I'm in Love

[Headwax.]

Hi RMcknee

Sorry I didn't explain myself very well about the assymetric panels.



line across here is flat courtesy of the concave and the shape of the panels. When you turn this board there;s a point where it suddenly accelerates at the beginning. I mucked around today in the surf doing different arcs in bottom turns and reckon the sudden increase in speed occurs when the board is running on this flat area .

[budgie]

Just sold the house so travel is a real option and I love Newy and the waves there. I love board swaps, we learn so much, can I ride yours Headwax?

Back in about 86 I was at a comp in Newcastle that Simon won YET AGAIN.

He deserved it coz he ripped and still does (well done Sparrow)


Anyway I had 2 grom kneelos in my new Gemini hire car and we drove round Newcastle at night with RADIOBIRDMAN playing on cassette at full blast, but for the life of me I cant remember who this anklebiters were.

Known for my poor memory can anyone enlighten me

Budgie

[fruitbat]

headwax those fins seem to be set back?what are there positions? your thread is good. I have had a quad roundtail concave and see the good points.

[RMcKnee]

Because of the width of a kneeboard given the correct depth of concave you'll find that the board will be operating much like a catarmaran in some parts of the wave.

I was wondering about this primarily because in another thread recently Budgie mentioned that his new heavily concave board wanted to ride up the face. This is a characteristic of hull bottoms.

HW, I'm assuming that part of the edginess you describe is due to a kind of amplified "hull" effect: when you put the board through a turn there is a pronounced tendency for the inside "hull" to be drawn up the face. The extra speed and and running on effects would natch derive from the apparent "flat" panel in the bottom engaging at both point X in a turn and when planing in a down-the-line speed run. The result is a board that looks like a radical concave, turns with the sensitivity of a hull and planes like a board with a flat bottom.

Many years ago MP did a similar kind of trick on his own boards by shifting the apex of the bottom rocker. Low gear was weight aft of new apex, high gear was forward. You can see this in action in the footage of MP at Kirra in M.O.T.E.

Whatever the case, everything so far points to a fairly complex yet very well-balanced bottom configuration, confirming that DP's done a great job for you.

Budgie, I reckon there's a fair bunch of people disappointed that after the sale of your palatial pile and worm-farm you're considering a trip to Newcastle instead of Nias.

[Headwax.]

Hi Budgie, sure there are a few deserted beaches around here with not much chance of being run over.... well during the week anyways Let me know!

Fruitbat, it's great to see a few concaves coming out of the woodwork. I'll get back to you on the measurements asap. Need to find a ruler, heh.


RMcknee

HW, I'm assuming that part of the edginess you describe is due to a kind of amplified "hull" effect: when you put the board through a turn there is a pronounced tendency for the inside "hull" to be drawn up the face. The extra speed and and running on effects would natch derive from the apparent "flat" panel in the bottom engaging at both point X in a turn and when planing in a down-the-line speed run. The result is a board that looks like a radical concave, turns with the sensitivity of a hull and planes like a board with a flat bottom.

Well I'm impressed how you summed it up so succinctly. I remember that interview with MP where he talks about that sweet point where he can change gear by stepping on it. (Or maybe I remember someone telling me about it?)

Thanks for making me look harder at the board and discover that flat crosssection in the rocker! Who would have thought? I have a hunch you'f get the same thing in a different part of the rocker with a spiral vee? Just a hunch?

Whatever the case, everything so far points to a fairly complex yet very well-balanced bottom configuration, confirming that DP's done a great job for you

Couldn't agree moree! W'ere living in a golden age of kneelo shapers in Oz./ Parkes, Luke, Hart, Slats - all refining their stuff so well.

All we need is artis to get back on board.

Today I spent a few hours going through a box of old surfer mags. Tracks seafolly surfer, surfing world looking for an article by fitz in tracks on concaves, but I think it's in the other box! Ressurected a crawford interview form 1973?

Anyway, soemthing unrelated on Assymetry I'll post later.

cheers for now

sorry about the crap typing. Once I do a few sentences the typing box poops its pants and I can't see what I am typing.

No waves here uggh.

[Headwax.]

Fruitbat

check your PMs

cheers

[tomway]

Great post as usual HW Prompted some good discussion for the small kneelo community here and timely too as DP has just been over sampling some of our funky java waves and opening some eyes.

Couldn't agree moree! W'ere living in a golden age of kneelo shapers in Oz./ Parkes, Luke, Hart, Slats - all refining their stuff so well.

All we need is artis to get back on board.

Did you spot these when I posted a while back?

album_showpage.php?pic_id=21218

[Headwax.]

WOW, great boards Tomway, you are right I missed those beauties. I'm not often jealous you know. He's a great shaper artis, has so much knowledge shoved away in that head of his.

The wide point past centre certainly looks like it does the job. Makes that planshape line very elegant. They 23 inches wide? Out of interest what contours is steve a using on his (board) bottoms?

I spoke to him several times on the phone while he was in Oz last. He's really a confirmed quad rider! Would be interesting to grab him and have a wave or two. Though I don't know what he'd think of our summer slop having to ride it again!

How are those boards going? I imagine they go very vertical courtesy of the reduced rail line behind the wide point? How do they go in long cuttys? What waves do you ride. Six foot reef break off shore prefcetion all day every day I bet?

[albumimg]21218[/albumimg]

sorry I didn't see your post till today !!

RMcknee: I've been thinking (very dangerous I know) What exactly did you mean by hull bottoms? One or two or more?

[RMcKnee]

HW, this ain't the best example, but if you're of a certain vintage I reckon the board shown here http://www.surfresearch.com.au/00000326.html and the associated spiel ought to serve as something of an aide memoire ...

[Headwax.]

Thanks that's what I thought a hull bottom was Brain damage and all

RMcKnee wrote:

(snip)wanted to ride up the face. This is a characteristic of hull bottoms

I couldn't understand why this would be the case at first, but checking out those boards I can see that it could be related to the rail line rocker - train of thought being the extra curve between hull and tail makes the board turn up the face (or want to turn anywhere ) - when the rest of the board (ie the flatter stringer area) is "out" of the water.

Any thoughts on this?

Interesting how they went with chines to regain some of the board bottom for planing again.

[budgie]

Sorry HEADWAX but the correct term is CHIME not Chine.

I have ridden quite a few chimed rails and love them. will do it again soon when I get comfortable with my catamaran concave

[red]

Andrew,
Rail rocker vs centreline rocker?
Rail rocker gets to be a complex curve when rail curve gets into the picture.

But I think it can be to do with the rails not releasing owing to extra edge brought on by the conny meeting the undertuck.

Also rocker line might be flatter in the tail in this kind of board.

Want a tube rider? Deep vee, heavy rockered, tail kick. Will always drop out of the tube, but sacrifices in other respects. As you've found, rider compensation is the way out.

[Headwax.]

Hi Budgie

Interesting, I always thought it was chine because of angle it caused. There's a few definitions on the net. One eg is Chine:


But it's all semantics after all I also came up with Chine Rail as far as a chinese railway ...... heh.


Hi Dr Red,

How are you?

You're right about the tail vee and tube riding. Few years ago I had a tail veed board that let me ride in the foam bubble inside the barrel on beach break waves time and time again.... very interesting (I only came out once ho!). I gave it away to a friend because it let me down the rest of the time though.

Line of thought on the curvature of the rail..... simplest scenario mainly goes for when you are surfing down the line and mostly only your rail is in the water...


g
[/img]

I agree with 'But I think it can be to do with the rails not releasing owing to extra edge brought on by the conny meeting the undertuck' (whatever a conny and and undertuck is )

Hope you ar all getting more waves than I. The surf is so bad here I am the only one out....

[RMcKnee]

Any thoughts on this?

Interesting how they went with chines to regain some of the board bottom for planing again.

I can't really begin to pretend I understand the hydrodynamics of surfboard design in any more depth than I've already attempted on this thread. My limited grasp of the matter in question is that a displacement hull sits down in the water while a flat bottom provides a platform that planes over the surface of the water once moving at sufficient speed. What I was getting at re your deep concave was the idea that when the board's planing it's riding on the two outer edges of the bottom, rather like a catamaran. Looking at the rail shape in cross-section it appears really like a very rounded shape, similar to the old 50/50 rail, also similar to what GG used in the front half of Velo and similar spoons. I just didn't see any defined edge there at all and was wondering.

In all matters concerning board design I'll always defer to an experienced shaper like DP.

Re chines. I've always referred to a board incorporating a defined flat panel between the rail and the bottom as a board with chined rails. The sense in which chine is used in board design is as a noun meaning "join of side and bottom of ship etc." (COD)

Budgie's use of "chimed" has puzzled me for a while until I consulted my COD this evening wherein I found that it means (as a verb) to ring, (like a bell); a set of tuned bells; the sound made by said bells and also ... "the projecting rim at end of cask". Perhaps Budgie's been spending too much time in the barrel.

[frankfqr]

Two extremes, hull or chine, which both could be disected for either there positive or negative input to the forward entry point. Both IMO utilized by those that have logged the time into researching and riding what suits "there style" or what they hope to accomplish on the face. Hulls will climb and seek the power point or fall line (thanks for the term SF), perfect for point glides and distance speed. Chines will provide a release point at the rail edge to break that flow and inhance the feeling of looseness in the nose desirable to those in pursuit of the more verticle, lip smashing approach. My journey has brought me to a very subtle hull entry, 50/50 rails about 8inchs back foiling to a resin edge tail,short board, fins back. Seeks and holds the high line, or any line (barrel) but with minimul input can release and pivot to redirect. My current toy was my first "well known pro" shape in decades and I gave the man free reign cus I wanted to see his take. I got a subtle chine, knew what to expect, that thing falls off the face on it's own. Real zippy as you HAVE TO pump along from point A to B. Mind percieves speed of course due to the constant adjustments. But I contend why bother, I have no problem with the fast glide, you get to take in the view. My opinion to suit my style, and it's not verticle.