I converted a 1999 Mistral freestyle to a tri fin, this year, I used Probox surf boxes and fins, I tried both symetrical and asymetrical fins (these are flat on the inside) . While no way near as versesed as Ola in twins, and I know he has converted at least something with boxes from Witchcraft, who are probably the authority on tri fins. And since I have one, can somewhat attest to their prowlness.
I did the tri fin more on a engerineering concept, to see if I "could" do it, yes I did, and to see if it worked any better than the same board with a single fin, well.... it did/does go upwind better, it does turn more abrupt, it I'm sure weights more, with the additional boxes .. but not alot. I received guidance from Witchcraft and Ola, regards, toe in and placement of the thrusters.Toe if I measured correct 1.9 on the side bite thrusters, the Probox system . after quite alot of research, fit the bill, strong light weight, can change either the cant, which is angle of the fins, just by replaceing the insert, and a short adjustment of fore//aft like a USBox. My fin arrangement is center 17cm Tarifa wave fin, and thrusters either 5 " sym or 4"asym, the more puzzling aspect is the 4"asym //flat on the inside were noticeably faster , I cut down the original center fin to 22.5cm but never tried it. I rode back to back with a single center 30cm MFC , and those I just described, which form my observations.
I learned quite a lot of rocker this, v that, and surf fin technology. I tied the boxes into the very bottom of the board to re- enforce the installation, but would go no larger than 5" on these. Real wind fins are a unique box. I would probably suggest mini-tuttle as a alternative to what I did, for the fin boxes like the large fins on the new *Board Quads , these fins are going to become very popular, they are like a directional kite board fin.
My project kept me busy over the winter here in Colorado, so I have no regrets, a low cost board, and like you said, probably won't get sold.
My 2 cents is the Acid is not a good donor for this, the EVO or Kombat would be better. This a 104L, and for sure quite a bit different than my newer boards. With the right board I think a very promising result might occur, I just think the width in the back needs to be wider. The Real Winds, Open Ocean boards are long and narrow, with very short side fins.
I would leave you with this...
you can't make a racehorse out of a pig........but you CAN make a fast pig !
your HSM compadre TO2D
Last edited by carvesalot; 4th October 2009 at 09:38 AM.