Excellent post Doc!!  Now  why can't it be taken a step further...say with a car? 

Slick! Triumph Motorcycles had sprung hubs ages ago, but nothing as smooth as this.

Barb, A car weighs a lot more. But, there are cars which have independent suspension on each wheel, using a different mechanism because the wheels are tied (through differentials) to the drive shaft which powers them (not hands and arms):

Theoretically, the front and rear wheels could have those type of shocks/spokes, but I'm not aware how that would be superior to the current mechanism...

Gotcha!  It was just a thought, thinking to all those potholes out there! 

Lateral flex due to movement tolerances will render it useless in 'real' applications...

If I'm not mistaken the pictured suspension above or something very similar has been used on at least the Mars Rovers if not also the Moon Rovers.  This would give credence to Jafo's statement about real applications.  Like always though I expect to be proven wrong. 

What are you referring to, Jafo? The wheelchair and bicycle exist already...

(Translation: Turning at speed would be for sh!+) There would be balance issues as well especially at higher rpms.

Or tanslation....you won't see it in a car anytime soon.....think 'unsafe at any speed' good old Ralph ...

At higher RPM's the wheels of a car rotates, the centrifugal force would prevent the Shocks from re-centering the hub and there for the rim (outer part the tire attaches to) would stay off center and cause the car to shake violently and or the operator to lose control. Using Shocks strong enough to compensate for the centrifugal force would basically negate their ability to absorb shock.

If you have ever had a flat at high speed, had a wheel that was not balanced properly or a tire go out of round, you have felt a small portion of what it would be like..

A cars wheel is machined to be as circular as possible to ensure the wheels at high RPM's spin with a minimal loss of rotational balance.  Even the lug bolts and studs are engineered to center the wheel on to the hub as much as possible.  Any major variance at high speed/RPM can be dangerous..

HG_E got part of it....the other part is that motor vehicles' wheels are subjected to lateral loading.  It's imperative the rim remains physically aligned to the hub/axle.

Lateral loads even apply to bikes.....

...entering turn 1 at Phillip Island at 346 kph on a MotoGP bike with wobbly-wheels would raise a GP rider to an even greater level of 'insane'....

Well said Jafo. I didn't even think about the lateral loading during turns, I couldn't imagine how heavily that would change the slip angle much less the cornering coefficient as the tread rolls away from the road surface... What a nightmare ride that would be..

Well... we used bigger words ... and I never claimed to be short winded...