Just about every tire that you see on modern-day cars, trucks, and motorbikes are air-filled tires. This was not always the case however, in the mid-1800s solid rubber tires were the norm. So why are solid rubber tires not used anymore, what makes air-filled tires the standard today, and what are the alternatives?
The main reason when solid rubber tires are not used any more is due to the high degree of vibration they cause when driven on normal roads.
Why Shouldn’t You Use Solid Rubber Tires
We all know that the shock absorption system in a vehicle is used for a more comfortable ride in addition to performance and protecting the vehicle and its components. However, not all of us know that the tires are a part of that system. Because solid rubber is hard and not very compressible, solid rubber tires make for bad shock absorbers. If I were to put solid rubber tires on my car, the vibration of an uneven road surface along with potholes and speed bumps would shake my car to pieces.
What Is the Advantage to Using Solid Rubber Tiers?
The major advantage that solid rubber tires have over air-filled tires is that they are, well, solid, you will never get a puncture when using them, making them maintenance-free. This is advantageous in many different fields and settings. Solid rubber tires are often used for forklifts and other industrial vehicles where potential punctures are common.
Many bicyclists use solid rubber tires as well because bicycles are prone to punctures. Most commonly solid rubber tires are used on shopping carts which means they need little to no maintenance. Imagine doing your shopping and getting a flat in the frozen foods section.
What Are the Disadvantages to Using Solid Rubber Tiers?
Though the solid rubber tire is maintenance-free, the downsides are too negative to use on most vehicles. As mentioned above, the amount of vibration is too severe. The importance of the shock absorption a normal, pneumatic (air-filled) tire provides can be seen in the pinnacle of motorsports, Formula One.
Why Are Shock Absorption Characteristics So Important When It Comes to Tires?
Formula One is about to undergo a major rule change which will affect the look and design of the cars. One of the changes is related to wheel and tire size. The size of the tire is being increased by 5 inches from the 13-inch wheel to the 18-inch wheel, however; the tire itself will have a lower profile or aspect ratio, which will provide less shock absorption. Though the aspect ratio includes the tread, the majority indicates the amount of air in the tire.
With the new wheels, the aspect ratio is only decreased by about 1.5 inches from 6.5 inches to 5 inches, however; this change is so impactful that the teams are forced to redesign the entire shock absorption system.
Why Is the Weight Of Your Tire Is So Important?
Another major issue with solid rubber is the weight. The heaviest part of a normal pneumatic tire is the rubber itself. If you were to have a solid rubber tire that would fit a modern car it would be extremely heavy. Weight is such an important factor in the auto world that it is one of the major goals car manufacturers aim for.
Manufacturers have started using all kinds of new alloys and weight-saving structures in their designs. Lowering the overall weight of a vehicle is important because affects all aspects of driving. Handling is heavily impacted along with breaking and accelerating. Both braking and accelerating times are reduced which also increases fuel consumption because the engine must work harder the get the vehicle moving and up to speed.
Why Air-Filled Tires the Norm
Two different people are credited for the invention of the pneumatic tire. The first Robert William Thomson, a man from Scotland acquired the patent pneumatic tire in 1845. Unfortunately for him bicycles were not yet popular and the materials that Robert William Thomson used were expensive.
In 1887 John Boyd Dunlop also from Scotland constructed a pneumatic rubber tire for his son’s tricycle while they were living in Belfast, Ireland. This time the invention came at just the right time because bicycles were extremely popular, and automobiles were just starting to be used.
The whole reason for John Boyd Dunlop reinventing the pneumatic tire was because his son’s solid rubber tires made the tricycle ride extremely uncomfortable from all the bumpiness.
Now, pneumatic tires are used on almost every single vehicle which is operated on the road today. They are far lighter than solid rubber tires and offer superior shock absorption at an affordable price. The reason why they are shock absorbent is that air is a compressible gas.
When the tire hits a bump on the road the rubber gives way, making the inside area of the tire smaller, compressing the air. As the air in the tire is compressed the pressure in the tire increases, pushing back on the tire, causing it to regain its shape. This is much like a balloon, as you squeeze the balloon you can feel the resistance build and push back on your hands.
What Are the Alternatives?
Other than hopping in a Flintstones’ car or walking there are no real alternatives other than the airless tire. Airless tires have the same advantage as solid rubber tires in the sense that they cannot get a flat. Just like solid rubber tires this makes them popular on worksite vehicles such as backhoes and dump trucks. They are also commonly found on golf carts, riding lawn mowers, and scooters. Additionally, heavy-duty airless tires can often carry more weight than pneumatic tires.
The downsides to the airless tires are not negligible, however. Though not as much as the solid rubber tire, they do suffer from a lack of shock absorption. Some reports also show that the airless tires are prone to overheating, this usually only happens when the airless tires are used on heavy machinery because the tires do not dissipate heat well.
The biggest challenge for the airless tire, however; is that at speeds in excess of 50 mph (80 kph) the tires become unstable causing a high degree of vibration, much to the discomfort and danger of the passengers.
Unless you are driving a shop forklift or pushing a shopping cart, you are most likely not going to be using solid rubber tires. They are far too heavy and do not provide enough shock absorption. With an air filled tired we can make our daily commutes in comfort and style.