RZEOZU 35 Chain & 65T Rear Sprocket Upgrade Kit for Razor MX650 — 54mm Bore, 9/11/13T Motor Sprockets & Tools

RZEOZU's 35 chain and 65-tooth rear sprocket upgrade kit replaces the stock drive components on Razor MX650-style electric dirt bikes to deliver a stronger, serviceable drivetrain with selectable motor sprocket ratios.

This kit is designed to be a direct-fit-style replacement for many MX650-compatible models and offers tools and multiple front sprocket choices so you can tune speed versus torque. It includes a heavy-duty 65T rear sprocket with a 54 mm center bore and a 108-link #35 chain plus three motor sprocket sizes (9T, 11T, 13T). The package also supplies installation hardware, a flywheel adapter, master links, a chain breaker and wrenches to simplify swapping parts on the bench or at the trail.

How does this kit change performance on my Razor MX650?

Choosing a different motor sprocket alters final drive ratio, letting you prioritize top speed or hill-climbing torque. Larger front sprockets increase road speed and reduce motor RPM for a given wheel speed; smaller sprockets improve acceleration and climbing force. All components are sized to work together so shifting ratios stays reliable.

• Includes 9T, 11T, and 13T motor sprockets for tuning.
• 65T rear sprocket yields a lower rear gear reduction than many stock parts.
• #35 chain (108 links) and five master links for secure joining.
• Flywheel adapter aligns the sprocket to MX650-style motors (check motor type).

Will this fit my electric dirt bike and what should I check before buying?

The kit fits many Razor MX650 and similar models (including some MX500/SX500 variants) but requires a compatible motor shaft and mounting dimensions. Verify your motor type (MY1020 is compatible) and measure the motor sprocket mounting dimensions supplied in the listing to ensure a secure fit. The flywheel adapter helps adapt to common motor layouts, but match bore and bolt patterns first.

• Rear sprocket center bore: 54 mm (2.1") and overall diameter ~200 mm.
• Chain specification: #35 chain, 108 links, 5 master links included.
• Motor mount dimensions: 10 mm length, 8.5 mm width mounting diameter (approx).
• Compatible with MY1020-type motor; confirm motor sprocket fit before install.

What tools and hardware are included, and how easy is installation?

The kit ships with installation hardware and common hand tools so you can perform the swap at home with basic mechanical skills. Included items simplify separating and reconnecting the chain plus bolting the new rear sprocket and motor sprocket into place. Follow a step-by-step procedure: remove the wheel or chain guard as needed, take off the old sprockets, install the flywheel adapter and new sprockets, set chain tension, then test ride carefully.

• Package includes chain breaker, three wrenches, four screws, four nuts, and five master links.
• Flywheel adapter and sprocket bolts are supplied for alignment and fastening.
• Basic wrenching skills required; a torque wrench and thread locker recommended.
• Installation time: typically 45–90 minutes depending on experience and model.

Who is this for: This RZEOZU upgrade kit suits riders who want a durable replacement drivetrain or wish to tune their Razor-style electric dirt bike for different riding conditions. It's ideal for hobby mechanics, riders tackling steep terrain who need better acceleration, and owners looking to replace worn chain and sprocket parts with a complete kit that includes the bits and tools required for a straightforward swap. Verify motor type and mounting specifications before purchasing to ensure compatibility.