Tire of which the tread comprises wavy grooves

A tread for a tire, comprising:

• a tread surface in the new state that is intended to come into contact with a road surface during running and, opening onto this tread surface, at least one circumferential continuous wavy groove that opens discontinuously onto the tread surface in the new state, each wavy groove having external cavities that open onto the tread surface in the new state along a length (Le) and internal cavities that do not open onto the tread surface in the new state, the external cavities comprising a bottom of which the points that are innermost in the tread are at a distance from the tread surface in the new state, the internal cavities having a bottom of which the innermost points are at a distance from the same tread surface, these external cavities and these internal cavities being connected together by linking cavities, radially extending sipes, each radially extending sipe extending from a respective internal cavity to the tread surface, the radially extending sipes having respective circumferential ends spaced apart from the external cavities, this tread having at least two circumferential sipes formed from the bottom of the external cavities and along the entire length (Le) of these external cavities at the axial edges of the external cavities, said sipes having depths, measured from the bottom of the external cavities, at least equal to 50% of the difference between the maximum depth of the bottom of the internal cavities and the depth of the external cavities.