Kyosho UM552 Drive Hub Set Ultima RT5 RT6

The UM552 drive hub set supplies two drive hubs for the Kyosho Ultima RT5 and RT6 stadium trucks.

The drive hub is the component that transfers torque from the driveshaft out to the wheel, carrying the drive pin and locating the wheel on the axle. It is a high-stress part: every bit of power the motor makes passes through it, and it takes the shock loading of landings and the side loads of a truck cartwheeling into a pipe.

Worn hubs are easy to diagnose. You will feel play at the wheel, hear a knock under throttle, or find the drive pin has started to elongate its slot, all of which cost you drivetrain efficiency and eventually leave you with a wheel that will not drive at all.

These are genuine Kyosho service parts matched to the original dimensions, so they work with the stock axles, drive pins and wheel nuts with no shimming or modification. Two hubs are supplied, which covers both sides of the axle in a single pack. Kyosho lists this part for the Ultima RT5 and Ultima RT6 kits.