It is known that in bicycles made from composite material (i. e. fibers joined by a resin matrix) there are still provided regions where components are clamped which are suitable to perform specific connecting functions between the bicycle elements or for the mounting of accessories. For example, on composite handlebars there must be mounted the brakes and gears control assemblies, and the handlebars are in turn mounted on the element which connects them to the fork tube.

However these clamping regions are critical areas for the bicycle structure in that the composite material results rather delicate with respect to the stress concentrated in said regions. In fact the resin matrix is quite fragile and in case of clamping with excessive strength it could break into pieces, while the fibers do not withstand well the rubbing caused by the repeated contact with another element and/or the clamping means (e. g. screws, clips, clamps, etc.).

On the other hand it is not possible to make a bicycle in a single piece, and even providing structural reinforcements in the clamping regions by increasing the thickness of the composite material implies a higher manufacturing cost and a greater weight of the structure.

Therefore the object of the present invention is to provide a composite material structure and a relevant manufacturing method which are free from the above-mentioned drawbacks. This object is achieved by means of a structure wherein every clamping region is provided with a surface metal mesh integrated in the composite material. Other advantageous features of the present structure are disclosed in the subsequent claims.

The main advantage of the structure according to the invention is that of eliminating, or at least greatly reducing, the risk of failure in a clamping region thanks to the presence of the external metal mesh which protects the underlying composite material.

A second advantage of this structure, and of its manufacturing method, is that of extreme simplicity and low cost since it does not require substantial changes with respect to the conventional process.

Still another advantage of such a structure is the weight reduction achieved thanks to the fact that it is not necessary to reinforce the structure through an increase in the thickness of the composite material in the clamping regions, the weight of the metal mesh being much smaller than that of the reinforcement material.

Further advantages and characteristics of the structure and of its manufacturing method according to the present invention will be clear to those skilled in the art from the following detailed description of an embodiment thereof, with reference to the only drawing, annexed as fig. 1, wherein there are illustrated as an example handlebars with the brakes and gears control assemblies as well as the connection to the fork tube, as previously mentioned.

In said figure there are illustrated three structures made according to the invention, namely handlebars M, a front fork F (only part of its tube being seen) and the element connecting them. The latter provides a body A with a rear portion for connection to the tube of fork F, by introducing the tube in a vertically slotted bore and tightening a pair of screws V which engage corresponding threaded sockets embedded in the composite structure.

In the same way there is provided a front portion for connection to the handlebars M through a separate connector C, which clamps handlebars M onto body A by means of screws same as done for fork F. Moreover, two control assemblies G (only one shown in the figure) are mounted on handlebars M through clips S.

Therefore it is clear that this part of the bicycle includes four clamping regions of critical importance, in that a failure in any of these regions may cause an accident with a great risk to the user.

The novel aspect of these structures is the presence in said regions of an external metal mesh T, T', T"embedded in the resin matrix as last layer of the composite structure. In other words, wherever there is required a clamping the composite material is provided with a covering made of a metal mesh of titanium,

steel, aluminum or other suitable metal.

More specifically, handlebars M are provided with two lateral meshes T in the clamping regions for clips S and a central mesh T'in the clamping region for connector C, which in turn is provided with a mesh T'on the surface contacting handlebars M same as the semicircular seat of body A also provided with a mesh T'. In the same way, at the top of the tube of fork F there is provided a mesh T" which contacts a similar mesh T"provided on the surface of the rear vertical bore of body A.

In the light of the description above the manufacturing method of this type of structure is readily understood: a) the composite material structure is prepared through a conventional process; b) at each clamping region there is applied as last layer a metal mesh, which may be either pre-impregnated or applied dry and then manually coated with resin; c) the thus prepared structure is then cured.

It is clear that the above-described and illustrated embodiment of the structure according to the invention is just an example susceptible of various modifications. In particular, the metal mesh may also be limited to just a portion of the clamping region rather than extending on the whole surface if said limited covering is sufficient to assure the resistance of the structure.

Moreover it is obvious that several other elements of the bicycle where clamping regions are present can be made with the above-described metal mesh, such as: seat-holding tube at the clamp of the frame joint, vertical. frame tube at the clamp of the chain-shifter, diagonal frame tube at the fastening means of the bottle-holder, ends of the front and rear forks at the wheel hub securing nuts, front fork at the abutment of the bearing arranged between the fork head and the frame Finally it should be noted that the present invention, though described with specific reference to cycle structures, can clearly be applied to any other kind of composite material structure used in other fields.