Wilwood’s Sprocket Brake kits 140-10181 / 140-10181-P are for a 51 tooth sprocket and R/H caliper application. The sprocket-rotor bolt circle is consistent on all Harley Davidson models with a 5 x 3.25” bolt circle. The accompanying billet aluminum GP310 caliper is a 4 piston powerhouse, available in either chrome or a bright polished finish. Sprocket brake kits utilize a unique bracket design that combines the right elements of strength and style for your custom application.