Abstract: A sole structure for an article of footwear includes an outer sole component with a co-molded flex modifier component. The outer sole component is formed of a first mold material, such as a rubber mold material. The flex modifier component includes a fiber material and a second mold material. The second mold material may be mold compatible with the first mold material. The sole structure may be formed by co-molding an outer sole component blank or pre-form (e.g., rubber mold material), and a flex modifier component, e.g., in a hot press molding process using a molding system having a mold cavity configured to form the outer sole component. The flex modifier component may be formed (e.g., cut or stamped) from a sheet of flex modifier material, such as a thermoplastic extruded hot melt film sandwiched between fusion bonded non-woven fiber fabric material impregnated with a styrene-coated polymer.