Method and apparatus for securing a disc stack to a spindle motor hub. In some embodiments, a disc clamp assembly includes a spring clamp with an annular contact portion which contactingly engages a disc stack and a central aperture through which a hub projection of the spindle motor hub extends. A plurality of interlocking semi-annular shim segments interlock together to form a continuous retention ring assembly which wedges between the spring clamp and a shoulder surface of the spindle motor hub.