Zipp ZR1 Bearing Kit

This kit is specifically engineered for the ZR1 SL rear hub. While the standard ZR1 and ZR1 SL share some design DNA, the internal tolerances and components can differ, so it is best to confirm your hub model before purchasing.

Yes, this kit includes the necessary 61803 and 61903 bearings required to service your ZR1 SL rear hub. It is designed as a comprehensive replacement set to restore your hub's factory-smooth rotation.

The pre-assembled axle is included to simplify the maintenance process. By providing the axle with the bearings already seated or aligned, it reduces the risk of improper installation and saves you time in the workshop.

You should consider replacing your bearings if you notice increased friction, a gritty feeling when spinning the wheel by hand, or any perceptible play in the axle. If your wheel doesn't spin as freely as it once did, it is likely time for a refresh.

While the pre-assembled axle makes the process easier, you will still need standard bicycle maintenance tools to remove the cassette and end caps, as well as a bearing press to ensure the new components are seated perfectly square within the hub shell.