This 4-5/8" stroke 8-1/2" diameter flywheel assembly fits 2000-'06 internally balanced HD® big twin models as part of an S&S® 124" Hot Set Up Kit®. Sprocket shaft does not have a stock style bearing race pressed on. This flywheel assembly is for crankcases with Timken® sprocket shaft bearing. Flywheel assembly is three piece design. Pinion and sprocket shafts are forged as part of the flywheel. Assembly is trued to less than .0005" runout on pinion and sprocket shaft bearing surfaces, making them capable of higher rpm and fully compatible with gear drive cams.