PURPOSE: To prevent separation of a tyre by building up a carcass ply from a lamination of aromatic polyamide fiber codes and by determining the positions of the end of wound play, a rim flange, a terminal of a metal code reinforcing layer, and hard and soft parts of a rubber filler in a specified correlated relation.

CONSTITUTION: A carcass ply 6 is made up from a lamination of aromatic polyamide fiber codes and the end of the wind-up part 6' of the ply on a bead ring 4 is determined at a position lower than the extremity Rt of a rim flange Rf when a rim is fit to a tyre. A distance (i) of the part 9-1 of a metal code reinforcing layer 9 extending along a side part 3, measured from a reference line L-L at the lower end of a bead 5 is determined 5W30mm longer than a distance (h) measured in similar manner with respect to the part 9-2 and is ranged between 20 and 40% of the height H of the tyre. A distance (j) from the line L-L to the upper end of a hard rubber 10-1 of a rubber filler 10 is set to be shorter than a distance (k) from the same L-L to the upper end of a soft rubber 10-2, both ends of the rubbers being located higher than the upper end of the part 9-1. Separation at the end of the carcass may be thereby prevented.