Center Lock or six-bolt rotors: the hub makes the first choice

Count bolts or identify the lockring

A six-bolt rotor attaches with six bolts. Center Lock uses a splined interface and a lockring; lockrings can have internal or external tool fittings. Park Tool’s installation guide illustrates both. Identify the actual rotor and hub before buying a replacement, including diameter, thickness and brake approval.

The right tool has to fit around the axle

Check that the lockring and tool suit the hub’s axle/end-cap arrangement. For six-bolt hardware, follow the specified tightening sequence and torque; do not substitute random screws. A mounting adapter is a separate approved part, not a universal way to put any rotor on any hub.

Compare the wheels with their missing pieces

For a GRARO build, ask whether each wheel quote includes compatible rotors, lockrings or bolts, and the tools or workshop labour required. If one quote includes them and another does not, their headline prices are not equivalent.

For example, two wheel quotes may both say “160 mm rotor”, while one hub is six-bolt and the other Center Lock. The shared diameter does not make the rotors a direct swap. First identify the mounting interface, then ask for the exact rotor and any approved adapter kit. On a Center Lock quote, also identify the lockring and whether its tool can engage around the axle/end cap. A familiar-looking lockring is not enough: missing tool clearance can turn an apparently complete quote into a workshop job.

Choose the wheelset on its complete suitability and support. Rotor attachment alone does not prove superior braking, lower maintenance costs or easier swapping between wheels. For two wheelsets, rotor and cassette alignment still need checking. Keep rotor size and frame/fork approval separate from the hub mount, and check the cassette’s freehub interface separately too. Ask for a complete parts-and-labour quote before comparing prices.