Abstract: A heavy duty pneumatic radial tire comprises a pair of bead portions each containing a bead core, a radial carcass, a belt comprised of at least one belt layer, and a tread, in which (1) a tapering angle &thgr;C of an inner side of the bead core in the radial direction is within ±2° of a tapering angle &thgr;R of a bead seat part in an approved rim, and (2) a compression ratio Ca at a widthwise inner end of the inner side of the bead core is within a range of 102-115% of a compression ratio Cb at a widthwise outer end thereof.

Abstract: A heavy duty pneumatic radial tire has an outer profile of a tread portion in radial section of the tire having a given composite arc shape as a function of the internal structure of the tire, particularly a belt structure including at least two belt layers inclusive of main cross belt layers of steel cords.

Abstract: A pneumatic radial tire for construction vehicle comprises a carcass of a radial structure comprised of at least one rubberized steel cord carcass ply body and its turnup portion, and a stiffener rubber arranged above a bead core between the carcass ply body and its turnup portion. In order to improve the bead portion durability of this tire, a cord distance between the carcass ply body and its turnup portion passes through greatest value, minimum value, maximum value and smallest value from the vicinity of the bead core outward in the radial direction of the tire and heights of the carcass ply body corresponding to the above minimum and maximum values as well as height of the turnup end measured from the base line satisfy particular relations to a flange height FH of the standard rim.

Abstract: A pneumatic radial tire for construction vehicles comprises a radial carcass of rubberized steel cord ply, a stiffener rubber disposed on a bead core, and at least two reinforcing layers of rubberized fiber cord fabrics having different cord directions as a bead portion reinforcement. This reinforcing layer satisfies the particular height relations to the carcass ply and its turnup portion.

Abstract: At lest a portion of a core assembly for a pneumatic tire, which is mounted on an outer surface of a well portion of an annular rim to which the pneumatic tire is attached, is formed from an elastomer material. The radial height of the core assembly in a condition where an inner surface of a crown portion of the tire is in contact with an outer peripheral surface of the core assembly is set in a range of from 40% to 70% of the normal height of the tire, and the width of the outer peripheral surface of the core assembly is set at 0.5 or more times the radial height of the core assembly.