A heavy duty tire comprises a tread portion, a pair of sidewall portions,
a pair of bead portions each with a bead core therein, the bead core with
an aspect ratio (HC1/WC) of from 0.43 to 0.58, and a carcass comprising a
carcass ply of cords extending between the bead portions and turned up
around a bead core in each bead portion from the inside to outside of the
tire so as to form a pair of turnup portions and a main portion
therebetween, the turnup portion comprising a turnup main-part extending
along an axially inner surface, a radially inner surface and an axially
outer surface of the bead core smoothly, and a turnup sub-part extending
from the turnup main-part toward the main portion near the radially outer
surface of the bead core.