An article of footwear, including an upper configured to receive a foot and a sole structure fixedly attached to a bottom portion of the upper, the sole structure including a ground engaging outer member comprising: a baseplate having a bottom surface; at least a first ground engaging member extending substantially downward from the bottom surface of the baseplate to a free end of the first ground engaging member, the first ground engaging member having a substantially triangular cross-sectional shape over substantially an entire height of the first ground engaging member in a substantially horizontal plane, the first ground engaging member having a first sidewall edge, a second sidewall edge, and a third sidewall edge forming vertices of the substantially triangular cross-sectional shape; the first ground engaging member including a first sidewall having a concave portion that is concave in the substantially horizontal plane; wherein the first sidewall of the first ground engaging member has a height dimension extending between the baseplate and the free end of the first ground engaging member; wherein the first sidewall is concave in a horizontal direction over a substantial majority of its height dimension between the baseplate and the free end of the first ground engaging member; wherein the first ground engaging member includes a second sidewall and a third sidewall, wherein the first sidewall, the second sidewall, and the third sidewall are arranged to form three sides of the substantially triangular cross-sectional shape in the substantially horizontal plane; wherein the second side wall is concave in the substantially horizontal plane, and the third side wall is concave in the substantially horizontal plane; wherein the first sidewall, the second sidewall, and the third sidewall are concave in a substantially vertical plane; wherein the first ground engaging member is disposed proximate a peripheral edge of the outer member; wherein the first sidewall edge is disposed opposite the concave portion of the sidewall, the first sidewall edge being oriented facing toward the peripheral edge of the outer member; and wherein the concave portion of the first sidewall is oriented in a substantially lateral direction, facing away from the peripheral edge of the outer member. a baseplate having a bottom surface; at least a first ground engaging member extending substantially downward from the bottom surface of the baseplate to a free end of the first ground engaging member, the first ground engaging member having a substantially triangular cross-sectional shape over substantially an entire height of the first ground engaging member in a substantially horizontal plane, the first ground engaging member having a first sidewall edge, a second sidewall edge, and a third sidewall edge forming vertices of the substantially triangular cross-sectional shape; the first ground engaging member including a first sidewall having a concave portion that is concave in the substantially horizontal plane; wherein the first sidewall of the first ground engaging member has a height dimension extending between the baseplate and the free end of the first ground engaging member; wherein the first sidewall is concave in a horizontal direction over a substantial majority of its height dimension between the baseplate and the free end of the first ground engaging member; wherein the first ground engaging member includes a second sidewall and a third sidewall, wherein the first sidewall, the second sidewall, and the third sidewall are arranged to form three sides of the substantially triangular cross-sectional shape in the substantially horizontal plane; wherein the second side wall is concave in the substantially horizontal plane, and the third side wall is concave in the substantially horizontal plane; wherein the first sidewall, the second sidewall, and the third sidewall are concave in a substantially vertical plane; wherein the first ground engaging member is disposed proximate a peripheral edge of the outer member; wherein the first sidewall edge is disposed opposite the concave portion of the sidewall, the first sidewall edge being oriented facing toward the peripheral edge of the outer member; and wherein the concave portion of the first sidewall is oriented in a substantially lateral direction, facing away from the peripheral edge of the outer member.