JMCHstore 50T Rear Sprocket for Mini Bikes - 6-Hole Gold Zinc 207mm, #40/41/420 Chain

JMCHstore 50-tooth rear sprocket (#40/41/420) is a balanced-performance replacement designed to improve acceleration and top speed for compatible mini bikes while resisting corrosion and wear.

This sprocket is a direct-fit aftermarket rear wheel component for a range of small motorcycles and mini bikes, engineered to deliver dependable power transfer for 212cc-class and larger engines. Machined from high-strength steel and finished with a gold zinc coating, it aims to reduce chain slip, extend drivetrain life, and withstand high RPMs and tough conditions. The part suits several popular models but does not fit go-karts because of different mounting patterns.

What machines will this 50T sprocket fit?

The JMCHstore 50T sprocket is made to match #40, #41, and #420 chains and fits specific mini bike rear hubs with a 6-bolt pattern. Confirm your wheel's bolt circle and center bore before ordering to ensure compatibility.

• Compatible models listed include Coleman CT100U, CC100X, RB100/B100, Mega Moto MMB80/MMB105, Baja Doodle Bug DB30, Motovox MBX10, Oryxearth 105cc, and FPR GMB100 rear wheels.
• Mounting pattern: 6 holes, mounting hole diameter 6.5 mm, bolt circle (center-to-center) 49 mm.
• Center hole diameter: 37 mm; overall diameter: 207 mm (8.15 inches).

How does this sprocket change performance on my mini bike?

This 50-tooth sprocket finds the middle ground between torque and top-end speed so you gain smoother acceleration without sacrificing cruising capability. Precision-cut teeth help the chain seat consistently, reducing slip and vibration under load.

• Balanced tooth count offers improved off-the-line response with retained top speed potential.
• Precision machining reduces uneven wear and improves drivetrain efficiency.
• Gold zinc plating protects against rust so performance is more consistent in wet conditions.

Will it withstand heavy use and high RPMs?

Yes — the sprocket is stamped from high-strength steel designed to handle elevated loads common with upgraded engines. The corrosion-resistant coating and robust teeth geometry prolong service life under frequent use.

• Material: premium alloy/high-strength steel for durability under stress.
• Finish: gold zinc plating for long-term corrosion resistance.
• Intended for 212cc-class and larger engines, engineered to minimize chain wear.

What are the exact measurements and chain type I should buy?

The sprocket is made for #40/#41/#420 chain sizes and includes precise dimensions so you can match it to your wheel and chain. Double-check the bolt circle and center bore measurements against your rear hub drawings or existing sprocket.

• Teeth: 50T; compatible chain sizes: #40, #41, #420.
• Mounting bolt circle (center-to-center): 49 mm (1.93 in); center hole diameter: 37 mm (1.46 in).
• Overall diameter: 207 mm (8.15 in); six mounting holes, each 6.5 mm (0.26 in).

Who is this for: The JMCHstore 50T rear sprocket is ideal for riders upgrading or repairing mini bikes—especially owners of Coleman CT100U/CC100X, Mega Moto MMB80/MMB105, Baja Doodle Bug DB30, Motovox MBX10, and similar models—who want a corrosion-resistant, precision-made sprocket that balances acceleration and top speed. Do not purchase this part for go-karts; mounting patterns differ. Always verify your wheel's bolt pattern and chain size before installation to ensure correct fitment.