A tyre, the tyre comprising: a tread having a tread surface for contacting the ground and at least one groove-like recess therein forming a free space, the recess having a longitudinal extension A along the surface and a depth B measured in a radial direction with respect to a radial axis of the tyre from the tread surface to a radially innermost position, the recess having a first end and a second end, the ends (17,18) being opposite to each other along the longitudinal extension A, wherein the free space can be divided into a sipe portion opening to the tread surface and a groove portion located beneath and radially inwards the sipe portion, wherein in a cross sectional view transverse to the longitudinal extension A of the recess the sipe portion has a sipe contour and the groove portion has a groove contour with a longitudinal axis (X'), wherein a corresponding width of the groove contour has at least one local maximum Wg at a height H referred to a spatial extent E of the groove contour in the direction of this longitudinal axis (X'), wherein the resulting maximum width of the groove contour is bigger than a maximum width Ws of the sipe contour, and wherein the groove portion has at least one transition section along the longitudinal extension A of the recess, between the ends (17, 18), wherein the height H of the groove portion changes in this at least one transition section by an amount ΔH, wherein for the ratio ΔH/B of the amount ΔH to the depth B applies ΔH/B≥ 0.1, characterized in that for the at least one transition section the longitudinal axis (X') of the groove contour is inclined with respect to the radial axis of the tyre with an inclination angle α in the range -30° ≤ α ≤ 30°, and wherein the inclination angle α changes in the range -30° ≤ α ≤ 30° so as to form a profile path for the radially innermost position of a zigzag, wavy, sinusoidal or stepped configuration or a combination thereof, where the depth B is essentially constant. a tread having a tread surface for contacting the ground and at least one groove-like recess therein forming a free space, the recess having a longitudinal extension A along the surface and a depth B measured in a radial direction with respect to a radial axis of the tyre from the tread surface to a radially innermost position, the recess having a first end and a second end, the ends (17,18) being opposite to each other along the longitudinal extension A, wherein the free space can be divided into a sipe portion opening to the tread surface and a groove portion located beneath and radially inwards the sipe portion, wherein in a cross sectional view transverse to the longitudinal extension A of the recess the sipe portion has a sipe contour and the groove portion has a groove contour with a longitudinal axis (X'), wherein a corresponding width of the groove contour has at least one local maximum Wg at a height H referred to a spatial extent E of the groove contour in the direction of this longitudinal axis (X'), wherein the resulting maximum width of the groove contour is bigger than a maximum width Ws of the sipe contour, and wherein the groove portion has at least one transition section along the longitudinal extension A of the recess, between the ends (17, 18), wherein the height H of the groove portion changes in this at least one transition section by an amount ΔH, wherein for the ratio ΔH/B of the amount ΔH to the depth B applies ΔH/B≥ 0.1, characterized in that for the at least one transition section the longitudinal axis (X') of the groove contour is inclined with respect to the radial axis of the tyre with an inclination angle α in the range -30° ≤ α ≤ 30°, and wherein the inclination angle α changes in the range -30° ≤ α ≤ 30° so as to form a profile path for the radially innermost position of a zigzag, wavy, sinusoidal or stepped configuration or a combination thereof, where the depth B is essentially constant.