The Airless Tyre
Take a look at Michelin's "Tweel" Airless Tyre. It's a work in progress but we think the concept is very interesting!
Michelin first announced the Tweel in 2005. The name comes from combining the words 'tyre' and 'wheel'.
The Tweel doesn't use the traditional wheel hub assembly. Instead, a solid inner hub mounts the axel and polyurethane spokes surround the hub. A sheer band is stretched across the spokes, forming the outer edge of the tyre.
When driving, the Tweel spokes absorb the impact the same way air pressure-filled tyres do.
The spokes and tred bend slightly when they come into contact with the road, and then spring back into shape.
The Tweel can be built with stronger spokes for industrial vehicles and can be made to allow for different handling requirements.
Michelin say "the Tweel prototype… is within five percent of the rolling resistance and mass levels of current pneumatic tires". (Pneumatic = air pressure filled).
That translates to mean within one percent of the fuel economy of the tyres on your own car.
Comparing the Tweel with our conventional air pressure-filled tyres, there is one obvious bonus with the Tweel. A single puncture will not cause the tyre to fail!
Another aspect is the variation that air pressure has on the performance & safety of your vehicle. Lowering the air pressure of your tyres can improve traction, however this results in poor handling as as the 'stiffness' of the tyre is reduced. In a Tweel, the spokes support the tred independently and the stiffness is not affected.
The down side of the Tweel is the vibration it makes at high speed. Subsequently the noise coming from the Tweel is reported to be very loud. The vibration also generates more heat than the Michelin engineers would like.
* Information in this article comes from www.howstuffworks.com | 
