Abstract: A radial tire for heavy load vehicles having a steel cord-reinforced belt interposed between the carcass of radial structure and the tread, which comprises a rubber reinforcing layer extending from the center toward the edges along the inside of the tread and having at least one quarter the tread width, said rubber reinforcing layer being made of a rubber composition containing resorcin or a resorcin derivative as a reinforcing agent in addition to carbon black and silica and also containing hexamethylenetetramine or a melamine derivative as a methylene donor, said rubber reinforcing layer having a reinforcing factor of 2.2 to 5.7 which is defined by .sqroot.E'.multidot.d [where E' denotes the dynamic modulus (MPa) of the rubber reinforcing layer and d denotes the thickness (mm) of the rubber reinforcing layer].

Abstract: A pneumatic radial tire having highly durable bead structure is disclosed. One or more carcass ply layers of steel cords are turned up around a bead core from the inside to the outside. A reinforcing strip of steel cords is positioned outwardly adjacent to the turn-ups of carcass plies. A bead filler of approximately triangular sectional shape is disposed at the region enclosed by the carcass plies, the turn-ups of the carcass plies and the reinforcing strip of steel cords. The bead filler comprises high hardness rubber stock and medium hardness rubber stock. A cap of organic textile cord fabric covers an upper end of the reinforcing strip of steel cords. A fin-shaped rubber buffer having a hardness lower than that of the medium hardness rubber stock by 3.degree. to 20.degree. is disposed radially outwardly of the capped end and axially outwardly adjacent to the medium hardness rubber stock.

Abstract: A pneumatic radial tire having highly durable bead structure is disclosed. One or more carcass ply layers of steel cords are turned up around a bead core from the inside to the outside. A reinforcing strip of steel cords is positioned outwardly adjacent to and without extending radially outwardly beyond the turn-ups of carcass plies. A bead filler of approximately triangular sectional shape is disposed at the region enclosed by the carcass plies and the turn-ups of the carcass plies. The bead filler comprises high hardness rubber stock and medium hardness rubber stock. A cap of organic textile cord fabric covers an upper end of the carcass plies. A fin-shaped rubber buffer having a hardness lower than that of the medium hardness rubber stock by 3.degree. to 20.degree. is disposed radially outwardly of the capped end and axially outwardly adjacent to the medium hardness rubber stock. A reinforcing strip of organic textile cords may be further disposed outwardly adjacent to the reinforcing strip of steel cords.