Enduro Primary Belt to Chain Conversion Kit | 420 RK MXU | Surron Ultra BeeUltra Bee Primary Chain Drive Enduro Kit With 420 RK MXU Sealed Chain For serious off road and enduro racers the sealed RK chain kit is super durable and will last longer between lubes than non sealed chain kits. 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

Ultra Bee Primary Chain Drive Enduro Kit With 420 RK MXU Sealed Chain

For serious off road and enduro racers the sealed RK chain kit is super durable and will last longer between lubes than non-sealed chain kits.

• 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. 

Aligning the mid shaft shaft and swing arm will be much easier with the 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

MXU Replacement Chain

Apogee Performance Chain Lube