Radial tires for motorcycles comprising a tread portion, side wall portions, bead portions, a carcass, bead apexes made of a rubber having a high hardness, and optionally reinforcing cord layers arranged outside the bead apexes, said tread portion having shoulder grooves at the shoulder portion thereof and center grooves at the center portion thereof and the depth of the shoulder grooves being from 5 to 50% of the depth of the center grooves, whereby cracking of the shoulder groove bottom caused by providing the bead apexes made of a hard rubber or the reinforcing cord layers is prevented.