Kneeboard guns

[surfhorn]

In 1976-77 I was working at Freeline and took a standup board out at really big Pleasure Point and at Moss Landing and rode it as a kneeboard.

It was a design called a Stinger. Here are the dimensions as close as I can recall:

Length: 7'4"
Width: 19 1/2"
Nose: 12 1/2"
Tail: 11 1/2:

The single wing was up at about 21". Single fin long box with a 12" Rainbow flex fin pushed all the way up in box.

Went straight well; didn't turn. Danger to myself and others........but mostly others! LOL

[ross]

bud,
totally agree with your comments regarding good rocker and keeping planshape/bottom shapes simple in guns.
all the guns i have had made for me have had flyers and all the ones i have made myself have none(i hate em).
does anyone have a reason for the obsession our shapers have with flyers?
i'm intrigued
you also got me wondering how my boards would go in Hawaii,whether they might be to refined for the conditions.i spose theres only one way to find that out that session you described at Laniakea sounded horrific

[surfhorn]

Fliers (or wings) are used to break the flow of water off the rail. Especially helpful in longer lengths where you want a pivot or turning point. When riding guns - usually in bigger-faster surf- anything to help one turn is good.

[red]

Thanks Bud, lots of good info. It will take time to absorb. Ross I think you're right on the money.

Interesting that boards over 6' yet under 7' are considered guns. I'd consider almost anything under 7' not a gun. But I realise that there is far more to gun design than length.

I don't think I'll ever consider taking on big waves on a board under 7'0" again. (like the J-Bay posted, which I surfed 10 years ago on a 6'0"! - had to paddle out 1km behind Kitchen Windows.)

The difficulty with a long board (over 7') is in keeping the rail curve without widening out the board too much. I think I'm plumping for a board approaching 24" wide (remember this isn't a weensie 6'1" I'm talking about). I think I will get away with the width because standup guns are so much wider than shortbboards. 24" is fractionally wider than my shortboards which handle really well.
The width will allow me to hold the thickness to 2 5/8" or so and carry thickness to the rails, to stabilise the platform (you want the board to be almost 'self righting' when 7 tons of lip crashes down next to you, so you can drive around the section and not wobble onto the wrong rail).

I'd look at holding the nose at 17" or so. This will pull centre of mass forward, encouraging the board down the face. It will also give the board distinct direction when hammering.

Ahh, the tail. Herein lies the detail. To my mind, a clean barrelling (even if big) wave does not require a gun - just a board that can handle juice. Guns are needed when it's a bit ugly - sectiony, pushy, flattish takeoff (Sunset). So the tail does not need to be the kind you put into boards for dredging barrelling reefs, rather something more all-purpose. Exit the dramatic pin that starts 15" up, enter a more standard pintail that flows from the point of kneeling much more like an aggressive small wave board (from 19" wide at 18" forward to 16" wide at 12" forward to 9" at 6" from the tail)

You may expect a board with that much tail to be a handful under load, but a combination of continuous rocker (6' nose, 2" tail), rails foiled from max thickness at board centre to 1/2" in the tail and vee flat vee bottom will settle the board in the water, making it controllable and stable at high speeds and attendant bumpy conditions. Actually rail foiling is more complicated than that, involving changes to the way the rails roll off the stringer along its length, but I won't get into that.

My fins will toe in less for speed, lay over more for grip during hard bottom turns. I'll select fins with continuous rake and good tip, but go for more base (115-120mm) on the side fins (on a thruster). More base helps prevent the rail lifting out of the water. While this can be a problem when trying to be zippy, it will help keep the board under control during wrong railing (see smashing lip comment above)


I've discovered that ugly beaches is a good way of getting surf to yourself. Surfed Wooly on Friday on my 6'10" flashie. Not one standup wanted a bar of it because of the size, closeout sets, rips and crosswind. Had a ball. Up and running before the wave started to pitch. Cranking under the lip the way I learnt from the kids at Backyards in '05 and driving around really long sections, using rail length to cover ground impossible for a smaller board. And the paddling. What a pleasure to be able to compete with the rips on even terms.!

[hart]

I have read these posts and this thread, many times..and I have more to say than this

But somehow, the quote below remains the most salient issue at this time

At what point does drawing out the tail of the board to achieve the desired length (and so effectively moving the fins forward) start to become counter productive?

red is referring to the position of his fins relative to his postion on the board..inparticular his shin location.

Easy to say but..

All boards will drive if you cluster heaps of fins way back on the tail

All boards will pivot if you move fins (clustered or otherwise) far enough forward

That much, remains easy (as it always has)..its just the negative attributes of both above elements that bother us mostly

Why not take this fin observation further and apply it to our shapes?

By that I mean, if you have a tight fin cluster positioned close to your tail, you are going to keep area in your tail to compensate. Easy again.

Probably shape a fish (to provide release that otherwise would not exist)

And to keep the surfer close to his (tight) fin cluster (read shin location) with a board with lots of tail area, your length would be limited to allow them to do so.

By keeping so much straight in your outline means you would max-out (in length) at some point. You are restricted

Why then, should we limit ourselves by our choice of fins..number, cluster, or otherwise?

Area in your tail (as a result of your fin choice) combined with the resultant straighter line in your planshape will restrict the length that you may achieve/desire.

Comments elsewhere have said that thrusters will tend to skip..and to stage turns to avoid them becoming disengaged throughout a turn.

This is only upon the assumption that you surf with too wider a tail..because I know a pintail will not skate

Lets look to our boards for drive..for push..for foil

And not rely solely upon our fin-choice to achieve it

If your shape generates inherent drive and planing ability, then your fin location, type and number can be designed around your shins (it is about the surfer) read you..

and never the other way around

..and we haven't even mentioned bottom-curve

yet



hart

statistics

4 surfers

5' 10" to 6' 3"

80 to 95kgs

Each surfer fit and representing their Country on a World stage with boards from 6' 10" to 7' 6"

All surfers riding thrusters

All riding pintail derivatives

off topic

and for all those great surfers who could surf a door..is it any wonder why they choose not to

[ross]

ok Bruce my head is spinning.
i think i'll be re-reading that one
do you reckon we can get away with larger rocker in our larger boards due to the push of bigger waves?
i mean there are waves you want to outrun,but what about performance in heavy water?increased rocker is gonna tighten the turning circle no?
obviosly no-one wants to push water,its all about the happy medium,but i have been slowly reducing my planing area and tweeking it to find what suits me.
another thing i've been scratching my head about for in regards to pivot/turning is watching clubbies(surflifesavers) in very solid conditons riding there racing paddle boards from a kneeling position.i know that this is a fair bit different to what we are all trying to achieve but its interesting to watch the ease in which they manoevre these 10-12'(4" thick) foot boards.looking at them makes me feel as though boards in the 7' range are manageable.if i start surfing like a clubbie please shoot me
i was wondering when you (Bruce)were going to throw your substantial weight of knowledge into the thread

[red]

When I watch vids of standup surfers in 8' waves they drive off the bottom at the pitching lip, smack it, ride over it, tail slide around and free fall to the bottom, or they drive up at the crumbling foam and do the same.

Many kneeboarders are comfortable to do this an anything up to about 5', but only one or two even contemplate it when the surf is much bigger. I think that the difference is mainly in confidence in the equipment. Most performance kneeboards feel undergunned in sizeable waves, so it becomes a matter of survival through trim lines, seeking out tubes and turns away from the pitching lip.

I posted a concept 7'0" that i believe has some of the lines that I'm suggesting can work to help overcome some of these problems we experience (full nose and lot of tail). It is up for discussion.
album_showpage.php?pic_id=4931
It's a very specific piece of gear, designed to drive (and to be driven hard on rail from the upper body), go fast, have the area to drive over pitching lips, and yet remain manoeuvrable without huge weight transfers fore and aft.

Good to hear from you, Bruce.

[Headwax]

Red writes:

I think that the difference is mainly in confidence in the equipment.

I think its anatomical - related to the both shock absorption ability of the lower and upper leg in standup riders, and in their ability to maintain contact with the board through bump and grind and drop - by using both parts of their leg.

As opposed to a kneelo who mainly only has the expansion of the leg between knee and torso. He can howeever strectch out his leg - resulting in what a lot of good kneelos do - a tail first landing - to try and alleviate this disability.

Doesn't matter how good the kneelo is, imho there is a physical limit if you want to stay in touch with your board.

nice drawing (where are the colours tho?)

On a hunch i'd bring the middle fin up slightly, depending on the rake and tip area of the outer fins.

I'd also give the outer fins more base than drawn - by adding it at the front.

If you give yourself more flat spot in the middle of the rocker you may increase your sweet spot.

then again I could be bullshitting

[hart]

do you reckon we can get away with larger rocker in our larger boards due to the push of bigger waves?

Actually, no

Because we would be trying to out-think ourselves by doing so

By adding length to any surfboard generic we will generate more 'rocker'. You certainly wouldn't add twelve inches of foam (anywhere) and keep it straight

We add curve not by practical choice, but necessity of pure design

We must however, maintain the same amount of forward entry that we strive for in our shortboard bottoms (read low forward rocker)

Don't rely on the size of the wave to compensate for human frailty (or too much nose)

Guns do not have to push water due to their added curve..providing you put that curve in its rightful place

Simply put..Guns do not have larger rockers, only increased tail lift to offset the extra length of your rail (hope I didn't split any hairs with anyone)

And Ross having said that, the lift in your rail will bear no resemblance to the curve along your stringer

i mean there are waves you want to outrun

Before I shaped the Guns that were taken to NSG2005 I called a friend on the North Shore

I spoke to and asked the opinion of Jeff Bushman shaper

He asked me if my surfers were there to simply surf (and survive) or were they there to engage?

He said that I should not consider the "North Shore" aspect of the equation

He suggested that I shape exactly what I would for sizeable North Narrabeen (he has been to the Northern Beaches many times)

BUT..

If I wanted to allow the surfer to engage the wave (and not simply outrun it)

Then try this:

Shape a single concave (of a traditional 3 stage rocker) morphing into my spiral vee through the tail (as normal)..but drop a double concave into the single once you have



awesome thought

hart

spoke to Farrer today and NSG2005 is in the can as they say

I guess we'll soon see how closely I followed Bushman's advice

with every thanks to Jeff and Simon mentioned above

[john -]

:

and for all those great surfers who could surf a door..is it any wonder why they choose not to

ah semantics


something that "i" can both shape and ride, on the waves of communication that is a teachers break


never does to take the figurative literally

[red]

HW, I replied in a separate forum, because I'd prefer to keep this one focused on the design problem. Shrinking the fin triangle as you suggest will loosen the board up at the expense of drive. This works for smaller waves, but when there is power it's a case of channelling the energy effectively, rather than building in drift. You may be right about increasing the base, although standups often use smaller fins on bigger boards. I'd push the flat spot (rail to rail) a bit forward of the rocker low point, as this helps with planing.

Ross, not to forget that you still have to paddle over to, and into, the wave. As Bruce says, using power to overcome too steep rocker entry is not the way to go. A smooth entry board will paddle in better and go faster. There are other ways to deal with turnability.

Bushman is a great shaper. I grab every Bushman and Arakawa board I could lay my hands on when I'm in Hawaii and try to understand their design concepts. Such clean lines.

[hart]

Bushman is a great shaper. I grab every Bushman and Arakawa board I could lay my hands on when I'm in Hawaii

Hey red..

I forgot to mention that for everything I do over 6' 8", I use an Arakawa planshape curve to help me do it (proportionately speaking)

Surfing (and shaping) is such a wonderfully evolving process..

Take what we know is good..and cast aside the mediocre

hart

offtopic

And keep all those magic elements, safely locked up somewhere

[KAVA]

All boards will drive if you cluster heaps of fins way back on the tail

All boards will pivot if you move fins (clustered or otherwise) far enough forward

OK STUPID QUESTION?? WHY DONT I SEE BOARDS WITH THE FINBOX/PLUGS SET FOREWARD AND IN THE BACK ALSO? BECAUSE IT LOOKS GAY? OR IT SLOWS YOU DOWN THAT MUCH MORE?

And would your board actually perform well after switching fin position on that same board? from front to back or the other way?

[Anthony B]

When Bruce shaped my 6'0 i had the tail pulled in more than normal keeping in mind that i would be surfing some marginally solid waves.

I took the board out in sizeable 8 to 10 feet and felt almost to confident on it.I do wear flippers but find myself not really using them as the board is so easy to paddle onto.

First impressions im thinking that this board wont be coming out unless its 6'0 plus,wrong! it goes well in most conditions down to a couple of feet.

I dont know how many times guys have said to me hey that thing looks really gunny for a kneeboard.

So what does constitute a gun?

[Headwax]