the truth about wings (and bumps)

General Discussion
1

Hi all, I have a question. And I’ve already received multiple answers to this, but I’m trying to get alignment.

-What exactly do wings do?

let’s look at this image:

So: A and B are fairly similar boards, except for the area around the wings. the wings reduce tail width while keeping a fairly straight (although interrupted) rail line.

-Is B faster (down the line) because of the straight rail line?

-is A more maneuverable because of the more curve in the rail?

this would be my first read, but then B, due to the reduced tail surface, should “sink” the tail slightly better, giving in maneuvrability what the straight rail takes away.

now: which is which? is B faster AND just as maneuverable? and if that’s the case, how come wings are pretty much confined to “retro” or funboards?

all the top performance board seem to have an unbroken rail line, with a slight mellow bump at the most if anything. Is that just to simplify production? (good enough reason by the way).

anyway, I’m confused: one one hand I think I understand why people put wings on boards, on the other I can’t help but thinking that a nice curve that follows as closely as possible the same points would make for a board that performs pretty much the same.

How wrong am I?

any help greatly appreciated.

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2
Quote:

how come wings are pretty much confined to “retro” or funboards?

Usually (its a surfboard, so not always), High performance boards are ridden in bigger/powerful/faster surf (which provides the speed) and have a bit more rocker than retros (providing the maneuverability with a smoother outline). Retros and funboards are usually ridden in smaller/weaker waves with flatter rocker (providing easier paddling and drive, which inherently reduces maneuverability). If a retro is ridden in larger/more powerful surf, it becomes less pivotal (is that a word?). In order to increase the maneuverability at higher speeds it is useful to have a pivot point (a break in the rail line, such as a wing). Thus, you get a board, that when on small waves goes fast (allowing you to do maneuvers) but on bigger waves allows you to sink the tail in a turn (by breaking the surface of the water with the wing, allowing you to reduce the high speed planning effect).

Besides, wings also look cool, don’t they? Like a rocket ship, maybe that’s why they seem so fast!

3

Wings also induce eddy currents along the rail, increasing drag and slowing the board. Probably why most boards these days don’t have them. They do look cool, however.

4

more insight please!!! this topic is really helpful.

any info on how wings affect longboards? if they even do…

5

“eddy currents”? WTF?

tidbit 1: Surfing is about planing hulls, and to me this means that at some point the water separates from the rail. Once it has separated, it has no effect on the board.

tidbit 2: wings are separation points and thus (other things being equal) cause release, not drag. Since you lose some area behind them, there’s less skin friction holding you back. That’s not a drag inducer either.

6

Eddy currents…Hmmm… yet the speed dialer has them, and it’s a fairly fast board!

7

2 cents worth from the peanut gallery:

People say they give the tail more bite–a lot of people say that…I think it’s extremely micro if any.

I think the tightening tail area and ratcheting rail line actually does it. Break the arc or line(s) down toward the tail in some sensible way, and you’re good. AFAICT wings are just a treatment of area-reducing line.

Bumps are a whole other thing and they act as pivot/drive points if you put them in the right place.

8

I have a slightly harder time going backside on a board with wings (CI Sashimi).

is that because the broken outline doesn’t have an even grasp on the water or because the board is wider than others and I am not on my heels enough?

9

I’m not sure which is happening, but… (and I wouldn’t make up my mind about wings based on that one board):

Quote:

I have a slightly harder time going backside on a board with wings (CI Sashimi).

is that because the broken outline doesn’t have an even grasp on the water (if you spun out/lost the tail) or

because the board is wider than others and I am not on my heels enough (if you couldn’t get it to initiate turns)

If you are having a hard time turning that board I would say get your back foot back to the bump stop on your pad, to where you can have leverage enough to dig the wing in with your back foot. It seems like a wider board where the wings are on that board, than other boards intended for similar purposes with wings.

I’m betting you’re surfing your front foot and slightly too far forward? I always thought that board looked like it would be hard to surf because the wing is so far back. I think their Flyer with the much more forward bump is a better design. The MTF is a better front-footer too. With the tail as pulled as that one is, you can surf it front footed like the tail’s not there if you want to, or stomp on it and really root through a turn or a pivot.

If you watch Mark Richards in videos, you can see him use a front/balanced footing ahead of the wing, until he does a shorter radius turn, when he slides his back foot back behind the wing to make use of the pulled tail/wing. He surfs like he’s riding a skateboard, to me. Carves, and then uses the wing and tail like a kicktail on a skateboard.

Another (ugly) treatment of this whole thing is the Anacapa fish. Ease of manufacture, don’t ya know.

look at the relationship between the rail fins versus the wings, and the width at the wings versus the wide point width on all these

sashimi–designed for small waves by Al Merrick’s son–

to me it just looks like harder to access leverage of the line break based on widths and fins

MR retro twin --designed for small waves by MR

get your back foot right behind the fins and kicktail through your turn

Merrick MTF–cult board–small wave shredder, if’n you get the back foot back for deep roots

I see a fish outline embedded in the overall outline

Merrick Flyer – great small wave shortboard, by all accounts–backfoot pivotpumper though

Rusty Piranha–supposed to be a great small wave board–another backfooter

I think these wings are cosmetic mostly–the broken line is the function

Anacapa fish–just a broken line–cheap though

10

When a board moves through a liquid medium, drag occurs along the surface in accordance to the turbulence such motion generates. Eddies (or vortices) are the result of this turbulence and indicate increased viscous drag. Streamlining a board will reduce turbulence. Streamline is the linear flow of particles in line with each other across a surface. Anything that disrupts the streamline, such as wingers, will produce loss of streamlining, turbulence and the formation of eddies, all of which equate with increased viscous drag along the boudary layer of the fluid. Bumps or wingers disrupt the laminar flow, increase eddies and so forth. Result: of two boards with similar dimensions, the one whose rail line is disrupted by wingers will be slower. How much difference will this make on a late takeoff and quick planing on the face of the wave? Probably negligible, but might be noticeable to an experienced surfer on a rolling wave or when paddling.

In air, there are some aviation applications in which vortex generators on a wing will help maintain the boundary layer adhesion and prevent stalling, and it has been also demonstrated that fish can use eddies that their fins produce to push against while propelling themselves through the water and move faster. These are not at odds with the fact that nonstreamlined surfaces will be slower in the water. My Hanson twinzer has wingers and the board is very quick. The question is, would I notice an increase in speed due to decreased drag? I don’t think so. Would I want bump wings on a board, especially a long board, that I might shape or have shaped. Nope.

11
Quote:
but might be noticeable to an experienced surfer on a rolling wave or when paddling.

when I’m paddling through flat water, I would estimate that 90% of my 5’10" is under the surface.

12

Bud, that’s when the eddies are going to be most evident. When a board is on the surface and planing, an irregular rail line will still slow the board but it might not be as noticeable, if its noticeable at all. There are so many other variables that affect surfboard speed that it’s probably unrealistic to focus on any one in particular.

13

Hi Ron the point I was trying to make, I was trying to understand how a wing/bump on the rail is going to make any noticeable flat water paddling difference when 90% of my shortboard is underwater. With the list of things I’m dragging through the water on the topside alone - wax, tailpad, my body, trunks, leash, a couple bumps on the outline of the board seem insignificant

14

True enough. Rail irregularities are just another miniscule factor increasing drag. If it matters to someone, then the rail line should be taken into account. I like my twinzer for whatever magical confluence of design elements are working, the board just feels right.

15

Yeah,they look good going down the beach!!!

…In the water they have more deficits than benefits.Herb

16

Hi Moai, Ive always looked at any board/ craft as being a set of curves, the flatter or longer the curve the softer or straighter the turn or effect. A change in the front of the curve affects the introduction of the shape into a turn and a change at the rear of the curve affects the release or sustain of the turn.

Changes like bumps / flyers/ pigs hips … just break the smoothness of the curves interaction and provide release points. Of course a board with wings makes little diff until its up on its rail.

The strongest line is the one parrallel with the boards direction. ( And in contact with the water, natch)

Poorly said but I hope it helped.

Some of my designs with bumps are here… for a laugh…

http://s153.photobucket.com/albums/s225/SURFFOILS

17

Yet how about the E-wings on Octafish? I’ve been told they increase the turning ability of a board? I have a new one coming in about a week, so will report back on this.

I can’t believe TF would have been going faster without the double wings?

18

Okay, so I’ll admit to not being a shaper or physics professor right off the bat. And I understand that hard wings are a headache for shapers and an absolute chore for glassers.

But I’ve always read/figured/assumed that a hard wing allows more width to be carried further back- thus giving more planing area underfoot (in trim), with a straighter rail line, and the same hard release point as a board with a tail 1-2" wider. At least, when weight is forward/neutral.

This should mean you get at least the same down-the-line speed as a very wide-tailed board, but the ability to have a slightly narrower tail for more hold in steeper faces and/or better rail-to-rail turning ability.

Again, not a shaper or scientist, but I’m not sure what significant effect any “eddy” would have in a non-displacement, planing surface. Especially when weighed against the immediate, clean release of water flowing off a hard edge in the rail line. Who cares what the water does when it completely releases from the board? It no longer affects the board by definition. I thought that drag (and hence a measure of control/forgiveness) was primarily created at the rail when the rail is softer, due to the “suction” of water as it curls around the rounded surface.

Besides, a hard wing DOES look faster… Especially with pinlines…

Just my uninformed 2 cents. Anybody else want to try to clear this up?

19

From the begining of wings shapers have done every thing possible to get them to work as well as a non winged board ending with the elevated wing which is lifted out of the way leaving a normal wingless template to plane on.

20

I would suggest that the true difference in speed is caused by differences in tail area rather than any “eddies” or water flow changes once the water has been released.

My theory is that without bumps, an uninterrupeted rail line give more total tail surface area to the last foot of board, which translates into more planing surface and more speed…but at the cost of control. Decreasing the tail area abruptly with bumps or wings gives the rider the opportunity to sink the tail into the wave easier, which facilitates control, particularly in tight turns. This makes winged boards easier to stall into the tube, too.

That’s why it makes sense to me that small wave boards often have bumps/wings. Generally they’re wider to make use of less wave energy and to get maximum speed out of a small wave. But all that width is no good in the tail, as it’s harder to do tight radius turns on boards with ultra wide tails. The solution is to go wider and straighter in the hips, and bump it down in the tail to get some penetration on turns.

I built a board with wide, curvy hips and a pulled tail… a “modern fish” type thruster… that I found could have used a little more width carried back a bit further toward the tail. I felt that without wings, the board narrowed too soon, making the board feel unbalanced nose-to-tail… like trying to stand on an Indo Board. Had I carried the width back, kept a straighter outline, then bumped it down in the last 12 inches or so, I could have had the narrow tail for control, but kept the board more balanced through the middle.