Spare Oversized Pulley Wheels 13/19 Tooth For Your Ceramicspeed Ospw Systems. Fits The Following Ospw Systems:- Ospw Shimano 9200/8100 - Ospw Shimano 9100/9150 And 8000 Ss/850 Ss- Ospw Shimano Grx810/815 And Rx800/805- Ospw Campagnolo 11s Eps And Mechanical - Ospw Campagnolo 12s Eps Technology: Maintenance Of Ceramicspeed Oversized Pulley Wheels 13/19 Tooth:- No Set Rules Can Be Made For How Often Your Oversized Pulley Wheel System Should Be Maintained. Maintenance Frequency Depends On The Weather Conditions That You Are Riding In. See Below The Maintenance Advice For The Oversized Pulley Wheel Systems For Sram, Also Useful In The Case Of Shimano.