of the leg sections, a locking surface can be formed as a part of the positive engagement that cooperates with the locking element. The locking surface can extend substantially in the radial direction to the fork stem holder rotation axis. In the context of the present invention, substantially in the radial direction to the fork stem holder rotation axis means, on the one hand, that the locking surface can extend in the radial direction.Furthermore, an extension in a substantially radial direction also includes an extension in which the blocking surface runs parallel to the radial direction, in particular with a slight offset to the radial extension.

[0019] According to a further preferred embodiment, the fork stem support section can be designed like a pipe clamp and have two legs that define a receiving area between them for receiving the fork stem holder. To generate a clamping force for securing the fork stem holder, free ends of the legs can be connected to one another via a bolt or a tension rod such that a distance between the free ends can be reduced in order to reduce a dimension of the receiving area. In this way, the fork stem holder can be clamped firmly in the fork stem support section. A stem designed in this way can thus, on the one hand, block the rotational mobility of the fork stem holder through a positive engagement and, additionally, by generating a clamping force or a frictional connection between the fork stem holder and the fork stem support section.

[0020] The fork mount can have the sleeve already mentioned above. The sleeve can have sleeve sections 176, 178 that extend axially beyond the clamping body on both sides. The two sleeve sections 176, 178 protruding on opposite sides of the clamping body can be supported in the receiving area between the legs, forming a sliding bearing on the fork stem support section. The fork stem mount can thus be clamped by clamping the sleeve sections 176, 178 between the legs.

[0021] According to a further preferred embodiment, receiving openings delimited by circumferential walls can be provided in the free ends to receive the bolt, with an inner wall section of each of the circumferential walls protruding bulgingly into the receiving area. The wall section protruding bulgingly into the receiving area is designed in the manner of a hollow cylinder section and has a wall thickness sufficient to tighten the bolt or tension rod. On an outer circumference of the holder section, for example the clamping element of the fork stem holder, an elongated recess can be provided to receive the wall section protruding into the receiving area. In this way, the stem can be designed to be more compact in the longitudinal direction.

[0022] Furthermore, according to the present invention, a bicycle, in particular a mountain bike, is provided. The bicycle has a bicycle frame and a bicycle fork. The bicycle fork is secured to the bicycle frame by means of a stem as described above.

[0023] Further features are described in the following detailed description. Short description of the characters

[0024] Figure 1 shows a perspective view of a stem according to one embodiment, which is attached to a fork tube and carries a handlebar tube. Figure 2 shows the Figure 1 shown stem in a further perspective view. Figure 3 shows a front view of the stem. Figure 4 shows a sectional view of the stem along the Figure 3 shown longitudinal plane BB. Figure 5 shows a side view of the stem. Figures 6 and 7 show perspective views of a fork tube mount of the stem. Detailed description of embodiments

[0025] In the Figures 1 and 2 a stem 100 is shown. The stem 100 is in Figure 1 shown in a state in which it is attached to a fork stem 20 and has received a handlebar stem 10. The stem 100 has a handlebar coupling portion 102 and a fork stem coupling portion 104. The handlebar stem 10 is received in the handlebar coupling portion 102, and the fork stem 20 is received in the fork stem coupling portion 104. The handlebar coupling portion 102 and the fork stem coupling portion 104 are spaced apart from one another in the longitudinal direction of the stem 100.

[0026] The handlebar coupling portion 102 is configured like a pipe clamp and is capable of clamping the handlebar stem 10. The center of the handlebar clamp is shown as axis A3. A fork stem mount 108 is rotatably received in the fork stem coupling portion 104. The center of the fork stem 20, which coincides with a fork stem mount rotation axis, is shown as axis A1. The fork stem coupling portion 104 has a fork stem support portion 106 in which the fork stem mount 108 is received. More specifically, the fork stem mount 108 is received in a receiving area 142 formed between two legs 138, 140 of the fork stem support portion 106.

[0027] The more detailed structure of the stem 100 is described below with reference to the Figures 2 , 3 and 4 explained in more detail. Figure 3 shows a front view of the stem 100 in the longitudinal direction and Figure 4shows a sectional view along a section plane BB extending essentially in the longitudinal direction from Figure 3 .

[0028] As already described above, the fork stem coupling portion 104 includes the fork stem support portion 106. The fork stem support portion 106 includes two legs 138, 140 that extend rearwardly in the longitudinal direction of the stem 100, i.e., away from the handlebar coupling portion 104. As already described with reference to Figure 2 As described, the receiving area 142 for receiving the fork stem holder 108 is formed between the legs 138, 140. In the Figure 4In the arrangement shown, the fork stem holder 108 is received in the receiving area 142. The legs 138, 140 each have a free end 144, 146. The free ends 144, 146 are arranged at a distance from one another. In other words, a gap is provided between the free ends 144, 146. In the embodiment shown, the free ends 144, 146 of the legs 138, 140 are connected to one another via a bolt 148 such that the gap between the free ends 144, 146 can be enlarged or reduced when the bolt 148 is actuated. In this way, it is possible to enlarge or reduce the receiving area 142 or its dimensions. If the dimensions of the receiving area 142 are reduced with the fork stem holder 108 inserted, the fork stem holder 108 can be clamped in place.In other words, the steerer tube mount 108 can be frictionally locked in a desired position relative to the steerer tube support portion 106.

[0029] In the embodiment shown, a threaded bore is provided in the free end 146 of the leg 138, and a support area for contact with a head of the bolt 148 is formed in the free end 144 of the leg 140. The support area has a first contact surface 164 and a second contact surface 166 for supporting the head of the bolt 148 at the free end 144. The first contact surface 164 and the second contact surface 166 are arranged offset from one another in the axial direction along a longitudinal axis A5 of the bolt or a bolt receiving opening 162. In a relaxed position, as in Figure 4Accordingly, in the embodiment shown, in which the distance between the free ends is not reduced, only the first contact surface 164 is in contact with the head of the bolt 148. The second contact surface 166 only comes into contact with the head of the bolt 148 when the bolt 148 is actuated to generate a clamping force. The first contact surface 164 and the second contact surface 166 are therefore offset from one another such that a head of the bolt 148, when the fork stem holder 108 is clamped, optimally rests on the first contact surface 164 and the second contact surface 166 in order to achieve improved force distribution.

[0030] As it is in Figure 4 As is also shown, the legs 138, 140 extend on opposite sides of a longitudinal center plane E1 of the stem 100. The bolt 148 or the receiving opening 162 for the bolt 148 extends substantially perpendicular to the longitudinal center plane E1.

[0031] Figure 5 shows a side view of a section of the stem 100. This view shows the structure of the rear region of the stem 100 in the region of the free ends 144, 146 of the fork shaft support section 106. As already mentioned above, receiving openings 162 for receiving the bolt 148 are provided in the free ends 144, 146 in this region. The receiving openings 162 are delimited by circumferential walls 156. An inner wall section 158 of the circumferential walls 156 protrudes bulbously into the receiving area 142. In this way, it is possible to reduce the overall length of the stem 100.

[0032] As already shown in the Figures 4 and 5 As can be seen, the previously mentioned fork stem holder 108 is accommodated in the receiving area 142. The structure of the fork stem holder 108 is described below with reference to the Figures 4 to 7 described in more detail. As can be seen from the Figures 4 , 6 and 7As can be seen, the fork stem mount 108 has an asymmetrically shaped, pipe clamp-like clamping body 130. The clamping body 130 has two leg sections 132, 134. The leg sections 132, 134 define a receiving area 184 between them for receiving the fork stem 20. The leg sections 132, 134 each have a free end 150, 152. A gap is provided between the free ends 150, 152. The free ends 150, 152 are connected to one another by means of screws 180, 182. By actuating the screws, a distance or the gap between the two free ends 150, 152 can be reduced in order to reduce a dimension of the receiving area 184 for clamping the fork stem 20 in the fork stem mount 108. The free ends 150, 152 are designed as flange sections.

[0033] As already mentioned above, the fork stem mount 108 is asymmetrical. This is Figure 4clearly visible. In particular, the fork stem mount 108 has no symmetry with respect to a plane (not shown) passing through the gap formed between the free ends 150, 152. Furthermore, the fork stem mount 108 is not rotationally symmetrical with respect to the fork stem mount rotation axis A1.

[0034] A sleeve 168 is arranged in the clamping body, which is designed to receive the fork stem 20 and serves to support the fork stem holder 108 on the fork stem support section 106 in the manner of a sliding bearing. The sleeve 168 has sleeve sections 176, 178 that extend axially beyond the clamping body 130 on both sides of the clamping body 130. The two sleeve sections 176, 178 protruding on opposite sides of the clamping body 130 are supported in the receiving area between the legs, forming a sliding bearing on the fork stem support section. The fork stem holder 108 can thus be clamped in place by clamping the sleeve sections between the legs.

[0035] The clamping body 130 further has an elongated recess 160 extending in the circumferential direction of the clamping body 130, the shape of which corresponds to the shape of the wall section 158 protruding into the receiving area 142. In other words, the elongated recess 160 is configured to at least partially accommodate the wall section 158 protruding into the receiving area 142, thereby enabling a particularly compact design of the stem 100 in the longitudinal direction. The elongated recess 160 has a substantially straight section, which runs skewed to the fork stem holder rotation axis A1, and a curved section that extends around the rotation axis A1. The straight section is configured to come into planar contact with the wall section 158 protruding into the receiving area 142.

[0036] As already mentioned above, the fork stem holder 108 is rotatably held in the fork stem support section 106. In this way, it is possible to pivot the fork stem support section 106 around the fork stem holder 108 or a fork stem received in the fork stem holder 108. A pivoting range is limited, on the one hand, by contact of the wall section 158 projecting into the receiving area 142 with the straight section of the elongated recess 160 and, on the other hand, by contact of one of the legs 138, 140 with the fork stem support section 106. The pivoting range between these described end positions can preferably comprise 90°. In this way, it is possible to rotate a handlebar attached to the stem 100 by 90° relative to the fork stem between a use position and a non-use position.

[0037] In order to lock the handlebar in the use position, as already described above, a clamping force can be applied to the fork stem holder 108, more precisely to the projecting sleeve sections 176, 178, by tensioning the free ends 144, 146 in order to hold the fork stem holder 108 in the fork stem support section 106 in a rotationally fixed manner by means of frictional engagement.

[0038] In order to bring the fork stem holder 108 into a defined position for clamping it and to hold it there, the embodiment shown has a locking mechanism 110 for locking the rotational mobility of the fork stem holder 108. The structure of the locking mechanism 110 is shown in Figure 4clearly visible. The locking mechanism 110 has a plate-like locking element 114. The locking element 114 has a contact portion 116 at one longitudinal end and is pivotally supported at an opposite longitudinal end on a support portion 120 of the fork stem support portion 106. In the embodiment shown, the plate-like locking element 114 is pivotally supported on the support portion 120 about a pivot axis A2, which is oriented substantially parallel to the fork stem holder rotation axis A1.

[0039] The locking element 114 is attached to a leaf spring 122. More precisely, the locking element 114 is attached in the region of the contact section 116 or adjacent thereto to a fastening section 128 of the leaf spring 122, which is located between a fixing section 124 of the leaf spring and an actuating section 126 of the leaf spring. The leaf spring 122 is fixed on one side to the fork shaft support section 106 by means of the fixing section 124. In particular, in the embodiment shown, as in Figure 3 As can be seen, the leaf spring 122 is fastened by means of a screw 154 in the region of the support section 120, on which the locking element 114 is pivotally supported. The locking element 114 is further fastened to the fastening section 128 via a screw 155.

[0040] The leaf spring 122 is curved in sections around the fork stem holder's rotational axis A1. In the embodiment shown, the fixing section 124 and the actuating section 126 extend substantially parallel to one another. Thus, starting from the fixing section 124, the leaf spring initially extends substantially perpendicular to the longitudinal center plane E1 and then, in the region of the fastening section 128, initially inclined to the longitudinal center plane E1 and then curved around the fork stem holder's rotational axis A1 up to the actuating section 126.

[0041] An effective length between the attachment point of the leaf spring and the aforementioned contact section 116 is longer in this embodiment, whereby the path traveled by the contact section 116 is longer when the actuating section 126 is actuated. Furthermore, in this embodiment, the locking element 114 is oriented in a locking position such that an optimal force flow occurs in the longitudinal direction of the locking element 114 from the contact section 116 to the support section 120. The above-described structure of the leaf spring 122 also ensures a defined deformation of the leaf spring 122 when the contact section 116 is subjected to a force. In particular, an uncontrolled bulging of a section of the leaf spring 122, as could occur with a straight leaf spring, is avoided.

[0042] As already described above, the clamping body 130 has two leg sections 132, 134. A locking surface 136 is provided at a free end 152 of the two free ends 150, 152 of the leg sections 132, 134. This locking surface 136 serves as a cooperating part of the positive engagement to be created with the locking device 110. The locking surface 136 is in Figure 6 clearly visible and, in the embodiment shown, runs parallel to a radial direction to the fork stem holder rotation axis A1. The locking surface 136 is part of a locking section 118 at the free end 152. This locking surface 136 can come into contact with the contact section 116 or a side surface delimiting the locking element 114 in the longitudinal direction in the region of the contact section 116 when the locking element 114 is in the locking position.

[0043] By actuating the leaf spring 122, more precisely by displacing the actuating section 126 in the longitudinal direction of the stem 100 or along the longitudinal center plane E1, the locking element 114 can be pivoted between the already mentioned locking position, in which the contact section 116 of the locking element 114 can come into contact with the locking section 118 of the fork stem holder 108, and a release position, in which the contact section 116 cannot come into contact with the locking section 118 of the fork stem holder 108. In the Figure 4 In the state shown, the locking element 114 is in the locked position. In the locked position, the fork stem holder 130 is oriented such that the extension directions of the screws 180, 182 connecting the free ends 150, 152 are inclined to the longitudinal center plane E1, as shown in Figure 4The course of a longitudinal axis A4 of the screw 180 is illustrated in the figure. By moving the actuating section 126 forwards, i.e. downwards in Figure 4 , the locking element is pivoted towards the release position.

[0044] To enable pivoting of the fork stem mount 108, the fork stem coupling portion 104 further includes a recess 170 on one side of the fork stem support portion 106, more specifically in the leg 138, through which the free ends 150, 152 can pass when the handlebar is pivoted into a non-use position. Through this recess 170, as shown in Figure 5 shown, the clamp body 130 and the holder portion 112 of the steerer tube bracket 108 with the recess 160 formed thereon are visible. Reference symbol

[0045] 10Handlebar stem 20Fork stem 100Stem 102Handlebar coupling section 104Fork stem coupling section 106Fork stem support section 108Fork stem bracket 110Locking mechanism 112Holder section 114Locking element 116Contact section 118Locking section 120Support section 122Urging component, leaf spring 124Fixing section 126Acting section 128Fastening section 130Clamping body 132, 134Leg section 136Locking surface 138, 140Leg 142Receiving area 144, 146Free end 148Bolt 150; 152 free end 154 screw 155 screw 156 walls 158 wall section 160 elongated recess 162 receiving opening 164 first contact surface 166 second contact surface 168 sleeve 170 recess 176, 178 sleeve section 180, 182 screw 184 receiving area A1 axle, fork stem bracket pivot axis A2 pivot axis A3 axle A4 longitudinal axis A5 longitudinal axis E1 longitudinal center plane

Claims

1. Stem (100) for a bicycle, having a handlebar coupling section (102) and a steerer tube coupling section (104) provided spaced apart from the former, wherein the steerer tube coupling section (104) has a steerer tube support section (106) and a steerer tube holder (108) which is received rotatably in the steerer tube support section (106), wherein the stem (100) furthermore has a locking mechanism (110) for locking a rotational movability of the steerer tube holder (108) in at least one direction of rotation, wherein the locking mechanism (110) is configured to lock the rotational movability of the steerer tube holder (108) by means of a positively locking engagement with a holder section (112) of the steerer tube holder (108) located in the axial direction within the steerer tube support section (106).

2. Stem (100) according to Claim 1, characterized in that the locking mechanism (110) is provided substantially completely within the steerer tube support section (106).

3. Stem (100) according to Claim 2, characterized in that the locking mechanism (110) has a latching element (114) which can be moved between a locking position, in which a contact portion (116) of the latching element (114) can come into contact with a locking portion (118) of the steerer tube holder (108) to lock a rotation of the steerer tube holder (108), and a release position, in which the contact portion (116) cannot come into contact with the locking portion (118) of the steerer tube holder (108) to allow a rotation of the steerer tube holder (108).

4. Stem (100) according to Claim 3, characterized in that the contact portion (116) is arranged such that it can be moved to and fro in the direction of a steerer tube holder rotational axis (A1) of the steerer tube holder (108).

5. Stem (100) according to Claim 4, characterized in that the latching element (114) is pivotably supported on a support portion (120) of the steerer tube support section (106), preferably in such a way that the latching element (114) is pivotable about a pivot axis (A2) parallel to the steerer tube holder rotational axis (A1).

6. Stem (100) according to one of Claims 3 to 5, characterized in that the locking mechanism comprises a displacing component (122) which preloads the latching element (114) in the direction of the locking position.

7. Stem (100) according to Claim 6, characterized in that the displacing component (122) has a leaf spring which is preferably fastened on one side to the steerer tube support section (106), wherein the leaf spring is preferably of at least partially curved configuration around the steerer tube holder rotational axis (A1).

8. Stem (100) according to Claim 7, characterized in that the displacing component (122) is fixed on one side on the steerer tube support section (106) by means of a fixing portion (124) and, besides the fixing portion (124), has an operating portion (126) which can be handled by a user for adjusting the displacing component (122) in the direction of the release position and a fastening portion (128) which is preferably provided between the fixing portion (124) and the operating portion (126) in the direction of extent of the displacing component (122) and on which the latching element (114) is provided.

9. Stem (100) according to Claim 8, characterized in that the operating portion (126) protrudes laterally from the steerer tube support section (106).

10. Stem (100) according to one of the preceding claims, characterized in that the steerer tube holder (108) has an asymmetrically shaped, pipe clamp-like clamping body (130).

11. Stem (100) according to Claim 10, characterized in that the clamping body (130) has two leg portions (132, 134), which, between themselves, have a receiving region (184) for receiving a steerer tube portion, wherein, in order to generate a clamping force, a spacing between two free ends (150, 152) of the leg portions (132, 134) can be decreased to reduce a dimension of the receiving region (184), wherein a locking surface (136) is formed as a cooperating part of the positively locking engagement at a free end (152) of the free ends (150, 152), wherein the locking surface (136) runs substantially in the radial direction with respect to the steerer tube holder rotational axis (A1).

12. Stem (100) according to Claim 11, characterized in that the steerer tube support section (106) is formed in the manner of a pipe clamp and has two legs (138, 140) which, between themselves, define a receiving region (142) for receiving the steerer tube holder (108), wherein free ends (144, 146) of the legs (138, 140) are connected to each other via a bolt (148) in order to generate a clamping force for securing the steerer tube holder (108), in such a way that a spacing between the free ends (144, 146) can be decreased to reduce a dimension of the receiving region (142).

13. Stem (100) according to Claim 12, characterized in that receiving openings (162) delimited by surrounding walls (156) are provided in each free end (144, 146) for receiving the bolt (148), wherein an inner wall portion (158) protrudes in each case in a bulbous manner from the surrounding walls (156) into the receiving region (142), and wherein, in an outer periphery of the holder portion (112), an elongate depression (160) for receiving the wall portion (158) projecting into the receiving region (142) is provided.

14. Bicycle, especially mountain bike, with a bicycle frame and a bicycle fork, characterized in that the bicycle fork is held on the bicycle frame by means of a stem (100) according to one of the preceding claims.