Goodyear’s new Gatorback Sport ATV drive belt is the first CVT belt with carbon fiber reinforcement in its rubber compound. When handling an extreme load demand, the carbon fiber allows desired slippage on pulleywithout top-width belt distortion. After the extreme demand subsides, the carbon material restores the integrity of belt edges in order to handle the normal load demand.
May 2007 - Goodyear Engineered Products is hitting the trail with a "self-healing" carbon-fibreloaded ATV drive belt that can reduce the possibility of a long walk home. Goodyear Gatorback Sport is the first Continuously Variable Transmission or CVT belt with carbon fibre reinforcement in its body construction, according to Loren Danhauer, Goodyear chief belt engineer.
"Threadlike strands of carbon fibre are strong and flexible and weigh much less than steel of
similar strength," said Danhauer. "The fibre alignment in the rubber compound provides added
stiffness across the width of the belt."
Jonathan Cocco, marketing manager for Goodyear aftermarket products, said a Goodyear survey of quad riders shows they want precise, immediate throttle response and off-road durability whether for hunters, ranchers, fire rescue teams or sport enthusiasts. A CVT system varies the working ratio of two v-shaped pulleys linked by the belt, said Cocco. The distance between pulley flanges can fluctuate, allowing the belt to ride smoothly up or down the pulley, continuously changing the gear ratio and varying vehicle speeds. The pulleys are part of a power sensing drive that increases tension during acceleration and lowers tension when power is reduced. Danhauer explained that conventional CVT belt sidewalls can glaze and char from heat build up when engaged with pulleys under extreme loads. Materials from the top width of the belt then turn down and inward, creating vibrations that can quickly destroy the belt.
"Gatorback Sport regulates itself under extreme events," said Danhauer. "Its carbon fibre in the
rubber compound allows desired edge slippage without losing top width. When extreme demand
subsides, the belt self-heals and again picks up the load."
Danhauer added that tests he conducted show significantly improved top width wear and reduced belt weight loss. Cocco said Gatorback Sport is responsive and durable. "Its aggressive carbon fibre material maintains pulley grip without sacrificing belt wear," he said. "It provides quick, clean throttle response to help riders conquer steep hills and nasty mud pits, while withstanding inadvertent abuse, such as spin-and-runs."
Gatorback Sport’s performance was born from race technology introduced last year. Hendrick
Motorsports and eventual NASCAR Nextel Cup Series Champion Jimmy Johnson turned to
Goodyear for help after making mid-season engine adjustments for added horsepower that
increased demand on cam drive belts by 50 percent.
Goodyear quickly responded by mixing carbon fibre reinforcement in rubber compounds for the
new timing belt. The result was an advanced composite that withstood the increased loads and
higher temperatures, allowed engines to run more efficiently, and provided precision timing in a
very harsh environment.
"Buoyed by our success with carbon fibre, we went to work on the CVT belt for all-terrain
vehicles," said Cocco. "Its performance earns it the Gatorback name, joining a growing family of
popular Gatorback automotive belts that are used by all major NASCAR Cup Series teams and
are available in auto part stores and service centers."
While Gatorback Sport’s lateral strength comes from carbon fibre, its longitudinal strength comes from Goodyear Flexten aramid cords traveling the circumference of the belt. Flexten minimizes stretch, stabilizes overall length and maximizes horsepower transmission. "It adds up to predictable tension performance," said Danhauer, "and tension is as important to belts as air
pressure is to tires."
Engineers also took care when designing belt dimensions, precisely duplicating most major ATV
manufacturers' original equipment profiles and measurements for top width, length and sidewalls
to ensure proper fits.
Gatorback Sport’s top width range is 17 to 35 millimeters or 0.68 to 1.37 inches, while its length
range is 679 to 1106 mm or 26.75 to 43.56 inches.
