BlackStar 80R72 - 80 Pitch R Sprocket - 72 ToothThe BlackStar 80R72 is a 80 pitch R roller chain sprocket with 72 teeth, precision manufactured from SAE 1045 steel and features machine cut tooth profiles for smooth, reliable chain engagement. Requires a Split Taper Bushing (sold separately). Specifications Part Number 80R72 Chain Pitch 80 Number of Teeth 72 Bore Type Plain Bore Hub Style R Strand Count Single Material Steel Outside Diameter 23. 50" Pitch Diameter 22. 926" Approx. Weight 69. 400 lbs