I remember reading about these when the run-flat tires started to come out. Back then, they were having trouble with the rubber in the center that provides the cushioning getting fatigued. Once it stops bouncing back, you've got the equivalent of a flat, or at least low air pressure.

I can't see how they could get a curved contact patch area for a motorcycle tire to hold up, unless there were a super-wide rim, or very low profile.

You know, this used to be a helluva good country. I can't understand what's gone wrong with it. - George Hanson, Easy Rider