420 155mm 37T front and 17T rear sprocket set for 50cc-125cc motocross bikes, quads and karts

This 420 chain and sprocket kit is the ideal solution to breathe new life into your powersports vehicle. Designed specifically to fit 50cc to 125cc motocross and pit bikes, as well as mini bikes, ATVs, and 4-wheel go-karts, it's a perfect replacement for Coolster, Apollo, SSR, and many other models. The kit consists of a heavy-duty 420 chain, a 73mm front sprocket with 17 teeth (17T), and a 155mm rear sprocket with 37 teeth (37T). The 0.235-inch-thick front sprocket has 1.18-inch-spaced mounting holes, making it compatible with 17mm engine primary shafts. It comes with a mounting plate and two screws for secure installation.

Made from 45 steel and steel alloy, these sprockets benefit from a heat treatment that significantly increases their strength and durability, making them excellent against wear. Their design with an improved tooth curve helps reduce friction in the transmission, thus helping to extend chain life.

This complete kit is designed to easily replace your old, damaged chain and sprocket set, allowing you to get back on the road quickly and confidently.

**Package Contents:**

1 x 420 Chain

1 x 420 37T Rear Sprocket (155 mm)

1 x 420 17T Front Sprocket (73 mm)

1 x Mounting Plate

2 x Screws