Low-profile rear derailleur

Abstract

The utility model discloses a low-profile rear derailleur. The low-profile rear derailleur comprises a base component, a movable component, a connecting rod mechanism and a chain guide part, the base component is provided with an installation position, and the installation position is the position where the base component is connected with a frame of a bicycle. The connecting rod mechanism is hinged between the base component and the movable component, and the chain guiding piece is arranged on the movable component and comprises a chain guiding wheel and a tensioning wheel. The guide chain wheel is provided with a wheel plane, the installation position is provided with a reference point, and the reference point is the reference point closest to the radial center plane of the rear wheel of the bicycle; when the chain is located on the smallest flywheel sheet, the distance between the reference point and the wheel plane is larger than or equal to 0. The outward extending distance of the rear derailleur is small, so that the whole rear derailleur is almost hidden on the inner side of a bicycle frame, the riding safety can be improved, and the rear derailleur is effectively prevented from being damaged when the bicycle falls.

Description

TECHNICAL FIELD

[0001] The utility model relates to a bicycle technical field, concretely relates to a low profile rear derailleur. BACKGROUND

[0002] The rear wheel of a bicycle rotates with the freewheel of the bicycle. In a derailleur bicycle, the freewheel typically includes a plurality of freewheel segments. A rear derailleur is used to selectively engage the chain with one of the plurality of freewheel segments. Conventional rear derailleurs typically include a base member, a movable member supporting a chain guide, and a linkage connecting between the base member and the movable member to allow the chain guide to move laterally relative to the base member. The base member is typically mounted to the rear end of the bicycle frame by mounting bolts which are screwed into threaded holes on the frame.

[0003] During shifting, the linkage, the movable member and the chain guide all extend outwardly a considerable distance along the outside of the bicycle due to the nature of the lateral movement of the chain guide required to shift the chain between the plurality of freewheel segments, especially when the chain is engaged with the outermost freewheel segment of the freewheel. In the case of a pair of linkages with a coil spring sandwiched therebetween, this consequence is further exacerbated since the linkages must be spaced apart to accommodate the spring. As a result, the chain guide extending outwardly a considerable distance is prone to being struck or entangled with nearby objects while riding, especially when riding off-road in mountainous terrain. This consequence is exacerbated as the number of freewheel segments increases, thereby increasing the lateral distance the chain guide must travel, posing a safety hazard to the rider. SUMMARY

[0004] The utility model aims at overcoming the above-mentioned problems, providing a low profile rear derailleur, the rear derailleur extends outwardly a small distance, so that the rear derailleur is almost hidden inside the frame, which can improve the safety of riding, effectively avoiding the damage of the rear derailleur when falling the bicycle.

[0005] The utility model achieves the above-mentioned purpose through the following technical solutions.

[0006] A low-profile rear derailleur, comprising a base member, a movable member, a linkage mechanism and a chain guide; the base member is provided with a mounting position, which is the position for connecting the base member with the frame of a bicycle; the linkage mechanism is hinged between the base member and the movable member, and the chain guide is provided on the movable member and comprises a chain guide wheel and a tensioner; wherein the chain guide wheel has a wheel plane, the mounting position has a reference point, which is the reference point closest to the radial center plane of the rear wheel of the bicycle; when the chain is located at the smallest sprocket, the distance between the reference point and the wheel plane is greater than or equal to 0; when the distance between the reference point and the wheel plane is greater than 0, the wheel plane gradually approaches the reference point and then moves away from the reference point when the chain moves from the smallest sprocket to the largest sprocket; when the distance between the reference point and the wheel plane is equal to 0, the wheel plane gradually moves away from the reference point when the chain moves from the smallest sprocket to the largest sprocket.

[0007] The working principle of the above low-profile rear derailleur is:

[0008] When the distance between the reference point and the wheel plane is greater than 0, the wheel plane gradually approaches the reference point and then moves away from the reference point when the chain moves from the smallest sprocket to the largest sprocket; when the distance between the reference point and the wheel plane is equal to 0, the wheel plane gradually moves away from the reference point when the chain moves from the smallest sprocket to the largest sprocket. It is indicated that the reference point is closer to the sprocket, i.e. the mounting position is close to the smallest sprocket or located between the largest sprocket and the smallest sprocket; when the chain is located at the smallest sprocket position, the axial profile of the rear derailleur does not exceed the outside of the frame too much, so that the rear derailleur is almost hidden inside the frame, the whole rear derailleur structure is more compact, the profile is lower, and the safety of riding can be improved.

[0009] In an preferred embodiment of the utility model, when the chain moves from the smallest sprocket to the largest sprocket, the wheel plane gradually approaches the mounting position, then intersects with the mounting position, and finally moves away from the mounting position. In the above structure, when the chain is located at the smallest sprocket position, the mounting position is located between the largest sprocket and the smallest sprocket, and when the chain is located at the smallest sprocket position, the axial profile of the rear derailleur also does not exceed the outside of the frame too much.

[0010] In an preferred embodiment of the utility model, when the chain is located at the smallest sprocket position, the mounting position intersects with the wheel plane; when the chain moves from the smallest sprocket to the largest sprocket, the wheel plane gradually moves away from the mounting position. In the above structure, when the chain is located at the smallest sprocket position, the axial profile of the rear derailleur also does not exceed the outside of the frame too much.

[0011] One preferred scheme of the utility model, when the chain moves from the smallest flywheel piece to the biggest flywheel piece direction, the wheel plane will gradually approach the base member, then intersect with the base member, finally away from the base member. Its purpose is to make the base member between the biggest flywheel piece and the smallest flywheel piece, further improve the compactness of the base member, make the rear derailleur whole almost hide in the inside of the frame.

[0012] Preferably, the base member is provided with a mounting groove, the frame is provided with a downward protruding mounting protrusion, the mounting groove is connected with the mounting protrusion; the position of the mounting groove is the mounting position. In the above structure, the mounting groove and the mounting protrusion are matched to realize quick installation.

[0013] Preferably, the mounting protrusion is arranged on the lower end face of the frame and located at the front end of the bicycle rear axle. Its purpose is to arrange the mounting protrusion on the lower end face of the frame and located at the front end of the bicycle rear axle, so that the rear derailleur is closer to the inside of the frame after installation, and the outward protruding distance is smaller.

[0014] Preferably, the base member and the mounting protrusion are connected through a mounting bolt. The mounting bolt is convenient for installation and disassembly.

[0015] Preferably, the cross section of the mounting groove and the mounting protrusion is rectangular. Its purpose is to facilitate installation and positioning.

[0016] Preferably, the chain guide further comprises a tensioning arm; the movable member comprises an inner guide plate and an outer guide plate, the outer guide plate is fixed on the outer side surface of the inner guide plate, the chain guide wheel is rotatably arranged between the inner guide plate and the outer guide plate, the connecting rod mechanism is hinged with the outer guide plate, one end of the tensioning arm is rotatably connected to the outer side surface of the inner guide plate, and the tensioning wheel is arranged on the other end of the tensioning arm. In the above structure, the movable member comprises an inner guide plate and an outer guide plate, the inner guide plate and the outer guide plate are plate-shaped structures, and the tensioning arm is installed on the outer side surface of the inner guide plate, so that the structure of the rear derailleur is more compact, the outward protruding distance is smaller, and the distance between the chain guide wheel and the tensioning wheel can be changed, so that the chain guide can tension the chain in a larger range, absorb the extra slack of the chain, and ensure the tension of the chain.

[0017] Preferably, the chain guide further comprises a first chain guide plate and a second chain guide plate; the first chain guide plate and the second chain guide plate are oppositely arranged; the first chain guide plate is rotatably connected with the movable member, and the chain guide wheel and the tensioning wheel are arranged between the first chain guide plate and the second chain guide plate. The above structure is simpler, and the movement of the movable member drives the chain guide wheel and the tensioning wheel to move, realizing the switching of the flywheel piece.

[0018] Preferably, the wheel plane is perpendicular to the axis of the chain guide wheel, and the wheel plane is located at the center of the chain guide wheel.

[0019] Preferably, the mounting protrusion is provided with a mounting through hole for the mounting bolt to pass through.

[0020] Compared with the prior art, the low-profile rear derailleur has the following beneficial effects:

[0021] When the distance between the reference point and the wheel plane is greater than 0, the wheel plane gradually approaches the reference point and then moves away from the reference point when the chain moves from the smallest freewheel piece to the largest freewheel piece; when the distance between the reference point and the wheel plane is equal to 0, the wheel plane gradually moves away from the reference point when the chain moves from the smallest freewheel piece to the largest freewheel piece. It is illustrated that the reference point is closer to the freewheel piece, i.e. the mounting position is close to the smallest freewheel piece or located between the largest freewheel piece and the smallest freewheel piece; when the chain is located at the smallest freewheel piece, the axial profile of the rear derailleur does not exceed the outside of the frame too much, so that the rear derailleur is almost hidden inside the frame, the structure of the entire rear derailleur is more compact, the profile is lower, and the safety of riding can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a structure schematic view of the low-profile rear derailleur mounted on the frame in the first specific embodiment of the utility model.

[0023] Figure 2 It is an exploded view of the low-profile rear derailleur and the frame in the utility model.

[0024] Figure 3 It is a structure schematic view of the low-profile rear derailleur when the chain is at the smallest freewheel piece in the utility model.

[0025] Figure 4 It is a structure schematic view of the low-profile rear derailleur when the chain is at the largest freewheel piece in the utility model.

[0026] Figure 5 It is a structure schematic view of the low-profile rear derailleur in the utility model.

[0027] Figure 6 It is a structure schematic view of the low-profile rear derailleur in another perspective direction in the utility model.

[0028] Figure 7 It is a structure schematic view of the low-profile rear derailleur in another perspective direction in the utility model.

[0029] Figure 8The third structure schematic view of the low-profile rear derailleur in the third specific implementation manner of the utility model.

[0030] Figure 9 The third structure schematic view of the low-profile rear derailleur in the third specific implementation manner of the utility model.

[0031] Figure 10 The third structure schematic view of the low-profile rear derailleur in the third specific implementation manner of the utility model. DETAILED DESCRIPTION

[0032] In order to make the skilled in the art well understand the technical scheme of the utility model, the utility model is further described below in combination with examples and drawings, but the implementation manners of the utility model are not limited to this.

[0033] Example 1

[0034] Referring to Figures 1-7 The utility model discloses a low-profile rear derailleur, including base member 1, movable member 2, connecting rod mechanism 3 and chain guide 4, the base member 1 is equipped with installation position 1-1 (installation position 1-1 also can be called installation area), installation position 1-1 (installation area) is the position (area) that base member 1 is connected with the frame 5 of bicycle, connecting rod mechanism 3 is hinged between base member 1 and movable member 2, chain guide 4 is arranged on movable member 2, and chain guide 4 includes chain guide wheel 4-1 and tension wheel 4-4, wherein, chain guide wheel 4-1 has wheel plane 4-11, installation position 1-1 has reference point 1-11, and reference point 1-11 is one reference point 1-11 closest to the radial center plane of bicycle rear wheel, when chain is located the smallest freewheel piece 6, the distance L between reference point 1-11 and wheel plane 4-11 is greater than or equal to 0, when the distance L between reference point 1-11 and wheel plane 4-11 is greater than 0, when chain moves from the smallest freewheel piece 6 to the direction of the largest freewheel piece 6, wheel plane 4-11 will gradually approach reference point, coincide with reference point 1-11, then away from reference point 1-11, when the distance L between reference point 1-11 and wheel plane 6 is equal to 0 (that is, reference point coincides with wheel plane), when chain moves from the smallest freewheel piece 6 to the direction of the largest freewheel piece 6, wheel plane 4-11 will gradually away from reference point.

[0035] Referring to Figures 1-7, the distance between the reference point 1-11 and the wheel plane 4-11 refers to the distance when the reference point 1-11 is perpendicular to the wheel plane 4-11. The freewheel of the bicycle comprises a plurality of freewheel pieces 6, the diameters of the plurality of freewheel pieces 6 are different, corresponding to different gears, the freewheel is coaxially arranged with the rear wheel of the bicycle, the radial center plane is a plane perpendicular to the axis of the rear wheel of the bicycle, and a plane parallel to the radial direction of the rear wheel of the bicycle.

[0036] Referring to Figures 1-7 When the distance L between the reference point 1-11 and the wheel plane 4-11 is greater than 0, and when the chain moves from the smallest freewheel piece 6 to the largest freewheel piece 6, the wheel plane 4-11 gradually approaches the mounting position 1-1, then intersects with the mounting position 1-1, and finally moves away from the mounting position 1-1. In the above structure, when the chain moves from the smallest freewheel piece 6 to the largest freewheel piece 6, the wheel plane 4-11 gradually approaches the mounting position 1-1, then intersects with the mounting position 1-1, and finally moves away from the mounting position 1-1; it indicates that the mounting position 1-1 is located between the largest freewheel piece 6 and the smallest freewheel piece 6, when the chain is located at the smallest freewheel piece 6, the axial profile of the rear derailleur does not exceed the outside of the frame 5 too much, so that the rear derailleur is almost hidden inside the frame 5, the whole rear derailleur structure is more compact, and the profile is lower, which can improve the safety of riding. Axial profile refers to the axial profile of the rear wheel of the bicycle.

[0037] Referring to Figures 1-7 When the chain is located at the smallest freewheel piece 6, the mounting position 1-1 intersects with the wheel plane 4-11; when the chain moves from the smallest freewheel piece 6 to the largest freewheel piece 6, the wheel plane 4-11 gradually moves away from the mounting position 1-1. In the above structure, when the chain is located at the smallest freewheel piece 6, the axial profile of the rear derailleur also does not exceed the outside of the frame too much. When the distance L between the reference point 1-11 and the wheel plane 4-11 is greater than 0, the mounting position 1-1 and the wheel plane 4-11 can intersect. When the distance L between the reference point 1-11 and the wheel plane 4-11 is equal to 0, it indicates that the reference point 1-11 is located on the wheel plane 4-11, and the mounting position 1-1 intersects with the wheel plane 4-11.

[0038] Referring to Figures 1-7When the chain moves from the smallest sprocket 6 to the largest sprocket 6, the wheel plane 4-11 gradually approaches the base member 1, then intersects the base member 1, and finally moves away from the base member 1. The purpose is that the installation position is one of the areas on the base member 1, and the above structure makes the base member 1 located between the largest sprocket 6 and the smallest sprocket 6, so that the installation position is also located between the largest sprocket 6 and the smallest sprocket 6, further improving the compactness of the base member 1, so that the rear derailleur is almost hidden inside the frame 5.

[0039] Referring to Figures 1-7 , the base member 1 is provided with a mounting groove 1-2, the frame 5 is provided with a downwardly protruding mounting protrusion 7, and the mounting groove 1-2 is connected with the mounting protrusion 7; the position where the mounting groove 1-2 is located is the installation position 1-1, and the side position and the bottom position of the installation groove 1-1 constitute the installation position 1-1. The reference point in the embodiment is on the side position. In the above structure, by setting the mounting groove 1-2 and the mounting protrusion 7, the two are matched with each other, so that quick installation can be achieved.

[0040] Referring to Figures 1-7 , the mounting protrusion 7 is arranged on the lower end surface of the frame 5 and located at the front end of the bicycle rear axle 10. The purpose is that the mounting protrusion 7 is arranged on the lower end surface of the frame 5 and located at the front end of the bicycle rear axle 10, so that the rear derailleur is closer to the inside of the frame 5 after installation, and the outward protruding distance is smaller.

[0041] Referring to Figures 1-7 , the base member 1 and the mounting protrusion 7 are connected through the mounting bolt 9. By setting the mounting bolt 9, the installation and disassembly are facilitated.

[0042] Referring to Figures 1-7 , the cross sections of the mounting groove 1-2 and the mounting protrusion 7 are both rectangular. The purpose is to facilitate installation and positioning.

[0043] Referring to Figures 1-7 , the chain guide 4 further comprises a first chain guide plate 4-2 and a second chain guide plate 4-3; the first chain guide plate 4-2 and the second chain guide plate 4-3 are oppositely arranged; the first chain guide plate 4-2 is rotationally connected with the movable member 2, and the chain guide wheel 4-1 and the tensioning wheel 4-4 are arranged between the first chain guide plate 4-2 and the second chain guide plate 4-3. The above structure is simpler, and through the movement of the movable member 2, the chain guide wheel 4-1 and the tensioning wheel 4-4 are driven to move, so as to realize the switching of the sprocket 6.

[0044] Referring to Figures 1-7 , the movable member 2 and the first chain guide plate 4-2 are provided with an elastic reset assembly, and the elastic reset assembly is used for tensioning the chain. The elastic reset assembly can be a torsion spring.

[0045] Referring to Figures 1-7 , the wheel plane 4-11 is perpendicular to the axis of the chain guide wheel 4-1, and the wheel plane 4-11 is located at the center of the chain guide wheel 4-1. The wheel plane 4-11 can also be the plane formed by the chain guide wheel 4-1 and the tensioner wheel 4-4.

[0046] Referring to Figures 1-7 , the linkage mechanism 3 includes a first linkage 3-1 and a second linkage 3-2, one end of the first linkage 3-1 is hinged to the base member 1, the other end of the first linkage 3-1 is hinged to one end of the movable member 2; one end of the second linkage 3-2 is hinged to the base member 1, the other end of the second linkage 3-2 is hinged to one end of the movable member 2; the first linkage 3-1 and the second linkage 3-2 are hinged to different positions of the base member 1, and the first linkage 3-1 and the second linkage 3-2 are hinged to different positions of the movable member 2.

[0047] Referring to Figures 1-7 , the mounting protrusion 7 is provided with a mounting through hole 7-1 through which the mounting bolt 9 passes. The purpose is that the mounting bolt 9 passes through the mounting through hole 7-1, which can better connect the mounting protrusion 7 and the base member 1 together.

[0048] Referring to Figures 1-7 , the number of the flywheel pieces 6 is multiple, and different flywheel pieces 6 correspond to different gears. The smallest flywheel piece 6 is located outside the largest flywheel piece 6.

[0049] Referring to Figures 1-7 , the working principle of the above low-profile rear derailleur is as follows:

[0050] When the distance between the reference point 1-11 and the wheel plane 4-11 is greater than 0, the chain moves from the smallest flywheel piece 6 to the largest flywheel piece 6, the wheel plane 4-11 gradually approaches the reference point 1-11, and then moves away from the reference point 1-11; when the distance between the reference point 1-11 and the wheel plane 4-11 is equal to 0, the chain moves from the smallest flywheel piece 6 to the largest flywheel piece 6, the wheel plane 4-11 gradually moves away from the reference point 1-11. It is illustrated that the reference point 1-11 is closer to the flywheel piece, that is, the mounting position 1-1 is close to the smallest flywheel piece 6 or located between the largest flywheel piece 6 and the smallest flywheel piece 6; when the chain is located at the position of the smallest flywheel piece 6, the axial profile of the rear derailleur does not exceed the outside of the frame 5 too much, so that the rear derailleur is almost hidden inside the frame 5, the whole rear derailleur structure is more compact, the profile is lower, and the safety of riding can be improved.

[0051] Embodiment 2

[0052] Referring to Figures 8-9The chain guide 4 further comprises a tensioning arm 4-5; the movable member 2 comprises an inner guide plate 2-1 and an outer guide plate 2-2, the outer guide plate 2-2 being fixed on the outer side of the inner guide plate 2-1, the chain guide wheel 4-1 being rotatably arranged between the inner guide plate 2-1 and the outer guide plate 2-2, the connecting rod mechanism 3 being hinged to the outer guide plate 2-2, one end of the tensioning arm 4-5 being rotatably connected to the outer side of the inner guide plate 2-1, and the tensioning wheel 4-4 being arranged at the other end of the tensioning arm 4-5. In the above structure, the movable member 2 comprises the inner guide plate 2-1 and the outer guide plate 2-2, the inner guide plate 2-1 and the outer guide plate 2-2 are plate-shaped structures, and the tensioning arm 4-5 is installed on the outer side of the inner guide plate 2-1, so that the structure of the rear derailleur is more compact, the outward protruding distance is smaller, the distance between the chain guide wheel 4-1 and the tensioning wheel 4-4 can be changed, so that the tensioning range of the chain guide 4 to the chain is large, the extra slack of the chain can be absorbed, and the tension of the chain is ensured.

[0053] Referring to Figures 8-9 A resilient reset assembly is arranged between the tensioning arm 4-5 and the inner guide plate 2-1, and is used for tensioning the chain.

[0054] Referring to Figures 8-9 The connecting rod mechanism 3 comprises a first connecting rod 3-1 and a second connecting rod 3-2, one end of the first connecting rod 3-1 being hinged to the base member 1, the other end of the first connecting rod 3-1 being hinged to one end of the outer guide plate 2-2; one end of the second connecting rod 3-2 being hinged to the base member 1, the other end of the second connecting rod 3-2 being hinged to one end of the outer guide plate 2-2; the first connecting rod 3-1 and the second connecting rod 3-2 are hinged to the base member 1 at different positions, and the first connecting rod 3-1 and the second connecting rod 3-2 are hinged to the outer guide plate 2-2 at different positions.

[0055] Referring to Figures 8-9 One end of the tensioning arm 4-5 close to the tensioning wheel 4-4 is arranged to be inclined towards the outer side of the inner guide plate 2-1. The purpose is to ensure that the tensioning wheel 4-4 can be located on the same plane as the chain guide wheel 4-1 or be closer to the chain guide wheel 4-1, so that the chain is smoothly guided and tensioned on the tensioning wheel 4-4 and the chain guide wheel 4-1, the chain is prevented from falling off, and the stability of the chain in operation is improved.

[0056] The outer guide plate 2-2 is separated from the tensioning arm 4-5. That is, the tensioning arm 4-5 is connected with the inner guide plate 2-1 only, and is not directly connected with the outer guide plate 2-2. The outer guide plate 2-2 is separated from the tensioning arm 4-5. The inner guide plate 2-1 is indirectly connected with the tensioning arm 4-5. The purpose is to simplify the structure of the bicycle derailleur. The tensioning arm 4-5 does not interfere with the outer guide plate 2-2. The tensioning arm 4-5 has a large rotating range on the inner guide plate 2-1, thereby improving the tensioning range of the chain.

[0057] Embodiment 3

[0058] The other structures in the embodiment are the same as those in Embodiment 1. The difference is that the base member 1 in the embodiment is directly installed on the frame 5 of the bicycle, and is fixed by screws. The inner side of the base member 1 is provided with a mounting surface, which is directly in contact with the frame 5. The mounting surface constitutes the mounting position, and the reference point is located on the mounting surface.

[0059] The above is the preferred embodiment of the utility model, but the embodiment of the utility model is not limited by the above content, and any change, modification, replacement, combination, simplification made without departing from the spirit and principle of the utility model should be an equivalent replacement method, which is all included in the protection scope of the utility model.

Claims

1. A low profile rear derailleur characterized in that, The base member, the movable member, the connecting rod mechanism and the chain guide are provided; the base member is provided with a mounting position, which is the position for connecting the base member with the frame of the bicycle; the connecting rod mechanism is hinged between the base member and the movable member; the chain guide is provided on the movable member and comprises a chain guide wheel and a tensioning wheel; wherein the chain guide wheel has a wheel plane, the mounting position has a reference point, which is the reference point closest to the radial center plane of the rear wheel of the bicycle; when the chain is located at the smallest freewheel piece, the distance between the reference point and the wheel plane is greater than or equal to 0; When the distance between the reference point and the wheel plane is greater than 0, when the chain moves from the smallest freewheel piece to the largest freewheel piece, the wheel plane gradually approaches the reference point and then moves away from the reference point; When the distance between the reference point and the wheel plane is equal to 0, when the chain moves from the smallest freewheel piece to the largest freewheel piece, the wheel plane gradually moves away from the reference point.

2. A low profile rear derailleur according to claim 1, characterized in that, When the chain moves from the smallest freewheel piece to the largest freewheel piece, the wheel plane gradually approaches the mounting position, intersects with the mounting position and then moves away from the mounting position.

3. A low profile rear derailleur according to claim 1, characterized in that, When the chain is located at the smallest freewheel piece, the mounting position intersects with the wheel plane; when the chain moves from the smallest freewheel piece to the largest freewheel piece, the wheel plane gradually moves away from the mounting position.

4. A low profile rear derailleur according to claim 2, characterized in that, When the chain moves from the smallest freewheel piece to the largest freewheel piece, the wheel plane gradually approaches the base member, intersects with the base member and then moves away from the base member.

5. A low profile rear derailleur according to claim 2, characterized in that, The base member is provided with a mounting groove, the frame is provided with a downwardly protruding mounting protrusion, and the mounting groove and the mounting protrusion are connected in a matching manner; the position where the mounting groove is located is the mounting position.

6. A low profile rear derailleur according to claim 5, characterized in that, The mounting protrusion is arranged on the lower end surface of the frame and located at the front end of the rear axle of the bicycle.

7. A low profile rear derailleur according to claim 5 or 6, characterized in that, The base member and the mounting protrusion are connected through a mounting bolt.

8. A low profile rear derailleur according to claim 1, characterized in that, The chain guide further comprises a tensioning arm; the movable member comprises an inner guide plate and an outer guide plate, the outer guide plate is fixed on the outer side surface of the inner guide plate, the chain guide wheel is rotatably arranged between the inner guide plate and the outer guide plate, the connecting rod mechanism is hinged with the outer guide plate, one end of the tensioning arm is rotatably connected to the outer side surface of the inner guide plate, and the tensioning wheel is arranged at the other end of the tensioning arm.

9. A low profile rear derailleur according to claim 1, characterized in that, The chain guide further comprises a first chain guide plate and a second chain guide plate; the first chain guide plate and the second chain guide plate are arranged opposite to each other; the first chain guide plate is rotatably connected with the movable member, and the chain guide wheel and the tensioning wheel are arranged between the first chain guide plate and the second chain guide plate.

10. A low profile rear derailleur according to claim 1, characterized in that, The wheel plane and the axis of the chain guide wheel are perpendicular to each other, and the wheel plane is located at the center position of the chain guide wheel.

Images