Radial tire with asymmetric construction

A pneumatic tire having an inboard sidewall and an outboard sidewall when fitted to a vehicle comprising a reinforced carcass extending between bead regions through both inboard and outboard sidewalls and a tread region reinforced by a breaker extending between the tread edges beneath the rubber tread wherein the carcass in the outboard sidewall comprises a single ply of reinforced material having mutually parallel reinforcement cords extending substantially radially of the tire, the ply having one edge located under the breaker, extending from the breaker radially inwards through the outboard sidewall and being wrapped axially outwards around a bead hoop and being turned up to have its second edge radially outwards of the bead hoop, and the reinforced carcass for the inboard sidewall comprises a single ply of reinforcement material arranged with a first edge under and in overlapping engagement with the edge region of the outboard sidewall reinforcement, said first edge being adjacent to the inboard bead at an inboard shoulder, the single ply of the inboard side wall having a main portion extending radially inwards and a turn-up portion being wrapped around the inboard bead from inside to outside and extending radially outwards through the inboard sidewall to a point adjacent to an inboard breaker edge radially under said breaker and radially over the outboard sidewall ply in overlapping arrangement therewith, the overlap between both edges of the inboard sidewall reinforcement main portion and turn-up portion with the outboard sidewall reinforcement edge are in the range of 10%-20% of the width of the breaker.