A vibration damper assembly to absorb vibrations in a camshaft and sprocket system has a sprocket positioned around a camshaft, an inertia ring positioned around the camshaft and adjacent the sprocket, yet capable of moving independently of the sprocket, and a hub member positioned around the camshaft adjacent the inertia ring. Frictional material is interposed between the hub member and a rim portion of the inertia ring whereby the inertia ring and hub member slide with respect to one another along the frictional material to absorb vibrations from the camshaft through heat dissipation.