Patent ID: 7552754

Claim:
A pneumatic radial tire, the tire comprising at least two carcass reinforcing plies and a pair of opposing bead portions, each bead portion has a bead core and a bead apex, the at least two carcass reinforcing plies each have a main portion and two carcass turnups, each carcass turnup of each ply extending from each end of each carcass main portion and having a terminal end, each carcass main portion extending between the opposing bead cores, each of the four carcass turnups being located axially outward of the bead cores and portions of the bead apexes, wherein in each bead portion, there is a first minimum distance D MIN between a first carcass main portion and a corresponding first carcass turnup, as measured perpendicular to the tire equatorial plane EP, the first distance D MIN being not less than 50% of a maximum bead core width W B as measured perpendicular to the equatorial plane EP, wherein in each bead portion, radially outward of the first minimum distance D MIN , a radially outermost portion of the first carcass turnup extends at a first angle so the radially outermost portion of the first carcass turnup is divergent from the first carcass main portion, wherein in each bead portion, there is a second minimum distance D MIN between a second carcass main portion and a corresponding second carcass turnup, as measured perpendicular to the tire equatorial plane EP, the second distance D MIN being not less than 50% of the maximum bead core width W B as measured perpendicular to the tire equatorial plane EP, wherein in each bead portion, radially outward of the second minimum distance D MIN , a radially outermost portion of the second carcass turnup extends at a second angle so the radially outermost portion of the second carcass turnup is divergent from the second carcass main portion, the first angle being between 5° and 20° greater than the second angle.