HISTORY OF THE WHEEL
After fire, the wheel provided the greatest technological thrust for human survival and subsequent domination of the planet in ancient times. We could travel faster and farther, filling in the blank edges of the maps, shrinking the known world.
The first time we can place a date and origin on the wheel is 3,500 BCE, in Mesopotamia. They were sections of logs held a variety of ways beneath a platform. Cornering was troublesome as the rollers were a solid configuration. This led to a fixed axle with independent wheels mounted on the ends.
The next technological leap was the spoke. The use of spokes lightens a wheel considerably compared to a solid wood wheel. Crude attempts at this included leaving gaps between the planks. As more speed was necessary for hunting and war, less and lighter materials were used. Rims and spokes narrowed, eventually to the point a skilled worker was needed to build them. Ancient Egyptians and Greeks, known for their chariots, pioneered these efforts.
While the wheel is dated at 3,500 BCE, the tire is a much newer invention. Many of the names involved with the development of tires are still around today.
In 1844 Charles Goodyear patented (U.S. #3,633) the process to create vulcanized rubber. He discovered that if the rubber was combined with a curing agent, in this case sulfur, under high heat and pressure, the rubber could be shaped and formed. Without delving back into high school chemistry, the sulfur atoms form links between the chains of rubber molecules increasing strength, durability, heat resistance, and reducing stickiness.
Just three years later a 23-year-old Scotsman named Robert Thomson patented (U.S. #5,104) the pneumatic tire in the U.S. Thomson inflated an elastic belt of “sulphurized India-rubber” to “present a cushion of air to the ground or rail or track on which they run.”
The biggest step for tires came in 1895 when Michelin, after pioneering detachable bicycle tires earlier in the decade, fitted a set of pneumatic tires to the car l’Éclair for the Paris-Bordeaux-Paris race. Michelin would later pioneer the radial tire in 1946, making its marketing debut in 1949.
Prior to 1946 the typical tire construction was a bias ply. These rubber-coated fabric plies ran diagonally down one sidewall, across the tread and up the other sidewall. The plies alternated in opposite directions. The fabric improved from cotton to rayon to nylon to polyester over the years, but the basic construction hasn’t changed. Radials also use fabric plies, but just one or two plies and they run straight across the tire from bead to bead. Belts — plies with diagonal cords of fabric or steel — run the circumference of the tire. Radials run cooler, have a wider footprint, and a longer tread life, while bias ply construction results in a stronger sidewall (think drag racing benefits) and are generally cheaper.
Tire tech has progressed steadily. Radials became standard on all new American cars in 1983, pushed by consumers wanting better fuel economy (due to less rolling resistance). Now bias-ply tires occupy a niche market for period-correct users and a large segment of the drag-racing market. Radials represent over 98% of all tires sold today.
Before buying, you’ll need to know some important information.
Along the sidewall there is a series of letters and numbers,
something like P215/60 R 16 95V.
The latest breakthrough in tire technology is the airless tire. Michelin’s Tweel and Bridgestone’s Air-Free Concept Tire are some of the bigger names in the developing market. The Tweel is a combination tire and wheel using polyurethane spokes inside of a band of molded tread. The hub consists of deformable plastic matrix that can flex under load and return to their original shape. Bridgestone’s design debuted at the end of 2011. The internal spokes are a recyclable thermoplastic resin that gives the tire/wheel its shape, flexibility and strength. A rubber tread is on the outside to provide a traditional contact surface.
There are exciting advances to come in tire and wheel technology, but for the time being, just be glad you don’t need to shod a Bugatti Veyron. A set of the Super Sport’s Michelin tires costs $42.000 and they’ll last 10k miles — if you don’t treat it like a Veyron. The real kicker is on the third tire change, you’ll need to swap out the wheels — to the tune of $69000 — to ensure a proper bead seal.
- Chad Tyson - Ebay Motors -