Abstract: Tyre for vehicle wheels, comprising a tread band having a plurality of blocks, at least some of said blocks comprising at least one sipe (30) extending from an axially outer portion of the block up to an axially inner portion of the block along a predetermined trajectory and from a radially outer face of the block towards a radially inner portion of the block. The sipe (30) comprises, in any cross-section perpendicular to said predetermined trajectory, a main portion (400) having a first radial dimension and a first transversal dimension and, in a radially inner position with respect to the main portion (400) and adjacent to the radially inner portion of the block, a bottom portion (450) having a second radial dimension smaller than the first radial dimension and a second transversal dimension greater than the first transversal dimension.

Abstract: Tyre for vehicle wheels, comprising a tread band having a plurality of blocks, at least some of said blocks comprising at least one sipe (30) extending from an axially outer portion of the block up to an axially inner portion of the block along a predetermined trajectory and from a radially outer face of the block towards a radially inner portion of the block. The sipe (30) comprises, in any cross-section perpendicular to said predetermined trajectory, a main portion (400) having a first radial dimension and a first transversal dimension and, in a radially inner position with respect to the main portion (400) and adjacent to the radially inner portion of the block, a bottom portion (450) having a second radial dimension smaller than the first radial dimension and a second transversal dimension greater than the first transversal dimension.

Abstract: A tyre has a tread pattern comprising at least one circumferential sipe (10), having, in radial section, a profile comprising: a first zone (Z1) close to the radially outer surface (S), having side walls (11) mutually spaced apart according to a minimum width W1; a second zone (Z2), having a portion (Pt) in which the side walls (11) diverge from one another, and a portion of maximum width (Pmax) having a maximum section width W2; and a third zone (Z3) having a maximum width W3, less than W2, radially inner with respect to the second zone (Z2). In the third zone (Z3) the side walls (11) join with a bottom portion (Pf) defining a total depth (H10) of the sipe (10). The ratio between W2 and W1 is greater than 1 and equal to or less than 2. A geometric centre (G2) of the portion of maximum width (Pmax) lies at a depth (PG) comprised between 40% and 60% of the total depth (H10).