FRONT SPROCKET: 4054 K teeth number : 15 16CrNi4 Steel REAR SPROCKET: 2115 THF teeth number: 41 Rear sprocket C45 steel, long lasting CHAIN: 525GXW plates number: 108 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