A rubber tread of a tire includes cavities spaced radially inwardly from a running surface of the tread when new. Each cavity includes an incision, and a groove communicating with a radially inner end of the incision when the tread is new. The incision has a radially outer generatrix following an undulating profile having an amplitude of at least 20% of a maximum height of the cavity. A width of the incision is not greater than 2.5 mm, and the groove width is greater than 2.5 mm.