- Chain and sprockets have to work in perfect harmony: this is the reason why we have optimised the profile of the sprocket teeth. The result is perfect synchronisation in traction and rapid shifting thanks to the Ultra-Drive(TM) design. * Steel * Galvanized * Ultra-Drive * Single sprockets * Supplied with lockring * Optimized sprocket timing * Ultra-Drive system surface galvanization. * Weight 250g The nominal weight refers to the lighter specification among the available options.