PBR 270 53 TC4 : PBR Twin Color Aluminium Ultra-Light Self-Cleaning Hard Anodized Rear Sprocket 270 - 520 €52.30
AFAM 48012455 : AFAM Chain Kit 520XHR2 17/42 Super-Reinforced - Ultra-Light Hard Anodized Rear Sprocket €197.93
JT DRIVE CHAIN : DID/JT Chain Kit 420D 11/47 (OEM Ratio) Standard - Steel Standard Rear Sprocket €40.96