DirtyBike Primary Drive System With RK 420 GB MXU Chain – The Best Sealed 420 Chain Available

Don’t risk your stock belt failing in the middle of a ride — install a DirtyBike primary chain drive system. With the world famous RK 420 GB MXU chain, this is a necessary upgrade for the serious off-road rider and maintains stock gear ratio.

RK GB 420 MXU Sealed chain is one of the strongest and quietest 420 chains available. Master link makes for easier installation and the chain can be replaced easily without removing the swing arm.

Kit comes with DirtyBike exclusive 1mm aluminum alignment shim allowing you to adjust the sprocket alignment for a quieter, longer lasting drive system.

Installation Video

Buyers and Maintenance Guide

Installation Tool

Recommendations

Recommend	Use
219H standard chain	On road and light off road with stock power
219H RK O-ring and non-O-ring kits	On road and off road up to 16Kw
420 with sealed x-ring	Off road over 16Kw
420 with non-O-ring chain	Racing only. Very Loud!