Complex sentence: The closing of these competitor factories allowed Tornel free reign in the market but not for long since soon after competition began from foreign tire manufacturers which would turn out to be aggressive commercial rivals, such as Goodyear, Bridgestone, Michelin, Firestone, and BFGoodrich.
Split into simpler sentences: The closing of these competitor factories allowed Tornel free reign in the market but not for long since soon after competition began from foreign tire manufacturers which would turn out to be aggressive commercial rivals. Competition soon developed from Goodyear, Bridgestone, Michelin, Firestone, and BFGoodrich.