The present invention relates to a frame for converting a bicycle from electric-powered to muscle-powered motion and vice versa.

Conventional bikes or bicycles are usually constituted by a frame composed of various tubular elements so as to obtain a structure that is substantially composed by a substantially horizontal tubular body which, at one end, is radiused to a head tube for the steering system and to an oblique tubular body, and at the other end is radiused to a substantially vertical tubular body with which a seat post is associated.

At the connection of the seat post, and/or of the substantially horizontal tubular body and/or of the substantially vertical tubular body, oblique chainstays are usually connected, while at the connection of the substantially horizontal tubular body and of the substantially vertical tubular body, horizontal chainstays are connected, at the ends of such horizontal and oblique chainstays there being a seat for an axle of a wheel.

Conventional, muscle-powered bicycle frames, whether made of aluminum or of carbon, have on the lower part, at the junction between the substantially vertical tubular body, the oblique tubular body and the horizontal chainstays, a cylindrical seat for a bottom bracket which comprises a toothed wheel and pedal cranks for pedals which can be pushed by the user.

In electric bicycles, a battery pack is also provided, which is variously associated with the frame, and the electric motor is arranged for example on the rear wheel.

Electric bicycles are also known in which the motor is enclosed at adapted flanges, which define a closed body that forms part of the frame and which therefore cannot be removed, with which plastic components and/or coverings can be associated.

Alternatively, there are also other conventional frames in which a partially open flange is provided, but first the motor is fixed to it and then plastic components and coverings can be connected to it.

Such conventional bicycles are therefore created either as muscle- powered bicycles or as electric-powered bicycles, it not being possible to use one or the other type in a different mode to that for which the bicycle was purchased.

This entails a drawback, because a user must have two different kinds of bicycles if he or she wishes to go on an excursion or on tours of greater or lesser length and difficulty.

The aim of the present application is therefore to solve the above- mentioned technical problem, by devising a method that enables a user of an electric-powered bicycle to convert it rapidly and simply to a muscle- powered bicycle and vice versa.

Within the above aim, an object of the invention is to provide a method that enables a user to choose which type of bicycle to use for his or her excursions so as not to have to bring along additional weight on short excursions and, optionally, use the electric version for longer and more demanding tours.

Another object is to provide a method that enables a user to effect the conversion to the type of bicycle to be used in a very simple and rapid manner.

Another object is to provide a method that enables any user of the bicycle to carry out this conversion, even if that user cannot draw on particular manual skills or technical knowledge.

This aim and these and other objects which will become better apparent hereinafter are achieved by a method of conversion of a bicycle from electric- to muscle-powered motion, said bicycle being provided with a frame comprising electrical components for an electric motor and a battery, and with said frame it being possible to associate alternately and removably a first assembly for electric-powered motion, composed of a bash guard associated with said electric motor, powered by said battery, provided with a first crankset comprising a first chain ring associated with a chain or a second assembly for muscle-powered motion, composed of a splined flange with which a bottom bracket is associated which is provided with a second crankset comprising a second chain ring associated with a chain, characterized in that it entails:

- removing said chain only from said first crankset;

- removing said first assembly from said frame;

- disconnecting said electrical components from said electric motor;

- removing said battery from said frame;

- inserting and fixing said second assembly in said frame;

- repositioning said chain on said second crankset.

Further characteristics and advantages of the invention will become better apparent from the detailed description of a particular, but not exclusive, embodiment, illustrated by way of non-limiting example in the accompanying drawings wherein:

Figure 1 is a first side view of a frame for electric bicycles;

Figure 2 is a second side view of a frame for electric bicycles;

Figure 3 is an exploded view of the frame and the first assembly;

Figure 4 is a second view of the exploded view in the previous figure;

Figure 5 is a perspective side view of the frame and the second assembly, assembled;

Figure 6 shows the second assembly partially disassembled;

Figure 7 is an exploded view of components of the second assembly.

With reference to the figures, the reference numeral 1 refers to a bicycle frame that comprises a head tube 2, inside which seats for bearings are located for connecting a steering system or a handlebar and which is connected in a lower region to a front fork 3, a first, substantially horizontal tubular body 4, functionally connected at its ends to the head tube 2 and to an inlet 5 for mounting a saddle, a second, oblique tubular body 6 functionally connected in an upper region to the head tube 2, a third, substantially vertical tubular body 7 connected at its upper end to the first, substantially horizontal tubular body 4 at the inlet 5 and at its lower end to the second, oblique tubular body 6.

A rear stay 8 is associated at the rear with the third, substantially vertical tubular body 7 and comprises a pair of horizontal chainstays 9a, 9b and a pair of oblique chainstays 10a, 10b consisting of tubular bodies at the ends of which it is possible to rotatably associate a wheel 11 and a gearbox assembly 12.

At the connector between the second, oblique tubular body 6 and the substantially vertical tubular body 7 a first seat 13 for the removable connection is provided, by means of first screws 14 acting on first holes 15 defined on the frame 1 , of a first assembly 16 for electric-powered motion composed of a bash guard 17, a first, front support 20, a second, rear support 21 and an electric motor 19.

The electric motor 19 is contained within the first, front support 20 and the second, rear support 21.

The assembly 16 is associated, by means of adapted second screws 18, with the frame 1.

The first, front support 20 has a C-like shape in which the ends of the first wings 20a, 20b can be arranged at the first holes 15, said first wings having second holes 34a, 34b which accommodate one of the first screws 14 so as to allow the connection to the frame 1.

First tabs 24a, 24b protrude from the first base 23 of the first, front support 20, starting from the same side and on slightly inclined planes, said first tabs being perforated for the insertion of the second screws 18 which, with the interposition of adapted silent blocks (vibration damping elements) 25a, 25b, fix the bash guard 17 to the first, front support 20.

The second support 21 has a C-like shape on the second base 26 of which adapted first holes 27a, 27b are provided for interconnection to the bash guard 17 by means of adapted third screws 28a, 28b that pass through third holes 29a, 29b provided at the rear of the bash guard 17, second silent blocks (vibration damping elements) 30a, 30b being interposed between the bash guard 17 and the second base 26.

Mutually parallel L-shaped second tabs 31a, 31b protrude upward from the lateral ends of the second base 26, their second end wings 32a, 32b having, proximate to the terminal end, adapted fourth holes 33a, 33b for interconnection, by means of the first screws 14, of the assembly 16 to the frame 1.

The first assembly 16 is provided with a first crankset 35 comprising a first chain ring 36, with which the chain 22 can be associated, and a pair of pedal cranks 37a, 37b, which are fixed in a known manner to the electric motor 19.

The first chain ring 36 can be fixed to the electric motor 19 by means of an adapted connector 38.

As an alternative, a second assembly 39 for muscle-powered motion can be associated with the first seat 13, and is composed of a splined flange 40 provided with a pair of shoulders 41a, 41b, which are parallel to each other and protrude above a subframe 42 which is provided, at the front and transversely beyond the pair of shoulders 41a, 41b, with a second seat 43 for interconnection to the frame 1 by means of one of the first screws 14.

The subframe 42 has, to the rear of the pair of shoulders 41a, 41b, third tabs 44a, 44b, mutually parallel, proximate to the ends of which adapted fifth holes 45a, 45b are provided for interconnection, by means of one of the first screws 14, to the frame 1.

Each one of the pair of shoulders 41a, 41b has a third, axial seat 46 within which it is possible to removably arrange a bottom bracket having a second crankset 47 comprising a second chain ring 48 connected to a sleeve 49 which can be accommodated within the third, axial seat 46. A shaft 51 can be arranged, with the interposition of a bearing 50, within the sleeve 48, and pedal cranks 37a, 37b are connected to the ends of said shaft.

The splined flange 40 that constitutes the second assembly 39 therefore can be removably associated, by means of the first screws 14, with the first seat 13.

The method according to the invention initially entails, starting from the electric bicycle configuration shown in Figure 1, removing the chain 22 only from the first crankset 35.

Subsequently the first assembly 16 is removed from the first seat 13 of the frame 1 via the removal of the first screws 14.

Then the usual and various electrical components are unhooked or disconnected from the motor 19, such as for example a remote control, a central unit with associated display, a charging port, a range extender (supplementary battery), a battery, a connector for the motor, a speed sensor.

If required, the method then entails first disconnecting the connector which starts from the electric motor and connects to an additional first three- way connector, and then disconnecting a second connector which starts from the three-way connector and connects to the battery.

Then the battery is removed from the frame, and the second assembly 39 is inserted and fixed in said frame by means of the first screws 14.

Then all that is required is to reposition the chain on the second crankset 47.

In this manner a muscle-powered bicycle is obtained starting from an electric-powered configuration.

When the user wishes to return to the electric-powered configuration starting from the muscle-powered configuration for the bicycle, he or she will need to remove the chain 22 from the second crankset 47, then remove the second assembly 39 from the frame 1, insert the battery in the frame 1, insert the first assembly 16 in the frame 1 and fix it by means of the first screws 14, connect the electrical components to the electric motor 19, and reposition the chain 22 on the first crankset 35.

Thus it has been found that the invention fully achieves the intended aim and objects, a solution having been obtained that enables the end user to choose which type of bicycle to use for his or her excursions so as not to have to bring along additional weight on short excursions and, optionally, use the electric version for longer and more demanding tours.

This method for switching from an electric-powered configuration to a muscle-powered configuration and vice versa is extremely simple and rapid so as to enable any user to convert the bicycle even if he or she does not have specific manual skills or technical expertise.

Naturally the materials used as well as the dimensions of the individual components of the invention may be more relevant according to specific requirements.

The characteristics indicated above as advantageous, convenient or the like, may also be missing or be substituted by equivalent characteristics.

In the embodiments illustrated, individual characteristics shown in relation to specific examples may in reality be interchanged with other, different characteristics, existing in other embodiments.

The disclosures in Italian Patent Application No. 102022000021945 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.