Di-wheel bike that actually works

This thing cannot brake effectively in an emergency, which severely limits its real-world usefulness - it will just roll. The only route out of that, that I can see, is counter-rotating something with a large moment of inertia. If that something is the passenger, it will be extremely uncomfortable; if the mass is e.g. a flywheel, it'll add significantly to overall mass, reduce efficiencies, and add to overall forward momentum.<p>A long downhill stretch will also completely beat it (if it wants to maintain a constant speed downhill). Any flywheel or other counter-rotation system will have to keep accelerating for as long as the hill continues, or else it will tumble.

So what happens if you are riding at a good speed, and you hit a pothole or other obstacle that bends a wheel? That could make it so the carriage cannot rotate freely inside the wheel, leading to rapid rotation of the passenger. I would not expect a good outcome after that.<p>I think that is likely the downfall of this kind of vehicle. Yes, with slosh control you can make it work well in normal circumstances, comparable to other vehicles. The failure modes, though, lead to worse accidents than other vehicles, and I don't see any advantages of it in normal circumstances to counter that.

Beautiful if impractical. It could easily move as fluidly as a Segway with a bit of computer control and a few sensors.

That looks more like a portable circus ride. That rocking back and forth would get old really quickly.

So, is this actually a useful vehicle? Or is it just for circus stunts? The trouble with letting young bloods demo a new bike is, they don't ever use it normally.<p>For instance, can it accelerate without gerbiling?

The world would be a better place if we all had these.

I'm pretty sure I saw one of those on an episode of South Park. It doesn't end well.

one wheels bad, two wheels good?