The invention relates to a duplex cord for use as strength member in a belt bandage of a pneumatic vehicle tire, consisting of exactly two yarns that are twisted together at the ends, wherein the first yarn has a Z value of 600 mN/tex or more, and wherein the second yarn has a Z value of 75 mN/tex or less and a Y value of 150 mN/tex or less, where Z is the force normalized to the linear yarn density at which an elongation of 1% is obtained in the force-elongation diagram, where Y is the force normalized to the linear yarn density at which an elongation of 4% is obtained in the force-elongation diagram, and where the quotient X of the linear density of the first yarn divided by the linear density of the second yarn is in the range from 1.0 to 1.3.