The invention relates to a bicycle frame as well as to a bicycle comprising such a frame.
A bicycle frame is generally formed by the association of different tubes according to a
geometry allowing for the mounting in particular of wheels, of a drive system, of a
5 saddle and of a steering unit.
In particular, the frame is formed by respective disposition and association of the various tubes in order to obtain the desired geometry, said associations being in particular carried out by welding, brazing or gluing. 10
According to an embodiment, the frame comprises a saddle tube on either side of which extend a front structure comprising a steering tube carrying the front gear and a rear structure for mounting the rear wheel by connecting it to the drive system.
15 Conventionally, the front structure has an upper bar and a lower bar connecting the
saddle and steering tubes according to a geometry, for example substantially triangular, which is arranged in order to confer to the frame the expected rigidity.
Moreover, the rear structure comprises two lateral risers each formed of a strut and from 20 a base which are connected as a rear end bearing a means for associating the wheel, said risers being positioned respectively on one side of said wheel in order to provide for the association thereof in driving.
However, due to the number of tubes used, such frame structures have a substantial 25 weight. Furthermore, the multitude of tubes to be assembled generates a long manufacturing time as well as an increased risk of geometrical dispersion in the frames obtained.
In order to reduce the number of tubes, document DE-10 2007 038 109 proposes a
30 bicycle frame comprising a single upper bar and a single lower bar at the rear of which
extend in a single curved tube respectively a strut and a base which are arranged on either side of the rear wheel of the bicycle.
2

However, such a solution does not provide full satisfaction in that the carrying out of the frame remains complex, in particular concerning the mounting of the curved tubes on the steering tube and on the saddle tube, requiring several steps in particular of drilling, assembling and fastening between said tubes. 5
In particular, this embodiment proposes steering and saddle tubes that extend through passages formed in the curved tubes in order to form the respectively front and rear structures of the frame.
10 The invention aims to improve prior art by proposing in particular a bicycle frame
having a reduced number of tubes and of which the manufacture and the assembly are simplified, and this while still guaranteeing the rigidity and the geometry desired for said frame.
15 For this purpose, according to a first aspect, the invention proposes a bicycle frame
comprising a saddle tube connected to a single upper bar and a single lower bar, said bars each having a front end carrying a head tube, said frame further comprising a strut and a base each having a rear end that carries a means of association at respectively one side of a rear wheel of said bicycle, said strut - respectively said base - being formed
20 from a single tube with the upper bar - respectively lower bar -, said upper and lower
tubes being associated respectively to one side of the saddle tube by extending continuously on either side of said saddle tube.
According to a second aspect, the invention proposes a bicycle comprising such a frame
25 in the head tube of which a fork provided with a handlebar and with a front wheel is
mounted, said bicycle comprising a saddle mounted on the saddle tube and a pedal mounted under said saddle tube, a rear wheel being mounted between the strut and the base by being associated to respectively a means of association.
30 Other particularities and advantages of the invention shall appear in the following
description, given in reference to the annexed figures, wherein:
- figures 1 to 4 diagrammatically show a bicycle frame according to an embodiment of the invention, respectively as a perspective view of the front
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(figure 1), side (figure 2), as a perspective top view (figure 3) and top view (figure 4).
In relation with these figures, a bicycle frame is described hereinbelow, for example for
5 bicycles of the mountain or hybrid type, formed by the association of various tubes
allowing for the mounting of the various parts of the bicycle, in particular wheels, a drive system, a saddle and a steering unit.
The frame comprises a saddle tube 1 which is mounted substantially vertically and is
10 intended to receive a mounting rod of the saddle, said rod being associated to said
saddle tube preferentially in an adjustable manner in order to allow for the adjusting of the height of said saddle.
The frame also has a head tube 2 intended for the mounting of the front gear of the
15 bicycle and which is arranged in front of the saddle tube 1, said saddle tube and said
tube defining a sagittal plane P of the bicycle frame.
The head tube 2 is arranged to receive a fork for fastening the front wheel which is
mounted in said tube for example on ball bearings that form the headset. The upper end
20 of the fork can be provided with a stem for associating a handlebar of the bicycle that
extends above the head tube 2.
In particular, the frame comprises a single upper bar 3 and a single lower bar 4 which
are connected to the saddle tube 1 by each one having a front end carrying the head tube
25 2, said bars extending between said saddle tube and said tube according to a geometry
defining the size of said frame.
In relation with figures 1 and 2, the upper 3 and lower 4 bars extend between the head
tube 2 and the saddle tube 1 in a respectively substantially horizontal and oblique
30 manner, forming a front frame structure with a substantially triangular geometry in
order to allow for a sufficient frame rigidity. Alternatively, the upper bar 3 can be more or less inclined towards the rear in order to confer to the frame the expected rigidity.
4

Furthermore, the frame comprises a lateral strut 5 and a base 6 which are intended for the mounting of the rear wheel of the bicycle by connecting it to the drive system, in particular to the chain components of said system.
5 So as to limit the number of tubes of the frame its manufacturing time, a single strut 5
and a single base 6 are provided for the mounting of the rear wheel, said strut and said base extending on either side of said wheel in order to ensure the association thereof in driving.
10 In particular, the strut 5 and the base 6 extend respectively in an oblique manner from
the upper end of the saddle tube 1 and substantially horizontally from the lower end of said saddle tube, by each having a means of association allowing for the mounting of the rear wheel between said strut and said base.
15 In relation with figure 1, the strut 5 and the base 6 each have a rear end carrying a
means of association to respectively one side of the rear wheel. Each means of association can include for example a fastening bracket 7 which is provided with a rear opening of the mounting of an axis of the rear wheel, said bracket being added or formed as a single piece with respectively the strut 5 and the base 6.
20
The strut 5 and the base 6 are formed as a single piece with the respectively upper 3 and lower 4 bars. The frame as such has two main respectively upper 8 and lower 9 tubes which are connected to the saddle tube 1 by extending between the head tube 2 and respectively a side of the rear wheel, forming respectively an upper bar 3 / strut 5 unit
25 and a lower bar 4 / base 6 unit.
In particular, the upper 8 and lower 9 tubes are each curved by having an elbow portion on either side of which extend the strut 5 - respectively the base 6 - and the upper bar 3 - respectively lower bar 4. 30
In relation with the figures, the shape of the various tubes 1,8,9 and of the tube 2 of the frame is cylindrical, with the strut 5 and the base 6 having a tapered rear end bearing fastening bracket 7 to the rear wheel which is flat. The tubes 1, 8, 9 can be carried out
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using steel in order to favour rigidity and the resistance of the frame or using aluminium or a composite material, in particular with a carbon fibre base, in order to optimise the weight of said frame.
5 The upper 8 and lower 9 tubes are respectively associated to a side of the saddle tube 1 by extending continuously on either side of said saddle tube. As such, the frame is formed without the need for an operation of drilling and/or of cutting the tubes 1, 8, 9, simplifying the assembly of said frame and favouring the reliability in the carrying out of the geometry thereof.
10
To do this, it is provided to arrange the front ends of the bars 3, 4 by spacing them vertically and by offsetting them angularly in relation to the sagittal plane P according to a respective angle Di,D D2 which is arranged so that each one of the bars 3, 4 extends in a respective plane Pi, P2 from the head tube 2 to the saddle tube 1.
15
In the embodiment shown, the angles DiD □ D2 between the bars 3, 4 and the plane P are substantially of the same value, with planes Pi and P2 forming a reduced angle with the vertical. Alternatively, a different angular shift can be provided between each one of the bars 3, 4 and the plane P.
20
In particular, the upper 8 and lower 9 tubes are associated to the saddle tube 1 and carry the head tube 2 by the intermediary of connectors arranged in order to connect said tubes and said tube according to inclinations and predefined angles, guaranteeing the desired geometry of the frame.
25
The frame comprises a front connector 10 having a vertical sleeve 11 wherein the head tube 2 is arranged and two rear sleeves 12, 13 in each one of which the front end of a bar 3, 4 is associated. In relation with figures 3 and 4, the rear sleeves 12, 13 extend from the vertical sleeve 11 by being angularly offset, in particular by an angle equal to
30 respectively Di and C^D on either side of the plane P in order to make it possible to
arrange the bars 3, 4 in their respective plane Pi, P2.
6

Furthermore, the saddle tube 1 is associated with the upper 8 and lower 9 tubes by the intermediary respectively of an upper connector 14 and of a lower connector 15, said connectors each having means for associating a tube 8, 9 which are arranged on either side of said saddle tube. 5
According to the embodiment shown, the upper 14 and lower 15 connectors each have a vertical sleeve 16, 17 for mounting around the respectively upper and lower end of the saddle tube 1 and a lateral sleeve 18, 19 wherein the respectively upper 8 and lower 9 tube is associated.
10
In particular, the lateral sleeves 18, 19 extend horizontally on a left or right side of the vertical sleeve 16, 17, by being associated with the respectively upper 3 and lower 4 bars, more precisely before the elbowed portions of the respectively upper 8 and lower 9 tubes.
15
Advantageously, the tubes 8, 9 can be arranged so that the strut 5 and the base 6 extend substantially in the plane Pi, P2 of the respective bars 3, 4. Alternatively, it can be provided to form the upper tube 8 and/or the lower tube 9 with respectively a strut 5 and a base 6 that extend outwards or inwards in relation to the respective plane Pi, P2,
20 according to the needs for the mounting of the rear wheel.
In particular, the strut 5 and the base 6 can extend on the side of the saddle tube 1
whereon respectively the upper tube 8 and the lower tube 9 are associated, as such
avoiding a crossing of said strut and base behind the saddle tube 1 in order to allow for
25 the association of the rear wheel. In the figures, the base 6 extends from the left side of
the saddle tube 1, from said tube to the fastening bracket 7, as such facilitating the integration of the right side of the drive system of the bicycle.
The connectors 10, 14, 15 can each be made from a single piece, for example from a
30 plastic material, the various sleeves 11, 12, 13, 16, 17, 18, 19 having a cylindrical shape
that is complementary with those of the tubes 1, 8, 9 and with the head tube 2. The
various tubes 1, 8, 9 and the tube 2 can be associated with the corresponding sleeves 11,
7

12, 13, 16, 17, 18, 19 without a need for welding or gluing in order to optimise costs and the manufacturing time of the frame.
Furthermore, a reversible association can be provided of the tubes 1, 8, 9 to the
5 connectors 10, 14, 15, allowing for quick and easy mounting and dismounting of the
frame by the user, in particular in the case of a bicycle that has the form of a kit. In particular, the connectors 10, 14, 15 are arranged to allow for the assembly of the tubes 1, 8, 9 and of the tube 2 according to the predefined geometry for the frame, and this without a risk of dispersion in the relative disposition of said tubes.
10
According to the embodiment shown, the upper 8 and lower 9 tubes are mounted in the rear sleeves 12, 13 and lateral sleeves 18, 19 by press fitting then fastened in position by screwing. In particular, the press fitting of the tubes 8, 9 can be carried out by rotation and translation of said tubes in the corresponding sleeves 12, 13, 18, 19, the screwing
15 being carried out by means of screws passing though said sleeves and said tubes.
Moreover, the connectors 10, 14, 15 can be provided with means for associating other
parts and accessories of the bicycle, such as the saddle, brake cables or headlights. The
lower connector 15 can as such be provided with means for mounting a pedal of the
20 drive system and/or the upper connector 14 can be provided with means for mounting
the saddle rod of said bicycle.
In relation with the figures, the lower connector 15 has a case 20 for mounting the pedal
that extends under the vertical 17 and lateral 19 sleeves. The upper connector 14 is
25 provided with a tightening collar 21 that allows for the adjustable mounting of the
saddle rod in order to adjust the height of said rod to the size of the user and/or to the desired exercise position, said collar being formed in the upper continuity of the vertical sleeve 16 of said connector.
30 In order to optimise the rigidity of the frame, a second base 22 can be provided which
extends on the side of the rear wheel that is opposite that in which extends the first base 6, said second base extending from the saddle tube 1 to the rear end of the strut 5.
8

According to the embodiment shown, the second base 22 is added between the saddle tube 1 and the rear end of the strut 5, by having a front end that is associated to said saddle tube on the same side as the upper tube 8 and a rear end adjacent to that of said strut. 5
In particular, the rear end of the second base 22 carries a means of association with the rear wheel which is complementary to that of the strut 5. In relation with figure 2, the means of association of the second base 22 is a fastening bracket 23 having a rear opening that is superimposed on that of the fastening bracket 7 of the strut 5.
10
This embodiment makes it possible in particular to facilitate the mounting of the drive chain between the pedal and the rear wheel, in that the brackets 7, 23 can be separated in order to allow for the arranging of the chain around the second base 22 in order to be connected to said wheel, and this without opening said chain. Then, the tightening of the
15 rear wheel between on the one hand the brackets 7, 23 and, on the other hand the left bracket 7, induces a coupling of the brackets 7, 23 in order to ensure the association of said wheel between the base 6 and the strut 5.
The front end of the second base 22 is associated to the lower connector 15, in such a 20 way as to work as torsion between the pedal case 20 and the bracket 7 of the strut 5, making it possible to reinforce the rigidity of the frame, in particular for avoiding the twisting of the rear wheel.
9