Finally a lightweight option for speed sets and spur gears. This 56 tooth spur gear comes with an 18 tooth RR pinion, for increased top speed. Our gears are made with proper tooth profiles so the total number of teeth will always be 74. For example: 17/57, 18/56, 19/55 and so on. These gears are made from a tough and durable material that resists wear and allows for a significant reduction in rotating mass allowing for quicker acceleration and more power being delivered to the rear wheels.