PURPOSE: To make the stiffness of a bead toe portion by forming a slant area having same angle as a rim base portion and a larger slant area at a bead base portion, forming similar respective slant areas at the base of a bead wire divided portion and forming the slant area change portion in the slant area having same angle as the bead base portion.

CONSTITUTION: A slant portion Wa having nearly same angle as a rim base portion 12 and a slant portion W2 having a larger angle are formed at a tyre bead base portion 9. In a similar way, a slant portion a1 having nearly same angle as the rim base portion 12 and a slant portion a2 having a larger angle and formed at the base of a bead core 1 divided by the profile line of a bead wire, and the slant angle change portion is provided in the slant area W1 having same angle as the bread base portion 9. Stiffness of a bead toe portion 7 is increased so that the deformation of the bead toe portion is prevented and fitness of a rim is improved.