FRONT SPROCKET: 1248 K teeth number : 14 16CrNi4 Steel REAR SPROCKET: 897 EC teeth number: 48 Aluminium Alloy 7075T6, lighthess and with mud grooves on both sides for off road CHAIN: 520XSO plates number: 120 Affordable and long lasting performance chain. RK's XSO chain offer less torsional friction and increased high-stress high -speed performance proving a longer lasting chain at an affordable price. All RX-Ring chain have "X" shaped seal and improved metallurgy giving you 7 times longer wearlife than standard chain