ZF- Dual sprockets are among the highest quality and most technically advanced sprockets in the world. The secret is based on the combination of the durability of steel and the lightness of duralumin. This aluminum alloy is characterized by enormous strength and tightness as well as low weight. The tensile strength is about 11 times that of pure aluminium. Through hardening, duraluminium almost reaches the strength of steel. The result is a lower weight and higher resistance. Milled grooves in the bottom of the sprocket teeth guarantee optimal self-cleaning. These grooves ensure that the dirt cannot settle between the teeth and therefore the chain and sprocket do not wear out so quickly. The durability of ZF-Dual sprockets is approximately three times longer than pure aluminium sprockets and 50% lighter than steel sprockets.