Renthal sprockets are made from a special steel (with nickel, chromium and lead). Their centre is refined so it can combine strength and hardness in balance. It offers reduced weight. 14 teeth. TECHNICAL ADVICE. Changing the ratio recommended by the manufacturer gives the motorcycle different performance and different behaviour. Higher top speed - fuel economy (suggested for touring): fewer teeth at the rear, more teeth at the front. More acceleration - suggested for town: more teeth at the rear, fewer teeth at the front.