Seaflex™ Explained
 
This article explains Seaflex™. The stuff on flex is all in our humble opinion. Many others will want to disagree, or add more information than we can express here. We welcome the input; we are not engineers, but we do know that what we are explaining here works for us – very well. Our current UK contest and team rider successes speak for us.
 

All surfboards flex. We are very used to 30+ years of PU/Polyester board construction with a centre stringer giving centreline flex, and so used to the feel these surfboards give. It’s a part of surfing. Nose and tail flex and fins all add variations to flex patterns in a surfboard.  

Flex is essential – just a plane wing needs to flex or snap, so a surfboard needs somehow to direct energy and latent power into performance, and yet ride the variations in wave conditions. Whether this energy is from the surfer himself (we all know of powerful surfers who can surf planks), or from the surfboard or even the fins, the energy in a surfboard is dissipated in some way – in speed, projection, turns. Great surfers have an extremely fine feel for the flex patterns in boards, and use it accordingly. They can use the latent energy at every point, whether judging when to turn off the lip, or where to hit the bottom for best effect, or hang back in tubes.

Lack of flex makes a board feel dead, as many of those riding the new era of pop-out or RTM moulded boards are finding out.  They do not perform, are hard to get to places on a wave, tend to track, tend to be too buoyant, and while they float well and look good those qualities do not always translate into performance.

Too much flex is wasteful, and makes even great shapes flabby and soft. They just don’t perform. Even now a lot of surfboards are too floppy, too loose, and a lot of work has been done to try to get a more responsive quicker acting, surfboard. Thicker stringers stiffen but make heavier boards.  Unidirectional milled wood, as Gordon Clark championed and  US blanks continue makes flex patterns far more certain, yet a lot of riders swear by peeled ply as a stringer. (Australians were brought up on cross section ply while the Americans have all been bought up on milled wood stringers.) Adding more glass does not work; the boards become stiff brittle feeling. Different resins have different flex characteristics too – Iso 7X for example has twice the elongation at break of Silmar, which makes a less stiff board.   

 

There is a huge resurgence in custom surfboards. All but two of the top 44 still ride conventional boards, most with centre line stringers, because they are just so attuned to the feel that the slightest change needs almost a complete rethink of what they are doing. Just as a new horse feels very different to a rider and has to be ridden for a while to adapt, so a new board, especially a radical design, has to be proven.
 

Seaflex is different. It depends firstly on parabolic stringers.  Set to follow the rail line in pre-set patterns, parabolics change the feel, the flex of a surfboard by placing stresses in different planes. They no longer follow the centreline, but have more useable flex in twist and torsion than single stringer boards ever make possible. Every team rider of ours who has surfed a parabolic strung surfboard does not want to change back.

Getting the flex to remain useable, and not dissipate in parabolic boards was the first challenge. Getting the stringers to maintain a rocker was the second. US Blanks, in extensive work, solved the second problem, and have fine tuned setting parabolic stringers into an art form. (It is extremely difficult to place and maintain rockers in a parabolic surfboard, unlike a centre-stringered surfboard, where the rocker is the stringer).
 
Seabase started experimenting with Seaflex three years ago. Our first efforts depended on carbon fibre rails alone, or a combination of carbon with a centre stringer. They were reasonably successful. The board with carbon rails alone were prone to breakage. Interestingly, when some of our staff left at this point to try to replicate our success with their own business, more than 30 of the boards broke in half. Something was wrong.
 

We discovered part of the reason the flex in the rails upset the stringers – especially the thicker wooden milled stringers. Ply was probably used to twisting more, but the feel was “floppy”. Basswood in thinner strips worked well, but the ideal solution proved to be Balsa.  Expensive, (because it’s from totally renewable sources) and hard to get in any good length, we found out the perfect weight/flex combination was with flexible, tough and strong balsa milled uni-directionally. Then we discovered the best blank to use was the new superfused EPS blanks from US Blanks. US Blanks went right out there helping us sort out the real problem they had in getting a rocker into a parabolic blank, and keeping it there until it was glassed. Think of the stresses and effort involved – no longer one stringer down the middle containing the rocker, two stringers now followed the rails in an arc, while having to bend to the rocker. Difficult, but they cracked it. (US Blanks  are a great company –nothing is too much trouble. Professionals. Thank you Kim, Jeff & crew).

  

Now the new EPS blanks were laminated with an eco epoxy and specially patterned high modulus fibreglass, and then baked at elevated temperatures. These boards became tough, incredibly light (if needed) yet so very fast and easy to turn and transition from rail to rail. It is a revelation – these boards do not feel like epoxy pop-out boards do – they don’t chatter on the wave surface, they don’t track, they don’t feel stiff – they change direction quickly and with no loss of momentum. They work. They fly! They are lively, quick, and almost flighty. They need time to adjust too, the advance is that great. Ask our test rider Josh Knowles what he thinks. Actually, he doesn’t want to say in case others get the same 30% uplift in his surfing. He’s back for his fourth board.
 
Then, as a further advance, we reintroduced unidirectional carbon fibre to the rails. The balsa and carbon is an amazing combination. The board still twists and flexes, but not along a central plane, or a more floppy multi-axis via the parabolic arcs, rather the rails stay relatively stiff, (but not like a whole board is stiff) while the board still flexes. Incredible power, amazing drive, a very real noticeable increase in speed, while being just so tough, and light! The carbon railed boards load up with flex then release – they are so much more responsive, so much quicker rail to rail, it’s unreal!
 

You can do the up-side-down stomp test all day long and it won’t break. We have had one board in France trying to get broken, anyway possible. It hasn’t, after one year.(see that board here). After being surfed harder than any conventional board, it’s still in perfect condition, apart from a slight dent in the deck.

(This board is available for inspection at our France office – or call Yann for info) 
 

We even had to make some of the Quiver® Seaflex surfboards heavier – in testing in Australia the boards proved too light in offshore conditions, negating the extra speed and drive the boards gave. Knowing we can make them light and strong, however, means they make a perfect fun board, and a great contest board.  Normal Quiver boards can therefore be much stronger than normal, making them perfect boards for travelling.

So we’ve finished testing, and Quiver® Seaflex boards from a number of shapers are appearing on the market. (Luke Hart is the shaper of the moment, but Mark Neville is the longboarder favourite. Matt Barrow shapes for top surfers.)  

After the conventional Epoxy Quiver® range proved so successful most of the best UK surfers have at least one in their quiver. Josh Knowles (has 3)  Lee Bartlett, Tom Butler, (2) Alan Stokes, Aaron Evans, Lyndon Wake,  Adam Griffiths, (5) Candice O’Donnell, (4) Elliot Dudley (6).  This is the best proving team we could possibly have – the very best riders in the UK, where Quiver® Surfboards all began. The word is out.....
 
Quiver® Seaflex – a whole new beginning in great surfboards. Test ride one today by calling us, or visiting the showroom in Newquay.  
 
The Quiver Rail - EPS, Balsa,2 x  Unidirectional Hi Modulus Carbon Fibre and a silver heat reflective coating, if needed.

 

 Quiver Surfboards are made under licence to Quiver South Pacific – and is a registered brand name world-wide.

Seaflex is a trademark belonging to Seabase and used in conjunction with the parabolic surfboards made by Seabase. Licences available. Seabase is a registered trademark.