Pneumatic tire with cords directly contacting tread compound

A tire, comprising a crown extended by two respective sidewalls and two respective beads, and a carcass which is anchored in said beads, said crown having the following components, disposed in the following order with progression radially from the interior to the exterior with respect to the main axis of the tire:

• at least one reinforcing ply comprising parallel cords disposed at an angle α in the range 10-75° with respect to the circumferential direction;
• at least one radially outermost ply having an axial width comprised of cords which are spirally wound wherewith the cords themselves are substantially oriented in the circumferential direction, said circumferentially oriented cords having a radially outward side of the cords and a radially inner side of the cords, and
• a tread compound;
• wherein, in a substantial portion of the axial width of said at least one radially outermost ply, in any cross section perpendicular to the axis of the tire and intersecting a cord of said at least one radially outermost ply:
• said tread compound has direct contact with the radially outward side of the cords of said at least one radially outermost ply,
• there is a first decoupling layer comprising a decoupling compound different than the tread compound, said decoupling compound having direct contact with the radially inner side of the cords of said at least one radially outermost ply, the tread compound having contact with the decoupling compound in interfaces terminating axially on the cords of said at least one radially outermost ply;
• and
• the at least one radially outermost ply has a fill coefficient FC <0.4, said fill coefficient being defined as
• FC=Φ/p,
• where Φ is the cord diameter of said cords and p is the winding pitch between the cord axes of neighboring said cords comprising the spiral winding.