Why car tyres are inflated rubbers and not solid

For thousands of years, wheels were solid. And they worked, but riding around on them meant that every rut and pebble jostled the wheel, the vehicle and the rider. Imagine a heavy hub and a lightweight rim. It can spin up or down rapidly. A light hub and a heavy body or rim is retarded from spinning by its rotational inertia. You want a lightweight rim. Preferably something kept inflated by gas pressure.

Generally Tire plays the role of road holding ability. It just gives a assurance that while accelerating , braking or cornering there is enough communication between the road and tire. That in laymans term we say as friction.

Friction between tire and road is because of adhession ( sticky nature of tire) and other one is hysterisis ( deformation of tire surface on macroscopic level). So if you introduce any thing solid other than rubber like wood or metal. You wont hAve enough grip as these materials have poor adhession and hysterisis.

They were trying to ride around it, and untenable at high speeds. The pneumatic tire was invented for a very simple reason: to cushion the ride as you move along.

Reportedly, John Dunlop, inventor of the first practical pneumatic tire, was driven to make it because his young son would come back from riding his tricycle with headaches from all the bumps and vibrations.

Solid rubber is possible, and is used in some applications, but it makes the tire much heavier, and provides less shock absorption. Many attempts have been made to develop some kind of solid structure to fill the tire which can absorb shocks without adding excessive weight. Things from new rubber formulations to foam to structured springs have been experimented with, and some are commercially available, even now.

But the reality is, a simple rubber tube filled with air has a simplicity that’s hard to beat. Inventing something that can compete on absorption ability, lifetime and cost is really hard to do. It may happen someday, but we’re not there yet.

In summary, Pneumatic tires gives you flexibilty to control ride quality by adjusting tire pressure based on the load your carrying in your vehicle. So pnuematic tires has better traction , ride quality , low noise , costs low.