Device and method for changing center of gravity of bicycle according to situation

Abstract

The invention relates to a device and a method for changing the center of gravity of a bicycle according to situations. The invention relates to a device (1) for changing the center of gravity of a bicycle, in particular an electric bicycle, in order to adapt to the situation, comprising: an actuator (2) for changing the center of gravity of the bicycle; the at least one sensor is used for monitoring the riding state of the bicycle; and a control unit which receives and processes data from the sensor, determines the center of gravity of the bicycle adapted to the situation, and outputs a corresponding control signal to the actuator in order to perform a change in the center of gravity. According to the invention, the adjustment speed of the change of the center of gravity can be adapted to the riding state of the bicycle. The invention also relates to a system for changing the center of gravity of a bicycle to accommodate the situation and to a bicycle. The invention further relates to a method for changing the center of gravity of a bicycle in order to adapt the situation.

Description

Technical Field

[0001] The present invention relates to a device for changing the center of gravity of a bicycle, especially an electric bicycle, in an adaptive manner. The device has an actuator for changing the center of gravity, at least one sensor for monitoring the riding condition of the bicycle, and a control unit. The control unit receives and processes data from the sensor, determines the center of gravity of the bicycle in an adaptive manner, and outputs a corresponding control signal to the actuator to execute the change of the center of gravity. Background Art

[0002] The increasing demands in road traffic lead to an increasing need for safety measures, especially for riders. Due to the high center of gravity of bicycles, which is further increased by the rider, critical riding situations can occur, for example when braking. For e-bikes, this problem is exacerbated by the significantly higher speeds. At the same time, the demands on comfort are also increasing, especially as e-bikes are entering the field of vision of other or more targeted riders.

[0003] Thus, devices and methods for changing the center of gravity of an electric bicycle to adapt to the situation are known from the prior art. However, there is a need to further improve the known devices and methods. Summary of the invention

[0004] Therefore, the object of the present invention is to provide a device, a system, a bicycle and a method for changing the center of gravity of a bicycle according to the situation, which further improves the safety of the rider.

[0005] The invention provides a device according to claim 1 which achieves this technical object. This object is also achieved by a system according to claim 16, a bicycle according to claim 17 and a method according to claim 18. Advantageous embodiments are the subject of the dependent claims.

[0006] In particular, the task is achieved by a device for adaptively changing the center of gravity of a bicycle, in particular an electric bicycle, which device has an actuator for changing the center of gravity, at least one sensor for monitoring the riding condition of the bicycle, and a control unit, which receives and processes data from the sensor, determines the center of gravity of the bicycle adapted to the situation and outputs a corresponding control signal to the actuator in order to execute the change of the center of gravity.

[0007] According to the invention, the adjustment speed of the change of the center of gravity can be adapted to the riding state of the bicycle. In particular in critical riding situations, it is advantageous if the center of gravity of the bicycle is changed as quickly as possible to increase the safety of the rider. For example, if, for example, ABS sensors detect safety-critical braking or a critical tilt of the bicycle, it is advantageous to quickly lower the center of gravity.

[0008] At this point it should be noted that in the context of the present invention, the riding situation is understood not only as a riding operation, but also as a stationary operation of the bicycle. The generic term bicycle also includes single-track human-powered bicycles, electric bicycles or power-assisted bicycles, as well as multi-track cargo or transport bicycles or cargo bicycles (human-powered or with electric drive).

[0009] Preferably, the actuator is used to change the center of gravity by adjusting the height of the seat post of the bicycle.

[0010] Lowering the seat post also allows the rider to plant his feet firmly on the ground. On the other hand, in non-critical riding modes, a more ergonomic seating position is possible. These positions can be approached automatically according to the appropriate presets.

[0011] According to an advantageous embodiment of the invention, the actuator can have at least one drive unit and a transmission unit driven by the drive unit. The drive unit can be operated simply by means of an energy storage device, for example.

[0012] Different adjustment speeds of the seat post can be achieved in a simple manner, wherein the transmission unit has a shiftable transmission with at least two different transmission ratios, wherein the transmission ratio of the transmission unit can be selected depending on the riding conditions of the bicycle, so that the adjustment speed of the seat post in the lowering and lifting direction is adapted to the riding conditions of the bicycle.

[0013] An advantageous design can be achieved if the transmission unit has a freewheel that depends on the direction of rotation in order to adapt the transmission ratio to the riding situation of the bicycle. The freewheel can be used, for example, to lock a gear stage in one direction of rotation and to release it in the opposite direction, so that the full transmission ratio of the gear unit is available in the lifting direction and only a lower partial transmission ratio is available in the lowering direction. As a result, the adjustment speed in the lowering direction can be greatly increased.

[0014] For example, an electric motor may be used as the drive unit, and a single-stage or multi-stage planetary gear may be used as the transmission.

[0015] An alternative advantageous embodiment of the invention provides for adapting the adjustment speed of the seat post to the riding conditions of the bicycle by means of a suitable design of the transmission unit and / or the motor characteristic curve in the lowering and raising direction.

[0016] Furthermore, a force compensation element can advantageously be provided, which supports the extension movement of the seat post in the lifting direction. A spring bellows which can be pressurized can be provided as a force compensation element, which supports the extension movement of the seat post in the lifting direction. If the seat post has an additional spring component, the bellows can also advantageously be designed as a pressure accumulator for the spring component.

[0017] Alternatively, it is conceivable to provide a gas spring element as the force compensation element.

[0018] In an advantageous improvement of the present invention, the actuator can be designed as an electric spindle drive and comprises: a drive arrangement arranged in a housing, the drive arrangement having a drive unit and a transmission unit driven by the drive unit; a spindle rotatably driven by the drive unit around a rotation axis, the spindle being threadedly engaged with a spindle nut so that the spindle nut is non-rotatably displaceable in an axial direction within the housing; and a seat tube as an adjusting element for adjusting the height of the seat post, the seat tube being displaceable relative to the drive arrangement along a displacement axis by means of the drive unit.

[0019] Here, the spindle nut can be connected to the adjustment element in a form-fitting manner in such a way that the connection can absorb forces in the pressure direction. The form fit can be easily achieved by means of a clamping connection, wherein the spindle nut can be manufactured cost-effectively.

[0020] In order to improve riding comfort, according to an advantageous embodiment of the invention, a seat post with a seat suspension is provided. Examples include a parallelogram suspension seat post, which can be adapted using, for example, replacement spring elements.

[0021] Preferably, a gas-dynamic strut can be provided for adjusting the seat suspension, wherein an axially adjustable adjusting element for the gas-dynamic strut has a pressure chamber which can be variably filled with gas by means of a valve.

[0022] The mechanical seat suspension can be adjusted as required using the gas force in the pressure chamber. The valve enables the suspension to be easily adjusted at any time without removing the seat post. At the same time, the mechanical structure is better and permanently protected from external influences such as weather, rain, dust, etc., since no replacement is required to change the suspension and the suspension no longer needs to be easily disassembled. Individual adjustment of the suspension can only be performed by means of the valve.

[0023] The pressure chamber can be limited on the side facing the seat suspension by a plunger arranged in the seat tube so as to be axially displaceable depending on the gas volume in the pressure chamber, wherein a tappet arranged on the plunger is operatively connected to the mechanical seat suspension in such a way that an axial displacement of the plunger causes a change in the seat suspension. If the mechanical seat suspension is designed as a parallelogram spring unit with articulated side and support parts and a spring element, the spring force can be adjusted as required by adjusting the joint. For example, the spring element can be a mechanical helical compression spring or a deformable elastomer element. As already mentioned, it is no longer necessary to replace the spring element to adjust the suspension, and the spring element and the joint can be better and permanently protected from external influences.

[0024] According to a further advantageous embodiment of the invention, the sensor can be designed as a proximity switch which is designed to scan the contour of a brake disc of the bicycle.

[0025] The brake disk can have a cam for a positive connection with the carrier, and the cam can be scanned by means of the proximity switch. This enables a very fine signal resolution without the need for additional sensor elements. At the same time, the proximity switch and the brake disk provide a robust and cost-effective system to implement.

[0026] The object is also achieved by a system for adaptively varying the center of gravity of a bicycle, in particular an electric bicycle, having one of the above-described devices according to the invention and having an electrically operable main stand and / or a semi-automatic or fully automatic handbrake.

[0027] Furthermore, the object is achieved by a bicycle having the above-described device according to the invention or having the above-described system according to the invention.

[0028] A further aspect of the invention relates to a method for changing the center of gravity of a bicycle, in particular an electric bicycle, to adapt to the situation, the method comprising the following steps:

[0029] Capturing sensor data that depicts the riding state of the bicycle,

[0030] Evaluate sensor data and determine the center of gravity of the bicycle's adaptation situation,

[0031] generating a control signal for changing the center of gravity of the bicycle,

[0032] Outputting control signals to actuators to perform changes in the center of gravity,

[0033] Adjust the speed of the center of gravity change according to the riding conditions of the bicycle.

[0034] Preferably, the center of gravity is changed by adjusting the height of the seat post of the bicycle using an actuator. Advantageously, the height adjustment of the seat post is faster in a descending direction than in a raising direction, which can alleviate critical riding situations.

[0035] In a preferred embodiment, the center of gravity can be changed by means of a device as described above.

[0036] The present invention will be described below with reference to several embodiments. Identical or similar parts are marked with the same reference numerals. The drawings, the specification and the claims contain many combinations of features. Those skilled in the art will also advantageously consider these features individually and combine them into other advantageous combinations. Therefore, single or multiple embodiments can be advantageously combined with each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In the attached picture:

[0038] Figure 1A schematic diagram showing an actuator of a device for changing the center of gravity of a bicycle to adapt to the situation according to the present invention;

[0039] Figure 2 Shows Figure 1 A cross section of the actuator is shown;

[0040] Figure 3 shows a side view of an embodiment of the device according to the invention without a transmission unit for an actuator with a spring-loaded seat suspension;

[0041] Figure 4 Shown according to Figure 3 a side view of a device without a gear unit having an actuator with a spring-type seat suspension;

[0042] Figure 5 Shows Figure 4 A cross section of the device shown;

[0043] Figure 6 Shows Figure 5 An enlarged section Q of the cross section shown;

[0044] Figure 7 shows a cross section of another embodiment of a device according to the invention;

[0045] Figure 8 Shows Figure 7 The enlarged cross section Q of the cross section shown, and

[0046] Fig. 9 Shows Figure 7 An enlarged section R of the cross section is shown. DETAILED DESCRIPTION

[0047] Figure 1 An actuator 2 of a device 1 for changing the center of gravity of a bicycle to adapt to the situation is shown. In the context of the present invention, the bicycle may be a single track human-powered bicycle, an electric bicycle or an electrically assisted bicycle or a multi-track loading, transport or cargo bicycle (human-powered or with electric drive).

[0048] In order to improve the safety of a bicycle, a device 1 for changing the center of gravity of a bicycle to adapt to the situation according to the present invention includes an actuator 2 for changing the center of gravity, at least one sensor for monitoring the riding condition of the bicycle, and a control unit, which receives and processes data from the sensor, determines the center of gravity of the bicycle to adapt to the situation and outputs a corresponding control signal to the actuator to execute the change of the center of gravity.

[0049] For example, the speed signal can be generated by scanning the profile of the brake disk. For this purpose, one or more proximity switches can be used, by means of which the spiral arms of the brake disk are scanned.

[0050] Alternatively, a brake disc made of steel, arranged coaxially on a support made of, for example, aluminum, can have inwardly pointing, preferably eighteen cams for a positive connection with the support. These can be scanned with a suitable sensor, such as a proximity switch, to generate a signal for the bicycle speed. Thus, no additional sensor element may be required.

[0051] The adjustment speed of the center of gravity change is adapted to the riding situation of the bicycle so that the center of gravity of the bicycle can be changed as quickly as possible, especially in critical riding situations. For example, if safety-critical braking is detected, for example by ABS sensors, or a safety-critical tilt of the bicycle is detected by suitable sensors, it is advantageous to quickly lower the center of gravity.

[0052] In the described embodiment example, the center of gravity is changed by adjusting the height of the seat post 12 of the bicycle, but it is not limited thereto. The height can be automatically adjusted according to the riding position of the bicycle. It is also conceivable that the height adjustment is additionally controlled by the rider.

[0053] Lowering the seat post 12 also allows the rider to stand firmly on the ground with both feet. On the other hand, in non-critical riding modes, a more ergonomic seating position can be achieved. These positions can be approached automatically according to appropriate presets.

[0054] The actuator 2 has at least one drive unit 3 and a transmission unit 4 driven by the drive unit 3, wherein for example an electric motor is used as the drive unit and a single-stage or multi-stage planetary gear is used as the transmission. On a bicycle with an electric drive, the drive unit 3 can be operated using the battery of the electric drive.

[0055] According to the design example shown, the actuator 2 can be designed as an electric spindle drive.

[0056] As shown in particular from the cross section Figure 2 As can be seen in the figure, the actuator 2 comprises a drive arrangement arranged in a housing 5 having a drive unit 3 and a gear unit 4 driven by the drive unit 3, a spindle 6 which can be rotationally driven by the drive unit 3 around a rotation axis and is threadedly engaged with a spindle nut 7. The spindle nut 7 is arranged so that it can move in the axial direction within the housing 5 or a profiled tube 8 arranged in the housing 5. In addition, the actuator 2 has a seat tube 9 which is designed as an adjustment element for adjusting the height of a seat rod 12 which can be displaced relative to the drive arrangement along a displacement axis by means of the drive unit 3.

[0057] The profiled tube 8 can preferably be made of plastic and allows internal torque support of an axially displaceable spindle nut 7, which is connected to the seat tube 9 in such a way that the connection can absorb forces in the pressure direction. A simple clamping connection is conceivable. For this purpose, the spindle nut 7 can have elastic spring arms, which can be clamped in recesses of the profiled tube 8. The spindle nut 7 can also be connected directly to the seat tube 9 via a corresponding connection.

[0058] The profiled tube 8 has one or more nose-shaped protrusions 10 on its outside, which engage in complementary recesses 11 of the housing 5 to prevent rotation or transmit torque. Furthermore, an additional torque-transmitting connection can be achieved by partial deformation of the housing 5, wherein the material of the housing 5 is pressed into the material of the profiled tube 8. This connection also allows sealing between the profiled tube 8 and the housing 5.

[0059] In the present embodiment, the housing 5 forms a fixed part of a seat post that can be attached to the frame of a bicycle. On the other hand, the adjustment element 9 forms a height-adjustable part of the seat post 12, to which the seat 19 of the bicycle can be attached. When a change in the center of gravity of the bicycle is detected as being advantageous, the drive unit 3 is activated by the control unit and the seat post 9 is correspondingly moved in the axial direction along the displacement axis so that a change in the center of gravity can be achieved by adjusting the height of the bicycle seat post.

[0060] The seat post height adjusts faster in the descending direction than in the raising direction, which can significantly alleviate critical riding situations.

[0061] Different adjustment speeds of the seat post 12 can be adapted to the riding conditions of the bicycle, for example by suitable design of the gear unit and / or the motor characteristic curve in the lowering and lifting direction.

[0062] An alternative embodiment provides a transmission unit which is designed as a shiftable transmission with at least two different transmission ratios, wherein the transmission ratio of the transmission unit can be selected according to the riding conditions of the bicycle so that the adjustment speed of the seat post 12 in the lowering and lifting directions is adapted to the riding conditions of the bicycle.

[0063] In order to adapt the transmission ratio to the riding situation of the bicycle, the transmission unit can have, for example, a freewheel that depends on the direction of rotation. By means of the freewheel, the gear stage can be locked in one direction of rotation and released in the opposite direction, so that the full transmission ratio of the gear unit is available in the lifting direction and only a lower partial transmission ratio is available in the lowering direction. As a result, the adjustment speed in the lowering direction can be greatly increased.

[0064] It is also conceivable to design the device with a force compensation element, which supports the extension movement of the seat post 12 in the lifting direction. A spring bellows that can be pressurized can be provided as a force compensation element, which supports the extension movement of the seat post in the lifting direction. If the seat post 12 has an additional spring component, the bellows can also advantageously be designed as a pressure accumulator for the spring component. It is also conceivable to provide a gas spring element as a force compensation element.

[0065] The device described may be combined with an electric kickstand and / or semi-automatic or fully automatic brakes as part of a system for changing the center of gravity of a bicycle to adapt to the conditions.

[0066] The device 1 may also include Figure 3 A mechanical seat suspension 13 is shown, wherein a seat tube 9 is connected to the seat suspension 13. The mechanical seat suspension 13 can be designed as a parallelogram spring seat post with articulated side parts and support members 14, 15, 16, 17 and a spring element 18. Here, the seat tube 9 is connected to a first support member 16 and the seat 19 of the bicycle is connected to an opposite second support member 17, wherein the side members 14, 15 are each articulated to the support members 16, 17 to form a parallelogram. The spring element 18, designed for example as a mechanical helical compression spring, is known to be arranged between two of the parallelogram members 14 to 17 to provide suspension. The seat suspension 13 is connected to the seat tube 9 by means of the first support member 16 or by means of a connecting member 20 mounted on the first support member 16.

[0067] Figure 3 The seat suspension 4 is shown in a deflected state, with a maximum distance between the two support parts 16, 17. Figure 4 In the compressed state shown, the spring element 19 is compressed so that the distance between the support parts 16 , 17 is reduced.

[0068] The mechanical seat suspension 13 can be designed with minimum spring force because the device 1 provides a gas powered strut as described below. The gas powered strut is parallel to the seat suspension, which allows the total suspension force to be adjusted.

[0069] Figure 5 Shows Figure 3 and Figure 4 A cross section of the device 1 is shown. As can be seen, the actuator is designed as an electric spindle drive, the spindle 6 of which is arranged in the seat tube 9.

[0070] For gas powered suspension, a pressure chamber 22 is provided in the seat tube 9, which can be variably filled with gas or air by means of a valve 23. The mechanical seat suspension can be adjusted as required by the gas force in the pressure chamber 22. The suspension can be easily adjusted at any time using an air pump via the valve 23 without removing the seat post.

[0071] On the side facing the seat suspension 13 , the pressure chamber 22 is delimited by a plunger 24 which is arranged axially displaceably in the seat tube 9 .

[0072] The plunger 24 is guided in a sealed manner in the seat tube 9 and has a tappet 25 which also extends in a sealed manner through a recess in the connecting part 20. Figure 5 As can be seen in FIG. 1 , the free end of the tappet 25 projects from the connecting member 20 and is operatively connected to the mechanical seat suspension 13 via the cam 26 , so that an axial displacement of the plunger 24 causes a change in the seat suspension by adjusting the parallelogram members 14 to 17 .

[0073] On the actuator side, the pressure chamber 22 is defined by a sealing separating piston 27 which can be axially displaced in the seat tube 9 by means of the spindle 6. The sealing is achieved, for example, by an O-ring 28 positioned in an annular groove of the separating piston 27. In this embodiment, the spindle end 29 facing away from the actuator is in rotatable contact with the separating piston 27 or a projection 30 of the separating piston 27 in order to minimize friction. Figure 6 As can be seen in FIG. 1 , a projection 30 is arranged at the bottom of a recess 31 of the separating piston 27, so that additional guidance of the spindle end 29 is possible. Here, the pressure chamber 22 is also delimited on the side facing the seat suspension 13 by a plunger 24, which is axially displaceable in the seat tube 9 and whose entire plunger surface is active. This allows relatively high adjustment forces to be generated on the tappet 25.

[0074] Due to the presence of gas in the pressure chamber 22, the separating piston 27 remains in contact with the spindle 6 and is displaced in the seat tube 9 according to the adjustment movement. The gas pressure can thus act on the entire separating piston surface, which supports the extension force of the actuator in addition to the spring force of the seat suspension 13.

[0075] In this embodiment, the size of the pressure chamber 22 depends on the stroke, so that the gas dynamic support can be adjusted according to the stroke.

[0076] Figures 7 to 9 Additional embodiments are shown. Figure 7 A cross section PP is shown of another embodiment of the device 1 . As can be seen, the actuator 2 is designed as an electric spindle drive, the spindle 6 of which is arranged in the seat tube 9 .

[0077] The spindle 6 is driven in rotation about the axis of rotation by a drive unit of a drive arrangement not shown and is threadedly engaged with a spindle nut 7 not shown. The spindle nut 7 itself is provided for axial displacement within the housing 5 and is non-rotatably connected to a seat post 9 which is displaceable along an adjustment axis for adjusting the height of the seat post 12 relative to the drive arrangement by means of the actuator 2.

[0078] The connection between the spindle nut 7 and the seat tube 9 is designed in such a way that it can absorb forces in the pressure direction. For this purpose, an easily manufactured clamping connection can be envisaged, in which the spindle nut 7 has elastic spring arms that can be clamped in recesses in the seat tube 9.

[0079] In the present embodiment, the housing, not shown, forms a fixed part of a seat post 12 which can be attached to the frame of a bicycle.

[0080] For gas powered suspension, a pressure chamber 22 is provided in the seat tube 9, which can be variably filled with air by means of a valve 13. The mechanical seat suspension 13 can be adjusted as required by the gas force in the pressure chamber 22. The suspension can be easily adjusted at any time using an air pump via the valve 23 without removing the seat post 12.

[0081] On the side facing the seat suspension 13 , the pressure chamber 22 is delimited by a plunger 24 which is arranged axially displaceably in the seat tube 9 .

[0082] The plunger 24 is guided in a sealed manner in the seat tube 9 and has a tappet 25 which also extends in a sealed manner through a recess in the connecting part 20. Figure 7 As can be seen in FIG. 1 , the free end of the tappet 25 projects from the connecting member 20 and is operatively connected to the mechanical seat suspension 13 via the cam 26 , so that an axial displacement of the plunger 24 causes a change in the seat suspension by adjusting the parallelogram members 14 to 17 .

[0083] On the actuator side, Figures 7 to 9 The pressure chamber in the embodiment shown is defined by a separator tube 32 which at least partially surrounds the spindle 6 and protrudes into the seat tube 5. The separator tube 32 is essentially pot-shaped and bears closely against the seat tube 9 with a separator tube end 33 which is widened in cross section. For this purpose, the seat tube 9 has a shoulder 34 pointing radially inwards, which can be formed, for example, by shaping the seat tube material. In order to seal the separator tube end 33 relative to the seat tube 9, a gasket 35 with a radially extending sealing element 36 can also be arranged between the separator tube end 33 and the shoulder 34.

[0084] This gas dynamic support of this embodiment is independent of the stroke, since when the actuator is actuated, ie when the seat tube 9 is adjusted, the separating tube 32 moves together with the seat tube 9 along the adjustment axis.

[0085] From the shown Figure 7 The enlarged cross section Q Figure 8As can be seen in FIG. 3 , the separator tube 32 is guided with its other end 37 in a guide element 38 in the seat tube 9, wherein the guide element 38 has an axially extending recess 39 on its outer side. Through the recess 39, the air fed into the pressure chamber 22 via the valve 23 can also enter the annular space 40, which the separator tube 32 forms together with the seat tube 9. The pressure chamber 22 thus extends from the plunger 24 to the separator tube end 33, thereby providing a large pressure volume and a flat gas force characteristic curve.

Claims

1. A device (1) for changing the center of gravity of a bicycle, in particular an electric bicycle, to adapt to the situation, the device comprising: an actuator (2) for changing the center of gravity of the bicycle, at least one sensor, the at least one sensor monitoring a riding state of the bicycle, a control unit which receives and processes the data from the sensor, determines the center of gravity of the bicycle adapted to the situation and outputs a corresponding control signal to the actuator (2) in order to implement the change of the center of gravity, It is characterized in that The adjustment speed of the center of gravity change can be adapted to the riding conditions of the bicycle.

2. The device (1) according to claim 1, characterized in that The change of the center of gravity is achieved by adjusting the height of the seat post (12) of the bicycle with the aid of the actuator (2).

3. The device (1) according to claim 2, characterized in that The actuator (2) has at least one drive unit (3) and a transmission unit (4) driven by the drive unit.

4. The device (1) according to claim 3, characterized in that The transmission unit (4) has a shiftable transmission device with at least two different transmission ratios, wherein the transmission ratio of the transmission unit can be selected according to the riding state of the bicycle, so that the adjustment speed of the seat post (12) in the lowering and lifting directions is adapted to the riding state of the bicycle.

5. The device (1) according to claim 4, characterized in that The transmission unit (4) has a freewheel that depends on the direction of rotation in order to adapt the transmission ratio to the riding condition of the bicycle.

6. Device (1) according to any one of the preceding claims 3 to 5, characterized in that The adjustment speed of the seat post (12) is arranged to be adapted to the riding conditions of the bicycle by means of a suitable design of the transmission unit (4) and / or motor characteristics in the lowering and lifting directions.

7. Device (1) according to any one of the preceding claims 2 to 6, characterized in that A force compensation element is provided, which supports the extension movement of the seat post (12) in the lifting direction.

8. The device (1) according to claim 7, characterized in that A spring bellows capable of withstanding pressure is provided as a force compensation element, and the spring bellows supports the extension movement of the seat rod (12) in the lifting direction.

9. The device (1) according to claim 8, characterized in that The seat post (12) has an additional spring component, wherein the spring bellows is designed as a pressure accumulator for the spring component.

10. The device (1) according to claim 7, characterized in that A gas spring element is provided as a force compensation element, which supports the extension movement of the seat rod (12) in the lifting direction.

11. Device (1) according to any one of the preceding claims 3 to 10, characterized in that The actuator (2) is designed as an electric spindle drive, which comprises: A drive arrangement, which is arranged in a housing (5), and has a drive unit (3) and a transmission unit (4) driven by the drive unit (3), a spindle (6) which can be rotationally driven by the drive unit (3) about a rotation axis and which is threadedly engaged with a spindle nut (7) in such a way that the spindle nut (7) can be displaced in the axial direction in a rotationally fixed manner within the housing (5), A seat tube (9) is provided as an adjustment element (9) for adjusting the height of the seat post (12), the seat tube being displaceable relative to the drive arrangement along a displacement axis by means of the drive unit (3).

12. The device (1) according to claim 11, characterized in that The spindle nut (7) is connected to the adjustment element (9) in a form-fitting manner in such a way that the connection is able to absorb forces in the pressure direction.

13. Device (1) according to any one of the preceding claims 2 to 12, characterized in that The seat post (12) has a seat suspension (13).

14. The device (1) according to claim 13, characterized in that A gas-dynamic strut is provided for adjusting the seat suspension (13), wherein an axially adjustable adjusting element (9) for the gas-dynamic strut has a pressure chamber (22) which can be variably filled with gas by means of a valve (23).

15. Device (1) according to any one of the preceding claims 1 to 14, characterized in that The sensor is designed as a proximity switch which is designed to scan the contour of a brake disc of the bicycle.

16. A system for changing the center of gravity of a bicycle, in particular an electric bicycle, to adapt to the situation, the system comprising: The device (1) according to any one of the preceding claims and having Electric centre stand and / or semi-automatic or fully automatic handbrake.

17. A bicycle having a device (1) according to any one of the preceding claims 1 to 15 or having a system according to claim 16.

18. A method for changing the center of gravity of a bicycle, in particular an electric bicycle, to adapt to the situation, the method comprising the following steps: capturing sensor data depicting the riding state of the bicycle, evaluating the sensor data and determining the center of gravity of the bicycle's adaptation situation, generating a control signal for changing the center of gravity of the bicycle, outputting the control signal to the actuator (2) to perform the change of the center of gravity, • Adjusting the adjustment speed of said change of said center of gravity according to the riding conditions of said bicycle.

19. The method according to claim 18, characterized in that The change of the center of gravity is achieved by adjusting the height of the seat post (12) of the bicycle with the aid of the actuator (2).

20. The method according to claim 19, characterized in that The height adjustment of the seat post (12) is faster in a lowering direction than in a raising direction.

21. The method according to any one of the preceding claims 18 to 20, characterized in that The change of the center of gravity is performed by means of a device ( 1 ) according to any of the preceding claims 1 to 15 .

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