Tread for a tire having a rigidity gradient

A process for preparing a tread for a tire comprising:

• forming a mixture by incorporating in at least one diene elastomer more than 50 phr of an inorganic filler as reinforcing filler, between 2 and 15 phr of an inorganic filler-diene elastomer coupling agent, between 1 and 10 phr of a methylene acceptor;
• and
• optionally including carbon black, present in an amount less than 20% by weight relative to the quantity of total reinforcing filler, the quantity of total reinforcing filler being the sum of inorganic filler and carbon black;
• thermomechanically kneading the mixture, in one or more stages until a maximum temperature of between 130° C. and 200° C. is reached;
• cooling the mixture to a temperature of less than 100° C.;
• and then
• incorporating:
• between 0.5 and 5 phr of a methylene donor, and
• a vulcanization system;
• kneading the mixture having the vulcanization system until a maximum temperature of less than 120° C.;
• and then
• extruding or calendaring a rubber composition thus obtained in the form of a sulfur-vulcanizable tire tread,
• curing the sulfur vulcanizable tire tread;
• and
• obtaining a tire tread having a rigidity gradient that increases radially from a surface of the tread towards a inside of the tread after mechanical running-in of the tire.