I checked the archives and didn’t find an answer. I made a 6’1" x 20.25" MR winged swallow with 15" tail, 7" point to point and 3.25" deep split. Fins are 10.5" from tips and 1.25" off rail.
Currently have basic 4.25 base/4.5 high thruster fins in the 2 boxes ( no trailer box). Board is fun but has spun out at speed. To get more fin area I am considering either the FEN, K2, or 512. Any opinion on which would be best? I think Protecs are a good idea but I don’t think they make a shortboard fin large enough for my application. Any input is apreciated before I spend the $.
They are expensive but you might want ot give the vectors (462) with the hatchet trailer a try…
they might work nice on the MR you have…
I use them on my Gemini quad with 420 sides in the rear.
For $60 there a set a of classic keels you can get for futures as well.
I’ve tried these on my Mandala quad with out alot of success. Quads ride better as quads where as thrusters can be converted to twins with a trailer but a trailer is kind of key unless the tail is real wide… (over 14")
15" tail twins, I think you need either 5.5" fins or a small trailer.
Most of my 20" wide, 15" tailed twinfinners had 6.5" side fins, on a squash or diamond tail, and I’ve used up to 8" for steeper surf.
G&S gave me a 5’4" x 20 twin rounded squash, with 4.75" tall fins, and it only spun out every wave over chest high. Great board, works in surf you don’t care to surf.
I ended up routing the boxes out and adding FU 8" sides with woodies, and that board was actually pretty good up to 1.5 overhead, with 7" fins.
I have riddens Stevies fins on a fish he did for me…they are some of the best. Futures approached Steve about doing them for him. I can get you a pair if you want. I have been meaning to put shots of them on my site, but you can see them on the two fish on his section of the site. He is also doing some really nice quads now.
I have been messing around with twin fins for the last 2 summers, and have found the Futures FEN template to be my personal favorite template. I have tried the FEN, FT1, and TW1 on a twinzer. They will all spin out if pushed too hard, but the FEN is the most controlled. It has a little longer base which makes it drivier. I haven’t tried the K2, but I would think that would be more for a fish type board. Half the fun is trying different fins. Have fun!