Ultra Bee Primary Chain Drive Racing Kit With 420 RK MXZ Sealed Chain!

For serious off road and moto racers the non-sealed RK MXZ chain kit is the most efficient kit with the least amount of parasitic drag.

• More Efficient Than Belt
• Better Acceleration
• Longer Run Time
• Easy Maintenance
• Similar To Stock Gear Ratio
• Chain can be replaced without removing the swing arm

Be sure to include the DirtyBike Ultra Bee Swingarm Alignment Tool! Makes the job of aligning the mid shaft shaft and swing arm much easier. 

Note: If you are planning to use this kit with the EMBX XUB-80 motor the front sprocket will require modification. Please contact us for more information. 

Swingarm alignment tool

Buyers and Maintenance Guide