An improved sprocket profile for engaging a roller or bush chain smoothly
and preventing radial impact with the root of the tooth during
engagement. Contact between the sprocket teeth and the roller chain is
altered by providing teeth with a root radius equivalent to that of the
chain engaging component, with the center point of the root radius
located one chordal distance inside the sprocket's pitch circle. This
profile allows chain rollers or bushings to impact sprocket teeth
tangentially on their flanks rather than radially on their tooth root.