HomeGarageShock treatment: Fox shares details of Raptor’s new suspension

Shock treatment: Fox shares details of Raptor’s new suspension

Bicycle component has evolved into electronically controlled automotive off-road suspension star


When Ford unveiled its 2021 F-150 Raptor earlier this month, it noted such upgrades as revised 5-link rear suspension, the use of new Fox 3.1 Live Valve shock absorbers, and the availability of 37-inch tires, each employed to enhance the pickup truck’s already legendary off-road capabilities.

Fox Factory followed up with details about its new 3.1 Live Valve shocks “combining the best of semi-active, electronically-controlled compression damping with desert race-winning, position-sensitive internal bypass technology to provide a smooth and comfortable feeling on the pavement with aggressive control and stability at high speeds off-road in real time.”

Fox also supplies the internal bypass coil-over front shocks for the new Raptor. 

Justin Lofton recently posted the Live Valve’s first Unlimited class off-road racing victory, driving a Trophy Truck to victory in The Desert BlueWater race in Parker, Arizona. The racing team had been working for 18 months with Fox to develop the new shocks, but the history of the technology goes back much further, the company notes. 

Fox created a three-person advanced development team in 2011. Everet Ericksen was among those three people — another hand a PhD in magnetorheological fluids — and is credited with the development of the Live Valve.

Raptor, Shock treatment: Fox shares details of Raptor’s new suspension, ClassicCars.com Journal

In a news release, Ericksen notes that the project started with the so-called Simon valve developed for Cannondale bicycles using MR fluid technology. About a year later, Ericksen realized the project was not succeeding and started over.

In 1999, he was working for Tenneco Automotive, a Detroit-based automotive supplier, where he developed an electronic suspension for the Audi A6, only to have that project scrapped after 9/11.

“I think the concept of Live Valve was noodling in my brain since then and then collided with the unstable ‘Simon valve’ resurrection project and the power-hungry MR fluid project…” Ericksen said.

In 2012, Erickson had the Live Valve nearly ready. However, “There was one part of it that I couldn’t solve, so I took the design to Bob Fox and we worked on it together for about a month. He suggested one small detail that took it from not working to working. It was a great moment! Bob and I are both on the original patent.”

Raptor, Shock treatment: Fox shares details of Raptor’s new suspension, ClassicCars.com Journal

The new technology first was used in a bicycle application, Erickson added. Working with Bosch on software and electronics enabled the technology to be applied to full-size 4-wheel vehicles, Trophy Truck racing and now to the new F-150 Raptor.

Fox not only was a motocross racer, but a physicist who started developing his own suspension designs in 1974 and in 1978 launched the Fox Factory.

“Dancing the fine line between on-road comfort and off-road performance is something Fox does best,” noted Tony Pauly, Fox group director of marketing, “and we feel the new 3.1 Live Valve delivers on our promise to Ford to elevate the 2021 F-150 Raptor.”

According to the Fox news release, the “patented position-sensitive internal bypass damping combined with Live Valve electronic technology continuously and intelligently adjusts compression damping in real-time, delivering the optimal ride for any terrain or driving situation. By using vehicle sensors and accelerometers, Live Valve can instantly adapt to inertial, steering, braking, and acceleration inputs to actively maximize handling, comfort, and bottom-out resistance.”

The shocks are covered under the Raptor’s 10-year/150,000-mile warranty.

“Fox increased the shock bodies and internals from the previous design, allowing you to drive full tilt off-road with increased handling performance while significantly improving control over bigger obstacles. With a dynamic range of twice the prior valve design, the new electronic valve architecture shrugs off significantly larger hits with the feeling of bottomless travel and smooths out the most rutted out teeth-rattling washboards.”

Compared to the previous version used on the 2020 Raptor, Fox said the new Live Valve offers double the range of damping control of MY20 Live Valve system in the 35-inch wheel version and 2 1/2 times the range in the new 37-inchwheel version. 

The larger 3.1-inch diameter anodized aluminum shock bodies are “specially designed to withstand the higher internal pressures created by the new electronic valve’s wider dynamic range.”

Shocks are specially tuned for the 35- or 37-inch tire and offer a half inch of extra lift for the larger tire.

Fox said it also retuned and updated the mechanical damping of front shocks to deal with the few forces generated by the use of a more aggressive tire with increased wheel travel and updated suspension.

For more information, visit the Fox website.

Larry Edsall
A former daily newspaper sports editor, Larry Edsall spent a dozen years as an editor at AutoWeek magazine before making the transition to writing for the web and becoming the author of more than 15 automotive books. In addition to being founding editor at ClassicCars.com, Larry has written for The New York Times and The Detroit News and was an adjunct honors professor at the Walter Cronkite School of Journalism and Mass Communication at Arizona State University.


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