Are you asking if there is a hub where the freehub body will pull off when the lockring is reomoved? None I've ever seen. If you want to know if the cassette will pull off easily when the lockring is removed, yes all of the Shimano (steel and Ti) and Campy (Aluminum with tall splines) freehubs will let the cassette slide off easily. However, I am careful to torque the lockrings to full spec (40-50 Nm).