Bigger wave fin question

Hey guys

Ive got a scenario which is baffling me. I've been sup surfing and charging decent waves for a good few years now and down to playing on that size on 7'2 - 7'10 and 90-100l boards. Recently I got a new 7'10 x 28 x 4 (103l) carbon board. Good rocker, decent rails, squash tail and probably the best all rounder board I've had. The guy who sold it to me complained that the board just didn't Wana turn, but was great at everything else.
On the first try, I kind of agreed- it didn't want to turn as sharp as my 7'2 hyper nut (which is not meant for hollow waves either), so I changed out the Gerry Lopez quad fins that came with it and went to an old much smaller fcs hx3 nexus set in thruster. This helped a bit. I also tried other thruster sets but nothing made it feel magical.
I got used to it and could rip in smaller steeper waves- the board can handle a steep drop like a champ and best in hollow or heavier waves too. Where I can't seem to figure it out, is when it's overhead and strong offshore. The board just wants to run straight and struggles to want to break a line and turn. This is exactly what the guy who sold it to me said, but I thought I'd fixed it. As soon as it's strong off shore and big, the board doesn't Wana turn.

I thought going to a smaller set would losen it up (it did help in other conditions) but over this and the board just wants to run down the wave. Do I need a bigger fin for bigger stuff? I thought this would further give it drive and make it harder to cut speed and pivot?
i just don't get it. The Board has heaps of rocker and a lovely tail / tail line, I have more confidence taking a steep drop than any others before (I've had deep pro's, hokua's, JL super tech, starboard pro) etc.

Any ideas? Just seems odd that the previous owner said the same. He's on a 7'7 JL destroyer now and said it turns much better.

It may be that with offshore winds, you unconsciously move tour weight forward to push the nose down, and forget to move your back foot enough to turn tight.

For fins, you want to keep big sides for hold, but play with the center fin or rear fins size and position. The front fins are providing the main "wings", and the rear act as "stabilizers". But I don't thing it is a gear problem.

What can also happen in bigger waves is that you need to let the rail dig into the water before turning, so compared to turns at slower speed you must kind of delay a tiny bit the actual turn: if you turn too early, and are not ready for the increased centrifugal force, your body will straigthen up and you will stop the turn and "track". Basically you must adjust your "internal timer" to slow things down.

PS: narrower tails, and especially round / round pin, work magic in faster waves. Square tails are stabler, but become harder to roll.

Thanks guys- it shouldn't be a technique thing as I have not had this happen with any other boards before. I dig the tail hard in the offshore stuff but the board keeps going straight. It's a single to vee through the fins, rails hard at the back and feel kind of tucked under (hardish) most of the way forward too. It's got a good bit of curve and a lot of nose rocker with a Thinned out tail. As a thruster, it should carve up turns much tighter than my hypernut which is a quad, fat railed, fat tailed and no rockered board. It does feel like for it to really pivot, you have to be right on the very back of the tail (but seems strange that it would require this) for a 7'10? I've been running big sides and smaller centre for a long time (also tried this) but didn't make much of a difference. i wonder if it is something with the fin positioning? Seems To be most affected during strong off shore and bigger waves. Not sure if anyone else has ever noticed the same correlation?

Here's a couple of other pics on small waves that were almost too small to make turns work.

Having a Hypernut and tried various sizes I agree with Hoppo about that they turn different.
On your board the centrefin looks pretty forward and the tail rather wide.
The rails in the back looks on the picks very round where an sharper rails help to initiate the turns better. All stuff that works for low speed short turns and in a straight line but not when trying to turn at speed.

What works in smaller waves (width, thickness, curve in outline, large fins) fights you at speed. You just cannot engage the rail due to the lift being generated by the board. Technique can sometimes overcome this but it looks ugly. Thin narrow boards are the only solution. Either you paddle underwater as the elite guys do with negative volume or you go longer. For me at 100+ kegs it meant 10 footers which help on offshore takeoffs.

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colas said..

thegreatsup said..
Thanks guys- it shouldn't be a technique thing as I have not had this happen with any other boards before.

Each board has advantages and drawbacks, so you MUST adapt your technique to the board to enjoy it.

And... it is clear from your second picture that your front foot is way too forward to turn. Look at how your body instinctively tries to get as far back as possible to compensate the bad feet placement...

Basically for turns your front foot should be around the handle, and the back foot either on the front fins (wide bottom turns), between the fins (tighter turns), on the rear fin (top turn).
For instance:



And your rear foot should be always moving!

And here is a counter-example of bad foot placement: my rear foot is too far forward, note how the board does not want to get on the rail and thus stays flat:

I agree with Colas with your front foot placement being too far forward to be able to rip a hard turn. Rear foot needs to be right in front of the back raised kick for the board to turn sharply (you sound like you know this already).

I have the 7'8 hypernut and it turns so easy compared to my 8'0 sunova flash. You need to remind yourself to get back further before cranking a turn. The rear fin also seems up a fair way up from the tail.

Also the toe and cant of the front fins may be straight and not aimed to the centre stringer which would make it track and go fast and need some adjusting with your technique when turning.

You seem to have tried many fin setups and I would have suggested a smaller centre rear with he larger fronts which works well on my Sunova flash.

Maybe the board design itself is not totally correct eg. rocker profile, tail lift/kick, rails too sharp in the back 1/4 of the board.

Keep persevering with adjusting your technique on bigger waves and swapping fins and hopefully it will click.

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Kami said..
So, change the Nexus for a go with the H2 from FCS;

I - respectfully - disagree:
- nexus were the best "classical" (non s-wings / C-Drive / Quobba) FCS fins I used. I had the H2 and the H3 (nexus). H2 need to be constantly in ultra tight turns to show any advantages, whereas the H3 works also beautifully and smoothly at speed.
- no fin change will do anything as long as he is as far forward as on the pic. Save the money for more important things.

Mmm, hard to judge rocker on pics, but your board seem to have plenty of it, if I compare with the ones I use in good waves:
(The lower one is a 2019 Gong Alley 8'1" with a fast do-it-all rocker, the top one a 2022 with more rocker for hollower waves)

This is a pic from the last day in question. Set waves were prob a bit bigger than this and a lot of wind coming up the face + current pulling people out back.

It has a heavy single through the middle, which flattens the bottom through the middle of the board - making it faster in smaller waves and more stable to stand on. But it can limit its top speed and increases tracking as the speed gets high.

Here's a vid explaining bottom shape / concave - relevant @ 1:30.