'Flat ' inside foils on side fins.

Side fins with inside foil have a greater effective toe in angle, so should have the toe in angle reduced slightly

Any side fin which doesn't have a sharp leading edge actually does have an inside foil even if most of the inside surface appears to be flat. Take a look at what happens to the leading edge if it is blunted or rounded off at all. . . the position of the leading edge moves, effectively creating a slight elementary foil on the inside even thouh most of the inside surface is flat.

It is better to make a correct foil section on the inside as neither of the options shown below are ideal, the sharp leading edge creates turbulence and the rounded off edge with flat plane following it is not an efficient foil section

Gabe Steptoe of Foiled Concept shapes an Alaia

Here's Gabe shaping a radical looking alaia at foiled concept , from one of the paulownia alaia blanks we sent to the crew at the Loose-fit surfshop recently.

The photographs were taken by Simon Mitchell of Corduroy Lines

Rail convergence or divergence for tail riding and nose riding

What we do is examine the angle between the fin or fins and the tail rail, this angle gives an indication of the angle of attack of the fin when the board is turning or trimming ( whenever the board is running on a rail rather than just the bottom )

With a board with side fins this fin/rail angle can be altered with toe in, so that even a board with parallel rails in the tail ( like a Simmons for example ) can have an angle between the rail and the fin.

Boards with a single fin rely on the rails converging in the tail to get an angle between fin and rail.

When noseriding the situation is different because it's the nose rail angle which is determining the angle at which the fin is presented, and the nose rail angle is outwards rather than inwards. . . thus presenting the fin at a negative angle rather than a positive one.

If we look at a trimming situation it can be seen that when on the nose the negative angle of fin presentation points the fin in towards the face . . .. a narrower 'pig' nose tends to angle the fin in more than a wider one, as well as more importantly providing a longer section of diverging rail .

The converging tail rail section has much less influence as there is little or no rider weight on it.

This also explains why boards which tend to have long converging tail rail sections and a wide point forward are not noseriders . . . the converging tail rail presents the fin(s) at a positive angle of attack which means that the fin(s) point out away from the wave face. Boards like these prefer to trim off the tail with a slightly nose down attitude.

Just a few 'Duke' pictures.

The archetypical 'Duke' surf board is of course an alaia:

A longboarding design question

slipslide wrote:

Hi After a bit of advice. I am looking to either shape or buy a new longboard and i am looking for something that i can use and my wife can use. The arrival of an heir to my kingdom has resulted in the inability to travel with more than 2 boards and quite often 1. So i am after something that is very easy to paddle, catch waves and is stable. Right thats the wifes bit done, although that is the most important and comes 1st. I however would like something that just glides and can find a bit of speed. Something kinda old school, I personally like the classic California logs. So my question is what do i need to look for/any examples of boards you would recomend? I have shaped 4 boards so no profesional. The board will be used in small beach break waves. Thanks for your help as a happy surfing wife means more surfing for me

Roy Stewart wrote

Hi Slipslide,

It depends upon what you really want.

If you want a California log then that's what you'll get.

If you want a board which is going to be rewarding as a wave riding vehicle and easy for your wife to ride then don't get a California log.

The California log is a noseriding type, and you'll be sacrificing a lot of good surfboard qualities if you get one.

Countless times I have seen beginner surfers really stoked to just surf on a longboard, then comes the social tuning process from the 'accomplished' surfers. .. . it goes like this: " To ride a longboard properly one has to use the whole board" . .. . or " To ride a longboard properly one has to cross step and nose ride ". The cretins who do this form of brainwashing frequently ridicule those who ride longboards without noseriding as if it is wrong or ugly , while demanding that for social acceptance a bunch of ridiculous and useless antics are learnt as some kind of entry to the club requirement. The newbie surfer then stops enjoying themselves to a large degree, they becomne contrite, and earnestly try to noseride so that they can be a proper longboarder.

In my opinion, it's a sad thing to destroy a surfer's innocence by applying social pressure in this way. .. . . the pure joy of waveriding is replaced by a grotesque, difficult, pretentious and choreographed stage act kind of surfing which is not the real thing, it's just an act, and a 'put on'. . . the surfer becomes led by social demands and acceptance rather than by the feeling of wave, surfboard, and rider in a natural synergy.

So the basta*rds have a lot to answer for in my opinion.

We'll look at the pure surfing longboard design possibilities next, forunately it's easier to design a good pure surfing longboard than it is to design a bad noserider . . ... .. ..

Making alaia from Paulownia wood

One of the paulownia wood alaia blanks:





Making alaia from Paulownia timber, april 2009
http://www.youtube.com/watch?v=T3K9KEyxIwI

Here is a printer friendly file outlining how to make an alaia using a blank:

http://www.olosurfer.com/alaia-make-ur-own.pdf

Evolution in the parallel profile surfboard construction system

There has been an evolutionary process with our parallel profile construction system, it started in 1995 as a very thin flexible balsa lamination of four multi directional layers all of the same thickness ( essentially a springy bent balsa ply sort of like a diving board or ski ). The next step was leaving out parts of the two internal panels, thus making a hollow structure, but still with 4 layers the same thickness. Then ( still with balsa ) we made the middle panels thicker than the deck and bottom panels, thus increasing the depth of the hollow internal sections.

At that point we gave up using balsa and turned to redwood, pine, and cedar, so the system changed again as flat internal plank layers became narrow frames. Since then the system has become more varied, for thicker boards ( like SUP's ) we do up to four internal layers and the angles, thicknesses, and spacing of the frame and block layers varies according to the board.

Recently we have started pegging the frame junctions with tiny vertical struts to maximise strength in terms of resistance to internal pressure ( although we do vent ).

In addition to the construction details involved in the system there are numerous design features which we use, some of which are unique and intimately related to, or derived from the construction system. These are part of the wooden board building experience. Many people treat wooden board building as an exercise in reverse engineering i.e. reproducing a foam shape in wood. That is a legitimate approach but it's also interesting and productive to let the mateials and construction system lead the design . . . . for example the flex which can be had with wood.

Here the parallel profile system has been adapted for a kneeboard 'spoon' which has an upper and a lower deck:

The original Future Primitive 12 foot balsa pintail

This board was a milestone or breakthrough board in terms of design. Back in 1997, we contacted Paul Joske of Valla surfboards ( who is as far as we know the first person to use Paulownia wood in a surfboard, thanks Paul) after reading about a 12 foot foam board he had built. Paul had built the board to dimensions he obtained from Skip Frye, but was of the opinion that the Frye board ( and his own version of it) was much too flat in the rocker ( it had 5 inches of rocker) and too wide in the tail, he described as very poor in steep waves and hard to turn. Needless to say we dialled up the rocker, and produced a more curvaceous planshape, with our first ever circular arc extreme pintailand displacement tail, based on the notion that an ideal planshape for a longboard consists of an underwater foil cross section. The board was incredibly successful, and is a veteran of many hundreds of sessions.

Length: 12 feet
Width: 23 inches
Thickness: 2.25 inches
Construction: Multi directional balsa lamination:
Materials: balsa/epoxy/glass/graphite/marine ply

7 foot balsa wood tube slipper surfboard the '7 of hearts'

Here's the 'seven of hearts' built from balsa/epoxy/glass/graphite in 1995

This board was one of a batch of five in the same style ranging from 7 feet to 7'10"

Length: 7 feet
Width: 18 inches
Thickness: 1.5 inches
Flex: Moderate
Weight: 9 pounds
Construction parallel profile multi directional balsa lamination, solid with no chambering.

Ride report: A magic tube slipper !

Shown here with 'Marabout Slim' in Japan