Sram jockey wheel set forcerivalapexthe same hybrid ceramic cartridge bearings used in the new sram red rear derailleurs upper and lower pulleys are also available as an upgradable accessory to hop up your current drivetrain make the leap to reduced friction increased stiffness lighter weight and added durability with this secret weapon featuresweight 12g eachmaterial ceramic ballsstainless steel racescompatibility sram forcerivalapex rear derailleursbuysram componentsfrom cha