Shimano Rear Derailleur Pulley Assemblies. MPN: Y3E498020 - Shimano - Rear Derailleur Pulley Assemblies - Pulley Assembly. We are out East at 3063 Columbia Ave. - Lancaster PA, 17603 & out West at 3225 Grande Vista Dr. - Newbury Park, CA 91320 & 165 Design Place, #105 - Sparks, NV, 89441.