20 interesting statemente re quad v tri

[hart]

Sometimes..what they thought in the 'Olden Days' is a good start for tomorrow.

Unless you choose to ignore it.

Dorje, foil to me is what we had to put into single fins to make them go..because all we had was a rail (other than one big fin).

Multi fin boards however (from Twinnies up) showed how extra fins gave you extra GOOOO!!!

I really don't care whether you ride with one or six bloody fins..but why ignore the railine of your board in doing so?

And Wax..just cause Hollywood Actors stall..why should we?

You sound so resolved to stalling that you are 'designing' around it. As if it is an accepted thing.

Eliminate it fullstop.

And then think of something else........

Imagine something that fully repayed you for every inch you put in..and then more so?

E does equal M x C squared..if only we could get close.

And if we ignore the past completely, we're not in with a chance.

hart.

[OOK]

Red just had 3 surfs on Neils flashpoint 5, 11" x 23.5 now I know what you are talking about, what have I been doing for the last 5 years ? foils is good, effortless smooth catch free surfing with a board that can be placed any where you want - now I need to get a semi gun for the mentawais in sept.
Cheers DG

[surfhorn]

Hart, you're right on the beam when you speak about foil. The entire board is about foil and shape flowing into various areas of the KB.

You want a rail that enters the water like a surgeon's knife so that you can bury that rail and push off the water to propell yourself down the line. Without good flow off a well crafted rail you might as well be riding a couple 4x6 boards nailed together.

If you want to undestand flow, look to boat design and board design.

[K-man]

How are we thinking of foil here,in general terms?.My small wave twinzers are fat-2-7/8 flat out to the rail,and slightly foiled on the edge for easy grasp.I don't want a rail that buries deep,I want that rail to pop out as quickly as possible for a redirection,especially on cutbacks.Since the average waves I surf are under head high this might just relate to these kinds of waves,and my surfing style.

[hart]

K-man,

I think you are saying that you don't want a rail to bury deep..because it doesn't have the release that you want at other times.

There is a way to design a rail that enters..and a way to design that same rail to release.

It can't be low and catchy..but a low-aspect rail line (for entry), veed up from the bottom (for release), with a foiled deckline (for drive)..is a really good place to start.

Even for head height..and under.

hart.

[john -]

morning lads

metaphysical abstractions i can handle

physical abstractions not so good at - we all learn differently

soooo - exuse my slow to graspness

foiled by definition means there must be an un-foiled?

I am not properly understanding foiled - is it where the width of the board is placed? or the sharpness of the rail?

if there is foiled what is not foiled or unfoiled

the conversation is too good not to be able to be keep up

very basic explanation much appreciated

dorje

[hart]

dorje,

Foil to me is the hydrodynamic shape of the rail viewed longitudinally..it has little relationship to outline or widepoint.

An unfoiled rail is typical of most standups nowadays..like the rails are very parallel..thicknesses from nose to tail don't really vary. In fact a very common standup rail now has a very blocky / square last 12" into the tail..this to me is the absence of foil.

With the K-man's post above..he mentions his thickness of 2 3/4" that comes all the way out to his rail..this also to me, suggests an absence of foil.

Like, there is a deck..then a shoulder to the rail..the rail drops and then stops where the bottom begins.

In my post above I mentioned getting rid of the deck and the bottom..sound strange?

I believe that a board should in fact, be a fully foiled 'thing' that is not comprised of individual elements. I want my rail to commence at the stringer on the deck..and finish at the stringer on the bottom.

I don't want to see any straight lines..in any distribution of thickness..every millimetre of length should have a responding reduction of volume.

You can read the section on foil in 'Shapers Corner' that I wrote..and maybe look at Red's shaped blank in the (board) photo gallery..and maybe think of foil as the way that the water 'feels' your board.

But this is only if you want to surf of your rails..and a lot of guys don't.

I want to displace..and race. Whereas many other surfers look for other elements in their equipment to do so.

Now the Wax..I was just getting the French down and now you are slugging me with Latin.

Et tu Brutus..perhaps?



hart.

[K-man]

hart

See why they call ya professor,professor Well said and very simply put -eay to understand.
So...now that I've gotcha buttered,one last question to fit the last piece of puzzle[veed up from the bottom to release]Are we talking forward entry-along the entire rail line or something else

Thanks-K

[K-man]

Hart,
cancel the last post,somehow I missed your longer post which explained the bottom vee in detail.Since I don't rail surf but tail surf What's that mean-if anything?

[hart]

K-man,

Yes I am kinda feeling margarined..a little

And yeah..it not only helps forward entry..it lets your rails let go (release) even if you plant them in the wrong spot coming off the top for example.

I reckon a lot of times when kneeboarders fall off..it's not their fault..it's because something in their board either catches..or just won't let go.

But only lift that line off your bottom till just behind halfway..or to just behind your knee position..which ever is the greater.

From that point back it is all edge..or as edgey as you can get it..back to the blade in the tail..

And Mate, I'm no professor..I would've had to have studied Shakespeare to be called that!



PS

Now I've just posted and there's more hot butter......

The same would apply if you surf off your tail..it would probably mean you have..

1. Fins further back

2. Narrower noses

3. Hooky type style..both off the top and bottom.

Like not so fluid or rail to rail perhaps..but very good in contests.

hart.

[red]

Much of the talk about foil (i.e. An airfoil is the cross section of a wing. The airfoil shape and variations in angle of attack are primarily responsible for the lift and profile drag of the wing. - more at: http://www.owlnet.rice.edu/~mech594/han ... rfoils.pdf )

yet the emphasis by most has been profile of the rail in a section at 90 degrees to the stringer. While this foil has effect when rail is buried, the lift from this is largely towards the stringer (yes, there are net effects of forward movement and lift towards stringer)

There has been little emphasis on front to rear foil of rails, except in Hart's posts. How does the foil look if you slice the board parallel to the stringer. Since this is the primary direction of movement it is the most important foil line.

If an inch section is taken from the rail parallel to the stringer does it resemble an airfoil that gives upward lift; does it resemble one that gives downward lift or is it a plank (I know shapers who do this).
If a 2 inch section is taken?
Hence my earlier statement about lift in the stealth board being towards the nose of the board, in the direction of travel.

If lift's just towards the stringer you get a board that won't sit properly on rail and it will never accelerate during turns, but tends to stall (metaphysical "unfoiled")

Of course turns with the board flat to counteract rails with insufficient lift (bogging rails) or too much (corky rails) are always stall turns that shed speed, either by virtue of nose up-tail down aspect of board or from sideways push against the rails and fins.

I don't think this has anything to do with number of fins.

OOK,
Bar of soap, man - that's what I thought first time I saw one gliding through the water - slick and smooth as a bar of soap

[john -]

Very nice clarity Hart

you can come and explain it to my 5 and 6 year old students and they would get the stringer to stringer drift - their working on describing attributes of shapes - i will break out the playdough for some design prac

im in the know


thanks

dorje

[hart]

Sure Mate,

And you are also in the now..

hart.

[K-man]

Red,
good info stuff to digest,ideas for next board.On the boxy rail thing,this ''one'' board is very floaty.To me the corky aspect is what makes it work.Where talking small waves here.This particular board is not for verts,but for speed,cutting back,the fat rail just bouces off the wave and accelerates.But between you and the pro-errrrr hart one thing has me thinking.Does the board lose speed when cutting back?Never thought about it.
Got a decent NW. fun surf last night with my nefew and a few of the local ladies-bigger today so I'll pay attention to speed in cutties.

Thanks-k

ps-hart a little butter in return?[contest]