Wagner Engineering is improving SUV suspension to help prevent roll-overs.
"Roll over" -- an innocuous verb in the context of doggy tricks or Roth IRAs -- is anathema to SUV manufacturers. To date, most of the debate over SUV accidents has focused on separating treads and a high center of gravity. But Wagner Engineering, a start-up in Wallingford, Conn., is looking at the cars' suspension.
Today most SUVs have double-wishbone suspensions, whereby each tire is connected to the body by two wishbone-shaped structures. Wagner Engineering's suspension system, the Link-X, uses two single links that crisscross once, like an X, to connect each tire to the body.
Why is the Link-X setup groundbreaking? Suspension systems, says company founder J. Todd Wagner, comprise two basic parts: springs and links. Since the earliest cars, links have handled the relationship between the tires and the road, and springs have handled the vehicle's reaction to motion. With the Link-X, however, both springs and links play a significant role in the vehicle's reaction to motion; in fact, the links are responsible for 65% of the job of stabilizing a wobbly vehicle. "In a normal suspension, the links handle an average of only 2% to 3%," says Wagner. "They just keep the wheel attached to the frame."
Wagner, 30, an engineer, dreamed up the Link-X in April 1998. Lying awake one night, he realized that crisscrossing links could impart a balancing torque that the parallel links in a double wishbone could not. "I've always looked at forces that happen for free -- gravity, say, or velocity -- and tried to put them to work," he says. "In a car, when you corner, the tire wants to roll in the same direction as the body. That's the force that happens for free." His challenge was to devise a product that would capture that free force and turn it inside out.
The Link-X system will cost the same to build as today's suspensions -- about $400 a vehicle, says Wagner. He expects the first systems to be on the road by 2005.