Sprocket for roller chain

A sprocket for a roller chain having a succession of rollers, said sprocket having a plurality of teeth, with bottom surfaces located between adjacent teeth of the plurality, each tooth having a leading face and a trailing face, the trailing face of each tooth being opposite to the leading face of a next adjacent tooth, and each face having a proximal surface adjoining a bottom surface of the sprocket, and a distal surface joining the proximal surface at a meshing point and extending outwardly therefrom, wherein the meshing points on the opposed tooth faces of each pair of adjacent teeth are spaced from each other by a distance such that a circular, cylindrical chain roller in engagement with both of said meshing points is spaced from the proximal surfaces of said faces and from the adjoining bottom surface, and in which the distal surface of the trailing face of each tooth is in the form of a circular arc centered on a point at which the center of an immediately preceding chain roller is located when in contact with the meshing point on the leading face of the same tooth and the opposing meshing point of the trailing face of the tooth immediately ahead of said same tooth.