Method for operating a gear change on an electric bicycle

Abstract

Title: Method for operating a gear change of an electric bicycle The invention relates to a method for operating a gear change (1) of an electric bicycle (100) in which the gear change (2) has a chain gear change with a gear change device (3) which is arranged to move a chain of the bicycle between various sprockets (5).The method consists of detecting a gear change signal, actuating the gear change device (3) in response to the detection of the gear change signal, determining a first chain change instant at which the bicycle chain (4) is moved earliest by the gear change device (2), and reducing the motor torque of an electric bicycle drive unit at the first chain change instant to a predetermined gear change motor torque. The determination of the first chain change instant is based on an initial time interval between the start of a movement of the gear change device (2) and an earlier movement of the bicycle chain (4). Figure for the abstract: Fig. 1.

Description

Title of the invention: Method for operating a gear change on an electric bicycle State of the art

[0001] The present invention relates to a method for operating a gear change of an electric bicycle and an electric bicycle.

[0002] Bicycle gear shifters with chain-driven transmissions are known. The bicycle chain is moved between the sprockets by means of a gear-shifting device. Until the new gear is actually engaged after a gear change, the bicycle chain must usually rotate a certain number of times on the cassette. In electric bicycles, in addition to the instantaneous pedaling torque of the cyclist, there may be a motor torque from a drive unit applied to the drivetrain. This can lead to excessive mechanical stress on the drivetrain, particularly on the bicycle chain and wheels, during gear shifting operations. Description of the invention

[0003] The method according to the invention is characterized, however, by the fact that a particularly effective reduction of the torque applied to the bicycle chain during a gear change operation can be achieved by simple and inexpensive means. This makes it possible, in particular, to reduce wear and extend the lifespan of the gear system. This is achieved by a method for operating a gear system on an electric bicycle, wherein the gear system is a chain-driven gear system having a gear-changing device. The gear-changing device is arranged to move a bicycle chain over various sprockets. The method comprises the following steps: - detection of a gear change signal, - activation of the gear shifting device in response to the gear shift signal, which has been detected, - determining a first instant of chain change, at which the bicycle chain is moved earliest by the gear-changing device, and - reducing the motor torque of an electric bicycle drive unit at the first instant of chain change to a predetermined gear-changing motor torque, - wherein the determination of the first instant of chain change is based on an initial time interval between the start of a movement of the gear-changing device and the earliest movement of the bicycle chain.

[0004] As a gear-changing device, a guiding element for the bicycle chain can preferably be considered, such as, in particular, a switching mechanism and / or a reverser.

[0005] As an instant of chain change, we consider in particular an instant, at which, during the operation of changing gear, the bicycle chain is moved, for the first time, directly onto the sprockets.

[0006] The initial time interval between the start of the movement of the gear-shifting device and the earliest movement of the bicycle chain can be based on predetermined mechanical and geometric properties of the chain-driven gear shifter. This means that the initial time interval results, in particular, from a certain temporal delay in the actual movement of the bicycle chain directly on the sprocket relative to the initial movement of the gear-shifting device.

[0007] Preferably, one can estimate, as the first time interval and / or as the earliest instant of the movement of the bicycle chain, a time interval or an instant which is known in advance on the basis of the mechanical properties of the chain speed change and / or which has been determined by means of, for example, a calibration.

[0008] In particular, the exact first time interval or the earliest exact instant of the displacement may vary due to tolerances, environmental influences, wear conditions, or similar factors. Therefore, an evaluation of the earliest instant of the bicycle chain's displacement can be considered in a corresponding manner.

[0009] In other words, the method involves a controlled actuation of the gear-shifting device based on the detected gear-shifting signal. Next, the first chain-shift instant is determined, the instant at which the bicycle chain is moved by the gear-shifting device for the first time after the gear-shifting signal. In this respect, the motor torque of the electric bicycle's drive unit is reduced so that, at the moment of the chain-shift, the motor torque is predetermined. The first chain-shift instant is determined based on the first time interval between the start of the gear-shifting device's movement and the earliest actual movement of the bicycle chain.

[0010] Preferably, the engine torque for gear changes corresponds at most to a predetermined proportion of the previous engine torque, preferably at most 30%, in particular at most 20%. Alternatively, the engine torque The gear change torque is preferably a constant value defined in advance. The engine torque for gear change can be, for example, a maximum of 35 Nm, preferably a maximum of 25 Nm.

[0011] The method thus provides the advantage of enabling a particularly targeted and efficient reduction of the motor torque during the gear-shifting operation. By taking into account the initial time interval between the start of the movement of the gear-shifting device and the earlier actual movement of the bicycle chain, the moment of the reduction in motor torque can be determined with particular precision within the actual time interval of the bicycle chain's movement. This ensures, on the one hand, that during the movement of the bicycle chain during the gear-shifting operation, the reduced motor torque for gear shifting is applied, thereby allowing the gear change to be performed under a low load and thus with minimal wear.On the other hand, the reduction of motor torque can be adapted over time so that the reduction is as brief as possible to provide the cyclist with an effective boost and great riding comfort when the electric bicycle is in operation.

[0012] Preferably, the method further comprises the following steps: determining a second chain change instant at which the movement of the bicycle chain by the gear-shifting device ends no later than the movement of the bicycle chain, and increasing the drive unit's torque from this second chain change instant. In particular, the second chain change instant is considered to be the instant at which the movement of the bicycle chain directly on the sprocket has ended at the latest. Alternatively, or in addition, the second chain change instant is preferably considered to be the instant at which the bicycle chain is fully engaged with the new sprocket after the gear-shifting operation. The increase in the drive unit's torque is preferably carried out in this respect so that a target torque is determined in advance precisely at the second chain change instant.Preferably, the target motor torque can correspond to the motor torque before the gear-shifting device is activated, i.e., before the gear change operation. This allows for a simple, efficient, and time-saving increase in motor torque after the gear change operation. This provides efficient propulsion for the electric bicycle and greater comfort for the rider.

[0013] Preferably, the second chain change instant is determined on the basis of the first chain change instant and a chain change time interval. In this respect, the chain change time interval is defined as The time required for the bicycle chain to move between the sprockets during a gear change. This chain shift time can be determined in advance based on the mechanical and geometric properties of the chain drive. For example, the chain shift time can be calculated individually for each gear change and stored in memory. This allows for particularly simple and efficient controlled gear changes.

[0014] Preferably, the second chain change instant is determined based on the first chain change instant and a second time interval. This second time interval is defined as the interval between the start of the shifting mechanism's movement and the latest possible end of the bicycle chain's movement. This means that, for determining the second chain change instant, a second time interval is used that is independent of the first, and which, like the first time interval, begins with the start of the shifting mechanism's movement. This second time interval can, for example, be known in advance based on pre-known mechanical and / or geometric properties of the chain shifter.Preferably, the second time interval can be defined individually and known in advance for each possible gear change of the chain-driven transmission. The corresponding second time interval can be stored, for example, for each gear change. This allows the process to be carried out in a particularly simple and efficient manner.

[0015] In a particularly preferred manner, determining the first instant of chain change involves determining the number of sprocket revolutions, preferably from the instant of detection of the gear change signal. In a particularly preferred manner, alternatively or additionally, determining the second instant of chain change involves determining the number of sprocket revolutions, in particular, from the instant of detection of the gear change signal. In other words, a specific number of revolutions is determined, which occurred from the detection of the gear change signal until the first instant of chain change or, respectively, until the second instant of chain change. The times of chain change can thus be determined in a particularly simple and reliable manner, for example, by detecting and tracking the rotational movement of the sprockets.

[0016] Preferably, the first instant of chain change is reached when the determined number of revolutions reaches a defined number of speed change revolutions in advance. Alternatively, or additionally, the second chain shift point is preferably reached when the predetermined number of sprocket revolutions reaches a defined number of gear shift revolutions. In other words, starting from the detection of the gear shift signal, the sprocket revolutions are counted until the predetermined number of gear shift revolutions is reached, in order to initiate the corresponding planned action at the first / or second chain shift point. This allows for particularly simple and practical control of gear shifting operations, especially since it controls the rotation of the sprockets, which is relevant to gear shifting.

[0017] It is particularly preferable to define the number of gear changes individually for each gear shift. This means that, for each gear change operation, a number of gear changes is defined separately for each adjacent gear, adapted to each individual gear. This takes into account the different diameters and mechanical properties of the gears during the corresponding gear changes, allowing the reduction of engine torque to be carried out in a timely, highly precise manner, and in a way that is appropriate for the respective gear change.

[0018] Preferably, the determination of the number of sprocket revolutions is carried out on the basis of the number of sprocket revolutions and / or on the basis of the number of motor revolutions and an instantaneous gear ratio. This means that the number of sprocket revolutions can be detected directly, for example by means of a revolution sensor or, alternatively or additionally, preferably on the basis of the rotational speed of the drive unit motor and the instantaneous gear ratio, in which case the sprocket rotation is determined based on the mechanical relationship between the motor rotational speed and the gear ratio of the drive chain. Furthermore, alternatively or additionally, the number of revolutions can be determined on the basis of a detected pedaling frequency and an instantaneous gear ratio.This allows for reliable, simple, and inexpensive control of the rotational movement of the gears.

[0019] Preferably, the determination of the first instant of chain change, in particular, and / or the second instant of chain change, is carried out on the basis of the pre-defined time interval for the movement of the gear-shifting device and / or for the movement of the bicycle chain. In particular, the pre-defined time intervals are fixed based on the mechanical and / or geometric properties of the chain-driven gear change. For example, the pre-defined time intervals can be initially calculated and / or calibrated. Furthermore, it is preferable to store predefined time intervals for the movement of the gear shifter and / or bicycle chain in memory using a control unit. This allows the process to be carried out in a simple and efficient manner.

[0020] Preferably, the method further comprises the following steps: identifying a fully completed gear change, in particular, before reaching the second chain change instant; increasing the motor torque in response to the identification of a fully completed gear change; or, alternatively, preventing the reduction of the motor torque. In particular, the increase in motor torque is based on the motor torque present in the drive unit before the reduction. This means that, during the previously identified gear change, the motor torque is increased back to its original value before the gear change. Alternatively, preferably, particularly when the motor torque has not yet been reduced, the reduction of the motor torque is actively prevented if the desired gear change has already been identified as complete.This allows for rapid engine support in a particularly efficient and convenient manner.

[0021] Preferably, the identification that the gear change is complete is based on one or more sensor signals. For example, an instantaneous gear ratio can be determined and controlled using a pedaling frequency and a number of rear wheel revolutions, in which, in particular, it can be determined that the gear change is complete based on the determined gear ratio.

[0022] Preferably, the method further comprises the stages of: determining a pedaling torque curve as a function of time, estimating a future pedaling torque curve as a function of time based on the detected pedaling torque curve as a function of time, and generating the gear shift signal such that an estimated minimum of the pedaling torque curve as a function of time occurs during the movement of the bicycle chain by the gear shifting device. This means that the generation of the gear shift signal is controlled in a targeted manner, so that the time interval following the chain movement occurs precisely so that the minimum of the pedaling torque on the evaluated pedaling torque curve as a function of time is found during that interval.Preferably, the estimation of the pedaling torque curve as a function of future time is produced by assuming that the pedaling torque produced by the cyclist is periodic, specifically following a sinusoidal oscillation. This allows for the simultaneous adaptation of not only the synchronization of the motor torque at the moment of gear change, but also the gear change itself. optimally adapts to the pedaling torque curve as a function of time. This allows the overall torque of the bicycle chain to be maintained at a particularly low value during gear changes, thus enabling gear changes with exceptionally low wear.

[0023] Preferably, the gear shift signal detection is based on a gear shift signal produced manually and / or automatically. Preferably, a manually produced gear shift signal can be considered to be a gear shift signal produced by a cyclist manually, in particular by means of a gear shift lever. The gear shift lever can preferably be arranged to produce mechanical actuation, for example by means of a pull cable, or electronic actuation of the gear shifting device, in which, in particular, in all cases, an electrical signal is produced by the gear shift lever when it is actuation, as the gear shift signal.As an automatically generated speed change signal, one can consider in particular a speed change signal produced by means of a control unit which is preferably generated automatically, based on one or more parameters.

[0024] The invention also relates to an electric bicycle comprising a gear shift, which has a chain-driven gear shift having a gear-shifting device arranged to move a bicycle chain between various sprockets, in which, in particular, the sprockets are part of a cassette on a rear wheel hub of the bicycle, and a control unit arranged to perform the method according to the invention. The control unit is further preferably arranged for controlled actuation of a drive unit of the electric bicycle.

[0025] Brief description of the drawings.

[0026] Examples of embodiments of the invention are described in detail below, with reference to the accompanying drawings. In the drawing:

[0027] Fig. 1 is a simplified schematic view of a bicycle, in which a method is performed to operate a gear change according to a first example of an embodiment of the invention;

[0028] Fig. 2 is a very simplified schematic view of the process according to the invention;

[0029] Figure 3 is a simplified schematic view of a diagram having curves of signal as a function of time while the process of [Fig. 1] is carried out; and

[0030] The [Fig.4] is a simplified diagram with curves as a function of time of signals while the process is carried out according to a second example of embodiment of the invention;

[0031] Embodiment of the invention

[0032] Preferably all components, elements and / or units are provided with the same reference numbers in all figures.

[0033] Fig. 1 is a simplified schematic view of an electric bicycle 100, in which a method 10 is performed to operate a gear change 1 of the electric bicycle 100 according to a first embodiment of the invention.

[0034] Fig. 2 is a very simplified schematic view of the process of the first embodiment and Fig. 3 represents a simplified schematic view of a diagram 20 while process 10 is carried out.

[0035] The electric bicycle 100 comprises a drive unit 110 having a motor, which is, in particular, an electric motor. The motor can be supplied with electrical energy by means of an electrical energy accumulator 109 of the electric bicycle 100. The drive unit 110 is disposed in the crankset of the electric bicycle 100.

[0036] By means of a motor torque produced by the motor, the pedaling force of a cyclist of the electric bicycle 100, produced by muscle power, can be sustained in a motorized manner. The cyclist's muscle power can be applied by a crank drive 104.

[0037] The drive unit 110 further comprises a control unit 50, which is arranged to actuate the motor in a controlled manner. The control unit 50 can, for example, control an electrical actuation current for the motor actuation. The control unit 50 is also preferably configured to perform the method 10 according to the invention.

[0038] The electric bicycle 100 includes a gear change 1, which is a chain-driven gear change 2. The chain-driven gear change 2 includes a cassette 101 on a rear wheel hub of the electric bicycle 100. The cassette 101 includes a plurality of sprockets 5, by means of which various gear ratios can be obtained in the drivetrain of the electric bicycle 100.

[0039] The electric bicycle 100 is driven by a chain sprocket 107, which can be driven by the motor torque of the drive unit 110, as well as by the pedaling torque applied by the cranks 104. The resulting total torque is transmitted to the cassette 101 by the chain sprocket via the bicycle chain 4.

[0040] Furthermore, the chain-driven gear shifter includes a gear-shifting device 3, which can move the bicycle chain 4 between the various sprockets of the cassette 101 and thus change the gear ratio. The device 3 of Speed ​​change can be constituted in particular in the form of an inverter or a switch.

[0041] The gear-changing device 3 can, in this respect, be actuated by means of a gear-changing signal 15. The gear-changing signal 15 can be generated either automatically by the control unit 50, for example, based on various traffic parameters, such as bicycle speed and / or pedaling cadence. Alternatively, and preferably, the gear-changing signal 15 can be generated by means of a manual gear-changing device 8, which includes, for example, a gear-shifting lever.

[0042] In the method 10, a precise adaptation of the availability of the motor torque of the drive unit 110 to the gear-changing operations can be carried out, in order to make possible efficient and low-wear operation of the electric bicycle 100, as will be described below with reference to figures 2 and 3.

[0043] In the method 10, the gear change signal 15 is generated first. In response to the generation of the gear change signal 15, the gear change device 3 is immediately actuation. In particular, an actuator of the gear change device 3 is actuated in a controlled manner so that the gear change device moves the bicycle chain 4 onto another sprocket 5.

[0044] Immediately afterwards, a determination 12 of a first instant 21 of chain change takes place. The first instant 21 of chain change represents an instant when the chain 4 of the bicycle is moved at the earliest by the gear-changing device 3.

[0045] In [Fig. 3], the movement of the bicycle chain 4 is schematically shown by the time curve of the chain position 40. The movement of the bicycle chain 4, namely the shifting of the sprockets 5, takes place within a chain shift time interval 33, which is between the first instant 21 of the chain shift and a second instant 22 of the chain shift. At the second instant 22 of the chain, the movement of the bicycle chain 4 is stopped at the latest by the gear-shifting device 3.

[0046] The determination 14 of the instant 22 of chain change can be carried out at the same time as the determination 12 of the first instant 21 of chain change (see [Fig.2]).

[0047] At the determination 12 of the first instant 21 of chain change, a first lapse 31 of time is taken into account, between a start 23 of a movement of the gear change device 3 and the earliest movement of the chain 4 of the bicycle.

[0048] The start 23 is considered in particular to be simultaneous with the gear change signal 15. This means that, during the first time interval 31, there is already a movement of the gear change device 3, however, there is not yet a movement of the bicycle chain 4 due to the mechanical and geometric conditions of the chain gear change 2.

[0049] Preferably, the first time interval 31, and in particular also the second time interval 33 of the chain change, is known in advance for each distinct gear change, namely for all the various sprockets 5 based on the mechanical and geometric properties of the chain-driven gear change 2. The first time interval 31 and the time interval 33 of the chain change can, for example, be stored in a lookup table.

[0050] In the process 10, a reduction 13 of the motor torque 25 of the drive unit 110 is made to a predetermined gear-changing motor torque 26 at the first instant 21 of the chain change. During the chain change time 33, the motor torque 25 is kept constant at the gear-changing motor torque 26. In particular, the motor torque 25 is reduced so that it corresponds, at the latest at the instant 21 of the chain change, to the predetermined gear-changing motor torque 26.

[0051] Preferably, the torque 26 of the gear-shifting motor corresponds to a small torque value of, for example, a maximum of 10 Nm. Alternatively, preferably, the torque 26 of the gear-shifting motor may also correspond to a torque of 0 Nm.

[0052] Preferably, and at the earliest from the second instant 22 of chain change, a controlled increase 19 in the motor torque 25 of the drive unit 110 then occurs. The motor torque 25 can be increased back to its original value before the gear change operation.

[0053] In the method 10, the second time 22 of the chain change can be determined based on the sum of the first time interval 31 and the time interval 33 of the chain change. Alternatively, the second time 22 of the chain change can also preferably be determined directly based on a second time interval 32 between the start 23 of the movement of the gear-changing device 3 and the latest possible end of the movement of the bicycle chain 4 (see [Fig. 3]). The second time interval 32 can also preferably be known in advance based on the mechanical and geometric properties of the chain-driven gear change 2.

[0054] In the method, the times 21, 22 of chain change can be determined on the basis of a determination 12a of a number of revolutions of the sprockets 5 from the detection of the gear change signal 15. This means that it is possible to determine The number of revolutions of the sprockets 5, which is required between the detection of the gear change signal 15 and the first or second instant 21, 22 respectively of chain change. The reduction 13 and the increase 19 of the engine torque 25 can then be carried out in such a way that this is achieved when the corresponding number of revolutions of the sprockets 5 reaches the respective value.

[0055] The determination 12a of the number of revolutions of the sprockets 5 is preferably carried out on the basis of a direct detection of the number of revolutions of the sprockets based on a detected rotational speed of the motor, in particular, by means of a motor rotational speed sensor, as well as a known instantaneous gear ratio of the chain-driven gearbox 2. The instantaneous state of the chain-driven gearbox 2 can thus be controlled with particular precision.

[0056] The method 10 may further include identifying 16 a fully completed gear change before the second instant 22 of the chain change. This can be carried out, for example, on the basis of a control of the rotational speed and / or torque of the kinematic chain of the electric bicycle 100.

[0057] When the end of the gear change is detected before the start of the reduction 13 of the motor torque 25, the reduction 13 of the motor torque 25 can be prevented in a targeted manner. Alternatively or in addition, when a reduction of the motor torque 25 has already begun, the motor torque 25 can be directly and controlled to be increased again in response to the detection 16 that the gear change is completely finished.

[0058] The method 10 thus provides the advantage of enabling a particularly optimal and precise timing of gear-shifting operations and the availability of the motor torque 25. By precisely reducing the motor torque 25 during the actual movement of the bicycle chain 4 between the sprockets 5, i.e., during the chain-shifting time interval 33, a particularly low load on the bicycle chain 4 during gear changes can be achieved. This makes gear-shifting operations easy and efficient over time, and, above all, reduces wear on the chain-driven gear 2.In addition, the 25 motor torque reduction can be adapted, in a particularly precise and efficient manner, precisely to the gear change, thanks to which, moreover, a high level of comfort can be provided for the cyclist of the 100 electric bicycle.

[0059] Figure 4 is a simplified schematic view of a signal curve diagram 20 during the execution of a process 10 according to a second embodiment of the invention. The second embodiment corresponds substantially to the first embodiment shown in Figures 1 to 3, with the difference of Further synchronization of gear changes with the cyclist's pedaling torque curve. In detail, method 10 of the second embodiment further includes determining a pedaling torque curve 45 as a function of time, which the cyclist produces while pedaling. Specifically, the pedaling torque curve 45 is tracked over time. An estimation of a future pedaling torque curve 45 as a function of time is also performed based on the detected pedaling torque curve as a function of time.

[0060] The estimation of the future pedaling torque curve preferably takes place by assuming that the cyclist, in particular for uniform pedaling, produces a pedaling torque, which has a substantially sinusoidal curve as a function of time.

[0061] In the method 10 of the second embodiment, the gear shift signal 15 is generated in such a way that a minimum of the estimated pedaling torque-as-time curve appears during the movement of the bicycle chain 4 by the gear shifting device 3. In other words, the gear shifting operation is performed in a time-controlled manner, so that the chain movement occurs during minimum pedaling torque values. More specifically, the gear shift signal 15 is generated in a controlled manner so that the minimum 46 of the pedaling torque-as-time curve 45 is, in particular, in the middle of the chain shift time 33.This makes possible a particularly small overall torque on the chain 4 of the bicycle during the gear change operation, which in turn allows for switching operations with little wear and thus a long service life of the chain gear change 2.

Claims

Demands

1. A method for operating a gear shift (1) of an electric bicycle (100), wherein the gear shift (1) has a chain-driven gear shift (2) having a gear-shifting device (3) that is arranged to move a bicycle chain (4) between various sprockets (5) comprising the stages: - detection of a gear-shifting signal (15), - actuation (11) of the gear-shifting device (3) in response to the gear-shifting signal (15) that has been detected, - determination (12) of a first instant (21) of chain shifting at which the bicycle chain (4) is moved earliest by the gear-shifting device (3), and - reduction (13) of a motor torque (25) of a drive unit (110) of the electric bicycle (100) at the first instant (21) of chain shifting to a motor torque (26) of gear shifting determined in advance,- in which the determination (12) of the first instant (21) of chain change is carried out on the basis of a first lapse (31) of time between a start (23) of a movement of the gear-changing device (3) and an earliest movement of the chain (4) of the bicycle.

2. A method according to claim 1, further comprising the stages of: - determining (14) a second instant (22) of chain change, which is terminated at the latest upon movement of the chain (4) of the bicycle by the gear-changing device (3), and - increasing (19) the motor torque (25) of the drive unit (110) from the second instant (22) of chain change.

3. Method according to claim 2, wherein the second instant (22) of chain change is determined on the basis of the first instant (21) of chain change and a lapse (33) of chain change time, which is necessary for the movement of the chain (4) of the bicycle between the sprockets (5).

4. A method according to claim 2 or 3, wherein the second instant (22) of chain change is determined on the basis of a second time interval (32) between the start (23) of the movement of the gear change device (3) and the latest end of the movement of the bicycle chain (4).

5. A method according to any one of the preceding claims, wherein the determination (12) of the first instant (21) of chain change, in particular and / or of the second instant (22) of chain change comprises a determination (12a) of the number of turns of the sprockets (5), in particular from the detection of the gear change signal (15).

6. A method according to claim 5, wherein the first instant (21) of chain change in particular and / or the second instant (22) of chain change is reached when the determined number of revolutions reaches a number of revolutions of gear change defined in advance.

7. A method according to claim 6, wherein the number of gear changes for each gear change is defined individually for each gear change.

8. A method according to any one of claims 5 to 7, wherein the determination (12a) of a number of turns of pinions (5) is carried out on the basis of a number of turns of the pinions and / or on the basis of a number of turns of the motor and an instantaneous multiplication ratio.

9. A method according to any one of the preceding claims, wherein the determination (12) of the first instant (21) of chain change, in particular and / or of the second instant (22) of chain change is carried out on the basis of the time period defined in advance for the movement of the gear-changing device (3) and / or for the movement of the chain (4) of the bicycle.

10. A method according to any one of claims 2 to 9, further comprising the stages: - identification (16) of a fully completed gear change, in particular, before the second instant (22) of chain change, and: - increase of the motor torque (25) in reaction to the identification (16) of the fully completed gear change, or - prevention of the reduction (13) of the motor torque (25).

11. A method according to any one of the preceding claims, further comprising: - determination of a pedaling torque curve (45) as a function of time, - estimation of a future pedaling torque curve (45) as a function of time based on the pedaling torque curve (45) as a function of time that has been detected, and - production of the gear change signal (15) so that a minimum (46) of the estimated pedaling torque curve (45) as a function of time occurs during the movement of the bicycle chain (4) by the gear change device (3).

12. A method according to any one of the preceding claims, wherein the detection of the gear change signal (15) is carried out on the basis of a gear change signal (15) produced manually and / or automatically.

13. Electric bicycle comprising: - a gear shift (1), which has a chain gear shift (2) having a gear shifting device (3) which is arranged to move a chain (4) of the bicycle between various sprockets (5) in which in particular the sprockets (5) are part of a cassette (101) to a rear wheel hub (102) of the bicycle (100), and - a control unit (50) which is arranged to carry out the method (10) according to any one of the preceding claims.

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