FRONT SPROCKET: 4107 K teeth number : 15 16CrNi4 Steel REAR SPROCKET: 2146 ED teeth number: 41 Aluminium Alloy 7075T6, lighthess, 40 micron hard anodized for longer life CHAIN: 525GXW plates number: 110 The leading edge XW-Ring seal is made of an advanced nitrile butadiene composite and features six contact lips and two convex inner/outer stabilizers. This means four lubrication pools to protect against high-speed abrasion, heat build up, torsional flex and the loss of lubricant under these extreme conditions. As a result GWX chains provide the user with 10 times longer wearlife compared to standard chains