Abstract: Tread (1) for a pneumatic tyre, comprising a sequence of tread elements (5) forming an overall “V” shape with two lateral wings (7, 7?), each of said wings being formed from three tread blocks (11, 21, 31) separated therebetween by first and second grooves (15, 16); said three tread blocks (11,21,31) comprise at least one shoulder block (11) provided with at least a first sipe (111) having a “zig-zag” shape; each shoulder block (11) further comprises a channel (112) with a longitudinally evolution which extends on the shoulder block (11), until it reaches and emerges upon the corresponding second groove (15); the channel (112) with a longitudinal evolution comprises an end portion (300, 301) that opens onto said second groove (15), said end portion (300) having a variable depth, said terminal portion having at least one inclined portion (300) wherein the depth gradually decreases from the outside towards the inside of the pneumatic tyre, as the interface with this second groove (15) approaches.