Heavy load radial tire with specified carcass turnup

A heavy duty radial tire comprising

• a carcass including a carcass ply made of cords arranged at an inclination angle of 70 to 90 degrees with respect to the tire equator, the carcass ply comprising a main portion extending from a tread portion to a bead core in a bead portion through a sidewall portion, the main portion integrally provided with a turnup portion, the turnup portion turned up from the axially inside to the outside at said bead core and extending radially outwardly, and
• a bead apex disposed between the main portion and turnup portion of the carcass ply extending and tapering radially outwardly from the bead core, wherein
• said turnup portion extends radially outwards along the axially outer surface of said bead apex, and then from the radially outer end of the bead apex, it has a portion extending substantially parallel with and adjacent to the main portion of the carcass ply, and
• the length L of the parallel portion is 1.0 to 8.0 times the maximum section width CW of the bead core.