Got a thruster fish/hybrid with removable fins and would like to remove the center fin and put two larger side fins. Would this even resemble the feel of a twin fin (I’ve never ridden a twin so I can’t compare)? Or will I slide out on anything of 3 ft?
Just pour some Q-cell mixed with poly into the finboxes, then use glass-ons for your twins. Typically fish have larger side fins and lesser tow-in’s from what I know. Some fins are even parallel to the stringer.
It’d work fine.
Add about one inch of fin height when you remove the tail fin…more if you are surfing bigger, faster waves.
I have a better idea (in my opinion). Your board was shaped to be a thruster, and a thruster it is. The twin fins of the eighties were not shaped the same at all. They were wider in the tail and nose, thicker, and had less rocker.
If you take out the back fin it will, of course, still go and will be looser, no doubt, but It won’t have the same drive. The loss of the back fin will slow you down. Here’s why: You will lose tail stability, and your bottom turns and cutbacks will bleed away the energy.
My suggestion. Put the smallest fin you can find in your center box, about three inches, and you can even go smaller. That’s what I did, and now I have the looseness of a twin fin, but the stability of a tri fin.
I dig it.
Ditto.
I totally disagree!
I’ve made twin fins with varying outlines and WP’s, and all feel like twin fins, with the thrust and acceleration I was looking for, and the snappy feel both off the top and off the bottom.
You didn’t read the part …“increase size of your side fins”.
I’ve had twin fin 8’6" x 19" boards, funboards, mid 6’s, and plenty of sub 6’ers. Most could be ridden with smaller sidebites and tiny trailers, but that changed the snappy feel, especially backside.
When you just subtract tail fin sizing, you get a looser, but more prone to spinout small wave board.
When you increase the sidefin sizing, so it DOESN’T need the tail fins, it’s a whole different animal.
Thrusters have two fins, separated by roughly 7 inches in the fore-aft direction, that give it the drive and hold in the bottom turn.
This is unmatched in twin fins. Show me a twin fin that has fins large enough to span the fore-aft distance covered by the two engaged fins of a thruster!! In a thruster each fin has 4-5 inches of base and they are 7 inches apart. Even a long 8 inch classic fish fin can’t compete.
Taking the rear fin out of a thruster is certainly sub-optimal. Twins DO use larger fins. But, they still will not bottom turn like a thruster. And, in the same board, you will set the side fins a little further rearward on a twin than you would set the side fins on a thruster.
Some people like twins, especially for how they come off the top. But where it counts is how it comes off the bottom, and the thruster is the winner.
If you are looking for a more fishy feel on your thruster, try slightly larger rail fins and a slightly smaller center fin - it will looser it up.
I’m with Lee on this. Take that middle fin out, experiment. Maybe you’ll learn something! At the least you’ll learn how drastically the fins affect the performance of a particular board. You even might prefer the skatey-slidy feeling of a twin-fin setup. Keep this in mind though, usually twin fins are set a bit closer to the tail then the side fins on a thruster setup. Usually somewhere between an inch or two. This helps make the board a little more positive feeling. -Carl
Don’t forget…as a general rule, twin fin templates are wider and shorter!]
OTOH, thrusters are longer and narrower
Offsets placements of fins there.
Without seeing the board, there’s no way for anyone to tell you it will or won’t work.
Generally, the problem is that the bigger base will put the leading edge of the side fins too far up.
Twin fins tend to be very sensitive to outline-rocker-fin placement integration. Thrusters are a little more forgiving when it comes to the relationship of other aspects of of the board’s design components.
all you can do is try it and see if it works for you. I think you’ll have your best results with slightly bigger side fins and a small little trailer fin.
Definetly an early 80’s implementation of the Thruster
with the Clinker bottom?? maybe close…
Loads less rocker than a 90’s and later versions.
Perhaps why it works as a twin also.
nice my board is similar to this it’s 6’4 x 20 x 2.5 wider than usual, less rocker a full nose so I’m gonna try it when I get my bigger fins and make a plug for the missing center fin.
I had my first experience riding a twin this weekend. I have 4.5" sides set at 15" up on my 8’0" miniLB and tried removing the center in 3-5’ mush. The affect was way too skatey, and what seemed like zero drive. I’m sure having the sides further back would have helped some - but it def needs the rear fin on the present set up.
I will still try it again in better conditions, and would really like to try it on a smaller board. The one pro I did notice was how easily the thing snapped - most of the time too easy but I’m pretty sure that’s has a lot to do with the side fin placement (forward).
Best,
Herb
Herb, my 7’9" fun Bic has 6" tall side fins, 5.25 base (chord), a waiting set of 7.5" Chuck Ames side fins, and when the surf is overhead, I insert a 4" tail fin!
Your fins are ridiculously small, as a twin finner, even for SoCal waves. Don’t judge fin placement with such small fins.
Im gonna try this with my 6ft2 the fins on it are REALLY small (fcs g 3000s) but im also a grom.