33_z_ 6_z_2_z_ 23T sprocket for Nexus geared hubs Shimano Nexus Silver 23 teeth 4524667173359 Parts 4524667173359 Transmissions Sprockets cs nexus hub sprokett 23T SPRE CS Nexus Sprkt 23T SR Y33_z_6_z_2_z__z_ sprocket sprockets sproket Shiamno Simano Shim