This might strike some as being a very stupid question, but I can’t help but wonder…
Why do we have air in our car tires?? can’t they make a tire all in rubber? With our advanced sciences/technical knowledge, they should be able to come up with tires that have the exact right “softness”, equal to how a correctly inflatted a tire should be.
I don’t get it…!!
It’s been done to an extent I think with foam filled tires. One of the big problems with a solid tire even if the material is sufficiently soft is weight. Adding rotating mass makes it much more work for engine and brakes to get heavy tires rolling and to stop them. There are ways to do it but AFAIK it’s much more expensive than a conventional tire.
There’s a bit more to it than just “softness,” or the cushioning effect of the air core in your tires.
Air is a compressible fluid. Suppose, for example, that you hit a pot hole. The air supporting the contact area of the tread will “get out of the way” and interfere with adjacent air, and so on. In essence, all the air in the tire compresses at the same rate at the same time. This tends to distribute the load over the whole tire. (Somewhat. There’s still surface and solid mechanics to consider, but you get the idea.)
If you had a solid filler, the portion of the core “behind” the contact patch would have to absorb all of the load.
Did that make sense?
a bunch of reasons. first off, tires used to be solid rubber, and used to royally suck, bounce-wise. of course, it was hard rubber, but being solid didn’t help.
air-filled tires are a miracle of useful equilibriums (equalibria?). when a tire is undergoing constant compressions (that is, riding over bumps), the air inside heats up, and so it exerts a higher pressure against the insides of the tire. so the tire gets firmer. wait a minute. i kind of assumed that firmness is a problem when driving over bumpy terrain. that’s what i based my first paragraph on.
you know what? nevermind; skip that.
non-solid tires are better because they use a lot less rubber. keeps tires cheap for us, and profitable for the tire companies.
erm,
jb
My guess is they are harder to build. You have such a small amount of rubber and it is still hard to get constant consistancy inside that. That’s why they have to balance the tires. By making the tired solid, you are introducing a lot of area for varying densities. That is probably why you see them on slow moving vehicles such as forklifts. Also, the cushioning affect of is probably also very important. The cost of creating a uniform tire would probably be prohibitive for consumer use.
Solid tires are heavier. This extra mass would be concentrated at the edge of the wheel making it harder to speed up and slow down. This would hurt gas mileage, probably by quite a lot. I think this is the main reason for inflatable tires.
They would be more expensive because they use more material.
The only advantage I can see to the solid tire is that it would no go flat.
Forklifts, power wheelchairs, and BattleBots usually use solid-foam or foam-filled tires. Where high-speed operation is not required, and durability is more important than pothole-handling or gas mileage, you see them a lot.
I can’t remember where, but I though I saw an ad for a tire with air “chambers”. It was inflated, but if a nail or something penetrated the tire, only the one chamber would lose air, but not affect the entire tire. I don’t know if I am explaining it clearly, but think of a waterwheel covered by rubber.
Wouldn’t solid tires have bad traction because less of the surface of the tire contacts the road than a more pliable tire?
The “run flat” tires don’t have chambers. They use a rigid side wall. When the tire loses air, the side wall’s keep the ground off the wheel and allows you to drive slowly (I think on the Corvette top speed is 55mph with a flat) to a service station. A lot of high price cars are starting to have these. Corvette’s have for a few years now.
As for the OP, the biggest reason why you dont see it is weight, as has been said. Weight on a car is bad. Unsprung(weight not supported by the suspension) weight on a car is REALLY bad. I forget all the ways it is bad, but I know performance is the main one.
dead0man
Thank you all!
I am just sick of my car loosing air on a regular basis and the tires screeching each time I make a turn!
I tought I had the invention of the century!! j/k
Over or under-inflated tires are a great way to have serious accidents. I speak from experience, having followed some dimwit advice from an auto magazine.
Find out what the proper inflation pressure is. Usually this is on a sticker on one of the door pillars or thereabouts; it will also be in the car’s manual.
A tire that’s screeching is close to losing traction with the road. If that happens on two tires, you’ll spin out of control.
You’re right Partly… I do have to swing to a garage pretty soon…
As a side note, the Presidential limousines do have solid tires, though it’s more like a solid core made of big rubber disks, with an inflated buffer. The inflation makes the ride relatively soft, but if the tires are blown by bullets or spikes or whatnot, the limo can still beat a hasty, though bumpy, retreat.
I’d be a little skittish about the airtight chamber prinicipal, because we all know how well that worked on the Titanic.