asymmetric boards

General Discussion
1

I’m having a hard time finding much information online about asymmetric boards. I know they’ve been around since the 1960’s, but there is very limited information about the tests that have been done, and the results. There is plenty about asymmetric tail shapes (for surfing point breaks, where the idea is to make the board asymmetric so that it’s optimized for surfing on one rail down the line, but there is no information online that I can find about boards designed to ride normal waves in normal conditions.

The premise is this: As much as you’d like to weight, drive your board equally on your toe side as your heal side, you can’t. Your body does not bend the same way. Heel side you loose the flex/power of the ankle flex. Your ass drops in a different position, hips and upper body is different. To boot, your front foot is (almost always) pointed somewhat forward, putting your toes 2" to 3" further forward relative to your heel from the tail of the board.

So in theory, in order to make the board handle the SAME on the heelside turn as it does on a toeside turn, the board would have to be asymmetric in order compensate for our bodies not flexing/powering the same, to be have the same ride. This was the premise used to design the asymmetric race snowboards. As snowboards got narrower, so the degree of asymmetry offset was reduced until it became negligeable and commercially unviable in a shrinking market requiring 2x the number of board models (goofy/regular). But the theory remains sound.

So, in theory, to make a board handle the same on both turns, you need to move the hip and foil back on the heelside, shorten the rail length overall on the heelside, and give it more curve overall. The rail should also be slightly less boxy. The distance between the center fin and the side fin on heelside slightly less than on the toe side.

This is my theory, but I’d love to have a discussion about this. Some might disagree all together with the concept of the asymmetric board delivering a symmetric ride. Others may agree with the concept, but disagree with what should be done. Of course some of this may just be pure theory, but if there are folks who have also tried this, and their experiences, I’d love to hear it.

it just seems logic to me (not from a commercial viewpoint) that given we are asymmetric in flex/power/weight/position in our bodies, that a board should be asymmetric to compensate for this to deliver a symmetric ride.

Love to hear your thoughts.

Corran

2

Google Carl Ekstrom asymmetrical surfboard. I think you’ll find what you are looking for.

3

Great, thanks. Well, so far his theory, and how he solved it, is in complete accord with my theory (and experience from making race snowboards in the 1990’s).

http://theshaperstree.com/tales/versatile_shapes.asp

So I think I’m on the right track in how I’ve gone about addressing the problem. Now it’s fine tuning and refining.

I’ll post pix as soon as I have them. I’m shaping the board today.

Corran

4

This thread is really weird because this morning on my long commute into to work I started wondering if anyone had ever made an asymm surf board. It was prompted by someone asking me about snowboarding the other day and I was telling them about my favorite snowboard which was a Burton M5 assym.

5

I had some feedback on a “twisted” board some time ago on the forum.

This is the thread:

http://www.swaylocks.com/forum/gforum.cgi?post=349318;search_string=twisted%20board;#349318

Not exactly asymmetrical the way you mean it, but I guess this is related. Maybe the info on that thread will help you, so check it out.

yo

Stefano

6

TaylorO here on the forums is shaping all his own boards with assymetricalocity.

7

Stefano,

FYI, Carl not only had asymmetry in the outline of his boards, but he would also shape asymmetry in the bottom, tail portion of the board. So, you are on point with your comment.

8

Yeah, there is more to it than just the outline of course. Rail shape, rocker etc also all need to correspond or you’re only doing half the work.

Corran

9

How many times have you had a board that works better going frontside than backside or the reverse? Surfing on your forehand is a completely different animal than surfing on your backhand. I read somewhere that Tom Morey said that symmetry was on of the least important parts of surfboard design. I think that symmetry has more to do with how we want our boards to look than how we want them to surf. I remember PT experimenting with asymmetrical boards in the 70’s, but I do not recall who was shaping them.

10

Was it Tom Morey who was quoted as saying that “Symmetry is over rated”?

Michael Jones (MrJ here on Swaylocks), Peter Drouyn (Australian legend) and some old timers from Santa Barbara have done a bit with asymmetrical fin lay outs.

Although I’ve not tried it, fin layout seems like it would fit right in with your theories. The Drouyn example in particular would (IMO) probably have a major impact on how the board rides frontside vs backside.



11
Quote:

Google Carl Ekstrom asymmetrical surfboard. I think you’ll find what you are looking for.

Just for completeness: U.S. Patent # 3,337,886 (Applic: 1965; Awarded: 1967)

12

All my boards our unintentionally asymmetric, do think I am in violation?

13

http://www.swaylocks.com/forum/gforum.cgi?post=334086;search_string=guy%20takayama;#334086

14

You mean stuff like this?

They are not just for “point breaks”! Worked REALLY GOOD. I made these 1980 ±.Not the original fins but you can get an idea. Stiff frontside for laying out turns. Looser backside for “fold under” cutbacks. The one with the plastic fins was the “sacrificed” later in life and was the first “Zinger”.

Ekstrom told me that his favorite thing about asymmetric surfboards was that you did not have to worry if the tails were even.

15

I just talked about this w/afoaf. I’m with you, except in reverse - I’ve always felt stronger off my heels than my toes, and build my boards acordingly. Keep up the good thinkin’

TaylorO

16

Haha! I remember a few years ago doing these and they worked pretty darn good!

http://www.swaylocks.com/forum/gforum.cgi?post=232499;search_string=carvenalu%20asymetrical;#232499

I’ve been planning a SUP board for myself and I think this will get the ball rolling… Waves have been just insane here since Feb7th EVERYDAY!!! Ahwoooooooooooooooo!!!

Aloha,

Blane

17

The thing I’ve never quite understood about asymmetrical boards is: do you design them for ‘footedness", or for primary wave direction? Meaning, generally you’d want a shorter rail line for the off-the-top, snap/cutback than for the bottom turn, whether backside or frontside. So, living in SB, primarily land o’ right points, is the left hand rail shorter?

Or, for example, I’m much more front-footed- frontside- than backside, so it almost makes more sense to change the entry outline and rails, rather than the tail.

If I really let my mind go all Play-Do like, I can imagine something like this:

(maybe not quite that flippy in the tip…tricky bezier curves)

18

I seem to remember there were boards called hook tails back in the late 50’s…

Anyone know of these? They were meant for surfing a particular break and there were many versions of the same…

Great thread, keep it up…

19

BINGO! Carl Ekstrom and I had a discussion about the ‘‘weird’’ Australian boards called Hook Tails, in 1962. The next winter, 1963, I saw one on the North Shore. It was a Surfboards Australia board, a light orange colored lam. Well made board, as I remember. As far as I know, the Aussies got there first, on this concept.

20

This is a great discussion. Shaped and laminated the board yesterday, Putting in the 4WFD fins today (these can adjust front/back and toe-in/out so I can also play with the fins a lot to fine tune the idea. I already have a 1/2" offset between the rail fins (its a thruster set-up). The frontside rail is faster and has less curve to it and the hip is a little more centered. The backside is 1" wider, thus has more curve to the template and the hip is considerably further back. I’ve tried to give it a squashtail for both rails, so this means there is a dogleg in the tail to compensate (rather than going with a slated tail like the those boards from the 1980’s which effectively makes the frontside a pintail IMO. The backside ended up being offset from the stringer in the nose, and then I adjusted the curve and pulled it back in that first foot so the stringer is centered, even if the curves are very different.

Completely Eco board - all made with recycled polystyrene, bamboo stringer and bamboo fiber in the laminate. Only less eco thing is the epoxy resin.

I’ll post pictures tomorrow when its finished.

Thanks for all the comments and feedback. SO far it all makes sense and falls in line with what I’m doing.

FYI, I’m more concerned about how I RIDE rather than the wave shape (so I’m not making it for a point break). This would be for surfing beach breaks where I go left as much as I do right, bu that due to human anatomy, I don’t turn backside like I turn frontside (even if my backside is better).

Corran