Pneumatic tire for cycle wheel

Abstract

A pneumatic tire for a cycle wheel comprising a casing and two beads positioned on respective ones of lateral sides of the casing, the pneumatic tire having the shape of an open torus and defining an inner volume, at least one of the two beads having a shoulder projecting outward of the portion of the casing adjacent thereto, and a support positioned along a radial plane at a second end of the bead, the shoulder being positioned along a radial plane at a first end of the bead and comprising, on its outer surface, a first support surface and an edge, the first support surface being positioned between the edge and the casing, and the support surface being set back with respect to the edge. In a radial plane, the normal direction of the first support surface is substantially tangent to the casing, the support comprising a second support surface positioned on the inner side. The longitudinal modulus of the bead, or the equivalent modulus of the various constituent elements of the bead, is less than 2000 Mpa, and the transverse modulus of the bead, or the equivalent modulus of the various constituent elements of the bead, is greater than 50 Mpa or greater than 100 MPa.

Description

technical field [0001] The present invention relates to bicycle wheels; more particularly, the present invention relates to a new type of tire for bicycle wheels. The invention also relates to a rim intended to receive a new type of tyre. Background technique [0002] Bicycle wheels equipped with pneumatic tires have been in use since the beginning of the 20th century. Currently, there are two types of bicycle tires: tubular tires, often referred to as "boyau" and straight-sided tires (pneumatique à tringle), commonly referred to as "pneu". Both types of tires have their advantages and disadvantages. [0003] Document FR 778744 discloses an inner tube. The inner tube consists of a fabric ring, which may be coated with rubber, which is sewn to each other on both sides to form a tore. An air cavity is inserted into the interior of the loop prior to suturing. Then, a tread (bande de roulement) is glued on the outside of the pipe ring. The inner tube is glued to the rim. ...

AI Technical Summary

Problems solved by technology

[0015] The weight disadvantage of wheels and straight-sided tires in general, and non-tubular wheels in particular, has the consequence that professional cyclists do not use straight tires on the road or track. Side tires, likewise, are rarely used when traveling by bike on the road without an air chamber

In fact, the use of wheels without air chambers is currently limited to the field of off-road cycling, where the weight of the equipment is not as critical as for road riding

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