Unofficial Asymmetrical Board Design Forum

As for straight up snow boards… Ha! I rode regular boards, but I used hard shell boots in regular bindings, sans the high backs… A little bit of movement, but the shell gave me the leverage I needed toe side…

As they say, back to your regularly scheduled designing…

On the pictures of Carl Ekstrom's assymetricals and models he shows toe in on the keel outside the nose, and the quad side toe ins come together inside the nose.  Does anybody have any scientific info on how to layout an assymetrical fin setup?

Yes same question as Bandito, just shaped my first asymmetrical board and want to know about fin setup.
Im going to do a Twin setup on the toe side of board (goofy footer) which im assuming I will layout from the longest point on the board in a standard Twin position say 10 inches up to trailing edge with 1/4" toe , however it gets tricky when laying out the heel side Quad fins. Are the measurements taken from the longest point of the same side of board or are they taken from the longer toe side? hope that makes some sense heres a pic of tail,
thanks for any help and info…

Have also tried a few asymmetrics, would be great to try them on a good consistent point break to see whether i got my fin positions right. They seem to work well, i have compensated, somewhat, by moving backhand fins back a touch, and frontside forward. If i was doing a quad, or twin/ quad combo, i would measure from the back point on each side. [img_assist|nid=1057896|title=asymmetric bonzer 5 glass on paulownia side fins|desc=|link=none|align=left|width=35|height=100][img_assist|nid=1057895|title=asymmetric bonzer 5 /stubby 3|desc=|link=none|align=left|width=41|height=100][img_assist|nid=1057894|title=asymmetric bonzer 5|desc=|link=none|align=left|width=305|height=640][img_assist|nid=1057895|title=asymmetric bonzer 5 /stubby 3|desc=|link=none|align=left|width=263|height=640][img_assist|nid=1057896|title=asymmetric bonzer 5 glass on paulownia side fins|desc=|link=none|align=left|width=224|height=640]sorry about photos, first time posting them, couldn’t find how to remove them!

Thought this was also relevant, as asymmetrics also used to be known as can openers. Inspiration comes from the strangest places…[img_assist|nid=1057897|title=bonzer asymmetric inspiration|desc=|link=none|align=left|width=640|height=475]

A 70s asymetrical lightning bolt copy.

Greenlight Brian’s been doing a few asyms lately… maybe he’ll post 'em up.

Concerning fin set up that I went with,


Although I don’t have a picture handy, I did half traditional fish outline, and other half double wing/bump fish that was a couple inches shorter. 

On the traditional I used one keel fin, routed the fin box just the same as I would a Keel twin fin, only on box on that side.

As for the shorter double wing/bump side, I used a quad layout ProBox Larry had given me.


Not sure if this helps, but as for the performance it worked great.  Wish I still had it, it was snapped in two after passing it around for friends to try, lots of heavy use.


I’m thinking about doing another one, I still have the templates. EPS/Epoxy with a kevlar deck patch!



one is a bit of an experiment so I haven’t gone to extreme with the
outline. The curve on the heel-side only accelerates after the trailing
edge of the front fin. I’m still trying to make up my mind about the
fins; I’ll even go safe with a symmetrical thruster/quad or crazy with a
keel on the toe and half quad (maybe cutaway speedialers) on the heel.

Dims - 6’2" x 19 3/4" x 2 1/2"


''... keel on the toe and half quad (maybe cutaway speedialers) on the heel.''


Sounds good.    Go for it.

Get a link to Vinny Bryan, 1968, asymmetrical  board for the Honolua Bay contest- (Won the contest)-As far as I know, Vinny made the first contemporary  one I ever saw, and I didn’t  see another  one for at least 4 years-I believe it was 6’8"–Anyone with other data on this board, please shout–Mac

interesting.  Love to see a pic.

There's some interesting Asymetrical variations amongst these, by Bob Cooper -


I want to do an asym twinzer. Kind of a small difference: fang Jobson-style tail on my heelside, round on my toeside. 5’6 x 19.5" short, fat groveler.


based on my last one ( a round tail), I don’t think that is enough asym in the outline to feel much of the asym.  I think you will need to go a bit more asym with it.  below are a couple of shots of my asym on the right next to its test partner on the left. I just barely feel the outline asym.  I do feel the fins, though (offset and you can see).  it was a shot in the dark.



We've been working with Carl Ekstrom and he's done some crazy asymmetrical boards:

First one is a Simmons type hull but modified to a customer's specs:

[img_assist|nid=1059434|title=Carl Ekstrom with Scott Bass' Quad/Twinzer fish. Scott says it works unreal!|desc=|link=none|align=left|width=0|height=0]






 And this one is more performance fish like: 


[img_assist|nid=1059435|title=This board is more of a performance fish rather than Simmons style board|desc=|link=none|align=left|width=0|height=0]





This last one is what we've been focusing on in my shop, a shortboard

with more vert performance in mind...

[img_assist|nid=1059436|title=Post-lamination, this Asymmetric shows the two-tailed approach|desc=|link=none|align=left|width=0|height=0]





I think this one was 5'2"/5'4" (been writing down 2 lengths,) but was derived from a

5'10" regular board.

[img_assist|nid=1059437|title=Our finner Pat, puzzling with the offset center fin box for a thruster A_Symm|desc=|link=none|align=left|width=0|height=0]





The empasis of the center fin on the "toe side" rail was to give that side more

drive, but to offset this drive (and the opposite of was Carl was doing then) the

rocker off the tail was flipped (increased) about 3/8"

[img_assist|nid=1059439|title=5'4"/5'2" x 20-1/4" x 2-1/8" Goofy foot version.|desc=|link=none|align=left|width=0|height=0]





Sorry he's goofing off in this shot, but it shows the overall outline.  Basically a

round pin on the toe side and a favorite hybrid fish with a wing on the heel.  The

last 3 boards have shortened noses to get quicker swing which in turn allows for

less mid/tail rocker which in turn yields more speed.  Note also that the heel side

is shorter, BUT has less tail rocker off the tail (and between the feet.)

Now, before jumping to the conlusion that these boards are wild, the feedback

has been that they handle quite well.  They also paddle well which is a good sign.

I liked the comment that "if I closed my eyes, the board feels like a normal board,

but turns better and has more speed..." 

I want to also note that Carl Ekstrom and Chris Ahrens have been onto this for a

long time and that I'm just a short-timer on the newest ones (I did a few in the late

70's but not this crazy and was not as aware as now.)  Carl is great to work with, just a

class-act all the way, I really like his model-making, he was totally liking our computer

modelling so I'm stoked to report that he is up-to-date in that area.

Regarding the Vinny Bryan comment, there were a lot of creativity along those same

lines in our zone here too, and Benny Ferris and Jon Riddle made a lot of their Edge

Boards as asymmetricals, some VERY radical, which worked well but were superceded

by the next week's new thing,  ha ha.

So anyways, a lot has been going on lately, I got my newest personal A_Symm done

and hope to test it soon, maybe I'll post some pics if interested, it's 5'6"/5'8" x 19-1/4" x 2-3/8"

With what's been found out so far I know the design push has been going in the right direction.



George looks great the middle fin move makes my brain hurt. I am working on a diamond tail for my heelside and a thumb for toe but am moving shops so maybe in a couple of weeks.

Have any of you guys thought about changing the toe in on the fins? I was originally thinking of a swallow on one side and round on the other (see pic below) and then totally changing the template on the round side, since the center line from nose tip to tail tip would be shifted. Since the rail line would be longer, then the wide point should move back and the toe should be moved out. I can’t figure out what less toe in would mean when you’re turning on the other rail. 

From Rusty’s blog:




Asymmetrical: Who says tails have to be symmetrical? My first board was an Ekstrom asymmetrical. I’ve built a few over the years and had a couple good riders swear by them. I made myself one last year and had a blast on it. Swallow wing on the frontside, roundtail on the backhand. Drive and release toe side, shorter, power arcs heelside.


nice Discussion guys, in the early ninetys i had a local customer who was known as “crazy dave”! being known as “feraldave” we had quite a synergy… he had me create him all kinds of assymetrical performance thrusters, we started out just moving fins, then fin templates and on to outlines as well. i wish i written down some of the stuiff i learned then, i didnt even take photos… those day as i was beggining to to try to crack a market, experimenting and unusual looking boards were seen as a negative and scared potential customers.

 thanks to todays trends and market we can do amazing and fun experimentation and customers respect you for it… i did a assym mini sim/style commander combo a while back, i challenged my self to make it and cut it on my aps3000. it was actually really easy to do and totally repeatable. i will try dig up some pics. i know that it went insane and as someone else said if you close your eyes it went like a normal board only better!

 im really tempted to do a couple in my Dynocore™ tech  glassing now… i would love to do an assym 3 channel/pintail for a couple of bali/ Glands famous lefts to try out!