HPI Racing Heavy Duty Spur Gear 43Tx5mm Savage XL (Opt) HPI114587

The more teeth on the clutch bell (or fewer the teeth on the spur gear) the more top speed with slightly reduced acceleration, ideal for smooth surfaces or longer straights. The fewer number of teeth on the clutch bell (or the higher number of teeth on the spur gear) better the acceleration and torque with slightly less top speed, ideal for rough terrain and steep hills.