So... I was thinking, how could you simulate the monopole principle with permanent magnets? It would have to be done by pairs, both poles are equal in strength. What if you align the opposite pole faces towards each other in a ring on a wheel? Basically, laying the magnets on their side, spaced apart in attraction, no terminating pole ends.
Wouldn't this be like a monopole relative to another magnet on it's side outside of the wheel? I haven't tried it yet, just thought of it today. It's probably been tried before and I'm overlooking something.