DE20111247U1 - Bicycle adjustment - Google Patents

Description

Fahtad adjustment device

The present invention relates to a bicycle adjustment device, in particular an adjustment device for adjusting the height of the front wheel suspension, the rear wheel suspension, the saddle or the handlebar stem of a bicycle, e.g. a mountain bike.

On conventional bicycles, the height of the front wheel suspension, the rear wheel suspension, the saddle or the handlebar stem cannot be changed or can only be changed with great effort.

The invention aims to provide a novel bicycle adjustment device with which the height of the front wheel suspension, the rear wheel suspension, the saddle or the handlebar stem can be easily adjusted. 25

The invention achieves the above and other objects by the subject matter of claims 1 and 2. Advantageous developments of the invention are specified in the subclaims.

If the bicycle adjustment device according to the invention is installed in a bicycle, the user of the bicycle can easily adapt the bicycle geometry to the respective conditions. For example, the height of the front and/or rear wheel suspension can be changed while the bicycle is in use.

The adjustment device according to the invention is particularly suitable for mountain bikes. For example, the front wheel can be retracted when going uphill on the mountain bike and extended again when going downhill. Alternatively, the rear wheel can also be extended when going uphill and retracted again when going downhill. 5

This means that the risk of rollover and the strain on the arms and wrists can be reduced when driving downhill, as the rider's centre of gravity is moved further back. When driving uphill, the rider's centre of gravity can be moved further forward. This improves power transmission and prevents the unpleasant and strenuous rise of the front wheel.

The present application refers to the international application PCT/EP 01/00074 of the same applicants, the disclosure of which is incorporated in its entirety by reference into this application.
15

In the following, the invention is explained in more detail using embodiments and the accompanying drawing. In the drawing:

Fig. 1 shows an adjusting device according to a first embodiment of the invention in longitudinal section;

Fig. 2a shows an adjusting device according to a second embodiment of the invention in longitudinal section;

Fig. 2b is a perspective view of the adjustment device shown in Figure 2a;

Fig. 2c is a detailed view of the upper portion of the plunger shown in Figures 2a and 2b in longitudinal section;

Fig. 3 shows an adjusting device according to a third embodiment of the invention in longitudinal section;

Fig. 4 is a detailed view of the device shown in Figures 2a, 2b, 2c and in Figure 3.
adjustment device used switch;

Fig. 5a shows an adjusting device according to a fourth embodiment of the invention in
longitudinal section;

Fig. 5b is a perspective view of the adjustment device shown in Figure 5a;

Fig. 5c is a detailed view of the upper section of the plunger shown in Figures 5a and 5b
in longitudinal section;

Fig. 6 an adjusting device according to a fourth embodiment of the invention in
Longitudinal section; and

Figure 7 is a detailed view of an alternative embodiment of a device shown in Figure
2a, 2b, 2c, and the switch usable with the adjustment device shown in Figure 3.

Fig. 1 shows an adjustment device for adjusting the height of the front wheel suspension of a bicycle according to an embodiment of the present invention. A pneumatic cylinder 30a is mounted at its lower end via a screw connection to a guide tube 37a. A tube 37b and a piston rod 32a connected to it are attached to a steering unit 7a consisting of handlebars, steering tube and (fork) bridge. A piston 31a is arranged at the lower end of the piston rod 32a and is guided in a sliding manner in the pneumatic cylinder 30a. The tube 37b and the piston rod 32a can be moved longitudinally relative to the guide tube 37a and the pneumatic cylinder 30a, i.e. in the direction of an arrow A.

The first cylinder chamber 34a, i.e. the "plus chamber", is formed by the pneumatic cylinder 30a. The second cylinder chamber 35a, i.e. the "minus chamber", is an annular cylinder chamber formed by the pneumatic cylinder 30a, the piston rod 32a and the piston 31a. The lower outer surface of the piston 31a, which delimits the first cylinder chamber 34a at the top, is larger than the annular upper outer surface of the piston 31a, which delimits the second cylinder chamber 35a at the bottom.

A through-opening is provided in the piston 31a, which connects the first cylinder chamber 34a with the second cylinder chamber 35a and which can be opened or closed by a valve. The valve is connected to an actuating device 85a, which is guided upwards through the piston 31a or the piston rod 32a up to the height of the steering unit 7a. The actuating device 85a has an actuating element 86a at the height of the steering unit or the handlebar. If this is actuated, the valve opens or closes.

When the valve is closed, a force balance is established between the "plus chamber" and the "minus chamber" on the piston 31a, with the piston 31a, the piston rod 32a and the tube 37b assuming the position shown in Figure 1 in relation to the guide tube 37a and the pneumatic cylinder 30a, for example. When the valve is opened, the "plus chamber" 34a and the "minus chamber" 35a are connected to one another so that pressure can be equalized between the chambers. The piston 31a, the piston rod 32a and the tube 37b move upwards in the direction of arrow A in relation to the guide tube 37a and the pneumatic cylinder 30a. If the valve is closed again, a force equilibrium between the "plus chamber" and the "minus chamber" is again established on the piston 31a, whereby the piston 31a, the piston rod 32a and the tube 37b assume a second position in relation to the guide tube 37a and the pneumatic cylinder 30a, which e.g.

above the position shown in Figure 1. In this position the bike is particularly suitable for downhill rides.

To ride uphill, the valve is opened again and the piston 31a, the piston rod 32a and the tube 37b are pressed downwards by the user of the bicycle in relation to the guide tube 37a and the pneumatic cylinder 30a in the direction of arrow A. This can be achieved, for example, by the user of the bicycle exerting a force on the steering unit 7a from above in the direction of arrow B. If the valve is closed again, a force equilibrium is again established on the piston 31a between the "plus chamber" 34a and the "minus chamber" 35a, with the piston 31a, the piston rod 32a and the tube 37b assuming a third position in relation to the guide tube 37a and the pneumatic cylinder 30a, which is, for example, below the position shown in Figure 1. In this position, the bicycle is particularly well suited for riding uphill.

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B · ♦···

At the lower end of the pneumatic cylinder 30a, an element 33a made of elastic material is arranged. Above this there is a float element 38a, which seals the first cylinder chamber 34a from the cylinder chamber in which the elastic element 33a is arranged.
5

2a, 2b and 2c show an adjustment device according to a further embodiment of the present invention. Referring to Figure 2b, a pneumatic cylinder 10a is connected at the lower end to a wheel suspension (not shown) on which a front wheel of a bicycle can be suspended. A piston-shaped tappet 17b is attached to a steering unit (not shown) consisting of handlebars, handlebar tube and (fork) bridge of the bicycle, the lower, wider end section 17c of which is guided in a sliding manner in the pneumatic cylinder 10a according to Figure 2a. The tappet 17b and the pneumatic cylinder 10a have a substantially circular cross-sectional contour, the outer diameter of the lower end section 17c of the tappet 17b corresponding substantially to the inner diameter of the pneumatic cylinder 10a. The plunger 17b is displaceable relative to the pneumatic cylinder 10a in the longitudinal direction, i.e. in the direction of arrow A.

The outer wall of the pneumatic cylinder 10a encloses a first cylinder chamber 14a, which forms a "plus chamber". The "plus chamber" 14a is limited at the bottom by a floating piston 19a, and at the top by the underside of the lower end section 17c of the tappet 17b. In order to seal the "plus chamber" 14a at the bottom, annular sealing elements 19c are provided on the outer wall of the floating piston 19a, which are arranged in correspondingly shaped annular grooves of the floating piston 19a. In a similar way, in order to seal the "plus chamber" 14a at the top, annular sealing elements 19b are provided on the outer wall of the lower end section 17c of the tappet 17b, which are arranged in correspondingly shaped annular grooves of the tappet 17b.

Furthermore, the outer wall of the pneumatic cylinder 10a encloses a second, annular cylinder space 15a, which forms a "minus chamber". The "minus chamber" 15a is limited downwards by the annular top of the lower end section 17c of the plunger 17b, upwards by an annular seal 17d attached to the top of the pneumatic cylinder 10a, and inwards by the outer wall of a middle, less wide section 17a of the plunger 17c. In order to seal the "minus chamber" 15a upwards,

Ring-shaped sealing elements 19b are provided on the outer and inner walls of the seal 17d, which are arranged in correspondingly shaped annular grooves of the seal 17d. The middle, less wide section 17a of the tappet 17c is guided in a sliding manner in a circular central hole of the seal 17d, and is thus displaceable in the longitudinal direction, i.e. in the direction of arrow A, relative to the seal 17d.

The area of the underside of the lower end section 17c of the tappet 17b, which delimits the first cylinder chamber 14a at the top, is larger than the area of the annular upper side of the lower end section 17c of the tappet 17b, which delimits the second cylinder chamber 15a at the bottom.

A first hydraulic line 16a runs longitudinally through the middle of the tappet 17b and is connected to the "plus chamber" 14a at the bottom. The first hydraulic line 16a has a substantially circular cross-section. A second hydraulic line 16b also runs longitudinally through the tappet 17b and is connected to the "minus chamber" 15a at the bottom, e.g. via corresponding holes. The second hydraulic line 16b has an annular cross-section and is separated from the first hydraulic line 16a by a tubular intermediate element 18.

A valve 19 is provided at the top of the tappet 17b, through which air can be pumped from the outside into the first hydraulic line 16a and into the "plus chamber" 14a. The valve 19 prevents the air from the "plus chamber" 14a and the first hydraulic line 16a from escaping to the outside again. According to Figure 2c, the first hydraulic line 16a at the top of the tappet 17b is connected via a horizontal bore 13a to a first hose 12a shown in Figure 2a, and according to Figure 2c, the second hydraulic line 16b is connected via a horizontal bore 13b to a second hose 12b shown in Figure 2a. Between the two hoses 12a, 12b, a switch 11 is provided, which fulfils the function of a valve between the hoses 12a, 12b: With the help of the switch 11, a hydraulic connection can be established between the hoses 12a, 12b, or the hose 12a can be separated hermetically from the hose 12b.

If the switch 11 is closed, i.e. the connection between the hoses 12a, 12b is separated, a force equilibrium is established at the lower end section 17c of the plunger 17b.

between the "plus chamber" 14a and the "minus chamber" 15a, whereby the tappet 17b assumes a first position in relation to the pneumatic cylinder 10a. If the switch 11 is opened, the "plus chamber" 14a and the "minus chamber" 15a are connected to one another via the first hydraulic line 16a, the first hose 12a, the second hose 12b and the second hydraulic line 16b, so that pressure equalization can take place between the chambers 14a, 15a. The tappet 17b then moves upwards in the direction of arrow A in relation to the pneumatic cylinder 10a. If the switch 11 is closed again, a balance of forces between the "plus chamber" and the "minus chamber" is again established at the lower end section 17c of the plunger 17b, whereby the plunger 17b assumes a second position in relation to the pneumatic cylinder 10a, e.g. the position shown in Figure 2a. In this position, the bicycle is particularly suitable for downhill rides.

To ride uphill, the switch 11 is opened again and the plunger 17b is pressed downwards by the user of the bicycle in relation to the pneumatic cylinder 10a in the direction of arrow A. If the switch 11 is closed again, a balance of forces between the "plus chamber" and the "minus chamber" is again established at the lower end section 17c of the plunger 17b, with the plunger 17b assuming a third position in relation to the pneumatic cylinder 10a, which is, for example, below the position shown in Figure 2a. In this position, the bicycle is particularly well suited for uphill rides.

An upper, wider end section of the floating piston 19a is guided in a sliding manner in the pneumatic cylinder 10a. In a corresponding manner, a lower end section of the floating piston 19a is guided in a sliding manner in a spacer 10b which is fastened to the lower end of the pneumatic piston 10a. The floating piston 19a is therefore displaceable in the longitudinal direction relative to the pneumatic cylinder 10a, i.e. in the direction of arrow B, and serves as a lower damping element.

The area of the upper side of the upper end section of the floating piston 19a, which delimits the first cylinder chamber 14a downwards, is larger than the area of the annular underside of the upper end section of the floating piston 19a, which delimits a lower air chamber 14b upwards.

A valve 19d is provided at the bottom of the pneumatic piston 10a, through which air can be pumped from the outside into the lower air chamber 14b. The valve 19d prevents the air from escaping from the lower air chamber 14b to the outside. In order to seal the lower air chamber 14b from below, ring-shaped sealing elements are provided on the outer wall of the spacer 10b, which are arranged in correspondingly shaped ring grooves in the spacer 10b.

At the upper end of the spacer 10b, an additional damping element is provided in the form of a ring-shaped rubber stop 19e, in the center hole of which the narrower middle section of the floating piston 19a is guided. Alternatively, the rubber stop 19e can be omitted. The sealing elements 19c are designed in such a way that a stop provided on the pneumatic cylinder 10a prevents the floating piston 19a from being displaced too far upwards.

Figure 3 shows an adjusting device according to a third embodiment of the invention. This is identical to the adjusting device explained in connection with Figures 2a, 2b, 2c, except that instead of the damping elements used there - formed by the floating piston 19a and the rubber stop 19e - several superimposed, ring-shaped elastomers 29f, 29g, 29h, 29i are used as damping elements. A spacer disk 22a, 22b, 22c is arranged between each two elastomers 29f, 29g, 29h, 29i. Each spacer disk 22a, 22b, 22c has a projection at the top and bottom, which extends into a center hole of an elastomer 29f, 29g, 29h, 29i. A float element 21 is arranged above the uppermost elastomer 29f, which seals the "plus chamber" 24a enclosed by the pneumatic cylinder 20a at the bottom

Figure 4 shows a detailed view of the switch 11 used in the adjustment device shown in Figures 2a, 2b, 2c and in Figure 3. The switch 11 is attached to the handlebars of the bicycle, for example by means of a screw. According to Figure 2a and Figure 4, the first hose 12a is connected to a first passage opening 40a and the second hose 12b to a second passage opening 40b of the switch 11. The first passage opening 40a is connected to a first, cylindrical cavity 41a which extends downwards from the top of the switch 11. In a corresponding manner, the second passage opening 40b is connected to a second, cylindrical cavity 41b. The

· ■

The two cavities 41a, 41b are connected to each other via a central cavity 41c, which tapers upwards in a stepped manner.

An upper, wider end section of a switching element 42 is slidably guided in the first cavity 41a. A middle, narrower section of the switching element 42 is slidably guided in the middle cavity 41c, and a lower, wider end section of the switching element 42 is slidably guided in the second cavity 41b. The switching element 42 is thus displaceable within the switch 11 in the longitudinal direction, i.e. in the direction of an arrow C.

In order to seal the first cavity 41a towards the top, annular sealing elements 45 are provided on the outer wall of the switching element 42, which are arranged in correspondingly shaped annular grooves of the switching element 42.

The lower outer surface of the lower, wider end section of the switching element 42, which delimits the second cavity 41b at the top, is larger than the annular upper outer surface of the lower, wider end section of the switching element 42, which delimits the first cavity 41a at the bottom. The switching element 42 is pressed upwards by the resulting pneumatic forces. In the process, an annular sealing element 44 is pressed against the annular upper outer surface of the lower, wider end section of the switching element 42, as well as against an annular lower outer surface of a step-like shoulder of the middle cavity 41c. As a result, the first cavity 41a is pneumatically separated from the second cavity 41b, and thus also the plus and minus chambers 14a, 15a shown in Figure 2a, which are connected to the respective cavities 41a, 41b.

If the switching element 42 is pressed downwards in the direction of arrow D by the user of the bicycle against the air pressure, the sealing element 44 is released so that air can flow from the first cavity 41a via the middle cavity 41c into the second cavity 41b, or vice versa. If the switching element 42 is released again by the user, it is pressed upwards again in the direction of arrow C due to the pneumatic pressure. As a result, the first cavity 41a is again pneumatically separated from the second cavity 41b, and thus also the plus and minus chambers 14a, 15a shown in Figure 2a, which are connected to the respective cavities 41a, 41b.

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: &iacgr;

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Instead of the switch 11 shown in Figure 4, the switch 111 shown in Figure 7 can also be used in the adjustment device shown in Figures 2a, 2b, 2c and in Figure 3 for pneumatic separation of the "plus chamber" and the "minus chamber". The switch 111 is attached to the handlebars of the bicycle using a screw, for example. The first hose 12a shown in Figures 2a and 4 can be connected to a first, horizontal passage opening 140a, and the second hose 12b can be connected to a second, horizontal passage opening 140b of the switch 111 according to Figure 7. The passage openings 140a, 140b are connected to a cylindrical cavity 141a that runs through the switch 111 in the longitudinal direction.

A cylindrical lower section of a switching element 142 is slidably guided in the cavity 141a. The switching element 142 is thus displaceable within the switch 111 in the longitudinal direction, i.e. in the direction of an arrow C.

In order to seal the passage openings 140a, 140b against each other, an annular sealing element 145a is provided on the outer wall of the switching element 142, which is arranged in a correspondingly shaped annular groove of the switching element 142.

In a corresponding manner, further sealing elements 145b, 145c are provided further up and further down on the switching element 142 on its outer wall, which sealing elements are also arranged in correspondingly shaped annular grooves of the switching element 142. The sealing elements 145b, 145c serve to prevent air from escaping downwards from the lower passage opening 140b via the cavity 141a, and from escaping upwards from the upper passage opening 140a via the cavity 141a.

The cavity 141b is expanded upwards in a stepped manner in an upper region of the switch 111. A spring element 146 is supported downwards on the top of the step. A switch button 147 is provided at the upper end of the switching element 142, on the underside of which the spring element 146 is supported upwards. As shown in Figure 7, the spring element 146 winds in a spiral around a likewise cylindrical section of the switching element 142. The switching element 142 is pressed upwards by the spring force.

•♦ ·

If the switching element 142 is pressed downwards in the direction of arrow D by the user of the bicycle against the spring force, the upper passage opening 140a and the lower passage opening 140b come into contact with a groove 148 cut out of the switching element 142 in a ring shape between the upper and lower sealing elements 145a, 145b. As a result, air can flow from the upper passage opening 140a via the groove 148 into the lower passage opening 140b, or vice versa. If the switching element 142 is released by the user, it is pressed upwards again in the direction of arrow C due to the spring force. As a result, the upper passage opening 140a is pneumatically separated again from the lower passage opening 140b, and thus also the plus and minus chambers 14a, 15a shown in Figure 2a which are connected to the respective passage openings 140a, 140b.

5a, 5b, 5c and 5d show an adjustment device according to a further embodiment of the present invention. Referring to Figure 5b, a pneumatic cylinder 50a is connected at the lower end to a wheel suspension (not shown) on which a front wheel of a bicycle can be suspended. A piston-shaped tappet 57b is attached to a steering unit (not shown) consisting of handlebars, steering tube and (fork) bridge of the bicycle, the lower, wider end section 57c of which is guided in a sliding manner in the pneumatic cylinder 50a according to Figure 5a. The tappet 57b and the pneumatic cylinder 50a have a substantially circular cross-sectional contour, the outer diameter of the lower end section 57c of the tappet 57b corresponding substantially to the inner diameter of the pneumatic cylinder 50a. The plunger 57b is displaceable relative to the pneumatic cylinder 50a in the longitudinal direction, i.e. in the direction of arrow A.

The outer wall of the pneumatic cylinder 50a encloses a first cylinder chamber 54a, which forms a "plus chamber". The "plus chamber" 54a is sealed at the bottom by a float element 61. For this purpose, an annular sealing element is provided on the outer wall of the float element 61, which is arranged in a correspondingly shaped annular groove of the float element 61.

In the adjusting device shown in Figures 5a, 5b, 5c, 5d, as in the adjusting device shown in Figure 3, the pneumatic cylinder 50a is provided with

element 61 has several ring-shaped elastomers 69f, 69g, 69h, 69i arranged one above the other, which function as damping elements. Between each two elastomers 69f, 69g, 69h, 69i there is a spacer disk 62a, 62b, 62c. Each spacer disk 62a, 62b, 62c has a projection at the top and bottom, which extends into a center hole of an elastomer 69f, 69g, 69h, 69i.

The "plus chamber" 54a is limited at the top by the underside of the lower end section 57c of the tappet 57b. To seal the "plus chamber" 54a at the top, ring-shaped sealing elements 59b are provided on the outer wall of the lower end section 57c of the tappet 57b, which are arranged in correspondingly shaped annular grooves of the tappet 57b.

Furthermore, the outer wall of the pneumatic cylinder 50a encloses a second, annular cylinder space 55a, which forms a "minus chamber". The "minus chamber" 55a is limited downwards by the top of the lower end section 57c of the tappet 57b, upwards by an annular seal 57d attached to the top of the pneumatic cylinder 50a, and inwards by the outer wall of a middle, less wide section 57a of the tappet 57c. In order to seal the "minus chamber" 55a upwards, annular sealing elements 59b are provided on the outer and inner walls of the seal 57d, which are arranged in correspondingly shaped annular grooves of the seal 57d. The middle, less wide portion 57a of the tappet 57c is slidably guided in a circular center hole of the seal 57d, and is thus displaceable in the longitudinal direction, i.e. in the direction of arrow A, relative to the seal 57d.

The area of the underside of the lower end portion 57c of the tappet 57b, which delimits the first cylinder space 54a at the top, is larger than the upwardly directed surfaces of the lower end portion 57c of the tappet 57b, which delimit the second cylinder space 55a at the bottom.

An elongated cavity 56b runs longitudinally through the center of the tappet 57b. The cavity 56b has a substantially ring-shaped cross-section. A hydraulic pipe 56a is arranged in the cavity 56b in a longitudinally displaceable manner and is connected at the bottom to the "plus chamber" 54a.

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According to Figure 5c, a valve 59 is provided at the top of the hydraulic pipe 56a, through which air can be pumped from the outside into the hydraulic pipe 56a and into the "plus chamber" 54a. The valve 59 prevents the air from the "plus chamber" 54a and the hydraulic pipe 56a from escaping to the outside again.

According to Figure 5d, a lower, wider end section of the hydraulic pipe 56a fulfills the function of a valve: As shown in Figure 5d, the outer surface of the lower, wider end section of the hydraulic pipe 56a is tapered towards the top (here: in the form of a cone). Accordingly, the inner surface of the cavity 56b in the region of the lower, wider end section 57c of the tappet 57b is also tapered towards the top (here: provided with a step).

The pneumatic forces acting on the lower outer surface of the hydraulic pipe 56a push the hydraulic pipe 56a upwards in the direction of an arrow C. In doing so, an annular sealing element 59b is pressed against the conical upper outer surface of the lower, wider end section of the hydraulic pipe 56a, as well as against the annular lower inner surface of the step provided on the lower, wider end section 57c of the tappet 57b. This pneumatically separates the "plus chamber" 54a from the "minus chamber" 55a.

If the hydraulic pipe 56a is pressed downwards in the direction of arrow B against the air pressure by the user of the bicycle as shown in Figure 5c, the sealing element 59b is released as shown in Figure 5d so that air can flow from the "plus chamber" 54a into the "minus chamber" 55a, or vice versa. If the hydraulic pipe 56a is released again by the user, it is pressed upwards again in the direction of arrow C due to the pneumatic pressure as shown in Figure 5d. This causes the "plus chamber" 54a to be pneumatically separated from the "minus chamber" 55a again.

If this is the case, a force equilibrium is established between the "plus chamber" 54a and the "minus chamber" 55a at the lower end section 57c of the plunger 57b, with the plunger 57b assuming a first position, e.g. the position shown in Figure 5a, in relation to the pneumatic cylinder 50a.

If the "plus chamber" 54a and the "minus chamber" 55a are hydraulically connected to one another as described above, pressure equalization can take place between the chambers 54a, 55a. The tappet 57b then moves upwards in the direction of arrow A in relation to the pneumatic cylinder 50a. In order to prevent the tappet 50a from being displaced too far upwards, or to prevent the top of the lower end section 57c of the tappet 57b from striking the seal 57d, a damping element 63 is attached to the tappet 57b above the lower end section 57c of the tappet 57b, which runs in a ring around the middle section of the tappet. The outer diameter of the damping element 63 is smaller than the inner diameter of the pneumatic cylinder 50a.

If the "plus chamber" 54a and the "minus chamber" 55a are separated again, a balance of forces is again established between the "plus chamber" 54a and the "minus chamber" 55a at the lower end section 57c of the tappet 57b, whereby the tappet 57b assumes a second position in relation to the pneumatic cylinder 50a, which is above the position shown in Figure 5a. In this position, the bicycle is particularly suitable for downhill rides.

For uphill riding, a connection is again established between the "plus chamber" 54a and the "minus chamber" 55a, and the plunger 57b is pressed downwards by the user of the bicycle in relation to the pneumatic cylinder 50a in the direction of arrow A.

If the connection between the "plus chamber" 54a and the "minus chamber" 55a is separated again, a force balance is again established between the "plus chamber" 54a and the "minus chamber" 54b at the lower end section 57c of the tappet 57b, with the tappet 57b assuming a third position in relation to the pneumatic cylinder 50a, which is, for example, below the position shown in Figure 5a. In this position, the bicycle is particularly suitable for uphill rides.

In an alternative embodiment, instead of the adjustment device shown in Figures 5a, 5b, 5c, 5d, the lower damping elements (ie the elastomers 69f, 69g,
69h, 69i) as a damping element, for example, an elastomer arranged around the less wide section 57a of the tappet 57c and attached to the tappet 57c can also be used (or, for example, a spring arranged around the less wide section 57a of the tappet 57c). By

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the stop of the elastomer or spring at the upper end section of the pneumatic cylinder
50a prevents excessive downward displacement of the plunger 57b.
Alternatively or additionally, below the pneumatic cylinder 50a or the cartridge
a spring must be arranged. This means that the cartridge "stands" on the wheel suspension or on the bottom of the fork, ie it is spring-mounted.

Figure 6 shows an adjustment device according to a further embodiment of the invention. This is identical to the adjustment device explained in connection with Figures 5a, 5b, 5c, 5d, except that instead of the lower damping elements used there (i.e. the elastomers 69f, 69g, 69h, 69i), a floating piston 69a and a rubber stop 69e are used as damping elements (as well as a spacer 69b and a valve 69d). The floating piston 69a, the rubber stop 69e, the spacer 69b and the valve 69d are identical in function and structure to the function and structure of the corresponding components explained in connection with Figure 2a.

Claims (11)

1. Bicycle adjustment device, in particular for adjusting the height of the front wheel suspension, the rear wheel suspension, the saddle or the handlebar stem, the adjustment device having a double-acting piston/cylinder arrangement with a first cylinder chamber ( 14a , 34a ) and a second cylinder chamber ( 15a , 35a ), characterized in that the two cylinder chambers ( 14a , 34a ; 15a , 35a ) can be connected to one another via a fluid channel ( 16a , 16b , 12a , 12b ). 2. Bicycle adjustment device, in particular for adjusting the height of the front wheel suspension, the rear wheel suspension, the saddle or the handlebar stem, the adjustment device having a double-acting piston/cylinder arrangement with a first cylinder chamber ( 14a , 34a ) and a second cylinder chamber ( 15a , 35a ) which are separated from one another by a piston, the area of the piston delimiting the first cylinder chamber ( 14a , 34a ) being larger than the area of the piston delimiting the second cylinder chamber ( 15a , 35a ), characterized in that a locking device ( 85a , 11 ) is provided for locking the piston. 3. Bicycle adjustment device according to claim 1, wherein the fluid channel ( 16 a, 16 b, 12 a, 12 b) can be shut off by means of a shut-off device ( 42 ). 4. Bicycle adjustment device according to claim 3, wherein the shut-off device ( 42 ) can be actuated by an actuating element. 5. Bicycle adjustment device according to claim 1, 3 or 4, in which the cylinder chambers ( 14 a, 34 a) are separated from one another by a piston, and in which the fluid channel is led directly from the surface of the piston delimiting the first cylinder chamber ( 14 a, 34 a) through the piston to the surface of the piston delimiting the second cylinder chamber ( 15 a, 35 a). 6. Bicycle adjustment device according to claim 5, wherein the shut-off device is arranged in the piston. 7. Bicycle adjustment device according to claim 1, 3 or 4, in which the cylinder chambers ( 14 a, 34 a) are separated from one another by a piston, and in which the fluid channel is guided from the surface of the piston delimiting the first cylinder chamber ( 14 a, 34 a) through the piston and the second cylinder chamber ( 15 a, 35 a) to an area lying outside the cylinder chambers. 8. Bicycle adjustment device according to claim 7, in which the shut-off element ( 42 ) is arranged in the area lying outside the cylinder spaces. 9. Bicycle adjustment device according to one of claims 3 to 8, in which the shut-off element ( 42 ) is held by means of air pressure in a position in which the fluid channel ( 16 a, 16 b, 12 a, 12 b) is blocked. 10. Bicycle adjustment device according to claim 9, wherein the shut-off element ( 42 ) has a piston, wherein in the blocking position of the shut-off element ( 42 ) a first outer surface of the piston is connected to the first cylinder chamber ( 14a , 34a ), and a second outer surface of the piston is connected to the second cylinder chamber ( 15a , 35a ), and wherein the first outer surface of the piston is larger than the second outer surface. 11. Bicycle having an adjustment device according to one of claims 1 to 10.