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Title:
BICYCLE STEERING ASSEMBLY
Document Type and Number:
WIPO Patent Application WO/2009/026721
Kind Code:
A1
Abstract:
There is provided a modular and adjustable bicycle steering assembly comprising a fork defining a wheel side and a handlebar side; a fork tube disposed on the handlebar side of the fork, the fork tube being adapted to be pivotally connected a bicycle frame and defining a pivot axis about which the fork is adapted to pivot to steer the bicycle when the fork is used in conjunction with the bicycle frame; a front member provided on the handlebar side of the fork; at least one spacer adapted to cooperate with the front member; and a support member adapted to be secured to the front member and to the fork tube, the support member defining a handlebar receiving portion for adjustably mounting a handlebar thereto. A method for assembling the bicycle steering assembly and a bicycle steering assembly kit are also provided.

Inventors:
RIOUX, Gervais (730 36ème Avenue, Lachine, Québec H8T 3L2, CA)
CANTIN, Gilles (180 River Road, Grand-Mère, Québec G9T 5K4, CA)
MORELLI, Michel (6891 rue Chambord, Montréal, Québec H2G 3C2, CA)
TCHOUKANOV, Artur (4998 Boulevard de Maisonneuve Ouest, Apt. 1106Westmount, Québec H3Z 1N2, CA)
BIDAL, Jean-Marie (249 70ème Avenue, Laval, Québec H7V 2P6, CA)
BELLEAU, Eric (1203 Boulevard Mont-Royal, Outremont, H2V 2H7, CA)
Application Number:
CA2008/001545
Publication Date:
March 05, 2009
Filing Date:
August 29, 2008
Export Citation:
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Assignee:
CYCLES ARGON-18 INC. (6833 Avenue de l'Epée, Bureau 208Montréal, Québec H3N 2C7, CA)
RIOUX, Gervais (730 36ème Avenue, Lachine, Québec H8T 3L2, CA)
CANTIN, Gilles (180 River Road, Grand-Mère, Québec G9T 5K4, CA)
MORELLI, Michel (6891 rue Chambord, Montréal, Québec H2G 3C2, CA)
TCHOUKANOV, Artur (4998 Boulevard de Maisonneuve Ouest, Apt. 1106Westmount, Québec H3Z 1N2, CA)
BIDAL, Jean-Marie (249 70ème Avenue, Laval, Québec H7V 2P6, CA)
BELLEAU, Eric (1203 Boulevard Mont-Royal, Outremont, H2V 2H7, CA)
International Classes:
B62K21/00; B62K19/00; B62K21/18
Foreign References:
US5429381A1995-07-04
US4391353A1983-07-05
US20080073870A12008-03-27
US7210694B22007-05-01
EP1612134A12006-01-04
US4008903A1977-02-22
Attorney, Agent or Firm:
SOFIA, Michel et al. (BCF LLP, 1100 René-Lévesque Blvd. West25th Floo, Montreal Québec H3B 5C9, CA)
Download PDF:
Claims:
What is claimed is:

1. A bicycle steering assembly comprising: a fork defining a wheel side and a handlebar side; a fork tube disposed on the handlebar side of the fork, the fork tube being adapted to be pivotally connected to a bicycle frame and defining a pivot axis about which the fork is adapted to pivot to steer the bicycle when the fork is used in conjunction with the bicycle frame; a front member provided on the handlebar side of the fork; and a support member adapted to be secured to the front member and to the fork tube, the support member being adapted to be connected to a handlebar.

2. The bicycle steering assembly of claim 1 , wherein the support member is adapted to, at least partially, circumvent the fork tube.

3. The bicycle steering assembly of claims 1 and 2, wherein the support member is provided with a variety of lengths between the fork tube and a handlebar receiving portion of the support member.

4. The bicycle steering assembly of claims 1 to 3, further comprising at least one spacer adapted to be disposed between the support member and the front member to adjust a distance between the fork and a handlebar receiving portion of the support member.

5. The bicycle steering assembly of claim 4, wherein each spacer is provided with a hollowed center therein.

6. The bicycle steering assembly of claims 4 and 5, wherein each spacer is made of extruded aluminum.

7. The bicycle steering assembly of claims 1 to 6, wherein the support member and the front member comprise a self centering mechanism.

8. The bicycle steering assembly of claim 7, wherein the self centering mechanism includes mating male and female elements provided on one and the other of the support member and of the front member.

9. The bicycle steering assembly of claims 1 to 8, wherein the support member and the front member define a play therebetween, the play being adapted to provide an adjustment between the support member and the front member.

10. The bicycle steering assembly of claims 1 to 9, wherein a handlebar receiving portion of the support member is adapted to provide a pivotal adjustment of a handlebar on the support member.

11. The bicycle steering assembly of claim 10, wherein the handlebar receiving portion of the support member defines knurls adapted to further secure the handlebar to the support member.

12. The bicycle steering assembly of claims 1 to 11 , wherein the support member defines a lancet arch shape adapted to facilitate air flow around the fork tube.

13. The bicycle steering assembly of claim 12, wherein the lancet arch shape is disposed on a forward side of the support member.

14. The bicycle steering assembly of claims 1 to 13, wherein the fork is adapted to receive brakes rearwardly from the pivot axis when the fork is installed on the bicycle frame in its normal operating position.

15. A bicycle steering assembly kit comprising: a fork defining a wheel side and a handlebar side; a fork tube disposed on the handlebar side of the fork, the fork tube being adapted to be pivotally connected to a bicycle frame and defining a pivot axis about which the fork is adapted to pivot to steer the bicycle when the fork is used in conjunction with the bicycle frame; a front member provided on the handlebar side of the fork; and a support member adapted to be secured to the front member and to the fork tube, the support member being adapted to be connected to a handlebar.

16. The bicycle steering kit of claim 15, wherein the support member is adapted to, at least partially, circumvent the fork tube.

17. The bicycle steering kit of claims 15 and 16, wherein the support member is provided with a variety of lengths between the fork tube and a handlebar receiving portion of the support member.

18. The bicycle steering kit of claims 15 to 17, further comprising at least one spacer adapted to be disposed between the support member and the front member to adjust a distance between the fork and a handlebar receiving portion of the support member.

19. The bicycle steering kit of claim 18, wherein each spacer is provided with a hollowed center therein.

20. The bicycle steering kit of claims 18 and 19, wherein each spacer is made of extruded aluminum.

21. The bicycle steering kit of claims 15 to 20, wherein the support member and the front member comprise a self centering mechanism.

22. The bicycle steering kit of claim 21 , wherein the self centering mechanism includes mating male and female elements provided on one and the other of the support member and of the front member.

23. The bicycle steering kit of claims 15 to 22, wherein the support member and the front member define a play therebetween, the play being adapted to provide an adjustment between the support member and the front member.

24. The bicycle steering kit of claims 15 to 23, wherein a handlebar receiving portion of the support member is adapted to provide a pivotal adjustment of a handlebar on the support member.

25. The bicycle steering kit of claim 24, wherein the handlebar receiving portion defines knurls adapted to further secure the handlebar to the support member.

26. The bicycle steering kit of claims 15 to 25, wherein the support member defines a lancet arch shape adapted to facilitate air flow around the fork tube.

27. The bicycle steering kit of claim 26, wherein the lancet arch shape is disposed on a forward side of the support member.

28. The bicycle steering kit of claims 15 to 27, wherein the fork is adapted to receive brakes rearwardly from the pivot axis when the fork is installed on the bicycle frame in its normal operating position.

29. A method for assembling a bicycle steering assembly, the method comprising: installing a support member on a fork adjacent to a fork tube; securing the support member to the fork; and securing the support member to the fork tube.

30. The method of claim 29, wherein the support member is adapted to, at least partially, circumvent the fork tube.

31. The method of claims 29 and 30, wherein the support member is provided with a variety of lengths between the fork tube and a handlebar receiving portion of the support member.

32. The method of claims 29 to 31 , further comprising installing at least one spacer between the support member and the fork, the spacer being adapted to adjust a distance between the fork and a handlebar receiving portion of the support member.

33. The method of claim 32, wherein each spacer is provided with a hollowed center therein.

34. The method of claims 32 and 33, wherein each spacer is made of extruded aluminum.

35. The method of claims 29 to 34, wherein the support member and the front member comprise a self centering mechanism.

36. The method of claims 29 to 35, wherein the support member and the front member define a play therebetween, the play being adapted to provide an adjustment between the support member and the front member.

37. The method of claims 29 to 36, further comprising the step of securing a handlebar to the support member, the support member having a handlebar receiving portion adapted to provide a pivotal adjustment of the handlebar on the support member.

38. The method of claim 37, wherein the handlebar receiving portion defines knurls adapted to further secure the handlebar to the support member.

39. The method of claims 29 to 38, wherein the support member defines a lancet arch shape adapted to facilitate air flow around the fork tube.

40. The method of claims 29 to 39, wherein the fork is adapted to receive brakes rearwardly from the pivot axis when the fork is installed on the bicycle frame in its normal operating position.

Description:

TITLE OF THE INVENTION

BICYCLE STEERING ASSEMBLY

CROSS-REFERENCE TO RELATED APPLICATIONS

This Patent Application relates to and claims priority on United States Provisional Patent Application No. 60/935,766, filed August 30, 2007, entitled BICYCLE STEERING ASSEMBLY and on United States Provisional Patent Application No. 60/935,811 , filed August 31 , 2007, entitled BICYCLE STEERING ASSEMBLY, which are included herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to a modular bicycle steering assembly adapted to be substantially mounted in front of a fork tube of a bicycle to improve the air flow around the head tube. The modular bicycle steering assembly can be rotatably attached to a conventional bicycle head tube and adjusted to accommodate riders of various sizes.

BACKGROUND OF THE INVENTION

As shown in Figures 1-5, a conventional bicycle is typically steered by means of a front fork 10 and a handlebar (not shown), which are rotatably attached to the frame 12 of the bicycle 14. The front fork 10 has a fork tube 16 inserted in the head tube 18 of the frame 12, wherein the fork tube 16 fixedly links a head 20 of the front fork 10 to the handlebar. The rotational movement of the fork tube 16 relative to the head tube 18 is ensured by a headset 22, typically comprising two bearing assemblies 24, 26, typically collectively referred to as a headset 22. As seen on Figure 3, a stem 28 is interposed between the fork tube 16 and the

handlebar (not illustrated) to secure the handlebar to the fork tube 16. The stem 28 is coaxial with the fork tube 16 on a rear end and projects a handlebar receiving portion 30 forwardly from the upper end of the fork tube 16 to dispose the handlebar (still not shown) in front of the fork tube 16. The fork tube 16 is secured to the head tube 18 with a headset plug 32 fastened thereon as it can be appreciated on Figure 4.

Typically, cyclists try to increase their performances by adopting aerodynamic positions, for example by trying to lower their torso and head so as to decrease wind resistance. Bicycles designers tend to design aerodynamic frames to reduce the air drag of the bicycle. Cyclists have also recourse to aerodynamically shaped handlebars to reduce the aerodynamic drag.

The load applied to the steering assembly by strong riders flexes the steering assembly thus reducing their efficiency to propel the bicycle. The size of a rider can significantly vary and some adjustability to the steering assembly is desirable to optimally fit the rider's ergonomics.

As a result, a bicycle steering assembly comprising a conventional stem 28 is not optimal. It would be advantageous that the handlebar be mounted to an aerodynamically shaped front fork 10. It would also be desirable that the handlebar be rigidly and adjustably mounted to the front fork 10.

Therefore, a need has been felt for providing an adjustable aerodynamic steering assembly for high-performance bicycles that can be mounted, inter alia, to conventional bicycle frames.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide an aerodynamic handlebar supporting assembly to which the handlebar of a bicycle can be mounted.

One aspect of the present invention provides a handlebar supporting assembly that comprises an aerodynamically shaped support member.

One other aspect of the present invention provides a handlebar supporting assembly comprising a support member and a base interfacing the fork, wherein the support member is fixedly mounted to the base.

A further aspect of the present invention provides a handlebar supporting assembly comprising a support member and a base adapted to receive at least one intervening spacer for adjusting the height of the support member.

One further aspect of the present invention provides a support member and a base adapted to receive at least one intervening spacer that is not circumscribing the fork tube for adjusting the height of the support member.

An aspect of the present invention provides a set of spacers of various thicknesses adapted to be interposed between the support member and the base so as to allow the elevation of the support member to be more precisely adjusted.

Another aspect of the present invention provides a front fork defining a rear indentation at an upper end thereof, to which the handlebar supporting assembly can be rigidly mounted.

A further aspect of the present invention provides, in combination, a handlebar supporting assembly and a front fork which can be rotatably mounted in front of the fork tube of a bicycle frame.

An aspect of the present invention provides a handlebar that is adapted to be secured on top of the support member without the support member circumscribing the handlebar. The support member being provided with a concave cylindrical portion adapted to mate with a corresponding convex cylindrical portion on the handlebar to angularly position the handlebar to the support member. Additionally, the handlebar is provided with knurls to further secure the position of the handlebar on the support member.

Another aspect of the present invention provides an integrated support member and fork provided with an aerodynamic shape adapted to improve the air flow around the fork tube of a bicycle frame.

Another additional aspect of the present invention provides rectilinear fork arms adapted to receive a wheel therebetween, the rectilinear fork arms being provided with an aerodynamic shape cooperating with the shape of the support member to improve the air flow around the fork tube and the bicycle frame.

One other aspect of the present invention provides a support member that is adapted to be self centered when assembled to a front fork base.

One additional aspect of the present invention provides a support member that is adapted to be self centered with a cooperating spacer.

An additional aspect of the present invention provides a bicycle steering assembly comprising a fork defining a wheel side and a handlebar side; a fork tube disposed on the handlebar side of the fork, the fork tube being adapted to

be pivotally connected to a bicycle frame and defining a pivot axis about which the fork is adapted to pivot to steer the bicycle when the fork is used in conjunction with the bicycle frame; a front member provided on the handlebar side of the fork; and a support member adapted to be secured to the front member and to the fork tube, the support member being adapted to be connected to a handlebar. Another additional aspect of the present invention provides a bicycle steering assembly kit comprising a fork defining a wheel side and a handlebar side; a fork tube disposed on the handlebar side of the fork, the fork tube being adapted to be pivotally connected to a bicycle frame and defining a pivot axis about which the fork is adapted to pivot to steer the bicycle when the fork is used in conjunction with the bicycle frame; a front member provided on the handlebar side of the fork; and a support member adapted to be secured to the front member and to the fork tube, the support member being adapted to be connected to a handlebar. One other additional aspect of the present invention provides a method for assembling a bicycle steering assembly, the method comprising: installing a support member on a fork adjacent to a fork tube; securing the support member to the fork; and securing the support member to the fork tube. The foregoing and other objects, advantages and features of the present invention will become more apparent upon reading of the following non- restrictive description of an illustrative embodiment thereof, given by way of example only, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the appended drawings: Figure 1 is a side elevational view of a partly exploded conventional bicycle steering assembly and a portion of a bicycle frame.

Figure 2 is a side elevational view of the partly exploded bicycle steering assembly of Figure 1 at a different level of assembly.

Figure 3 is a side elevational view of the partly exploded bicycle steering assembly of Figure 1 at a different level of assembly.

Figure 4 is a side elevational view of the partly exploded bicycle steering assembly of Figure 1 at a different level of assembly.

Figure 5 is a side elevational view of the bicycle steering assembly of Figure 1.

Figure 6 is a rear-right perspective view of a bicycle, according to a non- restrictive illustrative embodiment of the present invention; a complete bicycle steering assembly is being mounted to the bicycle frame;

Figure 7 is side elevational view of a fork of the bicycle steering assembly of Figure 6;

Figure 8 is a perspective view of a spacer adapted to be assembled with the bicycle steering assembly of Figure 6;

Figure 9 is a top plan view of a spacer of the bicycle steering assembly of Figure 6;

Figure 10 is a front-left perspective view of a support member of the bicycle steering assembly of Figure 6;

Figure 11 is a perspective view of a semicircular collar according to the non- restrictive illustrative embodiment, the semicircular collar being intended to secure the support member to the fork tube of the bicycle steering assembly;

Figure 12 is a side elevational view of a partly exploded bicycle steering assembly in accordance with a non-restrictive embodiment of the present invention;

Figure 13 is a side elevational view of the bicycle steering assembly of Figure 12 at a different assembly stage;

Figure 14 is a side elevational view of the bicycle steering assembly of Figure 12 at a different assembly stage;

Figure 15 is a side elevational view of the bicycle steering assembly of Figure 12 at a different assembly stage;

Figure 16 is a side elevational view of the bicycle steering assembly of Figure 12 at a different assembly stage;

Figure 17 is a side elevational view of the bicycle steering assembly of Figure 12 at a different assembly stage without handlebars;

Figure 18 is a perspective view of the handlebar assembly in accordance with a non-restrictive embodiment of the present invention;

Figure 19 is a perspective view of the handlebar assembly of Figure 18 at a different stage of assembly;

Figure 20 is a perspective view of the handlebar assembly of Figure 18 at a different stage of assembly;

Figure 21 is a perspective view of the handlebar assembly of Figure 18 when assembled to the support member; and

Figure 22 is a front-left perspective view of the assembled steering assembly with the handlebar assembled thereon.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

A bicycle steering assembly for a bicycle, in accordance to a non-restrictive illustrative embodiment of the present invention, will now be described. Referring to Figure 6, in general terms, according to the non-restrictive illustrative embodiment, there is provided a bicycle steering assembly 50 comprising a front fork 52 and a handlebar supporting assembly 54 pivotally connected to a frame 78.

The frame 78 comprises a crossbar 220, a seat tube 222, a down tube 224 and the head tube 76, all of which are linked together so that: a rear end 226 of the cross bar 220 couples to an upper end 228 of the seat tube 222, a lower end 230 of the seat tube 222 couples to a lower end 232 of the down tube 224; an upper end 234 of the down tube 224 couples to a lower end 236 of the head tube 76; and an upper end 238 of the head tube 76 couples to a front end 240 of the cross bar 220. The coupling of the rear end 226 of the crossbar 220 with the upper end 228 of the seat tube 222 is made in the vicinity of the seat of the cycle (not shown); the coupling of the lower end 230 of the seat tube 222 with the lower end 232 of the down tube 224 is made in the vicinity of the crankset 231 of the cycle; the coupling of the upper end 234 of the down tube 224 with the lower end 236 of the head tube 76 is made in the vicinity of the fork head

64; and the coupling of the upper end 238 of the head tube 76 with the front end 240 of the crossbar 220 is made in the vicinity of the handlebar 82. The combination of the down tube 224, the seat tube 222 and the crossbar 220 forms somewhat a triangle that has an open space between the front end 240 of the crossbar 220 and the upper end 234 of the down tube 224, wherein the open space is occupied by the head tube 76.

The head tube 76 has a cylindrical opening running therethrough from a top to a bottom surface of the head tube 76. The cylindrical opening is configured receive the fork tube 74 therein as seen on Figure 7. As best illustrated on Figures 12 and 13, a first annular depression 250 is defined on the bottom surface of the head tube 76, around the cylindrical opening. Similarly, a second annular depression 252 is defined on the top surface of the head tube, around the cylindrical opening. The first and second annular depressions 250 and 252 are configured so as to receive respectively first and second bearing assemblies 254 and 256, the two bearing assemblies typically being referred to as a headset.

Referring back to Figure 6, the handlebar supporting assembly 54 comprises a base 56, a spacer 58, and a support member 60. The spacer 58 removeably mates into the base 56. Similarly, the support member 60 removeably mates with the optional spacer 58 to set the height of the support member 60.

Turning to Figure 7, the front fork 52 is generally oriented along a steering axis 62. The front fork 52 includes a fork head 64 having a front member 70 and a rear indentation 66 that defines a rear surface 68 with a fork tube 74 extending therefrom. The front member 70 has a top surface 72 to which the base 56 is mounted to reinforce the top surface 72 and receives other parts thereon. Typically, the base 56 illustrated on Figure 8 is secured to the top surface 72. The fork tube 74 extends from the rear surface 68 and defines a steering axis

62 about which the steering assembly pivots. The fork tube 74 is adapted to be inserted into a head tube 76 of a frame 78 of the bicycle 80. The support member 60 is configured so as to receive a handlebar 32, with an aerobar 34 being typically mounted to the handlebar 82.

As best seen on Figures 6 and 7, the front fork 52 is also adapted to receive a braking system 244 on its rear side. The braking system 244 is fastened to the front fork 52 with a fastener secured to the brake receiving portion 246. The location of the braking system 244 between the down tube 224 and the front fork 52 reduces the air drag created by the braking system 244 in contrast with the classic configuration disposing the braking system 244 in front of the front fork 52.

The front fork 52 extends generally parallel to the steering axis 62 and comprises two substantially linear parallel arms 192, spaced apart at a sufficient distance for accommodating a wheel (not shown) therebetween. Each of the ends of the arms 192 forms a yoke 198 that allows the fixation of the wheel such that the wheel can rotate. In the vicinity of their upper ends, the two arms 192 unite into the fork head 64. The rear indentation 66 in the fork head 64 defines the rear surface 68 and the front member 70. The fork tube 74 projects from the rear surface 68, generally parallel to the steering axis 62. The fork tube 74 is fixedly attached to the fork head 64 with glue or mechanically secured with fasteners. The front fork 52 is intended to be rotatably mounted to the frame 78 by means of the fork tube 74 so as to allow a rotation of the front fork 52 around a steering axis 62. This arrangement will be explained later in this description.

The yokes 198 of the arms 192 are slightly forwardly positioned so that the rotation axis of the wheel is forwardly off-set with respect to the steering axis 62 by the distance necessary for ensuring the steering stability of the bicycle.

Steering geometry of bicycles is well known in the art and will not be discuss in more detail here.

The front member 70 of the fork head 64 has a front member front surface 200, that is lancet arch-shaped, and a front member rear surface 202 that is circle arc-shaped. The top surface 72 of the front member 70 defines a depression (not shown), which has a depression inner front surface (not shown) that is lancet arch-shaped and that generally follows a portion of the front member outer front surface 200, and an inner rear surface (not shown) that is circle arc- shaped. The depression inner front surface (not shown) of the depression (not shown) and the inner rear surface (not shown) of the depression (not shown) merge with depression rounded inner surfaces (not shown). The top surface 72 is flanked by two cylindrical bores (not shown) having respectively an axis, which is substantially perpendicular to the top surface 72. The top surface 72 has a threaded hole (not shown) that is substantially perpendicular thereto. The fork tube 74 projects from the rear surface 68, generally parallel to the steering axis 62, and is fixedly attached to the fork head 64.

The non-restrictive illustrative embodiment will now be described in more detail. With reference to Figure 8 to Figure 10, the base 56, the spacer 58 and the support member 60 of the handlebar supporting assembly 54 will now be described.

The base 56 is the part that is incorporated in the front member 70 to define the top surface 72 over which the support member 60 and/or spacer(s) 58 are superposed. The base 56 is not specifically illustrated in isolation in the figures. The base 56 is quite similar to the shape of the spacer depicted on Figure 8. Figure 8 will thus be used as a reference. The base 56 and the spacer 58 have a base top surface 84, a base outer front surface 86, a base outer rear surface 88 and a base bottom surface 90. The base outer front surface 86 is

aerodynamically lancet arch-shaped, and the base outer rear surface 88 is circle arc-shaped. The base outer front surface 86 and the base outer rear surface 88 define two base protuberances 92 directed rearwardly; the two base protuberances 92 each defining a rear rounded surface 94. The base 56 has a median portion 96 defining a base opening 98 extending from the base top surface 84 to the base bottom surface 90. The opening 98 does not exist on the base 56 because treads must be provided to secure the main bolt 276 thereto. The spacer 56 has an inner front surface 100 that is lancet arch-shaped and that generally follows a portion of the base outer front surface 86, and an inner rear surface 102 that is circle arc-shaped and that generally follows a portion of the base outer rear surface 88. The inner front surface 100 and the inner rear surface 102 merge at rounded inner surfaces 104 adjacent to respective base protuberances 92.

Each base protuberance 92 has a base cylindrical bore 108, the axis of which is substantially perpendicular to the base top surface 84. Similarly, each of the base protuberances 92 has an optional base rod 110 to help locate the base 56. The axis 62 is substantially perpendicular to the base bottom surface 90. The lower free end or tip 112 of the base rod 110 has a frustoconical shape. A base rim (not shown) positioned on the bottom of the inner front, rear and rounded surfaces 100, 102 and 104 of the base opening 98 follows the outline (not shown) of the base opening 98. A base skirt 118 is integrated externally on the base rim (not shown), so that the base skirt 118 projects downwardly and substantially perpendicularly to the base bottom surface 90. The external surface of the base skirt 118 is flush with the inner front, rear and rounded surfaces 100, 102 and 104 of the base opening 98.

Similarly, as best seen on Figure 9, an optional spacer 58 defines a spacer top surface 120, a spacer outer front surface 122, a spacer outer rear surface 124 and a spacer bottom surface (not shown). The spacer outer front surface 122 is lancet arch-shaped, and the spacer outer rear surface 124 is circle arc-shaped.

The spacer outer front surface 122 and the spacer outer rear surface 124 merge so as to define two spacer protuberances 128 directed rearwardly, the two spacer protuberances 128 each defining a rear spacer rounded surface 130. The spacer 58 has a median portion 132 defining a spacer opening 134 extending from the spacer top surface 120 to the spacer bottom surface (not visible). The spacer opening 134 has a spacer inner front surface 136 that is lancet arch-shaped and that generally follows a portion of the spacer outer front surface 122, and a spacer inner rear surface 138 that is circle arc-shaped and that generally follows a portion of the spacer outer rear surface 124. The spacer inner front surface 136 and the spacer inner rear surface 138 merge at rounded inner surfaces 140 adjacent to respective spacer protuberances 128. The spacer 58 is available in various thicknesses. For instance, thicknesses of 25 millimeters, 10 millimeters and 8 millimeters can be provided in a kit allowing the user to setup the handlebar at the optimal position.

Each of the spacer protuberances 128 has a cylindrical bore 142, the axis of which is substantially perpendicular to the spacer top surface 120. Similarly, each of the spacer protuberances 128 has a spacer rod (not visible on Figure 9), the axis 62 is substantially perpendicular to the spacer top surface 120 and coaxial with the axis of the corresponding spacer cylindrical bore 142. The lower free end or tip (not shown) of the spacer rod (not shown) has a frustoconical shape. A spacer rim 148 positioned on the bottom of the spacer inner front, rear and rounded surfaces 136, 138 and 140 of the spacer opening 134 follows the outline of the spacer opening 134. A spacer skirt 104 is integrated externally on the spacer rim 148, so that the spacer skirt 152 projects downwardly and substantially perpendicular to the spacer bottom surface (not shown) and such that the external surface of the spacer skirt 152 is flush with the spacer inner front, rear and rounded surfaces 136, 138 and 140 of the spacer opening 134.

Finally, the support member 60 (better seen on Figure 10) has a support member top surface 154, a support member outer front surface 156, two

support member lateral surfaces 158, two support member rear surfaces 160 with a semi-circular depression 162 defined therebetween, a support member bottom surface 164, a depressed surface 166 interposed between the support member outer front surface 156 and the support member top surface 154, and two projections 170 located respectively at the top of the two support member rear surfaces 160. The support member outer front surface 156 is lancet arch- shaped, with a bulge 172 projecting forwardly and merging with the depressed surface 166, and two support member protuberances 170 extending rearwardly. The support member 60 has a threaded-through bore 176 extending from the depressed surface 166 to the support member bottom surface 164. First and second pairs 178 and 180 of threaded bores flank the threaded-through bore 176.

The support member bottom surface 164 has two support member rods (not shown), each possess an axis substantially perpendicular to the support member bottom surface 164. The tip of the support member rod is frustoconical. A support member skirt 186 is integrated externally on the support member bottom surface 164, so that the support member skirt 186 projects downwardly and substantially perpendicular to the support member bottom surface 164 and such that the external surface of the support member skirt 186 is flush with the internal surface of the spacer opening 134 or of the base opening 98. On each of the rear surfaces 160 of the projections 170, there is a projection threaded hole (not shown).

Upon assembly of the base 56, the spacer 58 and the support member 60, the two spacer rods 144 are engaged in the corresponding base cylindrical bores 108. Similarly, the two support member rods 144 are inserted in the corresponding spacer cylindrical bores 142.

Likewise, the support member skirt 186 is engaged into the spacer opening 134, and the spacer skirt 152 is engaged into the base opening 98. In this manner, the support member bottom surface 164 is adjacent to the spacer top surface 120, and the spacer bottom surface 126 is adjacent to the base top surface 84. Also, the threaded-through bore 128 of the support member 60, the spacer opening 134 and the base opening 98 form a well that runs from the depressed surface 70 of the support member 60 to the base bottom surface 90. In so doing, the corresponding base 56, spacer(s) 58 and support member 60 are aligned to provide rigid means to adjust the handlebar supporting assembly 54 to accommodate various riders' physiologies.

Turning now to Figures 12 through 17, there will be described how the handlebar supporting assembly 54 is assembled, mounted to the fork 52 and how the fork 52 is rotatably mounted to the head tube 76 of the frame 78.

The steering assembly 50 of the present invention can be conveniently mounted to the head tube 18 of a conventional bicycle. This combination eliminates the need to have recourse to a stem 28, as is the case in a conventional bicycle 14. It also provides a mechanism adapted to set the height and the forward distance of the handlebars 32 in respect with the head tube 76 of the frame 78. The steering assembly 50 also provides a rigid steering structure thus minimizing material deflection when under significant stress. Typically, the front fork 52 is made of a composite material, i.e. a material comprising high strength fibers, such as glass fibers, aramid fibers, carbon fibers, etc. in a resin binder, notably epoxy or polyamide resin. Light weight metallic materials are also contemplated and considered to be within the scope of the present invention.

Upon assembly, the first bearing assembly 254 is inserted in the first annular depression 250; the fork tube 74 is inserted in the fork tube 256 cylindrical

opening; and the second bearing assembly 256 is inserted in the second annular depression 252.

The handlebar supporting assembly 54, which comprises the assembled combination of the base 56, the spacer 58 and the support member 60, mates with the front fork 52 by inserting concurrently the two base rods 110 in the corresponding two cylindrical bores 214 of the fork head 64. The base skirt 118 fits in the depression of the top surface 72 of the front member 70 so that the fork tube 74 is positioned behind the front member 70, the base 56, the spacer 58, and the support member 60.

The length of the fork tube 74 is defined so that the fork tube 74 has a protruding portion 258 that extends out of the head tube 76. A sleeve 260 is placed around the protruding portion 258. A semicircular collar 262, magnified on Figure 11 , having two holes 264 is disposed around a rear section of the protruding portion 258 of the fork tube 74, so that the two holes 264 are respectively aligned with the two projection threaded hole (not shown) of the rear surfaces 160 of the two projections 170 of the support member 60. Two screws 266 are driven respectively through the two holes 264 and the two threaded holes so as to firmly secure the semicircular collar 262 to the support member 60 to fixedly maintain the protruding portion 258 of the head tube 76 and the sleeve 260 therebetween. The sleeve 260 is provided with a slot therein to manage some contraction of the sleeve 260 when the semicircular collar 262 is tightened to the support member 60.

A compressor 268 is inserted inside the protruding portion 258 of the head tube 76. The compressor 268 has a bolt 270 that projects upwardly and slightly extends out of the protruding portion 258. A cap 272 having an internally threaded bush 274 on its bottom surface is screwed with the bolt 270 to pull and secure the fork tube 74. The semicircular collar 262 extends above the fork tube

74 to allow the cap 272 to rest on the upper edge of the semicircular collar 262 without contacting the fork tube 74. This mechanical arrangement permits, upon securing the bolt 270, to tighten the handlebar supporting assembly 54 with bearing assemblies 254, 256.

A main bolt 276 is driven through the threaded through bore 176 of the support member 60, the spacer opening 134, the base opening 98, and finally the cooperating threaded hole 73 of the top surface 72 to secure the support member 60 with the other parts to the fork 52. The length of the main bolt 276 is adapted to the thickness of the assembly to minimize the weight.

Turning now to Figures 19 through 22, there will be described how the handlebar 82 is mounted to the support member 60 of the handlebar supporting assembly 54.

The handlebar 82 has a top middle surface 284 which, upon assembly, is adjacent to the support member 60. The top middle surface 284 comprises a rectangular depression 286 having a bottom surface 288, the bottom surface 288 being pierced by two holes 290. Upon assembly, the two holes 290 are aligned either with the first pair of threaded bores 178 or the second pair of threaded bores 180. The rectangular depression 286 can be covered by an aesthetic and aerodynamic cap (not shown).

The handlebar 82 is mounted to the support member 60 by means of two bolts 278 driven through the handlebar 82 in either one of the first and second pairs 178, 180 of threaded bores that flank the threaded hollow 176. A plate 280 having two holes 234 is interposed between the two bolts 278 and the handlebar 82. Choosing between the first and second pair of holes depends on a desired angular position for the handlebar 82, which in turn reflects in a position adopted by a cyclist. Knurls are provided on cooperating adjacent

surfaces of the handlebar 82 and the support member 60 to ensure proper mechanical interaction between the parts while allowing substantial angular adjustment to the handlebar 82.

In operation, the front surface of the front fork 52 and the front surfaces of the base 56, the spacer 58 and the lower portion of the support member 60 all have cooperating lancet arch-shape to form a smooth aerodynamic surface. Likewise, the rear surface of the front fork 52 and the rear surfaces of the base 56, the spacer 58 and the lower portion of the support member 60 all have the same circle arc-shape, so as to form a cooperating surface adjacent to the rounded front surface of the head tube 76.

It is readily appreciated that it is possible to design the support member 60 in a single part with the base 56. Likewise, it is possible to add a spacer-like thickness to this unitary part to position higher the support member 60 thus the height of the handlebar 82.

In another non-illustrated embodiment of the present invention, the support member 60 is mounted directly to the top surface 72 of the front fork 52.

In another embodiment of the present invention, the base 56 does not have rods 110 defined thereon. Likewise, the top surface 72 of the front member 70 does not comprise the corresponding cylindrical bores 142.

Although the present invention has been described hereinabove by way of non- restrictive, illustrative embodiments thereof, these embodiments can be modified at will, within the scope of the appended claims, without departing from the spirit and nature of the subject invention.