RUTU ATV Rear Sprocket 420 37T — 48mm/68mm Bolt Spacing, Heat-Treated Steel with Mounting Screws

RUTU's 420 37-tooth rear sprocket is a hardened steel replacement for ATVs using 420 chains, sized with 48mm adjacent and 68mm opposite bolt spacing and supplied with mounting screws.

This replacement sprocket is designed for riders who need a durable, precisely machined rear gear that fits common 420-chain ATVs. Built from heat-treated steel with tooth-radius profiling, the sprocket balances wear resistance and smoother chain engagement. The listing includes the sprocket and the mounting hardware necessary for installation; confirm your ATV's chain size and bolt spacing before purchasing.

How do I confirm this sprocket fits my ATV?

Measure your current sprocket and chain before ordering. This RUTU sprocket matches 420 chains and has two critical hole-to-hole measurements: 48mm for adjacent holes and 68mm for holes on opposite sides. Also verify the chain pitch marked on a link.

• Check chain marking: look for a "420" stamped on a link or packaging.
• Measure bolt spacing: adjacent holes = 48mm, opposite holes = 68mm.
• Count teeth: this unit has 37 teeth (37T).
• Refer to your ATV manual for manufacturer-specific fit notes.

What performance differences will 37T rear sprocket make?

Changing rear sprocket tooth count adjusts acceleration and top speed. A larger rear sprocket (more teeth) increases low-end torque and climbing ability, while a smaller rear sprocket favors higher top speed but lowers torque. Keep the front sprocket unchanged for predictable results.

• 37T provides a balance between acceleration and speed for general trail riding.
• Adding teeth improves hill-climbing but reduces maximum speed.
• Removing teeth raises top speed but lessens low-speed pulling power.
• Test ride after install to fine-tune gearing for your riding style.

What materials and treatments are used to extend sprocket life?

The sprocket is manufactured from premium steel and undergoes heat treatment to strengthen the metal and resist wear. Tooth profiles include a radius curve that lowers transmission friction and helps chains run smoother, extending both sprocket and chain life.

• Heat-treated steel for improved hardness and longevity.
• Precision-tooth radius reduces chain impact and friction.
• Corrosion-resistant finish for outdoor use and durability.
• Supplied mounting screws compatible with specified bolt pattern.

How difficult is installation and what should I prepare?

Installation is straightforward for anyone comfortable with basic ATV maintenance, but follow safety and torque specifications. You will need standard hand tools, a torque wrench, and to verify bolt pattern alignment. If unsure, a service shop can complete the swap quickly.

• Required tools: wrenches, socket set, torque wrench, and chain tool if adjusting length.
• Confirm bolt spacing and thread compatibility before tightening.
• Inspect chain wear and replace chain or front sprocket if uneven wear exists.
• Follow manufacturer torque specs and re-check after a short ride.

Who is this for: Riders with ATVs or quads that use 420-series chains who want a robust, heat-treated aftermarket rear sprocket with the common 48mm/68mm bolt spacing. Ideal for enthusiasts who need dependable replacement parts for trail riding, recreational use, or light utility work and who can verify chain pitch and bolt pattern before fitting. Not compatible with chains other than 420; youth and children’s ATVs often use 420 or 428—confirm size before purchase.