2009 Honda U3-X Demonstration Video
A self-balancing unicycle experimental vehicle from Honda to be shown at the Tokyo Motor Show next month might just be history in the making. Weighing less than 10kg, the 24 by 12 by 6-inch U3-X experimental vehicle runs for an hour, is small enough to be carried onto an airplane as hand luggage, has a wheel which spins in two planes and is set to challenge, perhaps even change, society’s concept of personal mobility.

Though Honda’s U3-X is still experimental, only runs for an hour, isn’t as fast as the Embrio and is not hydrogen fuel cell powered, it is already in prototype form and weighs just 10 kg, rather than the 164 kg weight BRP expected of the Embrio in 2025.

Six years later, Honda’s U3-X is one sixteenth of the weight of the Embrio envisioned for 2025 – and 2025 is still more than a decade and a half away.

And though the HFT is two-wheeled rather than one, it has a top speed of 20 kmh, weighs in at 50kg and it is available now.

Clearly personal transport must get smaller and lighter, particularly if it is to share the footpath with humans made from flesh and blood. It also makes sense to make personal transportation devices easily backpackable, so they can be carried on public transport, and at just two feet tall and 12 inches by six inches in cross section, the U3-X is so small that it would never disrupt crowd flow or obstruct a railway carriage as we often see with bicycles on public transport around the world.
With the world’s most prolific demographic, the post-war baby boom moving into old age, Honda and the world’s number one automobile manufacturer (Toyota) both recognize that low speed, footpath bound mobility assist devices will be in great demand a decade from now. Toyota has also shown both walking- and wheeled-chair mobility assist devices in addition to its iREAL wheeled exoskeleton which I was lucky enough to try at the last full Tokyo Motor Show back in 2007.

Though it is a genuine engineering triumph of some magnitude in its entirety, the U3-X’s most remarkable piece of engineering is the Honda Omni Traction Drive System which enables both forward and backward movement as well as side-to-side movement.

The HOT drive is indeed one of the coolest things you have ever seen if you’re mechanically inclined and consists of many small motor-controlled wheels in-line connected to form one large wheel. Forward and backward movement is done by moving the large wheel, and side-to-side movement is done by moving the small wheels. By combining both, the U3-X moves diagonally, though to the rider, it’s more like thinking “I’ll go that way”, and away it goes.

When being carried, the seat and the footrests fold away so it looks more like a ghetto blaster than a transportation device.

And at Honda’s stated weight of less than 10kg, the light-weight it’s highly portable – indeed, it’s not that long ago that computers weighed more than this.

Though the Tokyo Motor Show is still four weeks away, and promises to be the most significant car show in recent history due to the plethora of eco-centric vehicles we’ll see, I’d be very surprised if the U3-X isn’t the vehicle that we’ll read about in history books a century from now. It just might be a landmark device in transportation history.
 Portable and less than 10kg in weight - the Honda U3-X The seats stow within the Honda U3-X when not in use The Honda U3-X, ready for use A pair of Honda U3-X experimental vehicles