Springing into the Limelight

The parabolic stringer is nothing new.  A picture that hangs in longtime La Jolla shaper Tim Bessell’s office bears testament to this.  Taken by Ron Church in 1963, a Huntington crowd looks on as Corky Carroll runs by.  Under one arm he carries a Hobie surfboard – more specifically, a high performance longboard with a parabolic stringer.  Two stringers run a few inches from the rail, following the perimeter of the board and crossing at the tail.
According to esteemed shaper Gary Linden, the parabolic stringer can be traced back to the hollow paddleboards built by Tom Blake in the 1930’s.  Bob Simmons also experimented with balsa rails in the 1940’s and 1950’s.  
But now the parabolic stringer has the industry’s attention.  
Last March, Firewire Surfboards emerged with what seemed like a mission to revolutionize surfboard design.  Backed with significant capital, Australian shapers Bert Burger, Nev Hyman, and Florida’s Greg Loehr pooled their shaping knowledge to create a different kind of product.
What was born was a never-before-seen board made of vacuum sealed, multiple-density grades of expanded polystyrene (EPS) foam.  But the real kicker of the design is the thin strips of balsa wrapped around the edge of the rails replacing the traditional down-the-center stringer.  These became known as “parabolic rails,” and Hyman claimed it to be the biggest design breakthrough since Simon Anderson’s thruster.  
And people listened, and even some of the best surfers in the world took an interest.  Not too much time passed before Taj Burrow came on board with Firewire.  Even Kelly Slater has been seen riding Firewire boards—some say he raved about the board’s ride—causing deal-signing rumors to fly.
What is it about a parabolic stringer that has the industry so captivated?  The key phrase here is “flex memory” (otherwise known as the restoration coefficient or recoil effect) or how quickly a material will return to its original shape after being flexed.  According to the Firewire guys, this is an indispensable element of design, having serious implications for turning.  “It’s like riding a snowboard,” says Chuy Reyna, Firewire’s Marketing Manager.  “You are able to store and unload energy from each turn.”
How exactly does this translate in the water?  On a board with a parabolic stringer, you lean into the stringer during a turn, and the stringer bends, shooting you into the direction that you are turning.  This means that more speed and acceleration is carried through each turn, creating more torque.  Gary Linden describes it as “directive spring back.”
“From the first turn, the immediate reaction was why have we been putting the stringers in the middle of the board all these years?” Linden says.  “We really haven’t been utilizing all that is available there.”
Flex sounds great, doesn’t it?  But flex is no good without strength.  “It’ a matter of balancing strength and flex,” says shaper Gary Linden, an enthusiastic supporter of the parabolic stringer.  “The farther the stringer is towards the rail the weaker the board is.  The closer it is towards the center, the stronger it is.” For Linden, who uses the parabolic design with Walker foam blanks, the answer is leaving two inches of foam on the outside.
For Tim Bessell, another enthusiastic supporter of this design, the strength/flexibility equation is dealt with differently.  According to Bessell, the problem is that wood of a traditional wood stringer breaks down after continual pressure and over time, jeopardizing strength and giving the board a dead feeling.  In his patented construction, he adds a layer of carbon tape glued to a wood stringer.  He says provides a strength and vivaciousness that lasts, without adding to the weight of the board.  
“The carbon with the wood is the magical formula for giving it even faster reflex memory,” Bessell says.
Tim  Bessell is convinced that it is only a matter of time before the parabolic stringer catches on and inspires a complete paradigm shift.   “I predicated that 80 percent of all high performance boards in the next 1 to 2 years,” he says.  “It’s a long learning curve, so it’s probably going to take more like 3 years.  They are here to stay.”



Sidebar

What do you think of the parabolic stringer?

Marcio Zouvi (Sharp Eye Surfboards)
“I can’t really say much yet.  The theory sounds good, but we have to see them in the water.”

Larry Ricci (South Coast)
“Surfers are a pretty conservative bunch.  It’s hard to get people to switch over overnight.  It takes time to validate the designs, but it seems exciting…they seem pretty lively.”

Mike Walker (The Walker Project)
“I have a couple.  We are in the R&D process…It’s a different flavor, a matter of what you are in to, but I think that flex is a huge issue.”

Jeff Battisti (Rat Surfboards)
“I think it’s cool, just another little dimension in surfboards.  It costs more, though, and is harder to shape.”

Shawn Ambrose (Shawn Ambrose Surfboards)
“When I saw Greg Loehr working with them, it made all the sense in the world.  I experimented with different designs…I have made over 500 boards that have a parabolic stringer.”