Low wind resistance bicycle head turning structure and its installation method

Abstract

The application discloses a low-wind-resistance bicycle head steering structure and a mounting method thereof, and belongs to the technical field of bicycles. The structure comprises a frame, a front fork, a bearing group, a locking mechanism and an aluminum sleeve. The front end of the frame is provided with a penetrating mounting groove, and the mounting head tube of the front fork is embedded into the mounting groove. The fork shoulder is raised and directly connected with the handlebar, and the traditional steering rod is cancelled. The aluminum sleeve is pre-buried in the mounting head tube, the middle annular receiving table of the aluminum sleeve forms upper and lower limiting table surfaces, and is used for axially limiting the upper and lower bowl group bearings. The locking mechanism comprises a locking end cover, a shaft center and locking screws. The shaft center is provided with a long slit. When the locking screws are tightened, the shaft center is radially expanded to make the aluminum sleeve and the mounting through hole in interference fit, and axial pre-tightening is applied to the bearings. The application greatly reduces the wind resistance of the bicycle head, simplifies the structure, reduces the weight, is convenient to assemble, and is suitable for high aerodynamic demand bicycles such as timing races and triathlons.

Description

Technical Field

[0001] This invention relates to the field of bicycle technology, specifically to a low-drag bicycle steering structure and its installation method. Background Technology

[0002] The steering mechanism of a bicycle typically includes components such as the head tube, fork, headset bearings, and seat tube. In the prior art, patent CN112739614B from Hillid discloses a steering system using a single-link suspension structure, with the steering rod integrated into the head tube and its lower end fixed to the top plane of the fork via a flange. This design still suffers from problems such as exposed steering rod, low fork shoulder position, high wind resistance, and numerous components. Another patent, CN208344466U, eliminates the seat tube, but the front of the frame still uses a support-type structure, with the fork engaging the steering shaft via a lug, resulting in a less compact aerodynamic shape.

[0003] In summary, existing bicycle steering structures mainly suffer from the following problems: (1) the steering rod is exposed, resulting in a large windward area, which is not conducive to reducing wind resistance; (2) there are many parts, leading to a complex structure; and (3) the fork shoulder is low, making it difficult to integrate with the handlebars to optimize aerodynamic shape. Therefore, this invention provides a low-drag bicycle steering structure and its installation method. Summary of the Invention

[0004] This invention aims to solve at least one of the aforementioned technical problems by providing a low-drag bicycle steering structure and its installation method, which significantly reduces front-end drag, simplifies the structure, reduces weight, and facilitates assembly. It is suitable for bicycles with high aerodynamic requirements, such as those used in time trials and triathlons.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A low-drag bicycle steering mechanism includes: The frame has a mounting groove recessed at its front end, which extends through the front front side and both sides of the frame. A fork, including a fork shoulder and a mounting head tube, wherein the mounting head tube is connected to the fork shoulder, the shape of the mounting head tube is adapted to the mounting groove and is movably embedded in the mounting groove, and the mounting head tube is provided with a mounting through hole from top to bottom; A locking mechanism is installed in the mounting through hole, and the locking mechanism can connect the mounting head tube to the vehicle frame; The bearing assembly is located within the mounting through hole and sleeved on the locking mechanism, enabling the mounting head tube to rotate about the central axis of the mounting through hole under force; the locking mechanism can apply axial preload to the bearing assembly.

[0006] Furthermore, the locking component includes a locking end cap, a shaft, and a locking screw. The locking end cap is placed between the top surface of the frame corresponding to the mounting groove and the top of the mounting through hole. The shaft passes through the mounting through hole and is connected to the locking end cap. The locking screw is inserted into the shaft from the bottom front end of the frame, passes through the locking end cap, and is connected to the top surface of the frame corresponding to the mounting groove. The bearing assembly is sleeved on the shaft, and the shaft confines the bearing assembly within the mounting through hole.

[0007] Furthermore, the bearing assembly includes an upper cup bearing and a lower cup bearing, both of which are sleeved on the shaft. The shaft cooperates with the locking end cap to confine the upper cup bearing to the top of the mounting through hole, and the shaft confines the lower cup bearing to the bottom of the mounting through hole.

[0008] Furthermore, the low-drag bicycle steering structure also includes an aluminum sleeve, which is pre-embedded inside the mounting head tube and coaxially arranged with the mounting through hole. The aluminum sleeve has a channel extending through it along its axial direction, and the shaft is coaxially arranged in the channel and confined within the aluminum sleeve. When the locking screw is inserted into the shaft and tightened, the aluminum sleeve expands radially and makes an interference fit with the inner wall of the mounting through hole.

[0009] Furthermore, a long slit is provided on the side of the shaft to connect the inner wall and the outer wall of the shaft, and the long slit extends along the length direction of the shaft.

[0010] Furthermore, the shaft includes an abutment section, an extension section, and a connecting section. The outer diameter of the abutment section is adapted to the inner diameter of the aluminum sleeve. One end of the extension section is connected to the abutment section. The outer diameter of the extension section is smaller than that of the abutment section and the extension section extends axially along the aluminum sleeve. The connecting section connects to the end of the extension section opposite to the abutment section and the outer diameter of the connecting section is smaller than that of the extension section. The connecting section is connected to the locking end cap.

[0011] Furthermore, the fork shoulder is provided with a mounting surface for fixing the handlebars.

[0012] Furthermore, the cross-section of the mounting groove is U-shaped, and the cross-sectional shape of the mounting head tube is adapted to the mounting groove.

[0013] Furthermore, the front end of the vehicle frame is provided with guide mounting rails on the top and bottom surfaces corresponding to the mounting groove. The guide mounting rails are used to position and guide the mounting head tube when it is installed.

[0014] A method for installing a low-drag bicycle steering mechanism includes the following steps: S1. Provide the aforementioned low-drag bicycle steering structure; S2. Install the upper cup bearing and the lower cup bearing on the upper and lower ends of the aluminum sleeve respectively; S3. Place the locking end cap on the side of the upper cup bearing that is away from the lower cup bearing; S4. Insert the shaft from bottom to top into the aluminum sleeve and screw it into the locking end cap; S5. Insert the mounting head tube, which is equipped with the locking end cap, the upper cup bearing, the shaft and the lower cup bearing, into the mounting groove; S6. Insert the locking screw into the bottom of the mounting slot corresponding to the frame and tighten the locking screw to make the upper headset bearing and the lower headset bearing form a stable axial preload between the frame head tube and the fork head tube, respectively, to eliminate bearing clearance until the fork and the frame form a rigid connection without looseness.

[0015] By adopting the above technical solution, the present invention has the following beneficial effects: 1. Significantly reduces wind resistance and improves aerodynamic performance: By eliminating the traditional independent steering rod and raising the fork to be directly connected to or integrally molded with the handlebars, the frontal height is significantly shortened, reducing the frontal area. Combined with the embedded mounting slot structure, the aerodynamic drag of the steering section is significantly reduced, making it particularly suitable for high aerodynamic demanding scenarios such as time trials and triathlons.

[0016] 2. Simplified structure and lightweight: The steering rod and its related connecting parts have been eliminated, reducing the number of parts and the overall weight. At the same time, the assembly process has been simplified and the manufacturing cost has been reduced.

[0017] 3. Good steering rigidity and stability: The locking mechanism applies axial preload to the upper and lower headset bearings through the shaft, locking end cap and locking screw, eliminating bearing clearance and ensuring a rigid connection between the fork and the frame, resulting in stable and reliable handling.

[0018] 4. Reliable protection for carbon fiber forks: The aluminum bushing is pre-embedded inside the head tube, and the annular bearing platform in the middle forms an upper and lower limiting platform to precisely limit the bearing; the long slot on the side of the axle causes it to expand radially, pushing the aluminum bushing to make an interference fit with the mounting through hole, dispersing the locking force, avoiding stress concentration that could damage the carbon fiber, and forming a two-way locking mechanism with good anti-loosening effect.

[0019] 5. Convenient assembly and precise positioning: The top and bottom surfaces of the frame mounting slot are equipped with guide rails, and the locking end cap and shaft abutment section can slide in along the guide rails to achieve quick positioning, reduce assembly difficulty, and improve assembly consistency. Attached Figure Description

[0020] Figure 1This is a schematic diagram of the connection structure between the frame and the front fork. Figure 2 This is a sectional view of the connection between the locking mechanism and the bearing assembly; Figure 3 Exploded view of the locking mechanism and bearing assembly after disassembly; Figure 4 This is a schematic diagram of the front end of the vehicle frame; Figure 5 This is a schematic diagram of the bottom structure for installing the head tube.

[0021] In the attached diagram, 1-frame, 11-mounting slot, 12-guide mounting rail, 2-front fork, 21-fork shoulder, 22-mounting head tube, 23-mounting through hole, 31-upper headset bearing, 32-lower headset bearing, 33-locking end cap, 34-shaft, 341-long slot, 342-abutment section, 343-extension section, 344-connecting section, 35-locking screw, 36-aluminum sleeve, 361-channel, 362-ring receiving platform, 363-upper limit platform, 364-lower limit platform. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or it may be centered within another component. When a component is described as "set to" another component, it can be directly set on the other component or it may be centered within another component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this article are for illustrative purposes only.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0025] like Figures 1 to 5 As shown, a preferred embodiment of the present invention provides a low-drag bicycle steering structure, including a frame 1, a front fork 2, a bearing assembly, a locking mechanism, and an aluminum sleeve 36.

[0026] In this embodiment, a mounting groove 11 is recessed at the front end of the frame 1, extending through the front and both sides of the front end of the frame 1 to form a forward-facing opening. This mounting groove 11 replaces the traditional closed circular steering head tube at the front end of a bicycle frame. The cross-section of the mounting groove 11 is U-shaped. Guide mounting rails 12 are also recessed at the top and bottom surfaces of the front end of the frame 1 corresponding to the mounting groove 11, used for positioning and guiding the head tube 22 during installation to ensure assembly accuracy. This innovative structure of the mounting groove 11 allows the fork 2 to be directly inserted from the front, eliminating the need for the steering rod to be inserted from above as in traditional structures, thus providing a structural basis for eliminating the independent steering rod.

[0027] In this embodiment, the front fork 2 includes a fork shoulder 21 and a mounting head tube 22. The fork shoulder 21 is raised relative to the front fork body, and a mounting surface for fixing the handlebar is provided on the fork shoulder 21. The handlebar can be directly fixed to the mounting surface, or the fork shoulder 21 can be integrally formed with the handlebar. The connection structure and method between the handlebar and the front fork 2 are conventional techniques in the art and will not be described in detail here. The mounting head tube 22 is integrally formed with the fork shoulder 21. The shape of the mounting head tube 22 is adapted to the mounting groove 11, that is, the cross-section is U-shaped, and it is movably embedded in the mounting groove 11. The mounting head tube 22 has a mounting through hole 23 running from top to bottom. Based on the structure that eliminates the independent steering rod, the fork shoulder 21 can be raised and directly connected to the handlebar, completely eliminating the independent steering rod located between the fork shoulder 21 and the handlebar in traditional bicycles. This design significantly shortens the height of the front part of the bicycle, reduces the frontal area, and thus reduces wind resistance, making it particularly suitable for high aerodynamic demand scenarios such as time trials and triathlons.

[0028] In this embodiment, the aluminum sleeve 36 is pre-embedded in the mounting through hole 23 of the mounting head tube 22. It can accommodate the carbon fiber fork and avoid damage caused by the locking force directly squeezing the carbon fiber. The aluminum sleeve 36 is coaxially arranged with the mounting through hole 23, and a channel 361 is opened through the aluminum sleeve 36 along its axial direction. An annular receiving platform 362 is provided in the middle of the aluminum sleeve 36. The annular receiving platform 362 extends radially inward from the inner wall of the aluminum sleeve 36. The inner diameter of the annular receiving platform 362 is smaller than the inner diameter of the aluminum sleeve 36, so as to form an upper limiting platform 363 at the upper end of the aluminum sleeve 36 and a lower limiting platform 364 at the lower end of the aluminum sleeve 36.

[0029] In this embodiment, a locking mechanism is installed in the mounting through hole 23 to connect the mounting head tube 22 to the frame 1 and to apply axial preload to the bearing assembly. The locking mechanism includes a locking end cap 33, a shaft 34, and a locking screw 35. The locking end cap 33 is placed between the top surface of the corresponding mounting groove 11 of the frame 1 and the top of the mounting through hole 23. The outer diameter of the locking end cap 33 is adapted to the inner diameter of the aluminum sleeve 36. The top of the locking end cap 33 is adapted to the guide mounting rail 12 on the top surface of the mounting groove 11 so that the locking end cap 33 can slide into the mounting groove 11 along the corresponding guide mounting rail 12.

[0030] The shaft 34 passes through the channel 361 of the aluminum sleeve 36 and is connected to the locking end cover 33. Specifically, the locking end cover 33 is provided with a threaded hole, and the top outer side of the shaft 34 is provided with an external thread. The top of the shaft 34 is screwed to the locking end cover 33 through the internal and external threads.

[0031] The locking screw 35 is inserted into the shaft 34 from the bottom front end of the frame 1 and passes through the locking end cover 33. It then connects to the top surface of the corresponding mounting groove 11 of the frame 1. Specifically, the top surface of the corresponding mounting groove 11 of the frame 1 is provided with a threaded hole, and the locking screw 35 is screwed into the threaded hole to achieve the connection.

[0032] The bearing assembly includes an upper cup bearing 31 and a lower cup bearing 32. The bearing assembly is located within the mounting through hole 23 and is fitted onto the shaft 34. The upper cup bearing 31 is confined by the shaft 34 at the top of the mounting through hole 23, and the lower cup bearing 32 is confined by the shaft 34 at the bottom of the mounting through hole 23. Specifically: The shaft 34 includes an abutment section 342, an extension section 343, and a connecting section 344. The outer diameter of the abutment section 342 is adapted to the inner diameter of the aluminum sleeve 36. The abutment section 342 is located at the lower part of the shaft 34, and its function is to cooperate with the inner wall of the channel 361 of the aluminum sleeve 36. When the locking screw 35 is tightened, the abutment section 342 is subjected to an upward pulling force, which transmits the preload force to the aluminum sleeve 36, and then to the entire mounting head tube 22. At the same time, the upper end face of the abutment section 342 forms a shoulder for abutting the inner ring of the lower cup bearing 32.

[0033] One end of the extension 343 is connected to the abutment section 342. The outer diameter of the extension 343 is smaller than that of the abutment section 342, and the extension 343 extends axially along the aluminum sleeve 36. The smaller outer diameter of the extension 343 reduces the overall weight of the shaft 34. The inner diameter of the lower cup bearing 32 is the same as the outer diameter of the extension 343, and the outer diameter of the lower cup bearing 32 is the same as the inner diameter of the aluminum sleeve 36. The shoulder of the abutment section 342 mates with the lower limiting platform 364 to limit the lower cup bearing 32 to the bottom of the mounting through hole 23. The connecting section 344 connects to the extension section 343 at one end opposite to the abutment section 342, and the outer diameter of the connecting section 344 is smaller than the outer diameter of the extension section 343, forming a stepped surface between the connecting section 344 and the extension section 343. The inner diameter of the upper cup bearing 31 is the same as the outer diameter of the connecting section 344, and the outer diameter of the upper cup bearing 31 is the same as the inner diameter of the aluminum sleeve 36. The upper limit platen 363 cooperates with the locking end cap 33 to limit the upper cup bearing 31 to the top of the mounting through hole 23. The connecting section 344 is connected to the locking end cap 33. Specifically, the top outer side of the connecting section 344 is provided with external threads for threaded connection with the locking end cap 33. When the locking screw 35 is tightened, the connecting section 344 drives the entire shaft 34 to pull downward, causing the locking end cap 33 to press the upper cup bearing 31, thereby applying axial preload to the entire bearing assembly, eliminating bearing clearance, and making the fork 2 and the frame 1 form a rigid connection without looseness.

[0034] The bearing assembly functions as a rotating joint between the frame 1 and the fork 2, bearing axial loads during riding, such as the downforce generated by the rider's weight, and radial loads, such as lateral impacts from the road surface. It also ensures that the fork 2 can rotate freely around the central axis of the mounting hole 23, significantly reducing steering friction resistance and improving handling and riding safety. The outer diameters of the upper headset bearing 31 and the lower headset bearing 32 are the same as the inner diameter of the aluminum sleeve 36, allowing the outer rings of the two bearings to form a stable radial fit with the inner wall of the aluminum sleeve 36. Furthermore, the overall function of the locking mechanism is to eliminate bearing clearance through axial preload, ensuring the rigidity and stability of the steering system and preventing shaking or abnormal noise during riding.

[0035] In this embodiment, a long slit 341 is provided on the side of the shaft 34, connecting its inner and outer walls. The long slit 341 extends along the length of the shaft 34 and passes through the abutment section 342, the extension section 343, and the connecting section 344. This long slit 341 makes the shaft 34 radially elastic. When the locking screw 35 is inserted into the shaft 34 and tightened, the radial dimension of the shaft 34 will expand slightly, pushing the aluminum sleeve 36 to expand radially outward, so that the outer wall of the aluminum sleeve 36 forms an interference fit with the inner wall of the mounting through hole 23. The presence of the long slit 341 achieves the following technical effects: dispersing the locking force and avoiding local stress concentration of the locking screw 35 that could damage the carbon fiber structure; forming a radial elastic clamping force, which, together with the axial thread tension force, constitutes a two-way locking, effectively preventing the locking screw 35 from loosening due to vibration; and providing guiding elasticity during assembly, making it easier for the shaft 34 to enter the aluminum sleeve 36 and automatically center.

[0036] In this embodiment, a method for installing a low-drag bicycle steering structure is also provided, which includes the following steps: S1. Provides the above-mentioned low-drag bicycle steering structure.

[0037] S2. Install the upper cup bearing 31 and the lower cup bearing 32 at the upper and lower ends of the aluminum sleeve 36, respectively. Specifically, push the upper cup bearing 31 into the upper inlet of the aluminum sleeve 36 so that the upper cup bearing 31 abuts against the upper limit platform 363, at which time the upper cup bearing 31 is located at the upper end of the aluminum sleeve 36; push the lower cup bearing 32 into the lower inlet of the aluminum sleeve 36 so that the lower cup bearing 32 abuts against the lower limit platform 364, at which time the upper cup bearing 31 is located at the lower end of the aluminum sleeve 36.

[0038] S3. Place the locking end cap 33 on the side of the upper cup bearing 31 away from the lower cup bearing 32.

[0039] S4. Insert the shaft 34 from bottom to top into the channel 361 of the aluminum sleeve 36 and screw the connecting section 344 to the locking end cap 33.

[0040] S5. Insert the mounting head tube 22, which is equipped with the locking end cover 33, the upper cup bearing 31, the shaft 34 and the lower cup bearing 32, into the mounting groove 11. Specifically, make the upper end of the locking end cover 33 correspond to the guide mounting rail 12 on the top surface of the mounting groove 11, and make the bottom of the abutment section 342 correspond to the guide mounting rail 12 on the bottom surface of the mounting groove 11, and then insert the mounting head tube 22 into the mounting groove 11 along the guide mounting rail 12.

[0041] S6. Insert the locking screw 35 into the bottom of the corresponding mounting slot 11 of the frame 1 and tighten the locking screw 35 so that the upper headset bearing 31 and the lower headset bearing 32 form a stable axial preload between the head tube of the frame 1 and the head tube of the fork 2, respectively, to eliminate the bearing clearance until the fork 2 and the frame 1 form a rigid connection without looseness.

[0042] The above description is a detailed description of the preferred embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit of the present invention should fall within the patent scope covered by the present invention.

Claims

1. A low-drag bicycle steering structure, characterized in that, include: The frame (1) has a mounting groove (11) recessed at its front end, and the mounting groove (11) passes through the front front side and both sides of the frame (1). The fork (2) includes a fork shoulder (21) and a mounting head tube (22). The mounting head tube (22) is connected to the fork shoulder (21). The shape of the mounting head tube (22) is adapted to the mounting groove (11) and is movably embedded in the mounting groove (11). The mounting head tube (22) has a mounting through hole (23) running from top to bottom. A locking mechanism is installed in the mounting through hole (23) and the locking mechanism is capable of connecting the mounting head tube (22) to the frame (1); The bearing assembly is located inside the mounting through hole (23) and sleeved on the locking mechanism, so that the mounting head tube (22) can rotate about the central axis of the mounting through hole (23) under force; the locking mechanism can apply axial preload to the bearing assembly.

2. The low-drag bicycle steering structure according to claim 1, characterized in that: The locking component includes a locking end cap (33), a shaft (34), and a locking screw (35). The locking end cap (33) is placed between the top surface of the frame (1) corresponding to the mounting groove (11) and the top of the mounting through hole (23). The shaft (34) passes through the mounting through hole (23) and is connected to the locking end cap (33). The locking screw (35) is inserted into the shaft (34) from the bottom front end of the frame (1), passes through the locking end cap (33), and is connected to the top surface of the frame (1) corresponding to the mounting groove (11). The bearing assembly is sleeved on the shaft (34), and the shaft (34) confines the bearing assembly within the mounting through hole (23).

3. The low-drag bicycle steering structure according to claim 2, characterized in that: The bearing assembly includes an upper cup bearing (31) and a lower cup bearing (32). Both the upper cup bearing (31) and the lower cup bearing (32) are sleeved on the shaft (34). The shaft (34) cooperates with the locking end cap (33) to limit the upper cup bearing (31) to the top of the mounting through hole (23), and the shaft (34) limits the lower cup bearing (32) to the bottom of the mounting through hole (23).

4. The low-drag bicycle steering structure according to claim 3, characterized in that: The low-drag bicycle steering structure also includes an aluminum sleeve (36), which is embedded inside the mounting head tube (22) and coaxially arranged with the mounting through hole (23). The aluminum sleeve (36) has a channel (361) extending through it along its axial direction. The shaft (34) is coaxially arranged in the channel (361) and confined within the aluminum sleeve (36). When the locking screw (35) is inserted into the shaft (34) and tightened, the aluminum sleeve (36) expands radially and is interference-fitted with the inner wall of the mounting through hole (23).

5. The low-drag bicycle steering structure according to claim 4, characterized in that: The side of the shaft (34) is provided with a long slit (341) that connects the inner wall and the outer wall of the shaft (34), and the long slit (341) extends along the length direction of the shaft (34).

6. The low-drag bicycle steering structure according to claim 4, characterized in that: The shaft (34) includes an abutment section (342), an extension section (343), and a connecting section (344). The outer diameter of the abutment section (342) is adapted to the inner diameter of the aluminum sleeve (36). One end of the extension section (343) is connected to the abutment section (342). The outer diameter of the extension section (343) is smaller than the outer diameter of the abutment section (342), and the extension section (343) extends along the axial direction of the aluminum sleeve (36). The connecting section (344) connects to the end of the extension section (343) away from the abutment section (342), and the outer diameter of the connecting section (344) is smaller than the outer diameter of the extension section (343). The connecting section (344) is connected to the locking end cap (33).

7. The low-drag bicycle steering structure according to claim 1, characterized in that: The fork shoulder (21) is provided with a mounting surface for fixing the handlebars.

8. The low-drag bicycle steering structure according to claim 1, characterized in that: The cross-section of the mounting groove (11) is U-shaped, and the cross-sectional shape of the mounting head tube (22) is adapted to the mounting groove (11).

9. The low-drag bicycle steering structure according to claim 1, characterized in that: The front end of the frame (1) is provided with guide mounting rails (12) on the top and bottom surfaces of the mounting groove (11). The guide mounting rails (12) are used to position and guide the mounting head tube (22) when it is installed.

10. A method for installing a low-drag bicycle steering structure, characterized in that, Includes the following steps: S1. To provide the low-drag bicycle steering structure as described in claim 4; S2. Install the upper cup bearing (31) and the lower cup bearing (32) on the upper and lower ends of the aluminum sleeve (36), respectively; S3. Place the locking end cap (33) on the side of the upper cup bearing (31) away from the lower cup bearing (32); S4. Insert the shaft (34) from bottom to top into the aluminum sleeve (36) and screw it into the locking end cap (33); S5. Insert the mounting head tube (22) equipped with the locking end cap (33), the upper cup bearing (31), the shaft (34) and the lower cup bearing (32) into the mounting groove (11); S6. Insert the locking screw (35) into the bottom of the mounting groove (11) of the frame (1) and tighten the locking screw (35) so that the upper headset bearing (31) and the lower headset bearing (32) form a stable axial preload between the head tube of the frame (1) and the head tube of the fork (2) respectively, eliminate the bearing clearance, and until the fork (2) and the frame (1) form a rigid connection without looseness.

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