WO2021243038A1 - System and method of use of an electromechanical drive - Google Patents

Abstract

Electromechanical drive systems are described for a vehicle. An example drive system for a bicycle includes a computing device with memory, a bicycle sprocket, and a motor. The sprocket can be attached to a wheel of the bicycle. The sprocket can comprise multiple sprocket segments that form a perimeter of the sprocket. The motor can be configured to move one or more of the sprocket segments in order to expand and contract a radius of the sprocket. An application can be stored in the memory, and when executed, the application can cause the computing device to determine a sequence for expanding or contracting the sprocket segments and cause a respective sprocket segment from the sprocket segments to expand or contract based at least in part on the sequence.

Description

SYSTEM AND METHOD OF USE OF AN ELECTROMECHANICAL DRIVE

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application No. 62/031 ,676, filed May 29, 2020 and titled “SYSTEM AND METHOD OF USE OF AN ELECTROMECHANICAL DRIVE, the entire contents of which is hereby incorporated herein by reference.

BACKGROUND

[0002] Bicycles can be equipped with multiple gears or sprockets to achieve different gear ratios. The gear ratios can be achieved because the sprockets are constructed with different diameter sizes. Bicycle riders can change sprockets at different times to account for different riding conditions or riding objectives.

SUMMARY

[0003] In accordance with the purpose(s) of the present disclosure, as embodied and broadly described herein, the disclosure, in one aspect, relates to a novel electromechanical and software system that enables the efficient peddling of a bicycle.

[0004] According one embodiment, among others, a drive system for a bicycle, comprises a computing device that comprises memory, a sprocket, and a motor. The sprocket can be attached to a wheel of the bicycle. The sprocket can comprise a plurality of sprocket segments that form a perimeter of the sprocket. The motor can be configured to move individual ones of the plurality of sprocket segments in order to expand and contract a radius of the sprocket. An application can be stored in the memory. When executed, the application causes the computing device to at least determine a sequence for expanding or contracting the plurality of sprocket segments. The application can also cause, via the motor, a respective sprocket segment from the plurality of sprocket segments to expand or contract based at least in part on the sequence.

[0005] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. In addition, all optional and preferred features and modifications of the described aspects are usable in all aspects of the disclosure taught herein. Furthermore, the individual features of the dependent claims, as well as all optional and preferred features and modifications of the described aspects are combinable and interchangeable with one another.

[0006] Additional advantages of the disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or can be learned by practice of the disclosure. The advantages of the disclosure will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure, as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, with emphasis instead being placed upon clearly illustrating the principles of the disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

[0008] FIG. 1A illustrates an automatic transmission bicycle, according to one embodiment described herein.

[0009] FIG. 1 B is an enlarged view of expandable sprockets from the automatic transmission bicycle depicted in FIG. 1 A, according to one embodiment described herein.

[0010] FIG. 2 illustrates a block diagram of a networked environment for the automatic transmission bicycle from FIGS. 1A and 1 B, according to one embodiment described herein.

[0011] FIGS. 3A-3C illustrate a progression of a sprocket expanding at different states, according to one embodiment described herein.

[0012] FIG. 4 is a flowchart illustrating the operations of a drive application from the networked environment of FIG. 2, according to one embodiment described herein.

DETAILED DESCRIPTION

[0013] With reference to FIGS. 1A and 1 B, shown are illustrations of an automatic transmission bicycle 100 (also referred to as “the bicycle 100”), which includes an electromechanical drive system 103 (also referred to as “the drive system”). The various embodiments of the present disclosure relate to novel designs, batteries, electric motors, software, sensors and mechanical constructs for implementing the electromechanical drive system 103. The various embodiments of the drive system 103 can provide for the variable and real time changing of the radius of each of the two sprockets (FIG. 1 B) that can work together, independently and simultaneously, to control the dynamic changing of the gear ratio, either increasing or decreasing the gear ratio. In this context, the two sprockets are connected by a chain.

[0014] FIG. 1 B illustrates an enlarged view of a first sprocket 106a and a second sprocket 106b (collectively “the sprockets 106”), which are one aspect of the drive system 103. The sprockets 106 are connected by a chain 107 and are comprised of multiple sprocket segments or sections 109a and 109b (collectively “the sprocket segments 109”) with variable radii, which are controlled by software, sensors and motors (FIG. 2). In some embodiments, the drive system 103 can initiate moving one of the sprocket segments 109 when a particular sprocket segment 109 reaches to a reference point 104 on the bicycle 100 (FIG. 1A).

[0015] In FIG. 1 B, the first sprocket 106a is illustrated as a front circular sprocket. The first sprocket 106a includes multiple sprocket segments 109a that move independently and perpendicular to the axis of rotation such that each sprocket segment 109a can have a variable radius. Reference arrow 112 refers to the linear motion that each sprocket segment 109 can move with respect to the center of the first sprocket 106a. For example, a first sprocket segment 109a may have a different radius than a second sprocket segment 109b, and so on. Each of the sprocket segments 109a can be independently operated by the drive system 103. [0016] In FIG. 1 B, the second sprocket 106b is illustrated as a rear circular sprocket. Similar to the first sprocket 106a, the second sprocket 106b includes multiple sprocket segments 109b that move independently and perpendicular to the axis of rotation such that each sprocket segment 109b can have a variable radius.

[0017] The various embodiments of the automatic transmission bicycle 100 provide multiple benefits over existing systems. For example, the embodiments improve the cycling performance of a rider by automatically adjusting the gear ratio based on various factors. Accordingly, the rider does not have to determine which gear the bicycle 100 should be in based on his or her riding environment. Additionally, the embodiments provide a design that requires less maintenance than existing systems because several mechanical components in traditional bicycle designs are omitted, such as having multiple sprockets for one or both bicycle wheels, a derailleur, cables for operating the derailleurs, and other mechanical components on a bicycle.

[0018] With reference to FIG. 2, shown is a block diagram of a networked environment 200 for the automatic transmission bicycle 100 (FIG. 1 A), which includes the electromechanical drive system 103. The networked environment 200 includes the drive system 103 and a client device 203, which are in data communication. The drive system 103 and the client device 203 can be in data communication over a network connection. The network connection may include a wired connection, a wireless connection, a cellular network, a WiFi network, a Bluetooth network, or other suitable network connections.

[0019] The drive system 103 can include the first sprocket 106a, the second sprocket 106b, the controller device 206, and other suitable drive components. The sprockets 106 a,b can include motors 209 a,b, sprocket sensors 212 a,b, and the sprocket segments 109 a, b, one or more batteries 215 a,b, and other suitable components.

[0020] The motors 209 a,b (collectively “the motors 209”) can move the sprocket segments 109 in order the change their radius or radii from the center of the sprocket, which can cause a change in the gear ratio for the bicycle 100. In some cases, each sprocket segment 109 can be attached to a separate motor 209. Additionally, the motors 209 can be used to move individual sprocket segments 109 at specific times. The motors 209 can be manipulated by the controller device 206 accordingly to a preset sequence executed by the controller device 206. In other cases, the motors 209 can be dynamically controlled by the controller device 206 in order to respond to the terrain being experienced by the bicycle 100. For example, in a scenario in which the bicycle 100 is going up a hill, the controller device 206 can change the gear ratio to account for the hill. By changing the gear ratio, the bicycle 100 can improve the cycling performance of the rider. For example, in the context of traveling uphill, the rider may desire a gear ratio that is easier to pedal. As such, changing the gear ratio can cause the motors 209 to expand or to contract the radius of the sprocket segments 109 for one or both sprockets 106.

[0021] In some cases, the motors 209 can be attached to a sprocket housing. The motor 209 can also be attached to an actuator that mechanically moves the sprocket segment 109 from a first radius distance to a second radius distance with respect to a center of a sprocket 106. Accordingly, a diameter of the sprocket 106 can be expanded and contracted while the bicycle 100 is moving without any input from the rider. The sprocket segment 109 can be moved in a linear direction either away from or toward a center of the sprocket 106. Thus, instead of moving a bicycle chain from one sprocket to another sprocket, the bicycle 100 can achieve different gear ratios by expanding and contracting the diameter of the sprockets 106. In some scenarios, the motor 209 can include a direct current (DC) electric motor, an alternating current (AC) electric motor, or other suitable types. The motors 209 can be powered by various rechargeable power sources.

[0022] The sprocket sensors 212 a,b (collectively “the sprocket sensors 212”) can provide segment data related to one or more of the sprocket segments 109. The sprocket segment 212 can be situated on the sprocket 106, the sprocket segments 109, a bicycle pedal, a bicycle frame, and other suitable locations. The sprocket sensors 212 can communicate the segment data to the controller device 206, which adjusts the operations of the sprocket segment 109 based on the segment data. The sprocket sensors 212 can be manipulated manually by a user or automatically by software algorithms or by current threshold levels. For example, the sprocket sensor 212 can provide data related to the current radius from a center of the sprocket 106, an orientation of the sprocket segment about the center of the sprocket 106, and other suitable data. Some non-limiting examples of sprocket sensors 212 can include a gyroscope, an accelerometer, a compass, a barometer, a proximity sensor, a position sensor, a global positioning system, and other suitable sensors.

[0023] The sprocket segments 109 can include various structural components of the sprocket 106. In some cases, the sprocket segments 109 can include discrete structural components that form a perimeter of the sprocket 106. For example, in an initial contracted state, the circumference of a sprocket 106 can be divided equally among each sprocket segment 109. In an expanded state, the sprocket segment 109 can be moved away from the center of the sprocket 106. In the expanded state, gaps can separate two sprocket segments 109.

[0024] The battery 215 can be attached to the sprocket 106 or the sprocket housing. The battery 215 can provide a power to the motor 209. In some implementations, each sprocket segment 109 can have a battery 215. In other implementations, one battery 215 can be attached to the sprocket 106 to provide power to all of the sprocket segments 109. In another implementation, the battery 215 can be omitted and the drive system 103 can provide power to the motors 209 for each sprocket segment 109. Additionally, in one example, the battery 215 is recharged or supplied power using magnetic induction technologies or a magnetic induction system. The battery 215 can also be recharged by an external charging device, such as an AC outlet or other suitable power source.

[0025] The controller device 206 can be a computing device that controls the operations of the drive system 103. The controller device 206 can include a device data store 218, a controller battery 221 , a bike sensor 224, and other suitable controller components. The controller device 206 can execute a drive application 227 for controlling the operations of the electromechanical drive system 103.

[0026] The device data store 218 can store settings data 230 for operating the drive system 103. The settings data 230 can include data mapping gear ratios to a radius for each of the sprocket segments 109. Accordingly, the gear ratios can be used to instruct the motor 209 expand or contract to a particular radius for a particular sprocket segment 109. The settings data 230 can also include a timing sequence for when to expand or contract each of the sprocket segments 109. For example, on the first sprocket 106a, a first motor 209a can cause a first sprocket segment 109a to expand its radius at a first instance of time. A second motor 209b can cause a second sprocket segment 109a to expands its radius at a second instance of time after the first instance. Accordingly, the first sprocket 106a can be expanded by each sprocket segment 109 extending its radius at different instances of time. In this non-limiting example, the first sprocket segment 109a is adjacent to the second sprocket segment 109a. As such, the sprocket segments 109a can be expanded or contracted in a clockwise sequence, a counterclockwise sequence, and other suitable sequences.

[0027] In other cases, the settings data 230 can store an exercise workout for a rider. The exercise workout can include a sequence of implementing different gear ratios at different times in order to achieve a particular exercise objective. For example, the bicycle 100 can be configured as a stationary bicycle with a trainer. The electromechanical drive system 103 can implement a first gear ratio for ten minutes in order to represent an uphill bicycle climb. Then, the electromechanical drive system 103 can implement a second gear ratio for the next twenty minutes to represent the bicycle traveling on a declining terrain or a flat terrain.

[0028] The drive application 227 can be used to control the operations of the electromechanical drive system 103. As such, the drive system 103 can individually control each motor on the first sprocket 106a and the second sprocket 106b. The drive application 227 can also be in data communication with the client device 203. The drive application 227 can receive settings data 230 from the client device 203. In other contexts, the drive application 227 can transmit to the client device 203 feedback data regarding the operations of the drive system 103. The drive application 227 can also transmit performance data 239 related to the rider.

[0029] Additionally, the drive application 227 can represent various software algorithms, software applications and software instructions that can be used in conjunction with the bike sensor 224, the sprocket sensor 212, and switches to control several functioning and performance characteristics of the bicycle 100 and the drive system 103. As an example, the software applications will work in conjunction with the sensors to determine the precise time to cause the individual sprocket elements to move based on their rotational location.

[0030] The controller battery 221 can be a power source used to power components of the controller device 206. In some embodiments, the controller battery 221 can also be used to provide power to the individual motors 209 for each sprocket 106.

[0031] The bike sensor 224 can refer to one or more sensors that may be situated on the drive system 103, a bicycle frame, a wheel, a pedal, or other suitable locations. In some embodiments, the bike sensor 224 can be used to detect the orientation of the bicycle 100. For example, the bike sensor 224 can provide data indicating the bicycle 100 is in an inclined orientation, a declined orientation, a flat orientation, or other suitable orientations. The orientation of the bicycle 100 can be used by the drive application 227 to determine the appropriate gear ratio for one or both sprockets 106 for the present orientation. As the orientation of the bicycle 100 dynamically adjusts, then the gear ratios for the sprockets 106 can be dynamically adjusted. Some non-limiting examples of the bike sensor 224 can include a gyroscope, an accelerometer, a compass, a barometer, a proximity sensor, a position sensor, a global positioning system, and other suitable sensors. One or more of these sensors can be included in the various embodiments.

[0032] Additionally, the bike sensor 224 can measure conditions such as velocity, acceleration, positioning of the bicycle 100, current positioning and location of various components such as the sprockets 106, the desired torque, and other suitable conditions. The attainment of user preferences and/or attainment of user goals can be used to determine the appropriate communication to be given to the electric motors either wirelessly or through direct current thereby causing the electric motors to rotate in the proper direction thereby increasing or decreasing the radii of the various sprocket elements.

[0033] The client device 203 can be used to communicate with the drive system 103. For example, the client device 203 can communicate user preferences and an exercise workout to be implemented by the drive system 103. In other cases, the drive system 103 can transmit to the client device 203 feedback data 236 on drive system 103, data on the rider’s performance 239 , and other suitable data. The client device 203 may comprise, for example, a processor-based system such as a computer system. Such a computer system may be embodied in the form of a desktop computer, a laptop computer, personal digital assistants, cellular telephones, smartphones, set-top boxes, music players, web pads, tablet computer systems, game consoles, electronic book readers, or other devices with like capability. The client device 203 may include a display 231.

[0034] The client device 203 may be configured to execute various applications such as a client application 233 and/or other applications. The client application 233 can be used to communicate with the drive application 227. Also, the client application 233 may be executed in the client device 203, for example, to access network content served up over the Internet. To this end, the client application 233 may comprise, for example, a browser, a dedicated application, or a user interface which may comprise a network page, an application screen, etc. The client device 233 may be configured to execute applications beyond the client application 233 such as, for example social networking applications, and/or other applications.

[0035] Additionally, the client application 233 can configure pre-set performance levels, user preferences, voice commands allowing the user to speak into the client application 233 to change the performance of the drive system 103, and artificial intelligence (Al) algorithms to predict the current performance of the drive system 103.

[0036] The client device 203 can also have a client data store 242. The data stored in the client data store 242 includes, for example, the feedback data 236, settings data 230, rider performance data 239, and potentially other data.

[0037] With reference to FIGS. 3A-3C, shown is a progression of the first sprocket 106a at different states while expanding its radius. The same progression can be implemented for the second sprocket 106b. For example, FIG. 3A illustrates the first sprocket 106a in an initial state. In the initial state, the sprocket segments 109a have their smallest radii from the center of the sprocket 106a, which can be considered as a first radius for each of the sprocket segments 109a. As illustrated, each sprocket segment 109a is in contact with the adjacent sprocket segments 109a. The initial state can be used to implement a first gear ratio.

[0038] In FIG. 3B, the motors 209a (FIG. 2) for each of the sprocket segments 109a have longitudinally moved the sprocket segment 109a away from the center to a second radius. The second radius is larger than the first radius. As illustrated, there are gaps between adjacent sprocket segments 109a. At the second radius, the illustrated state can be used to implement a second gear ratio.

[0039] In FIG. 3C, the motors 209a for each of the sprocket segments 109a have longitudinally moved the sprocket segment 109a away from the center to a third radius. The third radius is larger than the second radius. At the third radius, the illustrated state can be used to implement a third gear ratio.

[0040] Referring next to FIG. 4, shown is a flowchart that provides one example of the operation of a portion of the drive application 227 according to various embodiments. It is understood that the flowchart of FIG. 4 provides merely an example of the many different types of functional arrangements that may be employed to implement the operation of the portion of the drive application 227 as described herein. As an alternative, the flowchart of FIG. 4 may be viewed as depicting an example of elements of a method implemented in the controller device 206 (FIG. 2) according to one or more embodiments.

[0041] Beginning with box 403, the drive application 227 can receive sensor data from the sprocket sensors 212 and/or the bike sensor 224. The sensor data may include an angular orientation of the bicycle 100, a velocity of the bicycle, an altitude of the bicycle, a position of the bicycle 100, and other suitable data. The sensor data may also include feedback data 236 from the drive system 103 on the operations of the drive system 103. The sensor data may also include rider performance data 239.

[0042] The drive application 227 can utilize terrain or maptitude topographic mapping data to proactively determine elevation of a particular route to set the appropriate gear ratios to help the rider accomplish performance goals. In this context, the drive application 227 can use location data for the bicycle 100 in combination with the mapping data to determine a change in elevation along a route. Particularly, the drive application 227 can detect an upcoming change in elevation for the route and determine the appropriate gear ratio. The location data for the bicycle 100 can be determined by a GPS component for the drive system 103, the client device, or other component in the networked environment 200.

[0043] In box 406, the drive application 227 can determine an orientation of the bicycle 100 based on the sensor data. For example, the drive application 227 may detect that the bicycle is presently in an inclined position because the first sprocket 106a is at a higher elevation than the second sprocket 106b.

[0044] In box 409, the drive application 227 can determine the gear ratio for the sprockets 106 based on the orientation of the bicycle 100. For example, if the bicycle 100 is in an inclined orientation, then the drive application 227 can adjust to a gear ratio that is optimized for the inclined orientation. In other words, the gear ratio can be adjusted because the rider is going uphill. Alternatively, if the bicycle 100 is in a declined orientation, the drive application 227 can determine the appropriate gear ratio for the rider going downhill.

[0045] In some embodiments, the drive application 227 can determine the gear ratio based on the angular orientation of the bicycle 100 meeting a threshold. For example, if the angular orientation is between zero and 20 degrees, then a first gear ratio is selected. If the angular orientation of the bicycle 100 is between 20 and 40 degrees, then a second gear ratio is selected. [0046] In some embodiments, the drive application 227 can use a machine learning model to determine the optimal gear ratio based on various factors, such as the detected orientation of the bicycle 100, an exercise workout, user preferences, and other suitable factors. In this context, a machine learning model can be trained to determine the appropriate gear ratio in various manners. For example, in one implementation, a first input can be riding conditions of the bicycle 100, which may be provided from the sensors. The riding conditions can include the orientation of the bicycle 100, the detected conditions of the terrain for which the bicycle 100 is presently riding, or other suitable conditions. A second input can be a performance objective for a rider, which can serve as a desired output of the machine learning model. For example, the performance objective can be configured to select an easier gear ratio for an uphill terrain. A harder gear ratio can be selected for a flat terrain. .

[0047] The drive application can utilize machine learning algorithms and artificial intelligence to track the settings of the drive system during certain time intervals, during certain elevations or for achieving certain performance objects and prospectively adjust the gear ratios to provide for a consistent experience for the rider.]

[0048] After the gear ratio is determined, the radii of the sprocket segments 109 can be determined for one or both of the sprockets 106. The drive system can use sensors and computational algorithms to measure the current radii of the sprockets to determine the optimal radii of the sprocket segments to achieve the targeted gear ratio that will achieve the rider’s performance objective.

[0049] In box 412, the drive application 227 can determine a sprocket sequence for the sprocket segments 109. The sprocket sequence can include a sequence that instructs which individual sprocket segments should be expanded or contracted at a particular instance of time. For example, a first sprocket segment 109a can be expanded from a first radius to a second radius at a first time period. A second sprocket segment 109a can be expanded from the first radius to the second radius at a second time period after the first time period. The third sprocket segment 109a and the fourth sprocket segment 109a can also have a unique period of time for expansion or contraction as well.

[0050] In box 415, the drive application 227 can cause the appropriate motor 209 to move a particular sprocket segment 109a based on the sprocket sequence and the gear ratio. The particular sprocket segment 109a can be moved to a second radius when the sprocket segment 109a is detected as being in proximity to a reference point 104 (FIG. 1A) for the bicycle 100. For example, the reference point 104 can be a point on the downtube of the frame of the bicycle 100, or a point on the seat tube of the bicycle 100. In some examples, the proximity system may be set up to detect when a particular sprocket segment 109a is near the reference point 104. The motor 209a can be driven to move the particular sprocket segment 109a to a certain radius at the appropriate instance of time. The radius can be determined from the gear ratio. Then, the drive application 227 proceeds to the end.

[0051] It should be emphasized that the above-described aspects of the present disclosure are merely possible examples of implementations set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the above-described aspect(s) without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims. [0052] Disjunctive language such as the phrase “at least one of X, Y, or Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to present that an item, term, etc., may be either X, Y, or Z, or any combination thereof (. e.g ., X, Y, and/or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain embodiments require at least one of X, at least one of Y, or at least one of Z to each be present.

[0053] It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.

Claims

CLAIMS Therefore, the following is claimed:

1. A drive system for a bicycle, comprising: a computing device that comprises memory; a sprocket that attaches to a wheel of the bicycle, wherein the sprocket comprises a plurality of sprocket segments that form a perimeter of the sprocket; a motor that is configured to move individual ones of the plurality of sprocket segments in order to expand and contract a radius of the sprocket. an application stored in the memory, wherein, when executed, the application causes the computing device to at least: determine a sequence for expanding or contracting the plurality of sprocket segments; and cause, via the motor, a respective sprocket segment from the plurality of sprocket segments to expand or contract based at least in part on the sequence.

2. The drive system of claim 1 , wherein causing the respective sprocket segment to expand or contract further is based at least in part on a position of the respective sprocket segment with respect to a reference point.

3. The drive system of claim 2, wherein the application further causes the computing device to at least: determine the position of the respective sprocket segment about a center of the sprocket based at least in part on a sensor attached to one of the plurality of sprocket segments.

4. The drive system of claim 1 , wherein the respective sprocket segment is expanded or contracted perpendicular to an axis of rotation for the sprocket.

5. The drive system of claim 1, further comprising a battery that is coupled to the motor, wherein the battery provides power to the motor.

6. The drive system of claim 1 , wherein determining the sequence for expanding or contracting the plurality of sprocket segments further comprises determining a timing sequence for expanding or contracting the plurality of sprocket segments based at least in part on a reference point.

7. The drive system of claim 6, wherein the reference point is a point on a frame of the bicycle.

8. The drive system of claim 1 , wherein the application further causes the computing device to at least: determine an angular orientation of the bicycle based at least in part on sensor data received from a gyroscope sensor attached to the bicycle.

9. The drive system of claim 8, wherein the application further causes the computing device to at least: determine a gear ratio for the sprocket of the bicycle based at least in part on the angular orientation of the bicycle.

10. The drive system of claim 9, wherein the application further causes the computing device to at least: determine an updated radius for the respective sprocket segment based at least in part on the gear ratio for the sprocket.

11. The drive system of claim 1 , further comprising: an actuator that connects the motor to at least one of the plurality of sprocket segments, wherein the motor causes the actuator to move the at least one of the plurality of sprockets segments inward and outward in order to adjust the radius.