Pneumatic tyre with tread wear indicator

A pneumatic tyre, comprising:

• a tread having a circumferential direction, an axial direction, and a radial direction,
• the tread having a tread surface to come into contact with a ground and at least one circumferential groove which extends continuously in the circumferential direction, the at least one circumferential groove having a groove base, and at least one groove sidewall connected to the groove base;
• and
• at least one tread wear indicator in the circumferential groove that protrudes from the groove base and is connected to the at least one groove sidewall;
• wherein the groove sidewall has a cavity formed therein having a cavity base parallel to the groove base and cavity sidewalls extending in the radial direction to the tread surface, the cavity being open to the circumferential groove and the tread surface, wherein at least a portion of the cavity is positioned in a portion of the groove sidewall extending in the circumferential direction along the tread wear indicator,
• wherein the tread wear indicator protruding from the groove base forms a step, where the height of the tread wear indicator in radial direction corresponds to the height of the cavity base, and
• wherein the cavity has an opening in the tread surface that is formed so as to increase in the radial direction towards the cavity base as the depth of the tread decreases due to wear.