Truck steer tire, a mold and a method of molding

A radial ply pneumatic tire for the steer axle of a commercial truck having a casing, the casing having at least one radial ply extending to a pair of radially inner beads and having a belt reinforcing structure disposed radially outward of the ply, a tread disposed radially outward of the casing, the tire comprising

• a tread having a pair of shoulder tread ribs, each shoulder rib having an axially outer treadwall, each axially outer treadwall having a laterally inward extending circumferentially continuous side groove, the side groove having a groove depth (d) and a minimum groove width (w), the minimum groove width being 5 mm or greater and the ratio of groove depth to the groove width being 1.6 to 2.4, the side groove having a groove base having a radiused profile R, the radially inner portion of R being at least equal to one half the minimum groove width (w),
• a pair of sidewalls, one sidewall extending radially inwardly from each shoulder rib toward each radially inner bead.