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Centrifugal-center Tire

The center ridge of the tread rises at high speed.
  (+10, -8)
(+10, -8)
  [vote for,

A series of small weights are molded into the tire, along the center of the tread, well below the surface. At high speed, centrifugal force causes the center of the tire face to expand and rise. This increases the diameter of the tire, decreases the contact patch, reduces friction, reduces carcass squirm and increases gas mileage.

When the speed is reduced, the rubber of the tire (and perhaps an elastic band) pulls the weights back into line with the rest of the tread. Full contact is then restored, and good handling and braking are as with normal tires.

These tires are only for use in accomplishing high gas mileage. They are not for use in race cars or for rough roads.

baconbrain, May 21 2006

Low_20Friction_20Tire_20Design ...inspired by (?) [xaviergisz, May 21 2006]

The future of tire design? http://www.thatvideosite.com/v/7006
[xaviergisz, Dec 29 2012]


       i would think that the tire already does something like that on its own because of centrifugual force. makes sense to me. plus you gave me inspired by points. bun for ya
lolzcakes, May 21 2006

       Adding more unsprung mass would ruin the handling, and so would decreasing the contact patch. I'm also not sure if the centrifugal force would be enough to counteract the weight of the car on the tires. You might be able to do this by changing the tire pressure instead.
discontinuuity, May 21 2006

       Anything to reduce carcass squirm. [+]
epicproblem, May 21 2006

       Yeah, this was inspired by a couple of the other tire ideas posted lately--thanks to them all and the discussions. And thanks for the link, too--I was in a hurry.   

       It was also based on what does happen already. I've seen dragster tires bulging out from centrifugal force. They try to fight it, I'm trying to use it.   

       As for unsprung weight . . . yes, that would be increased, but I'm thinking that the tires themselves would flex enough to act as the springs for the centrifugal weights. The halfbaked aspect of this idea is the amount of weights that would be required, and the re-design of the tire bodies--both to be determined by experimentation.   

       Decreasing the contact patch would be bad, yes, as far as handling goes. As I said in the idea, this isn't for race cars. Or pseudo-race cars.
baconbrain, May 21 2006

       Losing grip proportionally to speed ? No, thanks; I prefer to pay with fuel the security margin.
piluso, Dec 30 2012

       Okay, having researched "carcass squirm" and found some related terms, I understand that this is not an effort to reduce the reaction of road kill to one's tire contact.   

       It would be nice (in Halfbakery terms) if this could be computer moderated. I'd like it at speed but if I have to brake suddenly I'd appreciate an instantaneous reshaping of my tire parameters.   

       Nice link, [xaviergisz]. I used to dream of motorcycles that could do that, back before it actually became tenuously possible.
normzone, Dec 30 2012

       If, instead of using centrifugal force, the tread was forced outwards by the horsepower applied to the wheel, then   

       a) the more power applied to the tire (ie: the higher the speed) the greater the fuel economy savings from a thinner tread, but   

       b) you'd lose every drag-race you entered, however   

       c) as soon as you laid on the binders the effect would reverse, creating a huge contact patch, thus more effective braking.   

       This could be accomplished by slanting the rubber "spokes" on sidewall-less tires (tweels), so they push outwards under power and pull inwards while braking, or some sort of nifty two-piece rims with a pumping action between the inner and outer rim, for regular tires.
FlyingToaster, Dec 30 2012

       bun for FlyingToaster and his spoke idea. The center line of the tire could be a hard, thin rib of harder material. This piece would have little grip thus less noise and friction. It would also roll side to side easily so in corners the rest of the tire would touch down.This would solve the high-speed grip issue mentioned by piluso. Toasters spokes will handle the same issue during braking.
Brian the Painter, Dec 31 2012


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