Gradient wheels

[bob12]

Think of a tire with many cavities of different pressure arranged radially or vertically or a mixture of both. How these tyres will perform on road I really don't know, but maybe they will reduce the braking distance.

Reward: A set of gradient wheels on a new car

[The_Wise]

Awesome idea. I guess the different pressure chambers would be similar to hard and soft tire rubber, except I guess as you said arranged them as desired. It would be a pain in the *beep* to inflate those type of tires...

[Michael D. Grissom]

Braking distance is mostly directly proportional to the porocity/softness of the road contact surface area of the tire (what your idea is trying to emulate) and the ability to brake as close to the skid point as possible (anti-lock brakes). I tried my best to figure out what it was that you were trying to accomplish with your idea but couldn't. However, it did lead me to another idea as lame as it may sound --> suppose your "cavities" were designed to rupture (or dissipate pressure) just before the shear stress required to break traction and thus effectively flatten the tire a little. This would increase traction and reduce braking distance which means that your idea would work! Engineering these 'bubbles' is WAY outside my realm of expertise so....

...are there any chemical engineers out there??? Biological engineers need not apply -- growing tires is another topic

[sevenizm]

Ok ok ok. How bout a pressurized chamber in the rim of the wheel. When brakes are applied some pressue is released to flatten the tire. Then after a full stop repressurize the tire. I want too also add that I am thinking of conventional tires not the type described in the original posting

As for the tire in the original post. The tire doesn't have to release the gas, just contract it while braking. There are many materials that expand with heat or electricty or pressure. Have these material in the tire, change the voltage, temp or pressure and the tire should grow or shrink. Or better yet, get rounder or flatter.

[Steve]

Ok ok ok. How bout a pressurized chamber in the rim of the wheel. When brakes are applied some pressue is released to flatten the tire. Then after a full stop repressurize the tire. I want too also add that I am thinking of conventional tires not the type described in the original posting.

This might need some more brainstorming - in a typical emergency situation, you would first slam the brakes and then steer clear of the object in front of you. The problem with flat(ter) tires though is that it makes steering less reliable and possibly more dangerous.

[Rishi]

It is true that it will need more thinking through. As MDG wrote,-'Braking distance is mostly directly proportional to the porocity/softness of the road contact surface area of the tire (what your idea is trying to emulate) and the ability to brake as close to the skid point as possible (anti-lock brakes)'.

In addition to that is the momentum of the vehicle and the friction between the tyre and the road. If the idea is to increase the contact area, can we think of deploying an extra wheel, which comes down only when the brake pedal is pressed? Alternataively, deflated tubeless tyres by the side of the normal tyres can be inflated by a mechanism suggested by sevenizm.

A different approach (MDG may be better fit to comment on this) could be to increase the drag (As they do in planes) by lifting a large flap on the roof.

Rishi

[Michael D. Grissom]

Over the years I've toyed with this solvable problem from many angles but could never get around what the car behind me would do to me if I ever used one.

I think they are on the right track with all cars being equipped with a type of radar that would allow the car to determine that an accident was in the making and execute the best corrective action. This should work as long as the computers op system isn't microsoft.