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Title:
CONVERSION KIT FOR CONVERTING A TWO-WHEELED CYCLE TO A THREE-WHEELED CYCLE
Document Type and Number:
WIPO Patent Application WO/2020/239575
Kind Code:
A1
Abstract:
The invention comprises a conversion kit for converting a cycle comprising a cycle frame with a rear fork, a front wheel and a single rear wheel, into a cycle with three wheels, comprising a front wheel and two rear wheels, wherein the conversion kit comprises: - a frame (10) comprising a right and a left rear-fork fastening point, - a right rear wheel (1030), - a left rear wheel (930), - a right support bar (600) which extends upwards and forwards from the frame, and which has a right bar-fastening point at its top end, - a left support bar (500) which extends upwards and forwards from the frame, and which has a left bar-fastening point at its top end.

Inventors:
DROST MAIKEL (NL)
TE VELTHUIS ERNST JAN GIJSBERT (NL)
Application Number:
EP2020/064067
Publication Date:
December 03, 2020
Filing Date:
May 20, 2020
Export Citation:
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Assignee:
DE VOORWERKERS MOBILITEIT B V (NL)
International Classes:
B62K5/02; B62K13/04
Foreign References:
US2995378A1961-08-08
US3827705A1974-08-06
US3834721A1974-09-10
Attorney, Agent or Firm:
EP&C (NL)
Download PDF:
Claims:
CLAIMS

1. Conversion kit for converting a cycle comprising a cycle frame with a rear fork, a front wheel and a single rear wheel, into a cycle with three wheels, comprising a front wheel and two rear wheels, wherein the conversion kit comprises:

- a frame (10) comprising a right and a left rear-fork fastening point (321 , 311),

- a right rear wheel (1030),

- a left rear wheel (930),

- a right support bar (600) which extends upwards and forwards from the frame, and which has a right bar-fastening point (601) at its top end,

- a left support bar (500) which extends upwards and forwards from the frame, and which has a left bar-fastening point (501) at its top end,

wherein the frame of the conversion kit is configured to be fastened to the cycle frame so as to be detachable,

wherein the conversion kit is configured to be fastened to the rear fork of the cycle via the right and the left rear fork fastening point and to be fastened to the cycle frame via the right and left bar-fastening point at a point which is situated above the rear wheel axle and, in side and top view, in front of the rear wheel axle,

wherein the conversion kit comprises a drive mechanism (1100) which is configured to be coupled to the original cycle drive mechanism of the cycle at the rear wheel axle, in such a way that the rear wheels of the conversion kit can be driven by means of the original pedals,

characterized in that the frame is substantially made from plate material.

2. Conversion kit according to claim 1 , wherein the plate material comprises several folds.

3. Conversion kit according to any of the preceding claims, wherein the frame

comprises:

- a left plate part (100) which forms a left side of the frame and a right plate part (200) which forms a right side of the frame,

- a left axle-supporting plate (310) which includes the left rear fork fastening point and a right axle-supporting plate (320) which includes the right rear fork fastening point,

- a central plate part (400) which connects the left plate part and the right plate part to one another, and wherein, in top view, the left axle-supporting plate and the right axle-supporting plate are situated in front of the central plate part.

4. Conversion kit according to claim 3, wherein the central plate part is configured to extend at least partly under the drive mechanism of the left rear wheel and the right rear wheel from a left side of the frame to a right side of the frame, wherein the central plate part, in rear view, in particular has the shape a U or a V.

5. Conversion kit according to any of claims 3 - 4, wherein the left plate part has a left main part (110) and a left transition part (120) which is situated on the inside thereof and slopes downwards and wherein the right plate part has a right main part (210) and a right transition part (220) which is situated on the inside thereof and slopes downwards, wherein the central plate part is connected to an inner edge of the left and right transition parts and connects these to one another.

6. Conversion kit according to any of claims 3 - 5, wherein a left fold or left bend (101) which extends in a longitudinal direction is situated between the left main part and left transition part, and wherein a right fold or right bend (201) which extends in a longitudinal direction is situated between the right main part and the right transition part.

7. Conversion kit according to any of claims 3 - 6, wherein the frame furthermore

comprises a central supporting part (300) which forms a further connection between the left main part and the right main part.

8. Conversion kit according to any of claims 5 - 7, wherein the left axle-supporting plate and the right axle-supporting plate extend upwards from the central supporting part.

9. Conversion kit according to any of claims 3 - 8, wherein the left plate part and the right plate part are oriented substantially horizontally or sloping outwards at an angle, except for the respective transition parts, with the axle-supporting plates being oriented substantially vertically and with the central supporting part being oriented substantially vertically.

10. Conversion kit according to any of claims 3 - 9, wherein the left plate part comprises a left front-edge fold (102), a left side-edge fold (103) and a left rear fold (104), in such a way that the left, front and rear edges of the left plate part are folded downwards, wherein the right plate part comprises a right front-edge fold (202), a right side-edge fold (203) and a right rear fold (204), in such a way that the left, front and rear edges of the right plate part are folded downwards.

11. Conversion kit according to any of the preceding claims, comprising a securing

member (20) which is configured to be fastened to the cycle frame and to fasten the right and left bar-fastening point to the cycle frame.

12. Conversion kit according to any of the preceding claims, wherein all connections between the conversion kit and the cycle frame are detachable and are, in particular, bolt connections.

13. Conversion kit according to any of claims 8 - 12, wherein the support bars are

connected to the left and the right plate part, respectively.

14. Conversion kit according to any of claims 3 - 13, wherein the left plate part and the right plate part each comprise a bar hole (112, 212) through which the left support bar and the right support bar, respectively, extend upwards.

15. Conversion kit according to any of the preceding claims, wherein the rear wheels are smaller than the original rear wheel, and wherein the axles of the rear wheels are offset in a downward position with respect to the original rear wheel axle, and wherein the axles of the rear wheels are offset in a rearward direction with respect to the original rear wheel axle.

16. Conversion kit according to any of the preceding claims, wherein both rear wheels are driven from a hub (1110) which is situated in the rear fork, and wherein the hub, in particular, is driven by the original cycle chain.

17. Conversion kit according to any of the preceding claims, wherein the conversion kit comprises a left drive mechanism (1120) and a right drive mechanism (1130) for independently driving the left and the right rear wheel, respectively, wherein a freewheeling bearing (1121 , 1131) is incorporated in both the left drive mechanism and the right drive mechanism, in such a way that each rear wheel can rotate faster, but not slower than the speed which is determined by a common part of the drive mechanism.

18. Conversion kit according to any of claims 1 - 17, wherein the conversion kit

comprises a left axle (900) and a right axle (1000), wherein the rear wheels are connected to the respective axles, wherein each axle is mounted on the frame so as to run on bearings in at least two locations (910, 920, 1010, 1020).

19. Conversion kit according to claim 17, wherein both rear wheels are connected to a common axle which is mounted on the frame so as to run on bearings in at least two locations by means of bearings which allow each rear wheel to rotate faster, but not slower than the speed which is determined by the drive mechanism, wherein the common axle is driven by a chain which is driven by a drive gear on the hub and which drives an axle gear on the common axle.

20. Conversion kit according to claim 18, wherein a left axle gear (1123) and a right axle gear (1133) are attached to the left axle and op the right axle, respectively, which are driven by a left chain (1124) and a right chain (1134), respectively. 21. Conversion kit according to claim 20, wherein the left chain and the right chain are driven by a left drive gear (1122) and a right drive gear (1132), respectively, wherein the left drive gear is a different gear than the right drive gear.

22. Cycle with three wheels, comprising a frame which is constructed according to any of the preceding claims.

Description:
Title: Conversion kit for converting a two-wheeled cycle to a three-wheeled cycle

Introduction

The invention relates to a conversion kit for converting a cycle with two wheels to a cycle with three wheels. Such conversion kits are known, for example from US3834721 and in the form of the Altena Bike Opus 3.

Background of the invention

Current conversion kits for converting a cycle to a tricycle are often expensive, heavy and visually unattractive. In addition, current conversion kits often require permanent

modifications to the original cycle frame, as a result of which returning to a cycle with two wheels is not readily possible. Also, the three-wheeled cycles which have been produced using these conversion kits often do not have ideal handling characteristics.

Summary of the invention

In order to solve at least one of these problems, the invention provides a conversion kit for converting a cycle comprising a cycle frame with a rear fork, a front wheel and a single rear wheel, into a cycle with three wheels, comprising a front wheel and two rear wheels, wherein the conversion kit comprises:

- a frame comprising a right and a left rear-fork fastening point,

- a right rear wheel,

- a left rear wheel,

- a right support bar which extends upwards and forwards from the frame, and which has a right bar-fastening point at its top end,

- a left support bar which extends upwards and forwards from the frame, and which has a left bar-fastening point at its top end,

wherein the frame of the conversion kit is configured to be fastened to the cycle frame so as to be detachable,

wherein the conversion kit is configured to be fastened to the rear fork of the cycle via the right and the left rear-fork fastening point and to be fastened to the cycle frame via the right and left bar-fastening point at a point which is situated above the rear wheel axle and, in side and top view, in front of the rear wheel axle,

wherein the conversion kit comprises a drive mechanism which is configured to be coupled to the original drive mechanism of the cycle at the rear wheel axle, in such a way that the rear wheels of the conversion kit can be driven by means of the original pedals,

characterized in that the frame is substantially made from plate material. By using plate material in the frame, this frame can be made lighter and less expensive to produce than if traditional frame tubes were to be used. Plate material has a higher air resistance than frame tubes, but in view of the expected limited speed of three-wheeled cycles, this drawback is acceptable.

In a preferred embodiment, a substantial part of the frame is made from a blank which has several folds, thereby making quick production possible. Folds can be made relatively easily and inexpensively and are easier and less expensive than welded connections.

In one embodiment, the plate material in the frame comprises several folds. This imparts greater strength to the frame, as a result of which thinner plate material can be used, thus further reducing the weight. In addition, the frame may be made from a relatively large blank, so that relatively few cutting operations are required to cut the blank from a plate. In addition, the loss of material may furthermore be kept to a minimum by efficiently fitting the plate parts on the blank adjacent to one another.

In one embodiment, the frame comprises a left plate part which forms a left side of the frame and a right plate part which forms a right side of the frame, a left axle-supporting plate which includes the left rear-fork fastening point and a right axle-supporting plate which includes the right rear-fork fastening point and a central plate part which connects the left plate part and the right plate part with one another,

wherein, in top view, the left axle-supporting plate and the right axle-supporting plate are situated in front of the central plate part. This arrangement of components contributes to the strength of the frame and the ease of installation of the conversion kit.

In a further embodiment, the central plate part is configured to extend at least partly under the drive mechanism of the left rear wheel and the right rear wheel from a left side of the frame to a right side of the frame, wherein the central plate part, in rear view, in particular has the shape of a U or a V. This configuration contributes to the strength of the frame and the ease of installation of the conversion kit.

In a further embodiment, the left plate part has a left main part and left transition part which is situated on the inside thereof and slopes downwards and the right plate part has a right main part and a right transition part which is situated on the inside thereof and slopes downwards, wherein the central plate part is connected to an inner edge of the left and right transition parts and connects these to each other. This configuration contributes to the strength of the frame. In a further embodiment, a left fold or left bend which extends in a longitudinal direction is situated between the left main part and left transition part and a right fold or right bend which extends in a longitudinal direction is situated between the right main part and the right transition part. These folds or bends contribute to the strength of the frame and are relatively easy to produce.

In a further embodiment, the frame furthermore comprises a central supporting part which forms a further connection between the left plate part and the right plate part. The central supporting part may also be connected to the central plate part. The central supporting part may be made of a stronger plate material than the rest of the frame, for example by using thicker material or by using a different material. This configuration contributes to the strength of the frame.

In a further embodiment, the left axle-supporting plate and the right axle-supporting plate extend upwards from the central supporting part.

In one embodiment, the left plate part and the right plate part are oriented substantially horizontally or sloping outwardly at an angle, except for the respective transition parts, with the axle-supporting plates being oriented substantially vertically and with the central supporting part being oriented substantially vertically. This arrangement inter alia contributes to an attractive appearance of the frame.

In one embodiment, the left plate part comprises a left front-edge fold, a left side-edge fold and a left rear fold, in such a way that the left, front and rear edges of the left plate part are folded downwards and the right plate part comprises a right front-edge fold, a right side-edge fold and a right rear fold, in such a way that the left, front and rear edges of the right plate part are folded downwards. The folded rear edges of the left and the right plate part may in this case comprise a diagonal fold. These folds contribute to the strength of the frame and contribute to an attractive appearance of the frame. The left front-edge fold, the left side- edge fold, the right front-edge fold and the right side-edge fold partly hide the bottom side from view and prevent sharp edges of the plate material from projecting laterally.

In one embodiment, the conversion kit comprises a securing member which is configured to be fastened to the cycle frame and to fasten the right and left bar-fastening point to the cycle frame. In one embodiment, all connections between the conversion kit and the cycle frame are detachable and are, in particular, bolt connections, screw connections or clamping members. As a result thereof, installation of the conversion kit on the cycle is simple and not permanent and the conversion kit can also readily be removed from the cycle, which makes it possible to convert it back to a two-wheeled cycle.

In one embodiment, the support bars are connected to the left and the right plate part, respectively. In a further embodiment, the left plate part and the right plate part each comprise a hole through which the left support bar and the right support bar, respectively, extend upwards. As a result thereof, the support bars can be attached on the inside of the folded edges of the left- and right plate part, which reduces the number of outwardly protruding parts on the frame compared to attaching the support bars on the outside of the frame. This reduces the risk of damage to the conversion kit or items which come into contact therewith and of injuries of the user and contributes to a visually attractive

appearance of the conversion kit.

In one embodiment, the rear wheels are smaller than the original rear wheel and the axles of the rear wheels are offset in a downward and rearward direction with respect to the original rear axle. This creates more space for the frame and makes it possible to adhere to the original height of the cycle.

In one embodiment, both rear wheels are driven by a hub which is situated in the rear fork, wherein the hub, in particular, is driven by the original cycle chain. This arrangement facilitates installation of the conversion kit and a potential conversion back to a two-wheeled cycle.

In one embodiment, the conversion kit comprises a left drive mechanism and a right drive mechanism for independently driving the left and the right rear wheel, respectively, wherein a freewheeling bearing is incorporated in both the left drive mechanism and the right drive mechanism, in such a way that each rear wheel can rotate faster, but not slower than the speed which is determined by a common part of the drive mechanism. This arrangement allows the wheels to rotate at different speeds, in which case the fastest wheel freewheels and the slowest wheel may be driven. If the wheels rotate at the same speed, both wheels may be driven. This arrangement provides good traction and straight line stability and permits the wheels to rotate at different speeds in corners, wherein the three-wheeled cycle behaves in an identical manner in left and right corners, because it is always driven by the inner wheel, unless this wheel does not have any or insufficient traction. In a further embodiment, both rear wheels are connected to a common axle which is mounted on the frame so as to run on bearings in at least two locations by means of bearings which allow each rear wheel to rotate faster, but not slower than the speed which is determined by the drive mechanism, wherein the common axle is driven by a chain which is driven by a drive gear on the hub and which drives an axle gear on the common axle. In this way, it is still possible for the wheels to rotate at different speeds while using a single drive chain and a single rear axle, in which case the fastest rotating wheel freewheels and the slowest rotating wheel may be driven.

In another embodiment, the conversion kit comprises a left axle and a right axle, wherein the rear wheels are connected to the respective axles, wherein each axle is mounted on the frame so as to run on bearings in at least two locations. In a further embodiment, a left axle gear and a right axle gear are attached to the left axle and to the right axle, respectively, which are driven by a left chain and a right chain, respectively.

In a further embodiment, the left chain and the right chain are respectively driven by a left drive gear and a right drive gear, wherein the left drive gear is a different gear than the right drive gear.

In a further embodiment, the rear axles are connected to the respective axle gears by a bearing which permits an axle to rotate faster than the associated axle gear, but does not permit an axle to rotate slower than the associated axle gear. In an alternative embodiment, the rear wheels are connected to the respective axles by a bearing which permits an axle to rotate slower than the associated wheel, but does not permit an axle to rotate faster than the associated wheel.

In a further embodiment, the conversion kit comprises a braking device for each of the two rear wheels.

It will be clear that aspects or embodiments of the invention can be combined.

Brief description of the figures

The figures illustrate examples of embodiments of the invention by means of which the invention is explained in more detail. The figures and the description thereof are intended to illustrate the invention and are not to be interpreted as limiting. Herein, the figures relate to the following:

Fig. 1 shows a diagrammatic illustration of an embodiment of the conversion kit installed on a part of a cycle frame, Fig. 2 shows a diagrammatic illustration of the embodiment of the conversion kit from Fig. 1 from a different angle,

Fig. 3 shows an blank illustration of the plate parts of the embodiment of the conversion kit from Figs. 1 and 2,

Fig. 4 shows a diagrammatic illustration of an alternative embodiment of the frame of the conversion kit,

Fig. 5 shows a diagrammatic illustration of the frame of the embodiment from Fig. 4,

Fig. 6 shows a blank illustration of the plate parts of the embodiment of the conversion kit from Figs. 4 and 5, in which the weld seams and bolt connections are denoted by means of letter codes.

Fig. 7 shows the embodiment from Figs. 4 - 6 of the conversion kit installed on a cycle.

Detailed description of the figures

Figs. 1 and 2 show different views of the same embodiment of a conversion kit for converting a cycle comprising a cycle frame 1 with a rear fork 2, a front wheel and a single rear wheel (both not shown), to a cycle with three wheels, comprising a front wheel and two rear wheels 930, 1030. For the sake of clarity, a number of components are not shown in the figures.

Figs. 4 and 5 show different views of the same alternative embodiment.

The conversion kit comprises a frame 10 which comprises a right and a left rear-fork fastening point 321 , 311 , a right rear wheel 1030, not shown in Figs. 1 and 2, and a left rear wheel 930.

The conversion kit furthermore comprises a right support bar 600 which extends upwards and forwards from the frame and which has a right bar-fastening point 601 at its top end, and a left support bar 500 which extends upwards and forwards from the frame 10 and which has a left bar-fastening point 501 at its the top end.

The frame 10 of the conversion kit is configured to be detachably fastened to the cycle frame. The conversion kit is configured to be fastened to the rear fork 2 of the cycle frame 1 via the right and the left rear-fork fastening point 321 , 311 and to be fastened to the cycle frame at a point which is situated above the rear wheel axle and, in side and top view, in front of the rear wheel axle, via the right- and left bar-fastening point 601 , 501. In the embodiment from Figs. 1 and 2, this point is situated on the saddle support bar 3 of the cycle frame 1 and a securing member 20 is used to fasten both support bars to the cycle frame 1. The conversion kit comprises a drive mechanism 1100 which is configured to be coupled to the original cycle drive mechanism at the original rear wheel axle, in such a way that the rear wheels 930, 1030 of the conversion kit can be driven by means of the original pedals.

The frame 10 is substantially made from plate material.

In the illustrated embodiments, the frame 10 comprises folds in the plate material 101 , 102, 103, 104, 201, 202, 203, 204. Furthermore, the frame comprises a left plate part 100 which forms a left side of the frame and a right plate part 200 which forms a right side of the frame, a left axle-supporting plate 310 which includes the left rear fork fastening point 311 and a right axle-supporting plate 320 which includes the right rear fork fastening point 321 , and a central plate part 400 which connects the left plate part 100 and the right plate part 200 to one another.

In top view, the left axle-supporting plate 310 and the right axle-supporting plate 320 are positioned in front of the central plate part 400.

In the illustrated embodiment, the central plate part 400 is configured to extend at least partly under the drive mechanism of the left rear wheel and the right rear wheel from a left side of the frame 10 to a right side of the frame 10. In rear view, the central plate part 400 may, in particular, have the shape of a U or a V.

The left plate part 100 comprises a left main part 110 and a left transition part 120 which is situated on the inside thereof and slopes downwards and the right plate part 200 comprises a right main part 210 and a right transition part 220 which is situated on the inside thereof and slopes downwards, wherein the central plate part 400 is connected to the inner edge of the left and right transition parts and connects these to one another.

Between the left main part 100 and the left transition part 120, there is a left fold or left bend 101 which extends in a longitudinal direction, and between the right main part 200 and the right transition part 220, there is a right fold or right bend 201 which extends in a longitudinal direction.

The frame 10 from the embodiment in Figs. 1 - 3 furthermore comprises a central supporting part 300 which forms a further connection between the left plate part 100 and the right plate part 200 and is oriented substantially vertically. The left axle-supporting plate 310 and the right axle-supporting plate 320 extend upwards from the central supporting part 300. In the illustrated embodiment, the left and right axle-supporting plates 310, 320 form part of the central supporting part 300. The central supporting part 300 is made from thicker plate material than the left plate part and the right plate part in order to achieve an optimum relationship between strength and weight of the frame.

The frame 10 from the embodiment in Figs. 4 - 7 does not comprise a central supporting part 400. This embodiment does however comprise a rear plate 1400 and reinforcing parts 1200, 1300. The left axle-supporting plate 310 and the right axle-supporting plate 320 extend upwards from the left plate part 100 and the right plate part 200, respectively. The rear plate forms a further connection between the left plate part 100 and the right plate part 200 and comprises the same diagonal folds 105, 205 as the left plate part 100 and the right plate part 200.

Except for the respective transition parts 120, 220, the left plate part 100 and the right plate part 200 are oriented substantially horizontally or sloping outwardly at an angle. The axle supporting plates 310, 320 are oriented substantially vertically.

The left plate part 100 comprises a left front-edge fold 102, a left side-edge fold 103 and a left rear fold 104, in such a way that the left, front and rear edges of the left plate part are folded downwards. The folded rear edge of the left plate part 100 also comprises a diagonal fold 105 which runs outwards from the centre and upwards. The right plate part 200 comprises a right front-edge fold 202, a right side-edge fold 203 and a right rear fold 204, in such a way that the left, front and rear edges of the right plate part are folded downwards.

The folded rear edge of the right plate part 200 also comprises a diagonal fold 205 which runs outwards from the centre and upwards.

The illustrated embodiments of the conversion kit are connected to the rear fork 2 of the cycle frame 1 by means of bolt connections at the left rear fork fastening point 311 , the right rear fork fastening point 321 , the left bar-fastening point 501 and the right bar-fastening point 601. The bottom sides of support bars 500, 600 are connected to the left and the right plate part 100, 200, respectively, and in the embodiment from Figs. 4 - 7 also to the rear plate 1400. The left plate part 100 and the right plate part 200 each comprise a bar hole 112, 212 through which the left support bar 500 and the right support bar 600, respectively, extend upwards.

In the illustrated embodiments, the rear wheels 930, 1030 are smaller than the original rear wheel and the axles of the rear wheels 900, 1000 are offset in a downward and rearward direction with respect to the original rear axle. Both rear wheels are driven by a hub 1110 which is situated in the rear fork 2 at the same location as the original rear wheel hub, the hub 1110 being driven by the original cycle chain. The conversion kit comprises a left drive mechanism 1120 and a right drive mechanism 1130 for independently driving the left rear wheel 930 and the right rear wheel 1030, a freewheeling bearing 1121 , 1131 being accommodated in both the left drive mechanism 1120 and the right drive mechanism 1130, in such a way that every rear wheel 930, 1030 can rotate at a speed which is quicker, but not slower than the speed which is determined by a common part of the drive mechanism.

The left drive mechanism 1120 and the right drive mechanism 1130 furthermore each comprise a drive gear 1122, 1132 on the hub 1110, an axle gear 1123, 1133 on the respective wheel axle and a chain 1024, 1034, the drive gear 1122, 1132 driving the axle gear 1123, 1133 by means of the chain 1024, 1034.

In the illustrated embodiment, the common part of the drive mechanism inter alia comprises the hub 1110, the original cycle chain (not shown) and the pedals (not shown). The illustrated embodiment comprises a left axle 900 and a right axle 1000, wherein the rear wheels 930, 1030 are connected to the respective axles, wherein each axle is mounted on the frame so as to run on bearings in at least two locations 910, 920, 1010, 1020. The left axle passes through an inner left axle hole 121 and an outer left axle hole 112 in the left plate part 100 and the right axle passes through an inner right axle hole 221 and an outer right axle hole 212 in the right plate part 200.

In order to be able to tension the original cycle chain of a two-wheeled cycle, the rear wheel is generally displaceable in the longitudinal direction. With a three-wheeled cycle, provided with the conversion kit of the present invention, the hub 1110 may be displaceable in the longitudinal direction using the same or a similar mechanism in order to be able to tension the original cycle chain. In this case, the frame moves along via the rear fork fastening points 311 and 321. In this case, support bars 500 and 600 may be adjustable in length.

The illustrated embodiment furthermore comprises a braking system for both rear wheels, which comprises an associated braking device 700, 800 for every rear wheel. The braking devices comprise a brake disc 710, 810, a brake calliper 720, 820 and a brake calliper holder 730, 830.

As is required, a detailed embodiment of the invention has been described above. However, it is assumed to be clear that other variations are also possible. Therefore, the figures and description of the figures are to be seen as illustrative and not as limiting for the invention which is defined in the claims. Key to reference numerals

1 Cycle frame

2 Rear fork

3 Saddle support bar

10 Frame

20 Securing member

100 Left plate part

101 Left fold

102 Left front-edge fold

103 Left side-edge fold

104 Left rear fold

105 Left diagonal fold

110 Left main part

111 Outer left axle hole

112 Left bar hole

120 Left transition part

121 Inner left axle hole

200 Right plate part

201 Right fold

202 Right front-edge fold

203 Right side-edge fold

204 Right rear fold

205 Right diagonal fold

210 Right main part

211 Outer right axle hole

212 Right bar hole

220 Right transition part

221 Inner right axle hole

300 Central supporting part

310 Left axle-supporting plate

311 Left rear fork fastening point

320 Right axle-supporting plate

321 Right rear fork fastening point 400 Central plate part

500 Left support bar

501 Left bar-fastening point

600 Right support bar

601 Right bar-fastening point

700 Left braking device 710 Left brake disc

720 Left brake calliper

730 Left brake calliper holder

800 Right braking device 810 Right brake disc

820 Right brake calliper 830 Right brake calliper holder

900 Left axle

910 Inner left axle bearing 920 Outer left axle bearing 930 Left rear wheel

1000 Right axle

1010 Inner right axle bearing 1020 Outer right axle bearing 1030 Right rear wheel

1100 Drive mechanism

1110 Hub

1120 Left drive mechanism

1121 Left freewheeling bearing

1122 Left drive gear

1123 Left axle gear

1124 Left chain

1130 Right drive mechanism

1131 Right freewheeling bearing 1132 Right drive gear

1133 Right axle gear

1134 Right chain 1200 Left reinforcing part

1300 Right reinforcing part 1400 Rear plate