Surf Science: Flex Theory

Taj Burrow springs into hyperdrive.

Flex Theory
Why "Flex" Is The New Buzzword In Surfboards

Words: Casey Koteen
D. Hump

In the earliest days of surfboard making, the main--and sometimes only--dimension that mattered was the length of the board. As the craft progressed, surfers started thinking more about things like width, thickness, and tail shapes. Eventually, things became even more refined, with people ordering specific bottom contours, rail shapes, rocker, and paying attention to fins, as well.

And now there's a new measurement vying for attention: flex. Other boardsports like snowboarding have put a heavy emphasis on flex technology. Although there have been explorations in the past, flex in surfboards is just beginning to be dialed in and understood. "As an industry, it hasn't been much of a consideration," says Bert Burger, an underground Australian shaping legend renowned for his use of alternative materials, who's lately found his way into the limelight. Burger's board-building technology has become the catalyst for Firewire Surfboards, the high-powered and well-funded surfboard company that also includes Nev Hyman, Greg Loehr, and others.

Even though flex has only recently begun to be considered consciously, Burger says that many modern design elements have coincidentally veered toward positive flex patterns. "The ironic thing is that when you look at some designs, like channels or concave, people have leaned toward certain designs that work better than others. Many of those make the board more flexy, so inadvertently a lot of guys have been working with flex but probably not realized it."

Fueling much of this new exploration of flex has been new board constructions, including Salomon, Aviso, Proctor's flexible epoxy, Firewire, and a host of others working with combinations of polystyrene foams and epoxy resins. With its "parabolic balsa rails" (thin balsa strips run the perimeter of the board's rails) in place of a traditional down-the-center stringer, Firewire has put an interesting twist on how boards flex.

"If the stringer is the bit that springs back," says Burger, "then ideally when that spring is coming from the rail line you get more use out of it." While many new board constructions are aimed at mimicking how a traditional polyester resin/polyurethane foam board works and flexes, for Firewire, the idea is to use the new construction to go beyond the limits of a standard board. "If you've got new materials and new construction techniques," comments Burger, "you're missing out on those benefits by trying to mimic the same old. Run with the new materials and performance characteristics and shape around them."

Getting deeper into this whole crazy flex business, there are basically two important characteristics of measuring it. One is how easily (or hard) it is to flex, the other is the rate of return, or how fast it flexes back. While shapers are still mostly using relative terms, like more and less flex (rather than an actual numerical measurement) to communicate how much a board flexes and its rate of return, it probably won't be long until there are board ordering cards with a blank space reserved for the amount of flex you like.

Originally published in the September, 2006 issue of Transworld SURF.