Hello I have sunova one with three fins (central large thruster) with two small ones near.
What would removing the two small ones do? Make it faster? Less stable?
Can i just remove them or will the open housing will create drag?
Tnx

Videos worth watching to learn.... yes they are for surfboards, not sups, but same principals apply. You won't notice drag from empty fin boxes.







I guess the most relevant question to ask is why do you want to remove the sides? What are you looking to do or improve?

Looking to improve speed. Question is whats the main role of the side fins.

Stability? Speed? Other?

Removing the side fins will noticeable increase the speed.
People do not think to remove the side fins, but they often are very surprised by the speed gain.

Filing the empty boxes is not necessary, the drag is not noticeable.
You can fill them with some foam strip if it bothers you.

The drawback of removing the side fins is that the board will hold less when banked into a turn, which is not an issue on small waves.
Side fins help just during hard carving turns, otherwise they just add drag.

Thank you! Much appreciated.

Agree with Colas re side fins and manouvres. They really help your board engage the rail through turns suiting contemporary rail to rail surfing. Singles need you to draw out your turns and cos of the speed and less drag and less manouvrability, surf with more glide and flow.
You've got to take different lines and approaches to wave faces and surfing, and adjust your headspace to suit. That's the beauty of it-so many different permutations and combinations.
Your best bet is to experiment and change your fin set up during the same surf sesh. Even take a fin key out with you and take the side fins off out the back after a few waves, shove them down your wetty, and enjoy the experiment/change. Just play around with it and feel it.
You'll really start doing your head in when you look at different styles and sorts of fins and there's plenty of feedback here and elsewhere. We got a saying that if you don't like your board change your fins.

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backbeach said..
Your best bet is to experiment and change your fin set up during the same surf sesh. Even take a fin key out with you and take the side fins off out the back after a few waves, shove them down your wetty, and enjoy the experiment/change.

So true!
If you have a chest zip wetsuit, it creates a pocket perfect to store fins, our ribcage doesnt flex so you do not feel them there.

Try also to keep only one side fin, to feel the difference it then makes turning right or left.

Also depends a lot on the shape and style of both the side and centre fins. If you have a narrow based flexible raked centre fin like A, removing the sides can slow the board down. This style of fin can be aided by having side fins generate more drive creating speed and acceleration. Well worth trying different size side bites v centre. Depending on the board and your goals, you could go anywhere from keeping this big fin with micro bites, or moving on to a proportional regular tri fin arrangement.

On the other hand, if your centre fin is stiffer and has a base with more area like B, it should stand-alone generate a lot of power. With these side fins are unnecessary. The extra drag is likely only to make the board slower and unmanageable. Nevertheless, many people who don't have tree stump thighs like the "twang" they get from a lone big flexible single fin.

Other considerations are the design of the board and your own style. Many boards are designed around the fins. For instance, performance boards typically three and a logger a single. Likewise, are you a power surfer, neutral flow, or still hoping to make the pro division? As the comment above, best thing is to experiment and see what suits the board and you!

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colas said..
Removing the side fins will noticeable increase the speed.
People do not think to remove the side fins, but they often are very surprised by the speed gain.

Filing the empty boxes is not necessary, the drag is not noticeable.
You can fill them with some foam strip if it bothers you.

The drawback of removing the side fins is that the board will hold less when banked into a turn, which is not an issue on small waves.
Side fins help just during hard carving turns, otherwise they just add drag.

Colas, I have a Fanatic Stylemaster (10', 145 L), I'm 68kgs and just starting out surfing. I surfed 50 years ago and thought it was time to get back into it :-).

I swapped out the 1+2 fins with a single raked fin (Captain Fin Raked 9.5"). I've only tried this in one session but I found the board to be a bit quicker. It seemed like I was getting onto more waves, but that may have been for other reasons. I was also trying to get my weight forward to project the board down the slope as you describe somewhere else.

But I also found the board harder to turn. Is this just because the single requires more weight on the back foot?

Is there any advantage at all to having the side bites if I'm surfing <3ft waves.

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grgd said..
But I also found the board harder to turn. Is this just because the single requires more weight on the back foot?

This because by removing the side bites you moved the fin surface center to the aft. Just move the single fin forward to compensate.

My advice is to put your single fin as forward as possible, and move it back a bit if you feel that the board is too squirelly or loses too much speed at the end of turns.

Also, if you want to put back the sidebites to try to perform more modern carving turns, losing less speed in turns than with a single fin, I would advise to get a small center fin, to set the board in a thruster setup (all 3 fins of the same size). This way you will feel more easily the difference between these two setups.

Otherwise, keeping a big center fin with sidebites will help control the board in bigger waves.

The Captain Fin Raked fin takes up nearly the whole fin box so the front edge of the fin is right at the front of the fin box. The total adjustment range is about half an inch.

The side bites are 4 1/2 inches and that can't change because Fanatic use a non standard fin box. The stock Fanatic centre fin is 8 inches in a US box.I could get a Greenough or similar fin down to about 6 inches. Not sure if I could get anything smaller.

^^^ what non standard box? I hate that crap from companies. But their web site shows what looks to be Futures sidies and US box ctr...?

You may find an old windsurf fin in US box, with shorter base that enables more movement fore and aft.

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Mark _australia said..
^^^ what non standard box? I hate that crap from companies. But they web site shows what looks to be Futures sidies and US box ctr...?

You may find an old windsurf fin in US box, with shorter base that enables more movement for and aft.

Not futures. It's their own thing.

I repeat then - I hate that crap.

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grgd said..
Tthat can't change because Fanatic use a non standard fin box.

The accept Future fins.

See my post at www.seabreeze.com.au/forums/Stand-Up-Paddle/SUP/Fanatic-allwave-Fin-set-up-2?page=1#2388497

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colas said..

grgd said..
Tthat can't change because Fanatic use a non standard fin box.

The accept Future fins.

See my post at www.seabreeze.com.au/forums/Stand-Up-Paddle/SUP/Fanatic-allwave-Fin-set-up-2?page=1#2388497

Thanks Colas. Yes I was a bit hasty in my comments on the Fanatic fin box.

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grgd said..
Thanks Colas. Yes I was a bit hasty in my comments on the Fanatic fin box.

On the other hand, the Fanatic box with its screws on the side may not work well with current future fins that have nearly all an hollowed-out base...

eu.futuresfins.com/en/13-surfboard-fins