Vertically movable front derailleur mounting adapter, mounting adapter mechanism, and mounting method

Abstract

To provide a vertically movable front derailleur mounting adapter, a mounting adapter mechanism, and a mounting method that are able to freely adjust a mounting position of a front derailleur.SOLUTION: A vertically movable front derailleur mounting adapter is composed of a seat tube side mounting portion 2 and a front derailleur side mounting portion 3. The seat tube side mounting portion 2 and the front derailleur side mounting portion 3 are integrally molded. A long-oval through-hole 4 is formed in the seat tube side mounting portion 2. A long-oval through-hole 5 is formed in the front derailleur side mounting portion 3. Providing two long-oval through-holes makes it possible to flexibly adjust a height according to various needs of a user. A seat tube to be mounted is preferably provided with three or more screw holes in a longitudinal direction thereof.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an adapter for mounting a front derailleur to the seat tube of a bicycle. [Background technology]

[0002] A front derailleur on a bicycle is responsible for front gear shifting, and uses a shift lever to operate a wire to move the chain and shift it between the outer gear and the inner gear. Generally, a front derailleur has a base (adapter) that can be attached to the seat tube of the bicycle frame, a chain guide for guiding the chain, and a movement mechanism that movably connects the chain guide to the base (see, for example, Patent Document 1).

[0003] The mounting position of the front derailleur must be adjusted vertically depending on the number of teeth on the chainring. The number of teeth on outer chainrings, even for road bikes, ranges from 56T to 40T. Furthermore, in recent years, there has been a growing need for larger outer chainrings to achieve higher speeds, and to meet this need, it is desirable to be able to freely adjust the mounting position of the front derailleur. On the other hand, the manufacturer has set an appropriate range for the mounting position of the front derailleur, so there is a limit to the adjustment range on the front derailleur side.

[0004] As a technique for adjusting the position of a front derailleur, Patent Document 1 discloses a front derailleur mounting structure in which a slot is formed in the base that extends radially of the chainring. This allows the distance from the center axis of the chainring to the front derailleur to be adjusted within the longitudinal length range of the slot. However, the front derailleur mounting structure of Patent Document 1 has the problem that it cannot be used for chain rings with significantly different diameter sizes.

[0005] To address this issue, a front derailleur mounting attachment for connecting the base and the movement mechanism is known (see Patent Document 2). However, the attachment in Patent Document 2 only has two through holes in the attachment itself, and fine adjustment of the vertical height is performed only through the elongated hole formed in the base, which limits the range of adjustment.

[0006] Also known is a bicycle front derailleur mounting device in which a long hole is formed in the seat tube (see Patent Document 3). This device allows the attachment position of the adapter to be adjusted using a mechanism provided on the seat tube side, but this has problems with strength. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-16792 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-70063 [Patent Document 3] Publication No. 61-54986 Summary of the Invention [Problem to be solved by the invention]

[0008] In view of the above circumstances, an object of the present invention is to provide a vertically adjustable front derailleur mounting adapter, a mounting adapter mechanism, and a mounting method that allow the mounting position of the front derailleur to be freely adjusted. [Means for solving the problem]

[0009] In order to solve the above problem, the vertically adjustable front derailleur mounting adapter of the present invention consists of a front derailleur side mounting portion and a seat tube side mounting portion, with one long hole formed in the longitudinal direction of the front derailleur side mounting portion for connecting the front derailleur, and at least one through hole formed in the longitudinal direction of the seat tube side mounting portion, so that the mounting position can be moved up and down to match the screw hole provided in the longitudinal direction of the seat tube of the bicycle frame. The vertically movable adapter mounting position, coupled with the elongated hole in the front derailleur mounting portion, provides two types of adjustment mechanisms, allowing for flexible adjustment to meet the diverse needs of users. The vertically movable adapter mounting position can be achieved by providing a through-hole in the seat tube mounting portion with a larger diameter or an elongated hole, or by providing a through-hole with a larger area than a threaded hole. It can also be achieved by providing three or more through-holes in the seat tube mounting portion. The adapter can be made from a wide range of materials, including metals such as aluminum and hard resins. The seat tube mounting part and front derailleur mounting part are preferably molded as a single unit, but they can also be molded separately and then connected. A front derailleur typically has a base that can be attached to the seat tube of a bicycle frame, a chain guide for guiding the chain, and a movement mechanism that movably connects the chain guide to the base. In this specification, the component that corresponds to the base is referred to as the "front derailleur mounting adapter," and the "chain guide and movement mechanism" are defined as the front derailleur. Note that in this specification, the "front derailleur mounting adapter" is also simply referred to as the "adapter."

[0010] In the vertically adjustable front derailleur mounting adapter of the present invention, the through hole is preferably a single elongated hole provided in the longitudinal direction of the seat tube-side mounting portion. This allows for easy adjustment of the adapter's mounting position. The longitudinal length of the elongated hole is preferably 5 to 50 mm. If it is less than 5 mm, the adjustment range becomes narrow, making sufficient adjustment difficult. Furthermore, by making it 50 mm or less, it is possible to achieve specifications that allow for flexible adjustment while maintaining strength.

[0011] The vertically adjustable front derailleur mounting adapter mechanism of the present invention includes a bicycle frame with three or more threaded holes in the seat tube and any of the front derailleur mounting adapters described above. By providing three or more threaded holes in the seat tube of the bicycle frame, a total of three adjustment mechanisms are provided, in conjunction with the height adjustment mechanisms for the front derailleur mounting portion and the seat tube mounting portion, thereby expanding the range of adjustment for the adapter's mounting position. The three or more threaded holes in the seat tube do not have to be arranged longitudinally of the seat tube, but may be arranged circumferentially. Circumferential arrangement allows for adjustment not only of the mounting position height but also fore-aft adjustment of the bicycle.

[0012] The vertically adjustable front derailleur mounting adapter mechanism of the present invention preferably has three or more screw holes formed along the longitudinal direction of the seat tube. By forming three or more screw holes along the longitudinal direction of the seat tube, the range of height adjustment for the adapter mounting position can be expanded. The pitch of the screw holes is not particularly limited, and can be, for example, 15 to 20 mm.

[0013] The method of attaching a front derailleur to a bicycle frame of the present invention connects the front derailleur and seat tube by connecting at least one of three or more screw holes provided in the seat tube of the bicycle frame to at least one through hole formed in the seat tube side mounting portion of a front derailleur mounting adapter consisting of a front derailleur side mounting portion and a seat tube side mounting portion, and fastening them with screws. [Effects of the Invention]

[0014] The vertically adjustable front derailleur mounting adapter, mounting adapter mechanism, and mounting method of the present invention, which allow the mounting position of the front derailleur to be freely adjusted, have the advantage of allowing the mounting position of the front derailleur to be freely adjusted. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of a front derailleur mounting adapter according to a first embodiment of the present invention; [Figure 2] Front view of the front derailleur mounting adapter of the first embodiment [Figure 3] Left side view of the front derailleur mounting adapter of the first embodiment [Figure 4] 1 is a plan view of a front derailleur mounting adapter according to a first embodiment of the present invention; [Figure 5] Attaching the front derailleur adapter to the seat tube [Figure 6] Installation instructions for the front derailleur to the front derailleur mounting adapter [Figure 7] Front derailleur mounting adapter installation diagram (Example 1) [Figure 8] Image of mounting to seat tube using conventional technology (Example 1) [Figure 9] Functional diagram of the front derailleur mounting adapter in Example 1 [Figure 10] Front derailleur mounting adapter installation diagram (Example 2) [Figure 11] Installation image using two screws (Example 2) [Figure 12] Installation image using three screws (Example 2) [Figure 13] Illustrative diagram of a seat tube in Example 3 [Figure 14] Front derailleur mounting adapter installation illustration (Example 3) [Figure 15] Illustrative diagram of the seat tube of Example 4 [Figure 16] FIG. 10 is an explanatory diagram of the attachment of a conventional front derailleur attachment adapter to a seat tube in accordance with a second embodiment of the present invention; [Figure 17] Image of installation of a conventional front derailleur mounting adapter to a seat tube in Example 2 [Figure 18] Illustration of a seat tube in the prior art [Figure 19] Front view of a prior art front derailleur mounting adapter [Figure 20] An explanatory diagram of a prior art front derailleur mounting adapter [Figure 21] 10 is a front view of a front derailleur mounting adapter according to a fifth embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0016] An example of an embodiment of the present invention will be described in detail below with reference to the drawings. Note that the scope of the present invention is not limited to the following examples and illustrated examples, and many modifications and variations are possible. Note that the seat tubes (7, 7a to 7d, 70) described in the following embodiments are actually arranged diagonally on the frame of the bicycle 100 as shown in Figure 14, but for the sake of convenience, the seat tubes (7, 7a to 7d, 70) in Figures 7 to 13, 15 to 18, and 20 are shown with their longitudinal direction vertical. [Example]

[0017] Figures 1 to 4 are external views of the front derailleur mounting adapter of Example 1, with Figure 1 being a perspective view, Figure 2 being a front view, Figure 3 being a left side view, and Figure 4 being a plan view. As shown in Figure 1, the front derailleur mounting adapter 1 of Example 1 is composed of a seat tube side mounting portion 2 and a front derailleur side mounting portion 3. The seat tube side mounting portion 2 and the front derailleur side mounting portion 3 are integrally molded. The adapter 1 is made of aluminum. An oval through hole 4 is formed in the seat tube side mounting portion 2. An oval through hole 5 is formed in the front derailleur side mounting portion 3. The length L1 from the upper end 4a to the lower end 4b of the through hole 4 shown in FIG. 2 is longer than the length L2 of the through hole 5 shown in FIG. 3, but they may be the same length, or the length L2 of the through hole 5 may be longer.

[0018] As shown in FIG. 4, the contact portion 21 of the seat tube side mounting portion 2 with the seat tube and the contact portion 31 of the front derailleur side mounting portion 3 with the front derailleur are curved inward.

[0019] Figure 5 is an explanatory diagram of how to attach the front derailleur mounting adapter to the seat tube. As shown in Figure 5, when attaching adapter 1 to seat tube 7, abutment portion 21 of seat tube side mounting part 2 is brought into contact with seat tube 7, and after aligning so that screw hole 9 and through hole 4 are in communication, the adapter is fastened and fixed using screw 6. Then, the front derailleur is attached to adapter 1.

[0020] Figure 6 is an explanatory diagram of how to attach a front derailleur to a front derailleur mounting adapter. Note that the front derailleur 80 in Figure 6 is a deformed illustration of only the front derailleur movement mechanism. As shown in Figure 6, the front derailleur 80 is abutted against the abutment portion 31 of the front derailleur side mounting portion 3, and is then fastened in place using the screw 8 via the washer 81.

[0021] Next, we will explain how to adjust the mounting positions of each. First, we will provide an overview of the seat tube and adapter in the prior art. Figure 18 is an explanatory diagram of a seat tube of the prior art. As shown in Figure 18, screw holes (9a, 9b) are provided in the seat tube 70. The screw holes (9a, 9b) are formed with female threads (not shown) and can be fastened by screwing them together. The distance P1 between the screw holes 9a and 9b is approximately 15 mm.

[0022] Figure 19 shows a front view of a conventional front derailleur mounting adapter. As shown in Figure 19, the conventional front derailleur mounting adapter 10 is made up of a seat tube side mounting portion 20 and a front derailleur side mounting portion 30. The seat tube side mounting portion 20 and the front derailleur side mounting portion 30 are integrally molded. Circular through holes (40a, 40b) are formed in the seat tube side mounting portion 20. An oval through hole 50 is formed in the front derailleur side mounting portion 30. The distance between the through holes 40a and 40b is equal to the distance P1, similar to the distance between the screw holes 9a and 9b.

[0023] FIG. 20 is an explanatory diagram of a prior art front derailleur mounting adapter. When mounting the adapter 10 to a seat tube 70 provided with two screw holes (9a, 9b) as shown in FIG. 20, the screw hole 9a shown in FIG. 18 is aligned with the through-hole 40a shown in FIG. 19 so that they communicate, and the adapter is secured using a screw 6a. Similarly, the screw hole 9b is secured to the through-hole 40b using a screw 6b. Note that the screw holes 9a and 9b, and the screws 6a and 6b, each have the same structure, and it is also possible to thread the screw 6b into the screw hole 9a, for example. The same applies to the screw holes (9c-9x) and screw 6c, which will be described later.

[0024] As shown in Figure 19, the front derailleur side mounting portion 30 of the adapter 10 has a long through-hole 50. When mounting the front derailleur 80, the mounting position can be adjusted by raising or lowering it within a height H4 range, as shown in Figure 20. For ease of explanation, the front derailleur 80 is not shown here, and only the mounting screws 8 are shown. This also applies to Figures 8, 9, 11, and 12. The mounting position of the adapter 10 on the seat tube 70 cannot be adjusted, so adjustment can only be made within the range of height H4. However, with the front derailleur mounting adapter 1 of this embodiment, the mounting position of the adapter 1 on the seat tube 70 can be adjusted, allowing for greater freedom of adjustment.

[0025] FIG. 7 is an explanatory diagram of how a front derailleur mounting adapter is attached, with (1) showing a seat tube of the prior art and (2) showing the front derailleur mounting adapter of Example 1. As shown in FIG. 7(1), screw holes (9a, 9b) are provided in seat tube 70. As shown in FIG. 7(2), through-hole 4 of seat tube-side mounting part 2 is an oval-shaped long hole, allowing for fastening with a screw at any position between upper end 4a and lower end 4b. Furthermore, length L1 from upper end 4a to lower end 4b shown in FIG. 2 is set to a length that allows a screw to be inserted at a position approximately twice the distance P1 between screw holes 9a and 9b.

[0026] FIG. 8 shows an image of a conventional method of attaching the adapter to a seat tube. (1) shows an example of an upward attachment, and (2) shows an example of a downward attachment. When attaching the adapter 1 to a seat tube 70 provided with two screw holes (9a, 9b) as shown in FIG. 8, the screw holes (9a, 9b) are aligned with the through-hole 4, and the adapter is secured using screws (6a, 6b). Because the through-hole 4 is an elongated hole, the adapter can be attached higher, with the screw 6b abutting the lower end 4b, as shown in FIG. 8(1), or lower, with the screw 6a abutting the upper end 4a, as shown in FIG. 8(2). Because the through-hole 5 is also an elongated hole, the attachment position can be adjusted up or down when securing the front derailleur 80 using the screw 8.

[0027] As a result, as shown in Figure 8(1), by setting the fixing positions of both the adapter 1 and the screw 8 higher, it is possible to mount the front derailleur 80 in a higher position. Also, as shown in Figure 8(2), by setting the fixing positions of both the adapter 1 and the screw 8 lower, it is possible to mount the front derailleur 80 in a lower position. In this way, by providing two adjustment mechanisms, the front derailleur mounting adapter 1 can be adjusted within the range of height H1, providing a structure that allows flexible adjustment to suit the diverse needs of users.

[0028] Figure 9 is a functional diagram of the front derailleur mounting adapter of the first embodiment. While Figure 8 shows an example in which the front derailleur 80 is mounted at the highest or lowest position, it may also be mounted without the screws (6a, 6b) contacting either the upper end 4a or the lower end 4b, as shown in Figure 9. Similarly, the screws 8 may also be mounted, for example, at approximately the longitudinal center of the through-hole 5. [Example]

[0029] In this embodiment, an example will be described in which the front derailleur mounting adapter 1 of the first embodiment is attached to a seat tube provided with three screw holes. Figure 10 is an explanatory diagram for installing a front derailleur mounting adapter, where (1) shows the seat tube of Example 2 and (2) shows the front derailleur mounting adapter 1 of Example 1. As shown in Figure 10(1), the seat tube 7 of Example 2 has three screw holes (9a to 9c) on the top and bottom. As mentioned above, the length L1 from the upper end 4a to the lower end 4b shown in Figure 2 is set to a length that allows a screw to be inserted at a position approximately twice the distance P1 between the screw holes 9a and 9b, so when attaching the adapter 1, it is possible to attach it using two screws or three screws.

[0030] FIG. 11 is an image diagram of attachment using two screws, with (1) showing an example of attachment upward and (2) showing an example of attachment downward. As shown in FIG. 11, when attaching the adapter 1 using two screws to the seat tube 7, which has three screw holes (9a-9c), the adapter is fixed using screws (6a, 6b) after aligning any two of the screw holes (9a-9c) so that they communicate with the through-hole 4. Because the through-hole 4 is an elongated hole, when fixing the adapter, as shown in FIG. 11(1), it is possible to fix the adapter by screwing the screw 6a into the screw hole 9a and the screw 6b into the screw hole 9b with the screw 6b abutting the lower end 4b. Alternatively, as shown in FIG. 11(2), it is also possible to fix the adapter by screwing the screw 6a into the screw hole 9b and the screw 6b into the screw hole 9c with the screw 6a abutting the upper end 4a. Furthermore, since through-hole 5 is also an elongated hole, when front derailleur 80 is fixed using screw 8, the mounting position can be adjusted up and down.

[0031] By providing three screw holes (9a to 9c) in the seat tube 7, the range of height adjustment is expanded by the distance P1 from the height H1 in Example 1 when the fixing positions of the adapter 1 and the screw 8 are both set to the highest, as shown in Figure 11 (1), and when the fixing positions of the adapter 1 and the screw 8 are both set to the lowest, as shown in Figure 11 (2), and can be adjusted within the range of height H2, resulting in a structure that allows flexible adjustment to suit the diverse needs of users. As in the first embodiment, the screws (6a, 6b) may be fixed without contacting either the upper end portion 4a or the lower end portion 4b.

[0032] FIG. 12 is an image diagram of installation using three screws, with (1) showing an example of installation above the front derailleur and (2) showing an example of installation below the front derailleur. As shown in FIG. 12, the adapter 1 can be attached to the seat tube 7 using three screws. Specifically, after aligning the screw holes (9a-9c) so that they communicate with the through-hole 4, the screw 6a is screwed into the screw hole 9a, the screw 6b into the screw hole 9b, and the screw 6c into the screw hole 9c. By using three screws for attachment, the adapter 1 can be more stably fixed to the seat tube 7.

[0033] Furthermore, since the length from the upper end of screw hole 9a to the lower end of screw hole 9c and the length from the upper end 4a to the lower end 4b of through hole 4 are both the same length L1, when fastened using screws (6a to 6c), the upper end of screw 6a abuts against the upper end 4a of through hole 4, and the lower end of screw 6c abuts against the lower end 4b of through hole 4 (see FIG. 10). This structure prevents adapter 1 from sliding up and down even if the screws become loose. In this case, height adjustment using seat tube side mounting portion 2 is not possible, but because through hole 5 is an elongated hole, the mounting position can be adjusted up and down within a range of height H3 when securing front derailleur 80 using screw 8. Because the longitudinal length L2 of through hole 5 shown in FIG. 3 is longer than the longitudinal length L3 of through hole 50 of adapter 10 of the prior art, even when secured using three screws, more flexible adjustment is possible compared to adapter 10.

[0034] When using two screws for fixation, screw 6a may be screwed into screw hole 9a and screw 6c may be screwed into screw hole 9c. Although adapter 1 can be fixed using one screw, it is preferable to fix it using two or three screws from the viewpoint of fixation stability. [Example]

[0035] FIG. 13 is an explanatory diagram of the seat tube of Example 3. FIG. 14 is an explanatory diagram of the installation of the front derailleur mounting adapter, with (1) showing the state before installation and (2) showing the state after installation. The seat tube 7a shown in FIG. 13(1) has five screw holes (9a-9e). The seat tube 7b shown in FIG. 13(2) also has five screw holes (9f-9j). However, while the screw hole spacing in the seat tube 7a is the same as the seat tube (7, 70) of Examples 1 or 2, the screw hole spacing in the seat tube 7b is a narrower spacing P2 than the spacing P1. Because the through holes 4 of the adapter 1 are elongated, they are not limited to the typical screw hole spacing P1 and can accommodate a wide range of specifications. Specifically, the spacing may be any spacing that allows screws to be fastened to the through holes 4 at two or more locations.

[0036] In the example shown in Fig. 14, screws (6a, 6b) are used to attach the adapter 1 to the seat tube 7b of the bicycle 100. Of the five screw holes (9f to 9j) provided on the seat tube 7b, the screw 6a is screwed into the screw hole 9h, and the screw 6b is screwed into the screw hole 9i. In this way, by making the bicycle seat tube a seat tube (7a, 7b) with more than three screw holes, the adjustment range of the adapter 1 can be further expanded, and ultimately the adjustment range of the front derailleur 80 can be expanded. [Example]

[0037] FIG. 15 is an explanatory diagram of a seat tube of Example 4. Unlike the conventional seat tube 70, the seat tube 7c shown in FIG. 15(1) has two screw holes (9k, 9l) and two screw holes (9m, 9n) arranged in parallel along the longitudinal direction. The seat tube 7d shown in FIG. 15(2) has five screw holes (9o-9s) and five screw holes (9t-9x) arranged in parallel along the longitudinal direction. By positioning the screw holes not only vertically but also horizontally, the adjustment range can be further expanded. The parallel screw holes may be arranged at the same height, as in the screw holes (9k, 9l) and (9m, 9n) shown in FIG. 15(1), or at different heights, as in the screw holes (9o-9s) and (9t-9x) shown in FIG. 15(2). [Example]

[0038] FIG. 21 shows a front view of a front derailleur mounting adapter of a fifth embodiment. As shown in FIGS. 21(1) to 21(3), in the front derailleur mounting adapter of the present invention, the through-holes provided in the seat tube-side mounting portion may be two or more elongated holes, and there is no particular limitation on the longitudinal length of the elongated holes. The front derailleur mounting adapter 1a shown in FIG. 21(1) is composed of a seat tube-side mounting portion 2a and a front derailleur-side mounting portion 3a, with oval through-holes (41a, 41b) provided in the seat tube-side mounting portion 2a. The front derailleur mounting adapter 1b shown in FIG. 21(2) is composed of a seat tube-side mounting portion 2b and a front derailleur-side mounting portion 3b, with oval through-holes (42a to 42c) provided in the seat tube-side mounting portion 2b. The rest of the configuration is the same as that of the front derailleur mounting adapter 1. 21(3) is composed of a seat tube side mounting portion 2c and a front derailleur side mounting portion 3c, and the seat tube side mounting portion 2c has oval through holes (43a, 43b). The rest of the configuration is the same as that of the front derailleur mounting adapter 10. In this way, by forming a plurality of elongated holes in the seat tube side mounting portion, it is possible to achieve a structure in which the mounting position of the adapter can be moved up and down, and the strength of the adapter (1a to 1c) can be improved.

[0039] The front derailleur mounting adapter 1d shown in Figure 21(4) is made up of a seat tube side mounting portion 2d and a front derailleur side mounting portion 3d, and seat tube side mounting portion 2d has approximately circular through holes (44a-44c). The length from the upper end of through hole 44a to the lower end of through hole 44c is the same as the length L1 of the front derailleur mounting adapter 1, and the spacing between through holes 44a and 44b, or between through holes 44b and 44c, is the same as the spacing P1 of the adapter 1. Other than the through holes, the configuration is the same as that of the adapter 1. In this way, by forming three or more substantially circular through holes in the seat tube side mounting portion, it is possible to realize a structure in which the mounting position of the adapter can be moved up and down.

[0040] (Other Examples) FIG. 16 is an explanatory diagram of the attachment of a conventional front derailleur mounting adapter to a seat tube in Example 2. FIG. 17 is an image diagram of the attachment of a conventional front derailleur mounting adapter to a seat tube in Example 2. As shown in FIG. 16, the seat tube 7 described in Example 2 has three screw holes (9a-9c), which allow height adjustment using the screw holes (9a-9c). Specifically, as shown in FIG. 17(1), the adapter 10 can be attached at a higher position by aligning the screw holes (9a, 9b) with the through holes (40a, 40b) of the adapter 10 so that they communicate with each other and fastening the adapter 10 with screws (6a, 6b). As shown in FIG. 17(2), the adapter 10 can be attached at a lower position by aligning the screw holes (9b, 9c) with the through holes (40a, 40b) of the adapter 10 so that they communicate with each other and fastening the adapter 10 with screws (6a, 6b). [Industrial Applicability]

[0041] The present invention is useful as an adapter for mounting a front derailleur to the seat tube of a bicycle. [Explanation of symbols]

[0042] 1,1a~1d,10 Front derailleur mounting adapter (adapter) 2, 2a to 2d, 20 Seat tube side mounting part 3, 3a to 3d, 30 Front derailleur side mounting part 4,5,40a,40b,41a,41b,42a,42b,43a,43b,44a~44c,50 Through hole 4a Upper end 4b Bottom end 6,6a~6c,8 Screws 7,7a~7d,70 seat tube 9,9a~9x screw hole 11 Chainring 12 Down tube 13 Crank 14 seat stay 15 Chainstay 21,31 Contact part 80 front derailleur 81 Washer 100 Bicycles H1~H4 height L1~L3 length P1,P2 interval

Claims

1. It consists of a front derailleur mounting part and a seat tube mounting part. a long hole for connecting a front derailleur to the front derailleur side mounting portion is formed in the longitudinal direction of the front derailleur side mounting portion; At least one through hole is formed in the seat tube side mounting portion, A vertically adjustable front derailleur mounting adapter that can be moved up and down to fit the screw holes provided in the longitudinal direction of the seat tube of a bicycle frame.

2. 2. The vertically adjustable front derailleur mounting adapter according to claim 1, wherein the through hole is a single elongated hole provided in the longitudinal direction of the seat tube side mounting portion.

3. 3. The vertically adjustable front derailleur mounting adapter according to claim 2, wherein the longitudinal length of the elongated hole is 5 to 50 mm.

4. A bicycle frame having three or more screw holes in a seat tube; Any of the front derailleur mounting adapters 1 to 3 above, A vertically adjustable front derailleur mounting adapter mechanism.

5. 5. The vertically adjustable front derailleur mounting adapter mechanism according to claim 4, wherein three or more screw holes are provided in the longitudinal direction of the seat tube.

6. A method of attaching a front derailleur to a bicycle frame in which at least one of three or more screw holes provided in the seat tube of the bicycle frame is connected to at least one through hole formed in the seat tube side mounting portion of a front derailleur mounting adapter consisting of a front derailleur side mounting portion and a seat tube side mounting portion, and the front derailleur and seat tube are connected by fastening them with screws.

Images