It's basically a cross between a Twinzer layout and a Quad layout.... The smaller fins up front tend to act like twinzer fore fins which promotes an attached water flow over the larger rear fins reducing turbulence .The front fins need to be closer to the back fins to promote this attached water flow...Notice there's less curve in the tip rake on the smaller front fins... The larger pair of the fins in the back benefit from increased flow between them when they're slightly closer together than standard quad spacing... It's a modern blending of 2 fin grouping concepts.... Excellent work !!

Simon made me a 6'2 triple glassed thruster backs in the 80's (i“m 6'5) and it went like a freaking bullet off the bottom on a late drop and could run down any one who dropped in. I had been waiting outside at Queenscliff during a QBC saturday clubbie comp and the wave of the day came through. So one of them dropped in heavily and told me f!ck off loudly so I rounded him up at the top of the wave and grabbed the nose of his board and tipped him over the falls. He went down screaming and i rode it back to the beach while his mates crapped themselves laughing. Simon was and is an absolute legend surfer and shaper and his custom boards didn't cost any more than one from the shop. Well it looks like you got the thrusters' second coming there.

Not been a bitch but did this in the late 90s and you're right, it's amazing! I showed it to Bob McTavish and he said he rode his 4 fins the same. So not new but as you are the best and fastest big wave surfer, the ball is now in your court! Can't wait to see the results this year.

Hope you're recovering well, taking it easy.

I was a lifeguard at Haleiwa Beach Park when Simon Anderson came out with that. Within weeks Saun Tomson, Buzzy, enen Mark Richards was trying out the thruster. My favorite board was a Thruster channel bottom. It was so fast

@xyzct

5 ай бұрын

Remember the Bing Bonzer?

Very educational, thanks Kai! How am I still in awe of watching you surf? Speaks to your magic.✨

Thank you Kai. Grateful.

I swapped the back and front quad fins on a Stretch quad to get more drive. It worked having the back fins longer and the front fins shorter.

Someone at YT wished they had thought of this first. As a longtime constant quad user, I look forward to trying these one day. I do a 5 fin setup with the nubby.

Thanks for this Kai.

Love it, Kai!

I’ve been riding quads with larger rear fins for years! Hanalei fins have many options too!

"since then it's the cluster they've used forever" is a hilarious statement 😂

Good info from the wizard himself, thanks.

Sick can't wait to try it

Looking fwd to giving them a try! 🤙🏽

There's a lot of potential for this.

Orcas: you’ll be hearing from my lawyer

Kai when those new fin going be on the market?

Awesomeness 👌 Where to buy a set?

The names of the fins CONTROLLERS MODEL 🤙🏄‍♂️🇺🇸🇵🇪

Ive recentlu added 2 extra fins to make 5. Added thrust and contr is great

Very cool. I am guessing these fin sets are more nuanced than simply putting a 'normal' set of rear quads in the front and the front fins in the back, but I'm keen to reverse a set of mine to see what happens.

@bencarr605

5 ай бұрын

Certainly will just reverse mine before drawing any conclusions. Big local swell Tuesday Wednesday so let’s see 🤙🏽

As Quads have the most variance in placement then any other fin configuration, that hugely effect how they feel underfoot. Have you found a fin placement that works best with this set up? And if so could you share that info as it is important to optimizing performance.

Isn't that what a twinzer set up is? Two larger fins back, two smaller fins front?

I seen that Kelly slater was riding with this fin configuration. So that says it all

FCS2 allows to change front and rear fins even in the water, boxes front and rear have same deep... my fin Guru Bruce Mckee show me that if i wanted more drive, this is a nice way, he used th Formula 1 cars as an example, he asked me... where are the big tyres? Front or rear?

Will they work in any board mark? Will they work in my 6’6” Ghost? That’s basically a short board for me these days. Don’t get old.

I want to try them

Go Kai! Where can the average surfer get ‘em?

How are they in 90 foot plus tho

Where to buy this???

Dont forget Glen Winton using quads in the 80s

so can I take the surf fins for the surf board and put them under a windsurf board?

@AN-yr7nm

5 ай бұрын

You can always try :) probably for wind or kitesurf you might need bigger fins :)

What foil are the fins front and back ? That make an big difference too

@finsdotsurf

5 ай бұрын

Right! Volume/Chord counts a lot too. Are these foils 50/50 or lifting toward/away from each other? Big differences between what you'd want at 3ft and 60ft as well. Hey try my fins out they have wings and are tuned for 2-15ft.

So how long until someone thought to change the fin placement in the quad setup? But seriously good job Kai although i do have to wonder how many quad shapers and lovers aren't going "why didn't I think of that?"

Back fin profile looks like a brewer style template.. kinda like Ryan Lovelace twinzer back fin template and way bigger canards.. this setup is sixk

Kai would know.

wow...!

Kai, show us the 3rd dimension of your fins! Surfers are still mostly blind to foil patterns and thickness/chord ratios. Check out what I'm up to.

I want em!!!!

So, logically, just switch the sizes of the quads I already have? the bigger ones on the back?

@Dobbs65

7 сағат бұрын

Not that easy... It's the precise location of the fins that's critical. I build a few kite-surfboards a few years back with a similar layout, although they were closer to a Twinzer configuration.... They were really fast, and carved well .... I should build some similar to this setup

🤙

more windsurf pleeeeeeeease

Skeg da skeg omg it's a skeg

Fins look sick but we both know you want a second go at that shaka

Gimmicks

More research is required on this... Because the explanation defies the laws of physics. You cannot create energy from nothing... So you cannot create thrust on a surfboard, you can only reduce drag. Also, you can... 😉... Create more lateral holding with a straighter fin set-up by moving the main holding fins aside. I suspect that you'll find that's where the strait line speed is coming from. ...a lowering of the drag. And the additional control is coming from the additional surface area, but the angles are more optimized for higher speed. This is kinda fluid dynamics 101. I suspect, however, that 'physics' is not why this is being promoted. It's the sales from all the "I want a set" and the "I can't wait to try them" people.

@timp024

5 ай бұрын

Venturi. What is the Venturi effect in simple terms? Venturi effect - Energy Education The Venturi effect describes how the velocity of a fluid increases as the cross section of the container it flows in decreases (like when flowing through a funnel). The energy in this increased speed comes by reducing the static pressure of the fluid. Without fluid dynamics modeling, you have to be a non traditional genius to naturally understand, and Brilliant to be able to explain it. I work in Watersports, and in my opinion more complicated then Avation, with the ability to do things the same but different.

REDBULL, KAI, where is the knowledge?! Best teams and tech on Earth and you're telling us the breakthrough is bigger fins in back? What airfoil patterns are worth a look in these fins, what chord/thickness ratios. You say it compresses between the fins 'like a jet', so they're generating lift aimed forward and toward the center? I've got 2nd and 3rd gen designs to learn how to create, but am working on more important stuff first that could help our surfing neighbors all over Earth. Buy some of my fins.

More of a twinzer in a weird way

Like a twinzer? 🤷🏾‍♂️

This whole idea, man, it's just not vibing with the science of water. Here's the thing: the thought that a fin can actually kick in some extra thrust seems way off the mark. When you're out there, catching a wave, it's all about riding that descent - that's your real speed boost, right? Anything else you stick in the water is just gonna drag you down, slow your roll. So, the trick is to keep things as sleek as possible, just enough to steer and keep your groove. Now, when it comes to this four-fin setup, it's a cool thought. It might just be the sweet spot - enough control without killing your speed. But saying it's creating thrust? Nah, that doesn't really hold water. It's more about slicing through, staying agile, and keeping upright on those waves. Those fins? They're there to help you carve and control, not to push you forward like some kind of motor.

YOuTube should treat you more better

these fins look good and no doubt Kai is pushing the limits, but amount of dogma in surfing is ridiculous. like removing center fin and replacing it with two fins and claiming to reduce drag is utter bollox. and all those wild theories about the flow.... gosh.

Sorry but those designs are old 60's 70's heard of a Banzai board? Bonsai fins ? Diamond fin .. Do your research already been invented long ago.

kai great waterman, physicist he is not. "Fins making funneling water like a jet" sorry buddy does not work that way. Do I think these might be great fins, yes, do they work probably. It just when pro surfers and shapers start talking physics its pretty bad. People who understand this stuff spend 10 years after high school, and do test after test to under stand what's happening. I think Kia has a GED, not a PHD from MIT

bla bla bla bla bla bla

Fins have not been the same for the past 40 years. Just do some research. Try read

@mtoto17

5 ай бұрын

you do the research dork 😀

@smurphas6119

5 ай бұрын

i mean he said ‘largely the same’ a very subjective statement that was clearly just intended to be combined with ‘that’s all about to change’ to create a hyperbole. also, it’s kai lenny. don’t embarrass yourself trying to tell one of the best big wave surfers in the world about surfing.

@Marionetax

5 ай бұрын

@@smurphas6119as simple as that. 👏🏻

@0warami_7oo

5 ай бұрын

Simon Anderson thruster

@nichobee

5 ай бұрын

Try surfing like Kai Lenny