The little black fins were an easy add-on… They have no cant or toe in, and are flat-foiled.
No real theory behind it, but it works well. A bit drivey-er and more solid than as a straight twin, but still rotational. (The board is a flextail behind the fins)
Any thoughts?
Hey Al,
Any Thoughts?
What about reducing size of side fins and then trying ones with, say 10 degree cant. Bit too much fin area IMO with current set up.
AND…tidy up ya yard, it’s a mess!
Rocky
Smaller main fins? I could throw some in. I’m liking little or no cant, though. The futures have whatever cant’s in the tabs.
Oh, and there’s a rake around here somewhere, you’re welcome to it. Its been kinda windy lately.
I have thought about this before.
What about low aspect ratio fins for the back (think bonzer side runners)?
Kind of like taking the side fin cutaway and moving it toward the stringer.
loike it
wish i could grab it off ya for a coupl of waves
I run a real similar setup on my favorite fishes, but I just use one small double foiled fin (in a probox, zero cant), in the center of the board placed forward just enough to put the fin tip even with forward end of the butt crack. It’s amazing how much it improves the ride…
I have thought about this before.
What about low aspect ratio fins for the back (think bonzer side runners)?
Kind of like taking the side fin cutaway and moving it toward the stringer.
Yes, those cutaway fins are a little bit washy. Maybe I’ll try some low, triangular wedges.
how would you describe the differences with or without that center?
The fin setup seems similar to the way Jeff Alexander’s Gemini board. I like the back fins placed a little closer to the middle and more evenly spaced out as opposed to closer to the rail and having more open space in the middle. I also think smaller back fins placed that way with little or no cant works well. I do think that they could be further back to get more drive from your turns.
I have photo of 3 multi finned small boards I have. One is a gemini copy my brother made with Charlie Price. The rear fins are too close to the center and the the front fins, so the board seems to make rotational turns as opposed to hard carving turns. The middle board is my interpretation of the fletcher 4-fin, but with a deep concave down the middle and hull like rails. The rear fins are double foiled and straight up with very little tow in. I like this board, but it’s not as good as my 5-fin fish from Greg Griffin. Just too many things put into that board. There’s also a shot of my interpretation of a 5-fin bonzer.
Having ridden my brother’s custom gemini from Jeff Alexander, I’d say that for a 4-fin board the spacing of the rear fins would be best somewhere between the two 4-fin boards in the photo.
I like the boards you’ve posted Allan. They seem to push the concept of what can be done quite a bit. The boards we make are all pretty much stuff that we want to try without worrying what others may think about them.
Hi Allan,
I tried something very similar a couple of years ago and it works great! In my opinion the small rear fins stabilized the “skaty” feel and turned the board into a much smoother carve.
Here’s a couple pics. I got the small fins from Clyde Beatty Jr.
http://i255.photobucket.com/…Boards/fishtail5.jpg
http://i255.photobucket.com/…Boards/fishtail3.jpg
P.S. I really like your idea of the flex tail. Lemme know if you ever need someone to help test ride. I’m not too far away. 
Marc
Not to hijack, but anyone tried a twin/twinzer setup, with regular (single or double-foiled) keels in the normal twin position with plugs for little twinzer fins, so you could ride as a twin or a twinzer? Would that be too much fin area or would it have any pivot benefits? I’m not a shaper and I’m broke, so telling me to try it myself isn’t helpful. I fugure one of you mad scientist types has given it a go.
Thanks,
-Charlie
The little black fins were an easy add-on… They have no cant or toe in, and are flat-foiled.
No real theory behind it, but it works well. A bit drivey-er and more solid than as a straight twin, but still rotational. (The board is a flextail behind the fins)
Any thoughts?
Allan, great stuff as usual, does everyone ‘get’ that fin sets close together reinforce their characteristics,(quads) and fin sets at a distance compete for/share control, so twinzer/quads are like a twin but with more drive and changing the distance between and size of the fins just varies the influence back and forth ?
In my experience Ive found that if you put 2 sets of fins far enough apart and make them big enough to vie for control it ends up like driving a car with a short and a long wheel base where they continually fight for drive and the turning arc is a bloody mess of variables.
Brett.
Quote:Allan, great stuff as usual, does everyone ‘get’ that fin sets close together reinforce their characteristics,(quads) and fin sets at a distance compete for/share control, so twinzer/quads are like a twin but with more drive and changing the distance between and size of the fins just varies the influence back and forth ?
In my experience Ive found that if you put 2 sets of fins far enough apart and make them big enough to vie for control it ends up like driving a car with a short and a long wheel base where they continually fight for drive and the turning arc is a bloody mess of variables.
Brett.
Thank, Brett,
By virtue of having done so many boards for people within a pretty tightly defined framework, I’ve developed a solid, objective foundation.
But surfing itself is so weird and subjective, that if you’re paying attention, you tend to know, intuitively, what’s going on with a board, and can play with variables.
I read here that Brewer, Barnfield, and other shapers were machinists by vocation. Whereas, for me, my vocation and training is in painting (shaping’s my day job), so I tend to approach things from a little different perspective. That makes me a very un-scientific board builder. So on my own time, I get an idea and go with it. Sometimes it works, sometimes it doesn’t- no big deal.
Maybe not the best approach for producing consistent, quantifiable results, but a good approach for making intuitive leaps (and having fun!).
Cut-aways reduce drive. How does it go with just two keels with no cut-away?
P.S. I really like your idea of the flex tail. Lemme know if you ever need someone to help test ride. I’m not too far away.
Marc
That could be arranged!
AG
Cut-aways reduce drive. How does it go with just two keels with no cut-away?
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My other twin-keels with a full base have a lot more positive, drivey feel.
The keel fins for the Futures boxes have to be cut away to allow the fin(s) to rock into the slots.
Usually I use Lokboxes for keels (but I didn’t want to risk wearing out my welcome using a friend’s jig, and I’d already bought the Futures jig- budget, and all that…)
I think we all congratulate the B-guys for their professional input and years of hard graft, it cant be easy to face decades of ‘blue-room’ when the final recipients are worrying about sand between their toes.
Equally, I applaud the work of the hobbyist, part-time, amateur,crank and kook shapers for working and thinking about something that will undoubtedly drain their money, confuse their thoughts and be a thorn in their sides for ever more. And with minimal reward.
My heart felt appreciation goes out to all levels of designers and shapers.
The future isnt, without you.
Brett.
Allan,
With shaping becoming so high tech nowadays, its refreshing to see someone still taking an un-scientific approach to surfboard design. Most of my better boards were the result of a bit or brain storming, gut feeling, was pleasing to the eye and plain luck. I hope you’ll again share with us the next thing you throw together.
