The ZF double sprockets are among the highest quality and most technologically advanced sprockets in the world. The secret is based on the connection of the strength of steel and the lightness of duralumin. This aluminum alloy is characterized by enormous strength and tightness as well as light weight. The tensile strength is about 11 times of pure aluminum. With hardening duralumin almost reached the strength of steel. been implemented is therefore a lower weight and greater durability. The milling in the tooth base of the chain wheel ensures optimal self-cleaning. Such millings ensure that dirt cannot start between the teeth and thus not wear out the chain and sprocket so quickly. The life of the double IF sprockets is approximately three times longer than pure aluminum sprockets and they are 50% lighter than steel sprockets. ideal for road and off-road.