Hey all,
I have shaped a number of single fins and 2 +1 boards so far but no twinnies. I was wondering if anyone had any idea of where to place fins on twins or the angle to set them. Also is the principle of moving the fin up the board for more snappy turns and closer to the tail for longer drawn out arcs the same? I’m shaping a pintail single winged board to be a twin at the moment.
Thanks in advance for advice, Felix
A few shapers I’ve had twins shaped for me set them up from tip of tail anywhere 6" - 10" , but that’s as far up I gone with. Yup. More stiff and drawn out turns with fins set further back nearer tail… FYI my loose twin had fins set at 10" from tips, and it was more pivoty, snappier off the top…almost slidey. Not sure what your looking for?
They seem to put the rear of fin 1 1/2" in off the rail, same for front, but then they add anywhere from 1/8"- 1/4" tow in from there… so your wide open there!
Can’t from nothing - to 4 deg is what I was told. I’m going w slight cant, and maybe two deg?
HOw long is the board?
Thanks Shapaholic2011
I had a fish glassed for me a couple of years ago but sold it a little while ago. so I had no idea on the fins but that seems to really ring bells.
Straight in the 6’0 mark. Any ideas?
10-10 1/2
1 5/8- 1 3/4 in from the rear of the fin
3 inches of toe from the front of the fin
3 degrees of cant with a heavy vee, 5-7 if more flat
Zach, I can picture you dims for fin placement (rear of fin base up from tail, in from rail, cant) except for toe-in. How do you measure the 3 inches ? Not being critical, just trying to match it up to the front of fin base @ fractions of an inch towards the stringer system which I am used to / understand. I admire your boards. -J
Hi Felix! I just go with whatever my Shaper would do…the twins for a 6’ board can be anywhere from 6-10" or so up. BUt if you’d be more into radical performance oriented surfing my twin I had custom designed we set my twins up at 10". Slight cant and 1/4" tow in as stated earlier. An 1/8" of tow in I’m thinking would prob give you faster down the line rides? Zero would be something to stay away from I think.
Are you talking about MR style fin or keels? I’m sure Zack means to measure 3" in from the rail to the front base of the fin? I set my keels anywhere from 7-10 1/2" from tail depending on lenth, base of keel & tail shape etc. Kinda prefer them slightly further forward than most! Definitely add some cant & toe. I never on my first and ended up grinding off my birch keels & resetting them, twice!!. The difference was staggering & taught me a lesson. Love that twin high line. Slanj
MR style, probably pretty flexy ones aswell
On my offshoot performance swallow/FISH thing I’m setting my keel fins at 6 1/2" up, and I might tow in 3/16" ? I was going to go 1/8" tow in, but I’m thinking it might be less performance oriented? And 1/4" tow in might be a bit slower? So I think a happy medium would be ideal… cant I think slight angle might be best for all around? Anyone?
I’ve had a couple Griffin twins. Very solid and drivey. No losing their shit in turns.
5 3/4" up, 1" off the rail, 1/8" toe, 6* cant
that far back, fins don’t have to be massive. 5x5".
Obviously pretty far back compared to MR etc.
i e also done some of my own why hatchet keels at 6" with no cant or toe.
Zero toe isn’t a big deal with twins
I was going to say 9.5 up. But, I’d go with the zackpooman’s numbers. Solid board maker and he surfs this kind of stuff. A keeled fish is a different animal than a 6 foot winged pin. So are Griffins twins, I recon. Mike
thanks for the info! I think I’ll tow at 1/8" and take it from there…I geuss I can’t believe it if I hear it…
Absoutely! MR style pin is a different beast to a keel traditional fish. The last board i stuck keels on was this big wide ol soap bar!
Hey all I’ve got a twin in the works and this seemed like a good spot to post a question regarding twin placement. I’m going with glass on fins that are very similar to an MR template. I see that 10-10.5" seemed like agreed upon numbers but this seems like a long way up? Would going with fins at 9 - 9.5" up, 1.5" off the rail, 3/16" of toe and a few degrees of cant seem alright? The board is only 5’6" x 19 3/8" so i’m hesitant to go too far up. If it helps I’m planning on a 6.5" wide tail with a small 1" deep swallow and a width of 14.75" at a foot up, no flyers. Kinda going for an original lost RNF style board.
Any help would be much appreciatd. Cheers 
I just made a 5’7" twin fish. I set the fins 8.5" up from the points. 4" cant and 1/8" toe. It goes great. I’m now in the process of making an MR style twin. It’s 6’ long. I’m using the Blending Curves “Alt C” template. I reckon I’ll go for 9" for this board. I still have to make the fins so it might be a while before I get to surf the board, but I’ll report back if you like.
I love twin fins. They’re such a different feeling from thrusters or quads. Great for those ho-hum sessions when you want to spice things up a bit. In saying that I still feel the best all-round configuration is the thruster.
Ended up placing the fins at 9.5" up, 1.5" off the rails, 3/16" toe and 4 degrees cant. The board is 5’6" and feels good with this setup. Fins are from Alkali.
epic
Hey everyone, rather than starting a new thread I figured I’d continue adding here since it’s mostly about twin fin placement.
I’m really enjoying this board so I’m going to do another twin. I found this one can often be a little too loose so I’d like to stiffen it up (just a touch).
I think I’m going to move the fins back. Will moving them back half an inch to around 9" make a noticeable difference?
Also will adding some vee in the tail help with the looseness? My thinking is that it will give it some extra stability by having the stringer act like a very tiny “fin”. I’m not sure though as I can also picture it giving a point for the board to roll from. Any thoughts?
My original board has a single concave through the centre which I will keep, but is basically flat from the fins back.
Cheers
I have very little experience with twins…
BUT, I have been experimenting with Twinzers for over a year.
My Twinzer mains are at about the 8" mark, 1 1/4 off the rail, 1/8" toe (over 4 1/2"), and 0* or 2* cant.
I have come to these numbers after being pointed in the right direction by a fellow Twinzer enthusiast and then experimenting with 4WFS boxes… As soon as I read your post, I thought to myself, “3/16 toe and 4* cant is too much. That board is gonna be too loose”… One of my twinzers, I started out with 6* cant, 1/4" toe. It was WAY too loose and felt like I had a basketball between the fins that I was constantly trying to balance on. I dropped the cant to 4* and it was still too much with little to no change. Then I dropped it to 2* and it felt good. No more basketball feeling, loose, drivey, FAST! … Dropping it to 0* didn’t feel any different than 2* so I left it at 2*… After I dialed in the cant, I started messing with toe… Dropping the toe added more drive… The more I dropped it, the more drive I felt. I settled at 1/8" as the best feeling of drive vs. loose… Hope that helps…
BTW, what size are your fins?
