Tires are typically not made entirely of plastic or rubber tubes for several important reasons:
- Strength and Durability: Tires need to support the weight of vehicles and endure various road conditions, including rough terrain, potholes, and high speeds. The materials used in tires, such as rubber and fabric cords, are chosen for their ability to provide the necessary strength, durability, and elasticity. Plastic, in most cases, lacks the strength and resilience required for this purpose.
- Heat Resistance: Tires generate heat during use, especially during high-speed driving. Rubber compounds have excellent heat resistance properties, which help prevent the tire from overheating and deteriorating while in use. Plastic materials would not withstand the heat generated by friction and deformation as well as rubber does.
- Flexibility: Tires need to flex and deform to provide grip and traction on the road. Rubber can deform and recover its shape, providing the necessary flexibility. Plastic, on the other hand, is generally more rigid and less able to deform in the same way without cracking or breaking.
- Shock Absorption: Tires play a crucial role in absorbing shocks and vibrations from the road, providing a smoother and more comfortable ride for passengers. Rubber’s natural elasticity and ability to absorb and dissipate energy make it a suitable material for this purpose. Plastic materials do not offer the same shock-absorbing properties.
- Puncture Resistance: Tires also need to resist punctures from sharp objects on the road, such as nails or glass. While rubber can resist punctures to some extent, it is often reinforced with materials like steel or nylon to improve puncture resistance. Plastic is generally more susceptible to punctures and cuts.
- Weight: Plastic tires would need to be significantly thicker and heavier to provide the necessary strength and durability, which would increase the overall weight of the vehicle and negatively impact fuel efficiency.
While there are some experimental efforts to create tires using alternative materials like airless or non-pneumatic tires, these designs typically use a combination of materials that provide the required strength, flexibility, and durability. For everyday vehicles and most applications, traditional rubber-based tires with internal tubes or tubeless designs remain the preferred choice due to their well-established performance characteristics.