The present invention relates to a process for improving the cured adhesion of at least two rubber components which contact each other in a pneumatic tire. The process involves the steps of assembling and vulcanizing a pneumatic tire wherein prior to vulcanization of the pneumatic tire, one of the components is a precured rubber compound and the other is an uncured rubber compound. The process involves using a precured rubber compound comprising from 40 to 100 parts by weight of natural rubber or emulsion-polymerized styrene-butadiene copolymer rubber containing 0.5 to 3 phr of a fatty acid, precipitated silica and no fatty acid other than contained in the natural rubber or emulsion-polymerized styrene-butadiene rubber.