Driven Racing 428 EVO TECH Rear Sprocket | Honda Grom

Description

Fine-tune your Honda Grom or Monkey 125’s gearing with the Driven Racing EVO TECH 428 Rear Sprocket. CNC-machined and case-hardened in the USA for maximum durability and smooth power delivery. Available in 34T–40T to optimize for acceleration or top-end speed.

Important — bolt pattern changed in 2022:

• 2014–2021 Grom / Monkey 125: use 34T, 35T, or 36T
• 2022+ Grom / Monkey 125: use 38T, 39T, or 40T

Technical Specifications

• Chain size: 428
• Inner diameter: 58mm
• Diagonal bolt spacing: 89mm
• Material: Case-hardened steel
• Made in USA by Driven Racing

Also Fits (428 Chain)

• Honda CR 80R (1985)
• Honda CT 70 (1969–1994)
• Honda XL 80S (1980–1986)
• Honda XR 70R (1997–1999)
• Honda ZB 50 (1988)

Gearing Guide

• Stock rear sprocket: 34T (2021 and earlier Grom) / 38T (2022+ Grom)
• Adding rear teeth — more low-end torque and acceleration; better for urban riding and short straights
• Removing rear teeth — higher top-end speed, lower RPMs; better for open road and long straights
• Removing 1 front tooth ˜ adding 3 rear teeth

California Prop 65 Warning: www.p65warnings.ca.gov