Bottom Shapes Of Simple Wood Paipos

[Uncle Grumpy]

On the winter solstice the SHF crew and the Pan Pacific Sliders had a fun gathering at San O, surfing, showing off home built wooden boards and potlucking like crazy.
That day I met a local guy who'd brought down several nice wooden boards and after talking for a while it turned out we had several mutual friends but somehow had never met each other.
Anyway,
He was kind enough to loan me a small red cedar paipo he'd built from fencing stock, on the proviso that I ride it and give him some feedback.
In the past couple months I've had the board out several times in varying conditions and I have some definite opinions.
Here's a shot of the bottom contour.

This is basically the opposite of most the boards I've made for myself recently.
It has that soft convex roll the length of the board and no rocker. I suspect he used some cupping in the boards to get so much shape from fence boards.
Outline

Decades ago, Surfer magazine ran an article by Tom Morey about water flow dynamics................

[Uncle Grumpy]

and one of the things I still remember years later, was the spoon illustrations demonstrating the Coanda effect and Newton's Law .

Coanda Effect: A moving stream of fluid in contact with a curved surface will tend to follow the curvature of the surface rather than continue traveling in a straight line.

spoon1[1].gif (2.4 KiB) Viewed 8267 times

Newton's law ("For every action there is an equal and opposite reaction")

spoon2[1].gif (2.78 KiB) Viewed 8267 times

The board with it's convex bottom is noticeably slower than the boards I have with a concave bottom shape........

I also was not thrilled with the sharp corners on the tail.

My 2 ¢
YMMV

[soulglider]

worth every bit.

science cant be argued with. the next time i ride a teaspoon under the faucet i'll make sure its upside down.

i've ridden concave, convex, flat, combos there of and have found that i cant really say i could tell a difference in actual speed, on a wave. some felt more slippery (perceived speed) than other shapes. i have found, no two waves are the same and i'm not in the same spot on every wave. so i'm not sure science can tell us exactly what works what way in a moving, changing, evolving, curving, flattening, building, mashing bundle of aquatic energy. depends a lot on the one riding them, either standing, lying, kneeling or whatever, their aptitude, desires and proficiency as well. how does the board loaned compare to your "fasty" ones in width, outline, rail shape etc, etc, etc.

i had one quarter two dimes and a nickel so i thought i'd spend it here.

[mrmike]

k.i.s.s. flat is were it at and I need change for my $.50

[Uncle Grumpy]

Ha HA I knew I could finally get some action around here!

structured_controversy[1].jpg (16.93 KiB) Viewed 8259 times

[Uncle Grumpy]

So yesterday, John, who built the paipo in question, came over and when we got around to talking about the board, first thing he says is
"You waxed the wrong side!"
Shoulda known..........

It'll finally be ridden right side up tomorrow at the Paipo Fest.

[bgreen]

Now that's a funny story. Reminds me of a guy who got his first board in the 70s and when it came to wax, his mother buffed the deck with floor wax.

Didn't stand up for too long on that wax job.

Did the guy ride your board?

Bob

[Uncle Grumpy]

No. He's been out of the water for a couple years due to an injury.

[Ted]

I gotta bring the Malama Kai with rolled bottom (and top) for you to ride. It seems pretty fast to me, but I have only ridden HPD and foam boards.

[Uncle Grumpy]

I've seen some of that nice island surf you ride Ted;
Comparing it to the gutless beach break I'm usually subjected to is like apples and oranges.
How do you feel that rolled bottom compares speed and control wise to the HPD?
I can see how a convex belly might allow more control in bigger/ more powerful waves.

[Ted]

Uncle,

Compared to the HPD, the Malama Kai allows much easier turning and top to bottom surfing. Speed is hard to judge as I never have both boards in the water at the same time. On my recent trip with the MK to Samoa, I found my inside hip dragging in the water when the wave started to throw - good for slowing down, but not good for all situations. The HPD seems faster, but that may be due to the one-arm-superman face near the water perspective; I think the Malama Kai is easier to set on a rail for down the line speed.

It would be great to get a couple boards in the water with a couple riders at a consistent break to compare notes.

[spudnut]

I agree that the Malami Kai allows much easier turning and top to bottom surfing than does the HPD. I also think that it is faster than the HPD in the case of my first Xylem. The HPD I believe is faster than my second Xylem. Last month I was out in some rough DOH+ surf. I really wish that I had the HPD then as I think that the wide tail would have helped me make the takeoffs a lot better than the narrower wood. I kept getting bumped just as I thought I had a wave.

[bgreen]

A recent surf trip, which offered a variety of conditions really highlighted that while most boards can surf most conditions, some boards go a lot better in certain conditions than others.

I have a board with a strong concave bottom, I got more tubes in an hour or so than I've had in months of surfs combined. My nofin made diving under piles of whitewater fun, but it doesn't have the off the mark speed of a Goddard style board. All these boards had their merits, the trick is picking the right board unless you have a pile on the beach to experiment with.

There is also the question of how you want to surf. I was watching some 60s HPD style footage, and on some waves, the surfers just looked like they were nuclear powered body surfers. Turns and speed lines, it is possible to have them both, but usually there is a preference.

The ultimate board, most of us are still seeking.

Bob

[rodndtube]

I agree that the Malami Kai allows much easier turning and top to bottom surfing than does the HPD. I also think that it is faster than the HPD in the case of my first Xylem. The HPD I believe is faster than my second Xylem. Last month I was out in some rough DOH+ surf. I really wish that I had the HPD then as I think that the wide tail would have helped me make the takeoffs a lot better than the narrower wood. I kept getting bumped just as I thought I had a wave.

Are both of the Xylem boards the Malami Kai model? Same length and design? I was wondering what would explain the pronounced difference in performance.

[spudnut]

Rod,

No they are not the same length and width. The rails on this board were made much thicker ( approx. 1/2"). The maneuverability is great but it is definitely slower.