CN111806621B

CN111806621B - Bicycle speed variator fine tuning method

Info

Publication number: CN111806621B
Application number: CN201910987007.XA
Authority: CN
Inventors: 庄恂谕; 洪培轩; 林宝文
Original assignee: Tektro Technology Corp
Current assignee: Tektro Technology Corp
Priority date: 2019-04-12
Filing date: 2019-10-17
Publication date: 2021-12-28
Anticipated expiration: 2039-10-17
Also published as: TWI704083B; TW202037528A; CN111806621A

Abstract

A bicycle speed changer fine adjustment method comprises the steps of judging the gear of a bicycle front speed changer and the triggering conditions of a first switch and a second switch; if the front transmission is in a first low gear and the first switch is triggered, fine-adjusting the front transmission from the first low gear to a second low gear; if the front transmission is in a second low gear and the first switch is triggered, determining whether to finely adjust the front transmission from the second low gear to a first low gear according to the gear of the rear transmission; if the front transmission is in a first high gear and the second switch is triggered, determining whether to finely adjust the front transmission from the first high gear to a second high gear according to the gear of the rear transmission; and if the front transmission is in the second high gear and the second switch is triggered, fine-tuning the front transmission from the second high gear to the first high gear.

Description

Bicycle speed variator fine tuning method

Technical Field

The present invention relates to a method of fine tuning, and more particularly to a method of fine tuning a bicycle derailleur for fine tuning a front derailleur.

Background

Generally, a bicycle is provided with a front chainset, a rear chainset, a chain, a front derailleur and a rear derailleur. The front fluted disc set and the rear fluted disc set respectively comprise a plurality of fluted discs with different diameters, and the chain is hung on one of the fluted discs of the front fluted disc and one of the fluted discs of the rear fluted disc. When the user steps on the pedal to rotate the front gear disc set, the chain drives the rear gear disc set to rotate so as to drive the rear wheel together, so that the bicycle can move forward. The front transmission and the rear transmission are respectively provided with a plurality of different gears, different gears of the front transmission respectively correspond to the gear discs of the front gear disc set with different diameters, and different gears of the rear transmission respectively correspond to the gear discs of the rear gear disc set with different diameters. Therefore, a user can shift the chain by switching the gears of the front transmission and the rear transmission, so that the chain can move on different fluted discs of the front fluted disc set and the rear fluted disc set to adjust the gear ratio between the front fluted disc set and the rear fluted disc set, thereby meeting the requirements of dealing with different road conditions.

However, when the front and rear derailleurs are in specific gear positions, the chain interferes with the chain guide member of the front derailleur. Therefore, the chain may continuously collide with the chain guide member to generate noise during the pedaling process of the user, thereby causing discomfort in riding. Therefore, how to avoid the interference between the chain and the chain guiding member of the front transmission when the front transmission and the rear transmission are under a specific gear is one of the problems to be solved by the research and development personnel in this field.

Disclosure of Invention

The present invention is directed to a method for fine tuning a bicycle derailleur, which solves the problem of the prior art that a chain interferes with a chain guiding member of a front derailleur when the front derailleur and a rear derailleur are in specific gears.

The technical problem to be solved by the invention is realized by the following technical scheme:

the present invention discloses a bicycle transmission fine-tuning method for fine-tuning a front transmission according to a gear of the front transmission and a gear of a rear transmission. The gears of the front transmission comprise a first low gear, a second low gear, a first high gear and a second high gear which are different. The first low gear and the second low gear correspond to a small plate of a front fluted disc of the bicycle. The first high gear and the second high gear correspond to a big plate of a front fluted disc of the bicycle. The bicycle speed changer fine adjustment method comprises the steps of judging the gear of the front speed changer and triggering the first switch and the second switch. And if the front transmission is in the first low gear and the first switch is triggered, fine-adjusting the front transmission from the first low gear to the second low gear. If the front transmission is in the second low gear and the first switch is triggered, whether the front transmission is finely adjusted from the second low gear to the first low gear is determined according to the gear of the rear transmission. And if the front transmission is in a first low gear or a second low gear and the second switch is triggered, switching the front transmission from the first low gear or the second low gear to a first high gear or a second high gear. If the front transmission is in a first high gear or a second high gear and the first switch is triggered, the front transmission is switched from the first high gear or the second high gear to a first low gear or a second low gear. If the front transmission is in the first high gear and the second switch is triggered, whether to finely adjust the front transmission from the first high gear to the second high gear is determined according to the gear of the rear transmission. And if the front transmission is in the second high gear and the second switch is triggered, fine-tuning the front transmission from the second high gear to the first high gear.

According to the bicycle transmission fine adjustment method of the embodiment, the first switch is triggered when the front transmission is in the first low gear position, or the second switch is triggered when the front transmission is in the second high gear position, so that the gear position of the current front transmission can be finely adjusted, the problem that a bicycle chain interferes with a chain guide member of the front transmission can be solved, and the comfort of riding the bicycle can be maintained.

In addition, the first switch is triggered when the front derailleur is in the second low gear position, or the second switch is triggered when the front derailleur is in the first high gear position, and the gear position of the front derailleur is finely adjusted according to the gear position of the rear derailleur to eliminate the problem that the bicycle chain interferes with the chain guide member of the front derailleur, or the gear position of the front derailleur is maintained to avoid the bicycle chain from interfering with the chain guide member of the front derailleur after fine adjustment.

In addition, the second switch is triggered under the condition that the front speed changer is in the first low gear or the second low gear, so that the front speed changer can be shifted, and the first high gear or the second high gear can be judged to be shifted according to the gear of the rear speed changer, so that the bicycle chain is prevented from interfering with a chain guide member of the front speed changer after being shifted.

In addition, the first switch is triggered when the front speed changer is in the first high gear or the second high gear, so that the front speed changer can be shifted out of gear, and the first low gear or the second low gear can be judged to be shifted according to the gear of the rear speed changer, so that the bicycle chain is prevented from interfering with a chain guide component of the front speed changer after being shifted.

Drawings

FIG. 1A is a schematic plan view of a front chainring, a rear chainring, a chain and a chain guide member of a front derailleur shown in a first low gear in accordance with the present disclosure;

FIG. 1B is a schematic plan view of a front chainring, a rear chainring, a chain and a chain guide member of the front derailleur shown in a second low gear in accordance with the present disclosure;

FIG. 1C is a schematic plan view of the front chainring, the rear chainring, the chain and the chain guide member of the front derailleur shown in the first high gear according to the present invention;

FIG. 1D is a schematic plan view of a front chainring, a rear chainring, a chain and a chain guide member of the front derailleur shown in a second highest gear in accordance with the present disclosure;

FIG. 2 is a partial flow chart of a method for fine tuning a bicycle transmission in accordance with a first embodiment of the present invention;

FIG. 3 is a schematic plan view of the front derailleur with the gear finely adjusted from a first low gear to a second low gear;

FIG. 4 is a schematic plan view of the gear position of the front derailleur being shifted from a first low gear position to a first high gear position;

FIG. 5 is a schematic plan view of the gear position of the front derailleur being shifted from a first low gear position to a second high gear position;

FIG. 6 is another partial flow chart illustrating a method for fine tuning a bicycle transmission in accordance with a first embodiment of the present invention;

FIG. 7 is a schematic plan view of the front derailleur with the gear finely adjusted from the second low gear to the first low gear;

FIG. 8 is a plan view of the front derailleur with the gear position maintained in the second low gear position;

FIG. 9 is a schematic plan view of the gear position of the front derailleur being shifted from the second low gear position to the first high gear position;

FIG. 10 is a schematic plan view of the gear position of the front derailleur being shifted from the second low gear position to the second high gear position;

FIG. 11 is a partial flow chart of a method for fine tuning a bicycle transmission in accordance with a first embodiment of the present invention;

FIG. 12 is a schematic plan view of the gear position of the front derailleur being shifted from a first high gear position to a second low gear position;

FIG. 13 is a schematic plan view of the gear position of the front derailleur being shifted from a first high gear position to a first low gear position;

FIG. 14 is a schematic plan view of the front derailleur with the gear finely adjusted from the first high gear to the second high gear;

FIG. 15 is a schematic plan view of the front derailleur with the gear position maintained in the first high gear position;

FIG. 16 is still another partial flow chart illustrating a method for fine tuning a bicycle transmission in accordance with a first embodiment of the present invention;

FIG. 17 is a schematic plan view of the front derailleur with the gear position shifted from the second high gear position to the second low gear position;

FIG. 18 is a schematic plan view of the front derailleur with the gear shifted from the second high gear to the first low gear;

fig. 19 is a plan view schematic diagram of the front derailleur with the gear finely adjusted from the second high gear to the first high gear.

[ description of reference ]

100 front fluted disc

110 small dish

120 big dish

A guide chain component

Dashed lines L1, L2, L3, L4

200 rear fluted disc

201 first toothed disc

211 eleventh fluted disc

C chain

S11-S35 steps

Detailed Description

Please refer to fig. 1A to 1D. Fig. 1A to 1D are schematic plan views of a front chain ring, a rear chain ring, a chain, and a chain guide member of a front transmission in a first low gear, a second low gear, a first high gear, and a second high gear, respectively, according to the present invention.

The invention discloses a bicycle speed changer fine adjustment method which is used for fine adjusting a front speed changer according to a gear of a rear speed changer.

The front derailleur corresponds to a front chainring 100 of a bicycle. The gears of the front derailleur include a first low gear, a second low gear, a first high gear and a second high gear, and the front gear 100 of the bicycle includes a small plate 110 and a large plate 120. When the front derailleur is in the first or second low gear, the chain guide member a of the front derailleur is a small plate 110 corresponding to the front gear 100 of the bicycle. When the front derailleur is in the first or second high gear, the chain guide member a of the front derailleur is the large plate 120 of the front disc 100 of the corresponding bicycle.

In detail, in the case where the front derailleur is in the first low gear position, the position of the chain guide member a of the front derailleur is as shown in fig. 1A, and the right side of the chain guide member a is located on the broken line L1. With the front derailleur in the second low gear position, the position of the chain guide member A of the front derailleur is as shown in FIG. 1B, and the right side of the chain guide member A is located on the dashed line L2 that is closer to the large plate 120 than the dashed line L1. It can be seen that the chain guide member a in the second low range is slightly closer to the large plate 120 than the chain guide member a in the first low range.

With the front derailleur in the first high gear position, the position of the chain guide member a of the front derailleur is as shown in fig. 1C, and the right side of the chain guide member a is located on the dashed line L3. With the front derailleur in the second highest gear, the position of the chain guide member a of the front derailleur is as shown in fig. 1D, and the right side of the chain guide member a is located on a dashed line L4 that is farther from the small plate 110 than the dashed line L3. It can be seen that the chain guide member a in the first high gear position is slightly closer to the small plate 110 than the chain guide member a in the second high gear position.

The gear of the rear transmission can be shifted, for example, between a first gear and an eleventh gear. That is, the gear positions of the rear transmission include first to eleventh gear positions. The first through eleventh gears correspond to first through eleventh chainrings 201 through 211, respectively, of the bicycle having a rear chainring 200 that is different in size from one another.

The bicycle chain C is hung on one of the front chainrings 100 and one of the rear chainrings 200 to connect one of the front chainrings 100 and one of the rear chainrings 200. The relationship between the bicycle chain C, the gear positions of the front derailleur and the gear positions of the rear derailleur will be exemplified below.

With the front derailleur in either the first low gear (FIG. 1A) or the second low gear (FIG. 1B) and the rear derailleur in the eleventh gear, the bicycle chain C is coupled to the small plate 110 of the front chainring 100 and the eleventh chainring 211 of the rear chainring 200. When the front derailleur is in the first (fig. 1C) or second (fig. 1D) high gear and the rear derailleur is in the eleventh gear, chain C of the bicycle connects large plate 120 of front chainring 100 and eleventh chainring 211 of rear chainring 200.

The bicycle chain C can be shifted by the chain guide member a of the front derailleur to move between the small plate 110 and the large plate 120, and the bicycle chain C can be shifted by the chain guide member (not shown) of the rear derailleur to move between the first chainring 201 and the eleventh chainring 211 of the rear chainring 200.

The bicycle speed changer fine adjustment method comprises the steps of judging the gear of the front speed changer and triggering the first switch and the second switch. If the front transmission is in a first low gear and the first switch is triggered, fine-adjusting the front transmission from the first low gear to a second low gear; if the front transmission is in a second low gear and the first switch is triggered, determining whether to finely adjust the front transmission from the second low gear to a first low gear according to the gear of the rear transmission; if the front transmission is in a first low gear or a second low gear and the second switch is triggered, switching the front transmission from the first low gear or the second low gear to a first high gear or a second high gear; if the front transmission is in a first high gear or a second high gear and the first switch is triggered, switching the front transmission from the first high gear or the second high gear to a first low gear or a second low gear; if the front transmission is in a first high gear and the second switch is triggered, determining whether to finely adjust the front transmission from the first high gear to a second high gear according to the gear of the rear transmission; and if the front transmission is in the second high gear and the second switch is triggered, fine-tuning the front transmission from the second high gear to the first high gear.

In the method for fine tuning a bicycle transmission, the first switch and the second switch are disposed on a gearshift brake handle of the bicycle, for example, and the controller is used for determining the gear position of the front transmission, the gear position of the rear transmission, whether the switches are triggered, the gear position of the rear transmission, the gear position of the front transmission being fine-tuned, and the gear position of the front transmission being switched, for example.

The bicycle transmission trim adjustment method will now be described in detail with reference to FIG. 2. FIG. 2 is a partial flow chart of a method for fine tuning a bicycle transmission in accordance with a first embodiment of the present invention.

First, in step S11, the gear position of the front derailleur is determined. If the front derailleur is in the first low gear position, the process proceeds to step S12, and the triggering of the first switch and the second switch is determined. If the first switch is activated, the process proceeds to step S13, where the front derailleur is finely adjusted from the first low gear to the second low gear.

That is, referring to fig. 3, fig. 3 is a schematic plan view illustrating the gear position of the front derailleur fine-tuned from the first low gear position to the second low gear position. If the first switch is activated with the front derailleur in the first low gear position, the gear position of the front derailleur is finely adjusted from the first low gear position to the second low gear position regardless of the gear position of the rear derailleur, moving the right side of the chain guide member A from the dashed line L1 to the dashed line L2, but maintaining the bicycle chain C on the small plate 110 of the front chainring 100.

In the aforementioned step S12, if the second switch is activated, the process proceeds to step S14, and it is determined whether the rear derailleur is in any one of the ninth gear position to the eleventh gear position. If so, the process proceeds to step S15, where the front derailleur is switched from the first low gear to the first high gear. If not, the process proceeds to step S16, where the front derailleur is switched from the first low gear to the second high gear.

Therefore, the second switch is the shift switch at this time. Further, the second switch is activated in a condition where the rear transmission is in any one of the ninth gear position to the eleventh gear position, and the gear position of the front transmission is switched from the first low gear position to the first high gear position. On the other hand, the second switch is activated under the condition that the rear transmission is in any one of the first to eighth gear positions, and the gear position of the front transmission is switched from the first low gear position to the second high gear position.

For example, please refer to fig. 4. Fig. 4 is a schematic plan view of the front transmission with the gear position shifted from the first low gear position to the first high gear position.

In the first low range and the eleventh speed range, the right side of the chain guide member A is located on the dashed line L1, and the bicycle chain C connects the small plate 110 of the front chainring 100 and the eleventh chainring 211 of the rear chainring 200. At this time, the second switch is activated, such that the front derailleur is shifted from the first low gear to the first high gear, and the right side of chain guide member A is moved from dashed line L1 to dashed line L3, such that bicycle chain C is connected to both large plate 120 of front chainring 100 and eleventh chainring 211 of rear chainring 200.

The foregoing is merely an example of the change made to the gear position of the front transmission when the second switch is activated under the condition that the front transmission is in the first low gear position and the rear transmission is in the eleventh gear position. In other cases, when the second switch is activated under the condition that the front transmission is in the first low gear and the rear transmission is in the ninth gear or the tenth gear, the gear of the front transmission is also switched from the first low gear to the first high gear.

On the other hand, please refer to fig. 5. Fig. 5 is a plan view schematically illustrating the gear position of the front transmission being shifted from the first low gear position to the second high gear position.

In the first low range and the first gear, the right side of the chain guide member a is located on the dashed line L1, and the bicycle chain C connects the small plate 110 of the front chainring 100 and the first chainring 201 of the rear chainring 200. At this time, the second switch is activated, and the shift position of the front derailleur is switched from the first low shift position to the second high shift position, moving the right side of chain guide member a from dashed line L1 to dashed line L4, such that bicycle chain C is connected to both large plate 120 of front chainring 100 and first chainring 201 of rear chainring 200.

The foregoing is merely an example of the change made to the gear of the front transmission when the second switch is activated under conditions where the front transmission is in the first low gear and the rear transmission is in the first gear. In other cases, when the second switch is activated under the condition that the front transmission is in the first low gear and the rear transmission is in the second, third, fourth, fifth, sixth, seventh or eighth gear, the gear of the front transmission is also switched from the first low gear to the second high gear.

Please refer to fig. 6. FIG. 6 is another partial flow chart illustrating a method for fine tuning a bicycle transmission in accordance with a first embodiment of the present invention.

If the front derailleur is in the second low gear position in step S11, the routine proceeds to step S17, where it is determined whether the first switch and the second switch are activated. If the first switch is activated, the process proceeds to step S18, where it is determined whether the rear derailleur is in any one of the fourth gear position to the eleventh gear position. If so, the routine proceeds to step S19 to fine-tune the front derailleur from the second low gear to the first low gear. If not, the process proceeds to step S20 to maintain the front derailleur in the second low gear.

That is, if the first switch is activated with the rear transmission in any one of the fourth to eleventh gear positions, the gear position of the front transmission is finely adjusted from the second low gear position to the first low gear position. On the other hand, if the first switch is triggered when the rear transmission is in any one of the first to third gear positions, the gear position of the front transmission is still maintained in the second low gear position.

For example, please refer to fig. 7. FIG. 7 is a schematic plan view of the front derailleur with the gear finely adjusted from the second low gear to the first low gear.

In the second low range and the eleventh speed range, the right side of the chain guide member A is located on the dashed line L2, and the bicycle chain C connects the small plate 110 of the front chainring 100 and the eleventh chainring 211 of the rear chainring 200. At this time, the first switch is activated, and the shift position of the front derailleur is finely adjusted from the second low position to the first low position, so that the right side of the chain guide member A is moved from the dashed line L2 to the dashed line L1, but the bicycle chain C remains on the small plate 110 of the front chainring 100.

The foregoing is merely an example of the change made to the gear position of the front transmission when the first switch is activated under the condition that the front transmission is in the second low gear position and the rear transmission is in the eleventh gear position. In other conditions, when the first switch is activated under the condition that the front transmission is in the second low gear and the rear transmission is in the fourth, fifth, sixth, seventh, eighth, ninth or tenth gear, the gear of the front transmission is also finely adjusted from the second low gear to the first low gear.

On the other hand, please refer to fig. 8. Fig. 8 is a plan view schematically illustrating the gear position of the front derailleur being maintained in the second low gear position.

In the second low range and the first range, the right side of the chain guide member a is located on the dashed line L2, and the bicycle chain C connects the small plate 110 of the front chainring 100 and the first chainring 201 of the rear chainring 200. At this time, the first switch is activated, and the front derailleur is maintained in the second low gear without moving the chain guide member a.

The foregoing is merely an example of the change made to the gear of the front transmission when the first switch is activated under conditions where the front transmission is in the second low gear and the rear transmission is in the first gear. In other cases, when the first switch is activated under the condition that the front transmission is in the second low gear and the rear transmission is in the second or third gear, the gear of the front transmission is also maintained in the second low gear.

If the second switch is activated in step S17, the process proceeds to step S21, where it is determined whether the rear derailleur is in any one of the ninth gear position to the eleventh gear position. If so, the process proceeds to step S22, where the front derailleur is switched from the second low gear to the first high gear. If not, the routine proceeds to step S23, where the front derailleur is switched from the second low gear to the second high gear.

Therefore, the second switch is the shift switch at this time. Further, the second switch is activated in a condition where the rear transmission is in any one of the ninth gear position to the eleventh gear position, and the gear position of the front transmission is switched from the second low gear position to the first high gear position. On the other hand, the second switch is activated under the condition that the rear transmission is in any one of the first to eighth gear positions, and the gear position of the front transmission is switched from the second low gear position to the second high gear position.

For example, please refer to fig. 9. Fig. 9 is a plan view schematically illustrating the gear position of the front transmission being shifted from the second low gear position to the first high gear position.

In the second low range and the eleventh speed range, the right side of the chain guide member A is located on the dashed line L2, and the bicycle chain C connects the small plate 110 of the front chainring 100 and the eleventh chainring 211 of the rear chainring 200. At this time, the second switch is actuated, the front derailleur is shifted from the second low gear to the first high gear, moving the right side of chain guide member A from dashed line L2 to dashed line L3, such that bicycle chain C is connected to both large plate 120 of front chainring 100 and eleventh chainring 211 of rear chainring 200.

The foregoing is merely an example of the change made to the gear position of the front transmission by the second switch being triggered under conditions where the front transmission is in the second low gear position and the rear transmission is in the eleventh gear position. In other conditions, when the second switch is activated under the condition that the front transmission is in the second low gear and the rear transmission is in the ninth gear or the tenth gear, the gear of the front transmission is also switched from the second low gear to the first high gear.

Please refer to fig. 10 for another aspect. Fig. 10 is a plan view schematically illustrating the gear position of the front transmission being switched from the second low gear position to the second high gear position.

In the second low range and the first range, the right side of the chain guide member a is located on the dashed line L2, and the bicycle chain C connects the small plate 110 of the front chainring 100 and the first chainring 201 of the rear chainring 200. At this time, the second switch is activated, and the shift position of the front derailleur is switched from the second low gear to the second high gear, moving the right side of chain guide member a from dashed line L2 to dashed line L4, such that bicycle chain C is connected to both large plate 120 of front chainring 100 and first chainring 201 of rear chainring 200.

The foregoing is merely an example of the change made to the gear of the front transmission when the second switch is activated under conditions where the front transmission is in the second low gear and the rear transmission is in the first gear. In other conditions, when the second switch is activated under the condition that the front transmission is in the second low gear and the rear transmission is in the second gear, the third gear, the fourth gear, the fifth gear, the sixth gear, the seventh gear or the eighth gear, the gear of the front transmission is also switched from the second low gear to the second high gear.

Please refer to fig. 11. FIG. 11 is a partial flow chart of a method for fine tuning a bicycle transmission in accordance with a first embodiment of the present invention.

If the front derailleur is in the first high gear position in step S11, the routine proceeds to step S24, where it is determined whether the first switch and the second switch are activated. If the first switch is triggered, the process proceeds to step S25, where it is determined whether the rear transmission is in any one of the first gear position to the third gear position. If so, the routine proceeds to step S26, where the front derailleur is shifted from the first high gear to the second low gear. If not, the routine proceeds to step S27, where the front derailleur is shifted from the first high gear to the first low gear.

Therefore, the first switch is the gear-reversing switch at this time. Further, the first switch is activated in a condition where the rear transmission is in any one of the first to third gear positions, and the gear position of the front transmission is switched from the first high gear position to the second low gear position. On the other hand, the first switch is activated under the condition that the rear transmission is in any one of the fourth to eleventh gear positions, and the gear position of the front transmission is switched from the first high gear position to the first low gear position.

For example, please refer to fig. 12. Fig. 12 is a plan view schematically illustrating the gear position of the front transmission being switched from the first high gear position to the second low gear position.

In the first-high gear condition of the front derailleur and the rear derailleur, the right side of the chain guide member a is located on the dashed line L3, and the bicycle chain C connects the large plate 120 of the front chainring 100 and the first chainring 201 of the rear chainring 200. At this time, the first switch is activated, the front derailleur is shifted from the first high gear to the second low gear, and the right side of the chain guide member a is moved from the dashed line L3 to the dashed line L2, such that the bicycle chain C is connected to the small plate 110 of the front chainring 100 and the first chainring 201 of the rear chainring 200.

The foregoing is merely an example of the change made to the gear of the front transmission when the first switch is activated under conditions where the front transmission is in the first high gear and the rear transmission is in the first gear. In other conditions, when the first switch is activated under the condition that the front transmission is in the first high gear and the rear transmission is in the second gear or the third gear, the gear of the front transmission is also switched from the first high gear to the second low gear.

On the other hand, please refer to fig. 13. Fig. 13 is a plan view schematically illustrating the gear position of the front transmission being shifted from the first high gear position to the first low gear position.

In the first-highest gear condition of the front derailleur and the eleventh gear condition of the rear derailleur, the right side of chain guide member a is located on dashed line L3, and bicycle chain C connects large plate 120 of front chainring 100 and eleventh chainring 211 of rear chainring 200. At this time, the first switch is actuated, and the forward gear position is shifted from the first high gear position to the first low gear position, such that the right side of chain guide member A is moved from dashed line L3 to dashed line L1, such that bicycle chain C is connected to both small plate 110 of front chainring 100 and eleventh chainring 211 of rear chainring 200.

The foregoing is merely an example of the change made to the gear position of the front transmission when the first switch is activated under the condition that the front transmission is in the first high gear position and the rear transmission is in the eleventh gear position. In other cases, when the first switch is activated under the condition that the front transmission is in the first high gear and the rear transmission is in the fourth, fifth, sixth, seventh, eighth, ninth or tenth gear, the gear of the front transmission is also switched from the first high gear to the first low gear.

If the second switch is activated in step S24, the process proceeds to step S28, where it is determined whether the rear derailleur is in any one of the first gear position to the eighth gear position. If so, the process proceeds to step S29 where the front derailleur is fine-tuned from the first high gear to the second high gear. If not, the process proceeds to step S30 to maintain the front derailleur in the first high gear.

That is, if the second switch is activated with the rear transmission in any one of the first to eighth gear positions, the gear position of the front transmission is finely adjusted from the first high gear position to the second high gear position. On the other hand, if the second switch is activated when the rear transmission is in any one of the ninth through eleventh gear positions, the gear position of the front transmission is maintained at the first high gear position.

For example, please refer to FIG. 14. Fig. 14 is a plan view schematically illustrating the gear position of the front transmission finely adjusted from the first high gear position to the second high gear position.

In the first-high gear condition of the front derailleur and the rear derailleur, the right side of the chain guide member a is located on the dashed line L3, and the bicycle chain C connects the large plate 120 of the front chainring 100 and the first chainring 201 of the rear chainring 200. At this time, the second switch is activated, and the shift position of the front derailleur is finely adjusted from the first high position to the second high position, moving the right side of chain guide member A from dashed line L3 to dashed line L4, but maintaining the bicycle chain C on the large plate 120 of the front chainring 100.

The foregoing is merely an example of the change made to the gear of the front transmission when the second switch is activated under conditions where the front transmission is in the first high gear and the rear transmission is in the first gear. In other situations, when the second switch is activated under the condition that the transmission is in the first high gear and the rear transmission is in the second, third, fourth, fifth, sixth, seventh or eighth gear, the gear of the front transmission is also finely adjusted from the first high gear to the second high gear.

On the other hand, please refer to fig. 15. Fig. 15 is a plan view schematically illustrating the gear position of the front derailleur being maintained in the first high gear position.

In the first-highest gear condition of the front derailleur and the eleventh gear condition of the rear derailleur, the right side of chain guide member a is located on dashed line L3, and bicycle chain C connects large plate 120 of front chainring 100 and eleventh chainring 211 of rear chainring 200. At this time, the second switch is activated, and the front derailleur is maintained in the first high gear without moving the chain guide member a.

The foregoing is merely an example of the change in gear position of the front transmission that results from the second switch being activated under conditions where the front transmission is in the first high gear position and the rear transmission is in the eleventh gear position. In other conditions, when the second switch is activated under the condition that the front transmission is in the first high gear and the rear transmission is in the ninth gear or the tenth gear, the gear of the front transmission is also maintained in the first high gear.

Referring to fig. 16, fig. 16 is still another partial flowchart of a method for fine tuning a bicycle transmission in accordance with a first embodiment of the present invention.

If the front derailleur is in the second highest gear in step S11, the routine proceeds to step S31, where it is determined whether the first switch and the second switch are activated. If the first switch is triggered, the process proceeds to step S32, where it is determined whether the rear transmission is in any one of the first gear position to the third gear position. If so, the routine proceeds to step S33, where the front derailleur is shifted from the second high gear to the second low gear. If not, the routine proceeds to step S34, where the front derailleur is shifted from the second high gear to the first low gear.

Therefore, the first switch is the gear-reversing switch at this time. Further, the first switch is activated under a condition that the rear transmission is in any one of the first to third gear positions, and the gear position of the front transmission is switched from the second high gear position to the second low gear position. On the other hand, the first switch is activated under the condition that the rear transmission is in any one of the fourth to eleventh gear positions, and the gear position of the front transmission is switched from the second high gear position to the first low gear position.

For example, please refer to fig. 17. Fig. 17 is a plan view schematically illustrating the gear position of the front transmission being shifted from the second high gear position to the second low gear position.

In the second highest gear and the first gear, the right side of the chain guide member a is located on the dashed line L4, and the bicycle chain C connects the large plate 120 of the front chainring 100 and the first chainring 201 of the rear chainring 200. At this time, the first switch is activated, the shift position of the front derailleur is switched from the second high gear position to the second low gear position, and the right side of the chain guide member a is moved from the imaginary line L4 to the imaginary line L2, such that the bicycle chain C is connected to the small plate 110 of the front chainring 100 and the first chainring 201 of the rear chainring 200.

The foregoing is merely an example of the change made to the gear of the front transmission when the first switch is activated under conditions where the front transmission is in the second highest gear and the rear transmission is in the first gear. In other conditions, when the first switch is activated under a condition that the front derailleur is in the second high gear and the rear derailleur is in the second gear or the third gear, the gear of the front derailleur is also switched from the second high gear to the second low gear.

On the other hand, please refer to fig. 18. Fig. 18 is a plan view schematically illustrating the gear position of the front transmission being shifted from the second high gear position to the first low gear position.

In the second highest gear position of the front derailleur and the eleventh gear position of the rear derailleur, the right side of the chain guide member a is located on the dashed line L4, and the bicycle chain C connects the large plate 120 of the front chainring 100 and the eleventh chainring 211 of the rear chainring 200. At this time, the first switch is actuated, and the shift position of the front derailleur is shifted from the second high gear position to the first low gear position, moving the right side of chain guide member A from dashed line L4 to dashed line L1 such that bicycle chain C is coupled to both small plate 110 of front chainring 100 and eleventh chainring 211 of rear chainring 200.

The foregoing is merely an example of the change made to the gear position of the front transmission by the first switch being triggered under conditions where the front transmission is in the second highest gear position and the rear transmission is in the eleventh gear position. In other conditions, when the first switch is activated under a condition that the front transmission is in the second high gear and the rear transmission is in the fourth, fifth, sixth, seventh, eighth, ninth, or tenth gear, the gear of the front transmission is also switched from the second high gear to the first low gear.

If the second switch is activated in step S31, the process proceeds to step S35, where the front derailleur is fine-tuned from the second high gear to the first high gear.

That is, referring to fig. 19, fig. 19 is a plan view illustrating the front derailleur with its gear finely adjusted from the second high gear to the first high gear. If the first switch is activated with the front derailleur in the second highest gear position, the gear position of the front derailleur is finely adjusted from the second highest gear position to the first highest gear position regardless of the gear position of the rear derailleur, moving the right side of the chain guide member A from the dashed line L4 to the dashed line L3, but maintaining the bicycle chain C on the large plate 120 of the front chainring 100.

Claims

1. A bicycle speed changer fine tuning method is used for fine tuning a front speed changer according to the gear of a rear speed changer, and is characterized in that the gear of the front speed changer comprises a first low gear, a second low gear, a first high gear and a second high gear which are different, the first low gear and the second low gear correspond to a small disc of a front fluted disc of a bicycle, the first high gear and the second high gear correspond to a large disc of the front fluted disc of the bicycle, and the bicycle speed changer fine tuning method comprises the following steps:

judging the gear of the front speed changer and the triggering conditions of a first switch and a second switch;

if the front transmission is in the first low gear and the first switch is triggered, fine-tuning the front transmission from the first low gear to the second low gear;

if the front transmission is in the second low gear and the first switch is triggered, determining whether to finely adjust the front transmission from the second low gear to the first low gear according to the gear of the rear transmission;

if the front transmission is in the first low gear or the second low gear and the second switch is triggered, switching the front transmission from the first low gear or the second low gear to the first high gear or the second high gear;

if the front transmission is in the first high gear or the second high gear and the first switch is triggered, switching the front transmission from the first high gear or the second high gear to the first low gear or the second low gear;

if the front transmission is in the first high gear and the second switch is triggered, determining whether to finely adjust the front transmission from the first high gear to the second high gear according to the gear of the rear transmission; and

if the front transmission is in the second high gear and the second switch is triggered, the front transmission is finely adjusted from the second high gear to the first high gear.

2. The method of claim 1, wherein the rear derailleur is switchable between a first gear and an eleventh gear, and the front derailleur is in the second low gear and the first switch is activated, further comprising:

judging whether the rear transmission is in any one of a fourth gear to the eleventh gear;

if so, fine-adjusting the front transmission from the second low gear to the first low gear; and

if not, the front transmission is maintained at the second low gear.

3. The method of claim 1, wherein the rear derailleur is switchable between a first gear and an eleventh gear, and the front derailleur is in the first high gear and the second switch is activated, further comprising:

judging whether the rear transmission is in any one of the first gear to an eighth gear;

if so, fine-tuning the front derailleur from the first high gear to the second high gear; and

if not, the front transmission is maintained at the first high gear.

4. The method of claim 1, wherein the rear derailleur is switchable between a first gear and an eleventh gear, and the front derailleur is in the first low gear or the second low gear and the second switch is activated, further comprising:

judging whether the rear transmission is in any one of a ninth gear and an eleventh gear;

if so, switching the front transmission from the first low gear or the second low gear to the first high gear; and

if not, the front transmission is switched from the first low gear or the second low gear to the second high gear.

5. The method of claim 1, wherein the rear derailleur is switchable between a first gear and an eleventh gear, and the front derailleur is in the first high gear or the second high gear and the first switch is activated, further comprising:

judging whether the rear transmission is in any gear from the first gear to a third gear;

if so, switching the front transmission from the first high gear or the second high gear to the second low gear; and

if not, the front transmission is switched from the first high gear or the second high gear to the first low gear.