The present invention is directed to a non-vulcanized rubber composition which is comprised of (1) 90 phr to 100 phr cis 1,4-polyisoprene; (2) 10 phr to 40 phr of pre-silanized precipitated silica; (3) 10 phr to 40 phr of carbon black, (4) 0.1 phr to 5 phr of a cobalt salt, and (5) 1 phr to 15 phr of a resinous reaction product of a methylene donor composition and a methylene acceptor composition. Moreover, the present invention is directed to a tire or tire component comprising the cured rubber composition.