[Bloody Sam Roberts]

Given a slow rim speed, a fixed central core would barely register as moving, no?

Of course. But what good is a slow rim speed? The rim woul;d need to move quickly enough to generate the needed force to simulate gravity. There would need to be a hub and there will be friction.

[Yardstick]

You don’t need no steenking hub.

And the rotation can be pretty slow if the diameter is large.