McCoy Four Fins? NOT!

marc atkinson's picture
marc atkinson started the topic in Tuesday, 24 Jul 2012 at 11:02am

So I've just been in contact with Geoff McCoy and he's bummed out to discover guys are playing around with his designs by changing the fin configuration to four fins etc. In Geoff's own words, "If they worked better I would make them but they don't."

I've worked closely with Geoff for different periods of my life since 1971 and he is without doubt the most gifted and knowledgeable board designer I've personally met and/or worked with, yet he also takes the prize for the least understood by the industry he help to build in Australia.

History doesn't record Geoff McCoy in a good light; a man of vision and progressive thinking, he has instead often been portrayed in a less than glorifying light. Knowing him as I do, I have to admit often he is his own worst enemy when it comes to speaking to media and the industry and his sometimes abrupt and abrasive manner often comes back and bites him on the arse as he gets misunderstood and miss quoted etc. Yeah, we've all got our crosses to carry.

But let's get back to surfboard design.....

All you guys out there re-configuring your McCoy's with different fin set ups, do so not understanding the physics behind the design and therefore you're playing with matches and generally your pockets going to get burnt.... it's not cheap to change a board to a four fin just to find out it's not what you were expecting and hoping for. Then you gotta sell it on and the next guy also finds it's a dog and goes around telling everyone McCoy's are fucked boards etc...

Now maybe you can see why old man McCoy gets pissed off.

If you're into Geoff's boards - which is like being switched into an entirely different world of surfing, and let's face it unless you're in that world you don't get to understand the brilliant complexities of it - be careful what you think will work well with McCoy designs. Chances are it won't work as your hoping or as the media is telling you it will work. And the reason it won't is simple.... the board's not designed to work that way.

Now I know there's a whole world out there where you can do what ever you like with surfboards and get told you're improving the design, but that's not Geoff McCoy's world.

I hope I've saved a lot of you a heap of $$$ that you were about to spend ..... Now you can go take your girl out for a night on the town.

Cheers,
Marc

stunet's picture
stunet's picture
stunet Saturday, 14 Nov 2020 at 6:56am

All things being equal, more surface area means more drive.

lostdoggy's picture
lostdoggy's picture
lostdoggy Saturday, 14 Nov 2020 at 7:10am

Lack of centre fin drag helps too, no?

stunet's picture
stunet's picture
stunet Saturday, 14 Nov 2020 at 7:18am

Yep, through a turn, water runs across the rear fin at a greater angle which creates drag - but also stabilises the board.

Westofthelake's picture
Westofthelake's picture
Westofthelake Saturday, 14 Nov 2020 at 8:06am

Ha well there ya go. It was a long time ago, and it does seem logical re the drag. But in that sense isn't 4 find more surface area than 3 fins and therefore more drag?

Maybe it's the stability that counterintuitively gives the driveability?

I mean I love a good cutty but remember that the quaddie was fast and easy, but a thruster just drives all the way through. I guess it depends on how fast you are going at the time, amongst other things.

stunet's picture
stunet's picture
stunet Saturday, 14 Nov 2020 at 8:20am

Yeah, with no rider input, more fin in the water creates more drag, however multi-fin boards are pumped for speed, with the pumping motion pushing fin face against water - more fin face = more drive.

There's a lot to discuss here, and the fundamentals aren't that complex when explained in isolation. Might do an article on it soon.

Westofthelake's picture
Westofthelake's picture
Westofthelake Saturday, 14 Nov 2020 at 8:37am

Cheers Stu. An article would be great. The nuances and science of design is way above my pay grade and any effort to de-mystify would be welcome.

Michael Bourne's picture
Michael Bourne's picture
Michael Bourne Saturday, 14 Nov 2020 at 10:54am

‘however multi-fin boards are pumped for speed, with the pumping motion pushing fin face against water - more fin face = more drive.’

Oh oh... of course that obviously raises the subject of the effectiveness of the ‘pump’. Think surfing a wave pool wave generated by a pissy little fucker. Sure, you can tweak all the little fucker’s variables to up the anti so to speak, but it would be like flushing the dunny, and jumping in... (think dribbleton and mid coast aspirations).

We know that the reality is, that the pump required to generate anything close to prompting the likes of goofball drawing the mighty storm from the scabbard is a beast of a thing.

However... two ‘epic’ subjects that are enough to drive swillnut executives into a gnashing, quivering, foaming, in fact even deafening, red mist (again) style meltdown are...

‘DON’T EVER FUCKING MENTION STINKIN’ GLUTES OR FUCKING HAIR EVER AGAIN!!!!!!’

In a nutshell.

Michael Bourne's picture
Michael Bourne's picture
Michael Bourne Saturday, 14 Nov 2020 at 12:01pm

The moral of the story???!!

If you get a typical east coast, ne seabreeze grovel, or newies nobbies debacle, please don't come back to the shed slathering, and blathering, and foaming and squwarkin' and jibberin', and frothing, about 'power packed slabs' an' 'pits', an' 'bombs' an' 'wedges' an' 'foamballs' an' 'slammin'', an' 'jammin'' an' 'carvin'' an' shite...

Please don't... not again... please stop...

No my little swillnuts, deep down, we all know the truth about those 'ne seabreeze grovels, or newies nobbies debacles', we all see through the 'slathering, and blathering, and foaming and squwarkin' and jibberin', and frothing, about 'power packed slabs' an' 'pits', an' 'bombs' an' 'wedges' an' 'foamballs' an' 'slammin'', an' 'jammin'' an' 'carvin'' an' shite...' don't we...

Think... 'haiya lifty'... again...

Carry on swillnuttin'... little swillnuts...

indo-dreaming's picture
indo-dreaming's picture
indo-dreaming Saturday, 14 Nov 2020 at 1:13pm

If there really is that many guys going to the effort of changing fin set ups on his boards, it's obviously because one guy did it and liked it and words got around and others are trying it, otherwise how many people would really go to the effort of getting a three plug board changed too a 5 plug board?

It's all subjective anyway, surfing is just as much about how it feels for the surfer, if a guy changes a board from a thruster to a quad, and he prefers it as a quad, then it works for him/her.

Westofthelake's picture
Westofthelake's picture
Westofthelake Saturday, 14 Nov 2020 at 8:34pm

Got me thinking about the old 4 vs 3 fin setup and found the below info (which seems logical):

"One point, on which Kelly Slater, Jeff Clark and most other pros and shapers who have experimented with four-fins agree upon is that quads are faster than thrusters. This is because they generate more drive through a turn and are able to hold a higher line (whether being pumped or not) on steep wave faces. This performance advantage quads have is due to their greater-fin surface area, which results in quads slipping sideways through the water less easily than thrusters (they "hold" more), resulting in more of the riders energy being redirected into forward momentum. In other words; quads are simply more efficient and so better than thrusters when it comes to holding a high line and doing rail turns.

This means that quads perform well in particular conditions where a surfer needs as much speed as possible, such as in big waves, deep barrel sections and tiny, "gutless" beach breaks.

The Quad's efficiency in turns also makes them particularly suited to power-surfers who want to hack-n-hold their way through full-rail turns, cutbacks and lip-smashes like Taylor Knox. However they're not so good in conditions which favour a new school approach. This is because their extra-speed and fin-surface area makes it harder to perform release-and-recover manoeuvres such as tail-slides, air reverses and any other moves which require the board to slide side-ways or backwards. In comparison, the thruster's relatively inefficient fin-set-up makes it tail much freer when the weight is taken off it, allowing riders to perform new-school moves with greater ease."

I've got a Wayne Lynch thruster I could turn into a quaddie. That'd be new...

stunet's picture
stunet's picture
stunet Saturday, 14 Nov 2020 at 9:22pm

Yep, all that WOTL, and the reason quads want to run laterally is because the extra fin area tries to force the board 90 degrees to the way the water is moving, which, in the case of a breaking wave, is up the face.

Think of a rudderless boat turning beam on at sea.

All finned board will do it, but the effect is pronounced on quads due to fin area.

indo-dreaming's picture
indo-dreaming's picture
indo-dreaming Sunday, 15 Nov 2020 at 8:37am

"However they're not so good in conditions which favour a new school approach. This is because their extra-speed and fin-surface area makes it harder to perform release-and-recover manoeuvres such as tail-slides, air reverses and any other moves which require the board to slide side-ways or backwards. In comparison, the thruster's relatively inefficient fin-set-up makes it tail much freer when the weight is taken off it, allowing riders to perform new-school moves with greater ease."

Hmm im surprised to read the tail slide bit, i find it much easier to slide the tail on a quad both forehand and backhand my tail rarely slides out with thrusters but with the quad set ups i run which are just average size fins push them hard and they slide, sometimes good if you pull of something amazing, but other times you just skip and slide and loose control.

Same with old school sliding 360s heaps easier on a quad.

I thought pros preferred thrusters as they just go better top to bottom, but I am surprised more pros don't ride quads.

I personally have a love hate thing with quads.

BTW. I've tried nubsters in quads and in theory they should work, but in my experience they suck, just feels like a quad dragging something, but dont have the benefit of a thruster, instead of the best of both worlds, to me it feel like the worst of both worlds.

drodders's picture
drodders's picture
drodders Saturday, 21 Nov 2020 at 11:12am

I probably should have posted my McCoy post on a new thread, didn’t really want to enter the quad vs thrust debate. It’s a board that feels great to surf.

For the record every board I’ve ever had with 5 plugs ends up a quad, or twin or quad plus nubster (they really make a difference when finishing round house cutbacks on a quad).

I’m sure the McCoy I have would fly as a quad, but I’ve been surfing it mostly in dribble and it flies down the line and surfs vertically very well.