CHOOSING YOUR TIRES
A Quick History of the Tire
The earliest cars were little more than motorized wooden carriages and buggies. As such, they often used wooden wheels with a band of iron around the wheel rim as a sort of tire. However, as cars increased in performance, drivers found that the metal tire was holding them back. The ride was jarring, and traction was poor on slippery surfaces. Thus, in 1895, the first rubber car tire was born.
In an early part of the twentieth century, tire makers experimented with various techniques to make their products perform better. One such experiment led to using soot from various industrial processes blended into the rubber mixture. Combined with cotton threads, the soot (which turned the rubber black) made the tire more durable, more stable, and allowed the tire to shed heat more easily. That discovery of using soot in tire rubber compounds led to the usage of a chemical material found into today’s tires, known as carbon black.
Those cotton fibers, interestingly, ultimately led to the use of cords and belts that are still used in tires today.
Classic or luxury cars are still occasionally fitted with whitewall tires – tires where the tread is traditional black, but the sidewall is white. Goodyear also produces a number of outlined white letter light truck tires where certain letters on the sidewall are outlined with a white compound. That white colored compound in both whitewalls and white outlined letters doesn’t have carbon black within it.
Why is Carbon Black Important?
Anything that can be done to improve the durability of a tire is incredibly important. After all, your tires are the only thing connecting your car to the ground. Your tires affect handling, acceleration, braking, and your ride comfort during your drive.
Chemical engineers have found that a tire made without carbon black would likely last 5000 miles or less. (Spectroscopy of Polymers, pg. 420, J.L. Koenig) For most drivers, that would mean replacing tires one to two times every year, which would be undesired by most consumers.
One further benefit of carbon black in tires is that it helps make rubber compounds more electrically conductive. Without carbon black in the tires creating a conductive path from the vehicle to the road (ground), static charges may be more likely to build up on vehicles as they travel and lead to an unanticipated static discharge, or shock.
The carbon black in the tire, as we have seen, is critical to help ensure a durable, safe, and high-performing tire. Further, black tires are easier to keep clean. Ask any classic car owner – whitewalls are a pain to keep gleaming, as they show dirt and discoloration easily and can stain from contaminants on the road. Black tires, on the other hand, are easy to keep looking fresh.