A modular bicycle with a variable configuration

Abstract

The present invention relates to a modular bicycle 1 with variable configuration, comprising a frame 2, which is configured as a step-through frame, which in the side view of the frame 2 comprises substantially straight main part 13 of the frame with downwards open U-shaped cross section at least in the area of the crankset in the situation of use. The said main part 13 of the frame 2 with U-shaped cross section is configured to receive a crankset module 14 removable from the frame 2 in single piece, which comprises, among other items, pedals 15, cranks 16, and the transmission drive wheel 25 of the crankset, and also a crankset motor 27 as an option.

Description

A MODULAR BICYCLE WITH VARIABLE CONFIGURATIONTECHNICAL FIELD

[0001] The present invention relates to a bicycle, more specifically a modular electric bicycle, and more specifically a modular bicycle frame that is adaptable for use as a so-called conventional bicycle propelled solely by human muscle power, as well as a so-called electric bicycle, which also has an electric motor for propulsion. The present invention is also directed to a bicycle that is adapted specially for the bicycles intended for the bicycle share systems and rental services, which allows the bicycle to be adapted according to the services provided and which allows for easy maintenance and repair.BACKGROUND ART

[0002] The international patent application WO2023180928A1 (published 28.09.2023) discloses a solution where a separate power drive can be installed to a regular bicycle, after which the bicycle can be used with an electric power drive. The separate power drive is fastened to the frame with special semicircular clamps. The drive shaft of the power drive has a sprocket wheel, which is aligned to the bicycle chain and made to engage with the chain.

[0003] As for the position, the sprocket wheel of the power drive is located above the sprocket wheel of the crankset of the bicycle, and the chain travels over the sprocket wheel of the drive, then over the sprocket wheel of the crankset, and finally over the sprocket wheel on the rear wheel shaft. With the shaft of the drive and the sprocket wheel, driving force is transferred to the sprocket wheel of the crankset, helping the user to minimize the force needed for cranking and propelling the bicycle more easily.

[0004] The disadvantage of this solution is that the electric drive motor and the battery are located in a single modular component, which makes the module very large and limits its possible locations of installation - in any case, the component must be located above the crankset, between the legs of the cyclist. In case of a failure of the electric motor or the battery, the entire component needs replacement - regardless of whether both or only one of these components require maintenance or repair.

[0005] This is a component to be added to a regular bicycle, which adds weight to the bicycle. When an electric motor is added, the mechanical crankset must remain on the bicycle to enable riding.SUMMARY OF THE INVENTION

[0006] The present invention solves the specific problems related to bike share and bicycle rental services, which are described more in detail below.

[0007] There are three most common systems on the bike share and rental service market - with charging stations, with replaceable batteries, and a hybrid system. In addition to three different systems and business models, it is a market that is not standardized - cities and operators set their requirements to the bicycles based on their experience and requests, which often makes them very different from each other. There are cities and settlements where it is possible to operate without special rules and requirements, and there are cities which set clear conditions and operators must participate in procurements to be able to operate their system.

[0008] The bicycles used on the market are often designed to operate with only one specific business model, which limits operators to a limited number of cities. However, there are also situations where the conditions set by the cities are so different within the framework of a single business model that the operator must use different bicycles in the cities where it operates. The changing market is also a problem. At the end of the operation period of 3 to 5 years specified in the procurement, it is difficult to win a new procurement again in the same city with the same bicycles or to find a new city with suitable conditions due to changing rules and requirements of the cities. As a result, the operators are unable to quickly find new uses for their bicycles, resulting in lost revenue. There is a need for bicycles which are designed for use in bike share and bicycle rental services, and which could be adapted to the different rules and requirements of cities and settlements, as well as to three different systems (business models) - in addition to the existing bike share systems.

[0009] Another problem for operators is the higher cost of electric bicycles compared to electric scooters, and the maintenance and repair work associated with electric bicycles. Compared to electric scooters, it is physically more complicated totransport bicycles with vans - due to the shape and geometry of a bicycle. There is a need for bicycles which enable quick replacement of the most frequently replaced components on the street, and only the defective component or module would be taken to the workshop, not the entire bicycle.

[0010] The present invention is proposed for solving the aforementioned problems, allowing operators to operate the modular bicycle in all three systems, adapting it to the specific characteristics of each system. Using only one bicycle makes it easier and more cost-effective to operate and manage the system. Operators can operate in several different business models at once do not have to worry about changes in rules and requirements. Maintaining and repairing bicycles on the street makes it possible to prevent costly back-and-forth transportation of bicycles and to minimize repair shop costs. The standby time of bicycles is minimal and it thus enables to generate higher turnover / profit.OBJECTIVE OF THE INVENTION

[0011] Objective of the present invention is to provide a modular electric bicycle, which can be adapted for three systems of bike share and rental service - with charging stations, replaceable batteries, and a hybrid system - and a bicycle, which can be maintained conveniently in the street. For three bike share and rental service systems, a replaceable battery pack must be configured as a module which enables to use batteries of different sizes, with a modular front fork which enables to use different front forks on the bicycle to ensure compatibility with charging stations from below at the height of the front wheel axle and higher from under the handlebar, and a modular crankset which enables to use both the mechanical crankset as well as the crankset motor.

[0012] Additional modular features include the modularity of the front basket which enables to use baskets of different sizes and shapes (e.g. sides closed, sides open) and a child’s seat; the modularity of the rear mudguard which enables to install several types of mudguards and a cargo box for problems couriers; and the modularity of the screen which enables to install on the bicycle several screens with a housing.

[0013] Modularity of a replaceable battery means that the bicycle frame has a socketfor receiving the battery pack as a separate frame component, enabling to install battery packs of different sizes. Depending on the area of a city or a settlement, cities need to use batteries of different capacity, to minimize operating costs related to the replacement of the battery. Battery pack as a module can be removable from the front, side, top or bottom of the frame.

[0014] Also, the battery pack and the crankset module can be together in a single module, which can be removed from the frame. This enables fast replacement of the battery pack in the street, and even if the bicycle is not used in the system with replaceable batteries, replacement of the battery is convenient and fast in other systems during maintenance and repair.

[0015] Modularity of the front fork means that front forks of available bicycles of bike share and rental service can be used on the bicycle, ensuring immediate compatibility with the existing systems. Another solution is a front fork arranged into the same modular solution of the frame, the lower part of which and the lower part of the handlebar are modular. This enables to replace a small component on the front fork and to make the bicycle physically compatible with different charging stations. As an example, there is an interface on the front fork on the front wheel axle, by addition of which the bicycle fits into charging stations at the height of the front wheel axle. As another example, the extension of the handlebar is modular, ensuring physical compatibility of the bicycle with the charging station from under the handlebar. In case of the developed modular front fork, it is thus possible to replace the lower or upper interface of the front fork in the street, if its power connections are corroded or if charging of the bicycle is not properly functioning for any other reason.

[0016] Modularity of the crankset means that the bicycle has a separate modular frame component or a so-called crankset module, to which a crankset motor or mechanical crankset is attached. The operator can use the same bicycle in cities and settlements that require a hybrid system - electric bicycles and regular bicycles. It is also possible to use several different crankset motors in the crankset module. The crankset module can be configured to be removable from below, side, or top of the frame. Thus, in the event of a failure of the crankset motor, it is possible to remove just the crankset module on the street and take it to the workshop - thedefective crankset module is replaced on the bicycle promptly on the street. Another use case is to replace the crankset module with a mechanical crankset module on the street in the autumn before the winter period, and the bicycles can be used all the year round without being taken to the workshop.TECHNICAL SOLUTION

[0017] For the above mentioned objectives, a modular bicycle with adjustable configuration is proposed, comprising a frame with a special configuration for that purpose.

[0018] The frame comprises a head tube to which a front fork is pivotally connected, a front wheel rotatably connected to the fork, a handlebar with an extension tube connected to the fork for steering the bicycle, a rear wheel rotatably connected to the rear fork of the frame, a crankset with pedals, cranks and a transmission drive wheel, a flexible power transmission element between the transmission drive wheel of the crankset and the transmission driven wheel of the rear wheel, a socket for accommodating a battery pack, and a seat tube for receiving a seat post with a saddle.

[0019] The frame of the bicycle of the invention is configured as a step-through frame, which in the side view of the frame comprises a substantially straight main frame part with a downwards open U-shaped cross section at least in the area of the crankset in the situation of use.

[0020] At one end of the main frame part (i.e. at the front end of the frame in the direction of travel of the bicycle) there is a diagonal tube arranged at an angle in relation to the main frame part, with the head tube for receiving the front fork at the other end. At the other end of the main frame part (i.e. at the rear end of the frame in the direction of travel of the bicycle), a rear fork with two parallel support profiles projecting from the sides of the main part is formed.

[0021] The said main frame part with a U-shaped cross section is configured to receive a crankset module, removable from the frame as a single piece, which comprises, among other items, pedals, cranks, and the transmission drive wheel of the crankset.

[0022] When the bicycle is configured as an electric bicycle, the crankset modulefurther comprises a crankset motor (auxiliary motor), the power of which is transferred to the crank shaft, on which the transmission drive wheel, i.e. sprocket wheel or pulley wheel, is located, from which the power is transferred to the transmission driven wheel of the rear wheel, which is a sprocket or pulley wheel.

[0023] In the first embodiment of the invention, the socket for fitting a battery pack is located at the front end of the main frame part, or in other words, this socket is located in the front part of the frame. In the first embodiment of the socket, a battery pack can be inserted into the socket from the end of the straight main part of the frame. In the second embodiment, a battery pack can be inserted into the socket in the situation of use of the bicycle from above in relation to the straight main part of the frame, in the third embodiment a battery pack can be inserted into the socket in the situation of use of the bicycle from below in relation to the straight main part of the frame, and in the fourth embodiment a battery pack can be inserted into the socket in the situation of use of the bicycle from the side of the straight main part of the frame.

[0024] In the second embodiment of the invention, the flexible drive-train or flexible power transmission element between the transmission drive wheel of the crankset in the crankset module and the transmission driven wheel of the rear wheel is configured as a chain drive, in which the transmission drive wheel of the crankset and the transmission driven wheel of the rear wheel are chain wheels.

[0025] In the third embodiment of the invention, the flexible drive-train or flexible power transmission element between the transmission drive wheel of the crankset in the crankset module and the transmission driven wheel of the rear wheel is configured as a toothed belt drive, in which the transmission drive wheel of the crankset and the transmission driven wheel of the rear wheel are pulley wheels.

[0026] In the fourth embodiment of the invention, the diagonal tube arranged at an angle in relation to the main frame part is configured as a straight or curved tube.

[0027] The frame is preferably made of metal, such as steel or most preferably aluminum alloy.

[0028] In the fifth embodiment of the invention, the bicycle is configured as an electric bicycle, comprising a battery pack in the frame and a crankset module comprising a crankset motor.

[0029] In the sixth embodiment of the invention, the bicycle is configured as a regular bicycle, where the crankset module comprises only muscle-powered cranks with pedals for transferring the power to the rear wheel.

[0030] In the solution of the invention, the crankset with pedals and cranks is integrated into a separate crankset module, which is attached as a whole to the main frame part with U-shaped cross section in a manner enabling its removal.

[0031] In the preferred embodiment of the invention, the crankset module with pedals and cranks comprises an electric crankset motor which is configured to be attached as a whole to the said main frame part with U-shaped cross section in a manner enabling its removal.

[0032] In the seventh embodiment of the invention, the crankset module with pedals and cranks is configured to be attached as a whole to the main frame part with U- shaped cross section in a manner enabling its removal - in this version, the crankset module does not comprise a crankset motor (i.e. auxiliary motor) and is operated only by muscular power of the rider.

[0033] The crankset module can be inserted into and removed from the main frame part with U-shaped cross section transversely to the direction of the frame in side view of the frame.

[0034] In the eighth embodiment of the invention, the bicycle is configured as an electric bicycle, comprising a battery pack in the frame and a crankset module comprising a crankset motor.

[0035] In the ninth embodiment of the invention, the bicycle is configured as a regular bicycle, where the crankset module comprises only muscle-powered cranks with pedals for transferring the power to the rear wheel, i.e. the bicycle is configured without an auxiliary motor.

[0036] The bicycle frame with modular adjustable configuration is configured as a step-through frame, where the front part and the main part of the frame are formed as a U-shaped profile, which is open downwards in side view of the frame. A diagonal tube is connected to the front part of the frame, to which the head tube is connected in turn. A seat tube is connected to the main frame part. The rear fork is formed as two parallel profiles protruding from the main frame part as an extension.A socket is formed for a battery pack in the front part of the frame. The main frame part has notches for the crank shaft included in the crankset module for receiving the crankset module.BRIEF DESCRIPTION OF DRAWINGS

[0037] The invention is described below with reference to the appended schematic figures, where:Figure 1 illustrates a side view and Figure 2 an axonometric view of a modular bicycle with adjustable configuration of the invention;Figure 3 illustrates an axonometric view with separated details of the frame of the bicycle of the invention, the crankset module arranged in the frame, with a battery pack, front fork, and handlebar with an extension tube;Figure 4 illustrates a spatial bottom view, Figure 5 a side view, and Figure 6 a bottom view of the frame of the bicycle of the invention with the crankset module moved out of it;Figure 7 illustrates an axonometric rear view and Figure 8 a side view of the frame of the bicycle of the invention with the crankset module moved out of the frame;Figure 9 illustrates an axonometric front view, Figure 10 a straight front view and Figure 11 a side view of the frame of the bicycle of the invention with the crankset module arranged in it and the battery pack moved out of the frame.DESCRIPTION OF EMBODIMENTS

[0038] For the sake of clarity, the same details and elements have the same reference numbers in different figures.

[0039] The bicycle 1 of figures 1 and 2 comprises a frame 2, comprising a head tube 4 receiving the front fork 3 and a diagonal tube 6 connected to the front part 5 of the frame 2. In the rear part of the frame 2 there is the rear fork 7 with the rear wheel 8 between it, surrounded by the rear mudguard 9. The front fork is inserted into the head tube 4 of the frame 2 in the manner enabling rotation, with a front wheel 10 attached into it in rotating manner. The handlebar 12 for steering the bicycle is connected to the front fork 3 via the extension tube 11 .

[0040] The crankset module 14 is inserted into the main part 13 of the frame 2 with U-shaped cross section, comprising cranks 16 with pedals 15 at the ends of the crank shaft (not separately illustrated) - see Figure 4.

[0041] In the illustrated embodiment, the front fork 3 comprises connection elements 17 for a charging station. The bicycle is also equipped with a front basket 18. A control module 19 with displays of the electric bicycle is arranged on the handlebar 12 - see Figure 3.

[0042] In the illustrated embodiment, the battery pack 20 (i.e. the battery module) is arranged in the front part 5 of the frame 2 and can be removed from the socket in the frame at the end of the frame 2.

[0043] The seat tube 21 for receiving the seat post 23 with the saddle 22 protrudes from the frame 2. In the frame 2 illustrated in the figures, the diagonal tube 6 is configured as a curved tube, but it can also be a straight profile.

[0044] As illustrated in Figure 4, the main part 13 of the frame 2 has U-shaped profile, which is open downwards. At this place, the frame 2 comprises notches 24 for receiving the crank shaft together with the transmission drive wheel 25, in the illustrated embodiment the chain wheel, with the flexible power transmission element 26, in the illustrated embodiment the chain. In the situation illustrated in figures 4, 5, and 7, the crankset module 14 is moved out of the main part 13 of the frame 2.

[0045] Figures 7 and 8 also show the crankset motor 27 comprised in the crankset module 14, which can be moved with the entire crankset module 14 in the direction indicated with the arrows into the main part 13 of the frame 2 comprising notches 24 for the ends of the crank shaft. Such configuration enables to replace the crankset module 14 without removing the rear wheel 8.

[0046] Figures 9, 10, and 11 illustrate the arrangement of the battery pack 20 in the front part 5 of the frame 2 in the socket formed by the frame. In addition to the illustrated embodiments, the battery pack may be removed from and installed into the frame from below, top, or side of the frame.

[0047] In the embodiments of the invention illustrated in figures 3 to 10, frame 2 is made of aluminum alloy profiles. The front part 5 and the main part 13 of the frame2 are formed as a U-shaped profile, which is open downwards. A diagonal tube 6 is welded to the front part 5 of frame 2, onto which in turn the head tube 4 is installed. Also, the seat tube 21 is welded to the main part 13.

[0048] In the illustrated embodiment, also additional supports adding rigidity are shown between the front part 5 of the frame 2 and the diagonal tube 6, and between the seat tube 21 and the frame 2, but the frame may be configured without them as well.

[0049] The rear fork 7 is formed as two parallel profiles protruding from the main part 13 of the frame 2 as an extension. For the battery pack 20, the front part 5 of the frame 2 is configured closed when viewed from the bottom, i.e. there is a socket for the battery pack 20 in the front part 5 of the frame 2. The main part 13 of the frame 2 has notches 24 for the crank shaft included in the crankset module 14 for receiving the crankset module 14. The seat tube 21 is configured with enlarged diameter, accommodating a separate thinner tube for receiving the seat post 23. The remaining space in the seat tube 21 can be used for fitting an additional electronic unit or battery pack. In the illustrated embodiment, there is the rear light of the bicycle at the top part of the seat tube 21 .

[0050] Such step-through frame 2 of the bicycle enables to configure the bicycle with mudguards of various design and construction, and to use different types of footrests, brakes, lights, and baskets 18.INDUSTRIAL APPLICABILITY

[0051] Bicycles of bike share and rental services are located on the streets of a city or a settlement, readily available for lending, or in specific charging stations or parking areas. The operator uses a software, which enables to monitor and check the condition of the bicycles. In case of a failure of the crankset motor, a member of the maintenance team of the operator takes an operational crankset motor together with the frame module from the workshop and drives to the location of the bicycle. On the street, the fixing bolts of the crankset module of the bicycle are loosened and the crankset module is removed from the frame.

[0052] After this, the operational crankset module brought from the workshop is installed and the fixing bolts are tightened. The bicycle does not need transport tothe workshop and is out of use only during the replacement of the module. The person who performed the maintenance takes the defective module with them, and the module (crankset motor) undergoes diagnostics and thorough inspection in the workshop to ascertain if the module can be repaired and reused. Depending on the result, the repaired module is used as a spare part or disposed of.

[0053] The system comprises a bicycle frame, a replaceable battery pack (battery module), a crankset module with a crankset motor, cranks, pedals, or a mechanical crankset substituting the crankset motor.

[0054] Bicycles of bike share and rental services are located on the streets of a city or a settlement, readily available for lending, or in specific charging stations or parking areas. Operators who operate round the year need to prepare the bicycles for winter period in the autumn. The battery pack and the crankset module comprising the crankset motor (electric motor) is removed for the winter period and replaced with a crankset module comprising only a mechanical crankset, i.e. in this configuration the bicycle is a regular bicycle, powered only by muscles of the rider.

[0055] A member of the maintenance team of the operator takes from the workshop a crankset module comprising only the mechanical crankset and drives to the location of the bicycle. They loosen the fixing bolts of the crankset module of the bicycle on the street and remove it from the frame.

[0056] A crankset module comprising the mechanical crankset taken from the workshop is replaced and the fixing bolts are tightened. Thus, the bicycle does not need to be transported to the workshop and is out of use only during the replacement of the crankset module.

[0057] The replaceable battery pack is also removed, and in case of a conventional mechanical bicycle, there is no need to replace it with anything else. The person who performed maintenance takes the crankset module and the battery pack, and they (crankset motor and the battery) undergo diagnostics and thorough inspection in the workshop to validate their condition. Depending on the result, the maintained crankset module and the battery pack are used as spare parts or disposed of.

[0058] An operator of a bike share and rental service originally operates electric bicycles with replaceable batteries in a city with no special conditions or rules of operation. As a result of intense use and expansion of the service, it is probable thatcities and settlements will want to partially regulate the market and organize corresponding procurements. Bicycle sharing with charging stations is a common requirement.

[0059] The operator adds a modular component to the front fork of the electric bicycle which is compatible with the charging station at the height of the axle of the front wheel or replaces a modular extension of the handlebar which is compatible with the charging station under the handlebar - depending on which charging station is required by the city or settlement.

[0060] The operator can adapt the same electric bicycles to the new conditions and changed requirements, and participate in the procurement and continue operation in the city or settlement. This prevents the periods of loss that would otherwise occur if the operator had to seek opportunities in other cities to use the electric bicycles which only have replaceable batteries.LIST OF REFERENCE NUMBERS

[0061] 1 bicycle2 frame3 front fork4 head tube5 front part of the frame6 diagonal tube7 rear fork8 rear wheel9 rear mudguard10 front wheel11 extension tube12 handlebar13 main part of the frame14 crankset module15 pedal16 crank17 connection element18 basket19 control module20 battery pack 21 seat tube22 saddle23 seat post24 notch25 transmission drive wheel 26 flexible power transmission element27 crankset motor

Claims

AMENDED CLAIMS received by the International Bureau on 16 December 2025 (16.12.2025)1. A modular bicycle (1) with variable configuration, comprising a frame (2), a front fork (3) pivotally connected to a head tube (4) of the frame (2), a front wheel (10) rotatably connected to the front fork (3), a handlebar (12) connected to the front fork (3) with an extension tube (11) for steering the bicycle, a rear wheel (8) rotatably connected to a rear fork (7) of the frame (2), a crankset with pedals (15), cranks (16) and a transmission drive wheel (25), a flexible power transmission element (26) between the transmission drive wheel (25) of the crankset and a transmission driven wheel of the rear wheel (8), a socket for accommodating a battery pack (20), and a seat tube (21) for receiving a seat post (23) with a saddle (22), wherein the bicycle frame (2) is configured as an open frame, which, in a side view of the frame (2), comprises a generally straight frame main part (13) which at least in the crankset area, has a U-shaped cross-section that, in the use situation, is open downwards, wherein at the end of the front part (5) of the frame (2) there is a diagonal tube (6) angled with respect to the main part (13) of the frame (2), at the other end of which there is the head tube (4) for receiving the front fork (3), and at the other end of the main part (13) of the frame (2) there is formed the rear fork (7) with two parallel support profiles projecting from the sides of the main part (13), and wherein said U-shaped cross-section frame main part (13) is configured to receive a crankset module (14) removable from the frame (2) in one piece, which comprises, among other things, the pedals (15), the cranks (16) and the transmission drive wheel (25) of the crankset, characterized in that the frame (2) is configured as a step-through frame, where the front part (5) and the main part (13) of the frame (2) are formed as a U-shaped profile, which is open downwards in side view of the frame, whereby the diagonal tube (6) is connected to the front part (5) of the frame (2), to which the head tube (4) is connected in turn, whereby the seat tube (21) is connected to the main part (13) of the frame (2), whereby the rear fork (7) is formed as two parallel profiles protruding from the main part (13) of the frame (2) as an extension of said main part (13), and whereby the socket is formed for the battery pack (20) in the front part (5) of the frame (2), whereby the main part (13) of the frame (2) has notches (24) for the crank shaft included in the crankset module (14) for receiving the crankset module (14).

2. Modular bicycle with variable configuration according to claim 1, characterized in that the crankset module (14) comprises an electric crankset motor (27).

3. Modular bicycle with variable configuration according to any preceding claim, characterized in that the socket for fitting the battery pack (20) is located in the front part (5) of the frame (2).

4. Modular bicycle with variable configuration according to claim 1, 2, or 3, characterized in that the flexible power transmission element (26) between the transmission drive wheel (25) of the crankset in the crankset module (14) and the transmission driven wheel of the rear wheel (8) is a chain drive.

5. Modular bicycle with variable configuration according to claim 1, 2, or 3, characterized in that the flexible power transmission element (26) between the transmission drive wheel (25) of the crankset in the crankset module (14) and the transmission driven wheel of the rear wheel (8) a toothed belt drive.

6. Modular bicycle with variable configuration according to any preceding claim, characterized in that the diagonal tube (6) arranged at an angle in relation to the main part (13) of the frame (2) is configured as a curved tube.

7. Modular bicycle with variable configuration according to any preceding claim 1 to 5, characterized in that the diagonal tube (6) arranged at an angle in relation to the main part (13) of the frame (2) is configured as a straight tube.

8. Modular bicycle with variable configuration according to any preceding claim, characterized in that the frame (2) is made of aluminum alloy.

9. Modular bicycle with variable configuration according to claim 1, characterized in that the bicycle (1) is configured as an electric bicycle, comprising the battery pack (20) in the frame (2) and the crankset module (14) comprising a crankset motor (27).

10. Modular bicycle with variable configuration according to claim 1, characterized in that the bicycle (1) is configured as a regular bicycle, where the crankset module (14) only comprises the cranks (16), the pedals (15) and the transmission drive wheel (25) to be operated by muscular power for transferring the power to the rear wheel (8).

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