Patent ID: 7870881

Claim:
A tyre for a vehicle wheel, comprising: a carcass structure, including a central crown portion and two axially-opposite sidewalls terminating in a pair of beads for attachment to a rim of the wheel; a belt structure coaxially associated with the carcass structure; and a tread band extended coaxially about the belt structure; wherein the tread band is axially extended between two opposite edges of the tyre, wherein the edges delimit corresponding shoulder portions at axially-outer positions of the tread band, wherein the tread band is provided with a raised pattern comprising a plurality of circumferential ribs and grooves; wherein each circumferential rib is delimited by an edge and a circumferential groove, wherein a cross section profile of the outermost circumferential rib of a first shoulder portion comprises a second rectilinear segment; wherein a cross section of a radially-external reference profile of the tread band comprises at least one curving stretch and a first rectilinear segment, wherein the curving stretch extends axially outward to an intersection with one of the circumferential grooves, wherein the first rectilinear segment is tangent to the at least one curving stretch, extends axially outward from the at least one curving stretch at the one of the circumferential grooves, and extends beyond a corresponding shoulder edge point of the first shoulder portion; wherein a cross section profile of the tread band is made from a consecutive succession of said at least one curving stretch and the second rectilinear segment, the second rectilinear segment being offset from the first rectilinear segment by an angle about a rotation point lying on the first rectilinear segment, the cross section profile of the tread band having a discontinuity of height δ because an axially-inner end of the second rectilinear segment is closer to the carcass structure than an axially-inner end of the first rectilinear segment, wherein the rotation point is axially outward of the corresponding shoulder edge point by a distance not more than 30% of a total width of the tread band; wherein the discontinuity gives rise to an increase in tyre/ground contact pressure at an inner axial point of the circumferential groove and to a reduction in the tyre/ground contact pressure at an outer axial point of the circumferential groove, as compared to a reference tyre not provided with the discontinuity of height δ; wherein the axially-inner end of the second rectilinear segment is located in a radially outer position with respect to an axially outer end of the second rectilinear segment; and wherein the height δ is between 0.2 and 1.5 mm.