Driven Racing 428 Rear Sprocket for Honda Grom and Monkey 125

Driven Racing EVO TECH rear sprocket for Honda Grom and Monkey 125cc with 428 chain.

Driven Honda Grom and Monkey 125 rear sprockets are available in 34t, 35t, 36t, 38t, 39t, and 40t options.

Please Note: 2022+ rear sprockets are not interchangeable with 2021 and earlier model Groms. Choose 34t, 35t, or 36t for 2021 and earlier models. Choose 38t, 39t, or 40t for 2022 and newer models.

The stock rear sprocket size on the 2021 and earlier Honda Grom is 34 tooth and you can go up to 35t or 36t to increase your low end acceleration.

The rear sprocket size on the 2022 Grom is 38t and you can go up to 39t or 40t to increase your low end acceleration.

A few rules regarding gear ratios for sprockets are as follows:

• Drop teeth on front/add teeth to rear = increased torque, increased acceleration, wheelies, racetracks with short straights
• Add tooth on front/reduce teeth on rear = increased top end speed, open road cruising, lowers RPMs, better gas mileage, tracks with long straights
• 1 down on the front is like adding 3 teeth on the rear
• The bigger the rear sprocket, the lower the gearing and the faster the acceleration

Please click here to view our Gear Ratio Chart!

• Available in 34, 35, 36, 38, 39, and 40 Tooth
• Case Hardened
• Fits #428 Chain
• Inner Diameter: 58mm
• Diagonal Bolt Spacing: 89mm
• Made in USA!