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

There is a good reason that we do not offer a 520 size chain for this bike. Over the same size sprocket a larger chain will create more heat because the larger links have to articulate considerably more that a smaller chain. This extra movement creates excess heat which can cause chain failure sooner. 

Make the job of aligning the mid shaft shaft and swing arm much easier with a DirtyBike Ultra Bee Swingarm Alignment Tool.

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

Apogee Performance Lube

420 MXZ Replacement Chain