In 1839, Charles Goodyear accidentally discovered how rubber could be 'vulcanized.' Since then, the most notable tire advancements can be counted on one hand. Scot Robert Thompson invented the pneumatic tire in 1846. (Forty-two years later, Dr. John Dunlop had to reinvent Thompson's discarded idea.) Michelin patented the steel-belted radial in 1946. Tubeless tires arrived in 1954 followed by the first run-flat designs in 1958 and low-profile sidewalls in 1968.
Add to this list of fearless pioneers John Scott who recently offered us what he calls a Camber Tire for testing and evaluation. In our June 2010 issue, Automobile Magazine selected this as one of the ten most significant emerging technologies. Now that we've enjoyed a few miles over the road on these tires and had the chance to conduct two preliminary performance tests, we're more convinced that the Camber Tire concept is worthy of our acclaim.
Twelve years ago, Scott -- a successful Wisconsin car dealer and mortgage broker -- was inspired by the sight of a grossly overloaded Lexus sedan exhibiting excessive rear wheel and tire camber. Instead of running vertically, the tops of the rear tires were tipped sharply inward. While most of us would have moved on to the next item in our daily routines, Scott was convinced there was something to be gained by orienting tires in this braced sea-leg manner. With his father's backing he sketched his Camber Tire idea and hired an attorney to conduct a patent search. In 1999, he was issued US Patent 5975176 for a "tire with a constantly decreasing diameter." Scott had invented the asymmetrical profile with an inner sidewall significantly shorter than the outer sidewall. While negative camber angles up to ten degrees might be beneficial, the first experimental tires Scott had made are molded with the tread angled two degrees.
In conjunction with a suspension adjusted to suit this radically different cross-section, Scott's Camber Tire delivers a long list of claimed benefits:
- Quieter running
- Reduced tread wear
- More predictable response during emergency maneuvers
- Increased track width
- Improved handling, braking, and high-speed stability
- Improved straight-line steering
- Superior performance during oval track racing
(See Scott's website, www.cambertire.com, for the patent disclosure and detailed list of performance claims.)
This sounds like too much to be true. The skeptic in us wondered why the major tire makers weren't on to this trick if it really paid such handsome dividends. There had to be a hitch. Driving on Camber Tires at the ragged limits of performance was the only way to see if they lived up to Scott's promises. When he offered that opportunity with some experimental tires manufactured by his initial partner M&H, we were the first independent organization to put Camber Tires to the test.
Before adjourning to the track, this primer might be useful. The phenomenon called camber thrust is what a leaning motorcycle uses to assume a curved path. Tipping the tops of both tires towards the center of a bend develops lateral forces at the two points where the bike's tire treads contact the pavement. These lateral forces, in combination with small steering angles, are what allows motorcycles to follow a curved cornering path.