Tire with improved transverse grip performance on snow-covered surfaces

A tire comprising a tread (10) which is intended to come into contact with a ground via a tread surface (15):

• the tread (10) comprising raised elements that are organized into at least two tread pattern elements MA, MB which are separated from one another at least in part by cuts (30) and extend radially toward an outside from a bottom surface (40) as far as the tread surface (15) over a maximum radial height Hsre at least equal to 6 mm;
• a path of a cut along the tread surface (15) defining a mean geometric profile which is situated at a mean distance from edge corners formed by walls of the cut;
• in a meridian section of the tire, a point M being defined at an intersection of the mean geometric profile (53) and of the tread surface (15), and at point M, Npsup being an external normal to the tread surface (15);
• a pitch PA or PB being respectively associated with the tread pattern element MA or MB, the pitch of a tread pattern element being a distance, measured on a circumference of the tire, between a point on the tread pattern element and a translated image of the point on an immediately next tread pattern element in a direction of running;
• a complete tread being obtained by repeating the tread pattern elements MA, MB at the pitches PA, PB over a complete circuit of the tire with PA<PB;
• each tread pattern element MA, MB comprising a first lateral portion ZB extending from one axial end of an edge of the tread (24G, 24D) over an axial width at most equal to 25% of an axial width W of the tread;
• and
• a longitudinal sipe being a cut in at least a lateral portion ZB of a tread pattern element MA, MB in which a distance between walls of material that delimit the longitudinal sipe is less than or equal to 2 mm and a depth of which is greater than or equal to 1 mm,
• wherein each first lateral portion ZB contains at least one longitudinal sipe (50) of which a path on the tread surface is a mean plane (53) that makes an angle Beta with a circumferential direction XX′, which angle, in terms of absolute value, is comprised within a range [0°, 20°],
• wherein the mean plane (53) of the at least one longitudinal sipe (50) makes an angle Alpha with the external normal Npsup, which angle is comprised within a range [3°;
• 55°], the angle Alpha being oriented from the external normal Npsup toward the mean plane (53), and
• wherein a sum of projected lengths of the at least one longitudinal sipe (50) in the circumferential direction XX′ onto all of the first lateral portions ZB is comprised between 0.5 times and 5 times the circumference of the tire measured in an equatorial plane.