Fins are way over rated—especially on a Mini Simmons.
My take has always been smaller and lower with fins on the Mini but Tom Wegener has taken the ‘less fin argument’ a few steps forward in his almost fin-less chinned vacuum creation.
Tom Wegener, shaper of the year in Australia, says he got the idea from the rails on a boogie board with “chinned vacuum rails.” He then accentuated the fin set-up with tiny little pegs—forget the keels on this design.
Essentially the idea is that the built-in chinned rail acts as a fin through the length of the board giving some stability through turns and maneuvers.
In fact, this rail replaces the necessity for the traditional keel fin set-up and allows the surfer to pull off radical 360 style maneuvers with ease (see video below).
More on Tom Wegener here.
Nocean. Agave between two pieces of Paulownia (we love Paulownia at MSS).
I have ridden a few ALL wood Minis and I find them heavy and stiff.
I like the idea more and more of using wood and foam.
I know a lot of guys either lean one way or the other but I think using a combination of these two materials might create the right mixture for an exceptional Mini Simmons.
Next month I’ll be shaping my first chambered Mini via Mark from Crooked Blanks—-we’ll all get some first hand experience (via this blog).
The big question for me is:
Oh yea, Ode to Nocean for this beautiful shape.
This is a resource guide to understanding Mini Simmons fin placement. Before we get started on how and where to place your Mini Simmons fins lets do a quick review of fin dynamics.
Basic fin placement characteristics that will influence your ride include the following:
Min Spread Cluster
A Mini Simmons in many ways goes against convention fin placement basics.
What does that mean?
Well, a spread out fin cluster will result in a longer turning arc—definitely a characteristic of most Mini Simmons surfboards. However, the spread out fin placement is traditionally used on longer boards and is made for waves with speed and power. This is why it’s sometimes difficult to snap a Mini off-the-top or made a quick mid face cutback.
In contrast a compacted fin cluster produces shorter turning arcs, you could try it on a Mini but I’ve never seen anyone do it, could be an interesting experiment.
*MSS Recommended Fin: two glass-on keel fins placed near to rail and tail
Fin Distance From Rail & Tail
A good place to start is to place your rear fin base one inch from the tail and one inch from the rail. The further back you place your fins the more drive you’ll get from the placement.
However, you are going to get lots of opinions on this one, but I like my Mini fins close to the tail (maybe 1/2 inch) and close to the rail (around 1 inch at the base). A more forward fin setup will be looser and have a short turning radius. The further back you place the fins, the tighter the hold and the longer slopping turns you’ll be able to perform—think snowboard carving.
You’ll likely want to play with fin distance to tail and rail as you shape more boards, altering the fin cluster dimensions can really impact total design characteristics—which is the fun of surfboard shaping.
*MSS Recommended Measurement: 1′ off tail + 1′ off rail (rear fin base measurements)
Fin tow is the percentage of tweak you give the fins off the 90 degree mark towards the stringer. The more tow you give, the looser a board feels in a turn. However, that tow comes at a cost because more tow equates to more drag while going down the line. Think about it, if you have two straight lines (or fins) moving forward in the water there is very little resistance (aka speed). Add an angle to that straight line and the water flow is disrupted—until you engage a turn, that’s where you need that tow to divert your forward energy into a new direction.
So that being said you want to find a balance between straight line speed and angled redirection. Unless you plan on just going straight. If you are shaping a board for a beginner you don’t need to worry about dialing in the exact tow. But if you put in too much tow you’ll find it hard to turn a board and the increased drag will make it slog in the water. (Slog = slow hog).
I recommend just a tad of tow, just enough to make sure your turns are fluid but not too much that you’ll be dragging your ass down the line.
*MSS Recommended Measurement: 1/4 inch of tow or at place 85 degrees.
The fin cant is the ‘lean’ of the fin off 90 degree center. More cant, leaning away from the stringer, will give a board less drive and projection out of turns and less cant offers the opposite.
Cant is the angle it makes in relation to the bottom of the surfboard. A fin that sticks straight up, perfectly perpendicular to the board’s base contour, is said to have a no cant. Canted fins point outwards, toward the rails of the board. Increasing the fins’ cant leads to a more responsive board through turns, while decreasing the cant (bringing it closer to 90°) makes the board faster, especially when traveling in a straight line.
I wasn’t a big proponent of cant on a Mini until recently when I rode one with about 4 degrees of cant. That ‘canted’ board really performed well and was a blast to ride. You’ll have to make up for the cant with a little more volume to help compensate for the extra drag created by the more dynamic angles.
*MSS Recommended Measurement: 2-4 degrees
The most interesting thing about tail design is the impact that it has on both speed and maneuverability (how you turn).
The tail is where all the aft energy is released.
The tail is you slicing surface on a turn, it either creates more resistance or facilitates flow.
A fish tail, aptly defined, will help you push water more easily through a turn.
Think of it this way, next time you are in the sea put your hand under water with your fingers together and make a sweeping movement, you’ll notice lots of resistance.
Do that same movement with your finger spread “Spok Style”, you’ll notice much more ease and fluidity. That same principle applies to surfboard tails.
The other thing to consider is that increased surface area in the tail, such as a classic mini squash, will be faster down the line. However, the extra surface area will slow you down in turn.
Let’s take a look at tails in more detail to understand what we want for our Mini.
In order to understand how a tail design affects a surfboard, we have to consider the mechanics of tail hydro-dynamics. It boils down to the fact that a more angular or knifelike shape will allow you to make sharper pivotal turns. Conversely, with a rounder surfboard tail shape you’ll obtain smoother and glider turns. Contemplate the surfing of Kelly Slater versus Joel Tuder’s and you get the idea.
Surfboard tail shape influences the grasp and release on the surface of the wave. Picture how water flows off the back of the board. Water is syrupy and follows the lines of the board. Curves hold water flow whereas corners allow water to break away and be free. Hence, curves can slow a board, and angles can increase the flow or speed of the water.
Think of a big wave gun and a longboard. The sharp nose on a gun allows for fast entry and the rounded nose of a longboard facilitates a slow and stable take off. Visualize the same two boards and think about their tails, a pin tail will hold the water longer and make it more stable in bigger surf and a square edged tail will release water making it looser and snap happy.
Pin tails are best for tracking and control. Imagine skipping down the face of a bomb at Puerto Escondido, you need to control your speed and draw a fast and straight line to make it through critical sections or you’ll get slammed like a Hulk Hogan takedown. Less surface area will cause the tail to sink or bite into the wave. You won’t be surfing your Mini at Puerto, you’d want to grab a board with a needle tail, something that holds tight in the pocket and isn’t made for quick turns.
More surface area equates to more lift and a rounded tail is just a pin with a wider arch. The added surface area allows for more speed in slow sections and lifts the rear of the board a tad—did you say stomp it! A round tail is best for big, fast , hollow waves where you need a bit more maneuverability than a pin but not so much that you’re going top to bottom. A round tail doesn’t quite jib with the Mini design so we’ll skip this one too.
The squash surfboard tail gets us closer to where we want to be when we think of a tail for a Mini Simmons because it allows for the most surfing versatility. The squash tail is the most common tail on the market, the square edge allows for quick release, giving the surfer responsive and loose turns. More surface area means more lift down the line, giving you speed and planability (sic). The wider the tail the more lift, that extra speed can help you get through flat sections of the wave and explains why big fat tails on the Mini Simmons do so well in mushy conditions.
The swallow tail is your classic fish tail, it’s really like two tails in one, offering a nice balance between speed and control. The swallow tail construction allows the shaper to create much wider shapes nose to tail, giving the surfer a very different experience. The upside-down “V” (the section between both tail points) allows for bite and control when making turns. It also gives the water a release point, but remember that when in a turn the pin on the opposite side of the turn must disengage before the tail can reengage on the other pin to pivot. This is why a swallow tail is sometimes hard to turn and will bog out if you hit a flat section in your cutback, that far pin just won’t disengage and can be like dragging an anchor through a Florida swamp. However, the swallow does allow for a much wider tail section and more surface area means more speed. Thus if you want to maintain your potential for speedy turns, grab a board with a shallower “V”.
The surfboard square tail is the grandfather of all tails. The square tail is like a knify squash, the corners of a square tail dig into a wave while turning and allow pivotal turns. Less curve in the rail means there is more stability. These are old school designs and aren’t used much anymore, except on longboards.
Mini Simmons Tail
I personally like a Mini tail that is somewhere between a square tail and a squash tail, the extra surface area is really going to give you some extreme speed through flat sections and the knifey rails will help you dig long curves into the face. I have also been experimenting with a slight outside “V” on the rear rail to help improve water flow—I’ll keep everyone posted on how that develops.
Ok, let’s get the basics out of the way first of all:
5.8 x 2.5
This one has pinched rails, that means that the rails are pinched toward the center of the rail-line (also know as rail apex) as opposed to curving down towards the waterline.
What is a pinched rail?
A 50/50 pinched rail board works best in a good clean face reef or point break type wave, some people also call them egg rails.
I wasn’t sure how they would work on a Mini but I wanted to try it.
Little Al from Santa Cruz gives us some great advice about pinched rails:
“You have to remember that the rail starts way back towards the center of the board, and the knifer the rail the closer to the center of the board the contour starts. a hard rail in the tail tends to be faster when surfing towards the tail. A hard rail in the tail tends to be faster when surfing towards the tail. For a long time I did not know why I did not like the hard rail in the tail boards. With a hard rail in the tail and a flat area in the tail the board would not stall in fact it woud speed up.”
“If you surf a floatier board at a reef/point break you get in early and have the time to stall and let the wave build up. If you surf a board without all that float and surf a beach break you need to get moving as soon as possible so a hard rail flat tail board is going to work best for you.”
Well, I like a board with both those characteristics so this one got pinched rails up front and hard rails in back.
I have yet to ride it at a reef, but at the beach-break it was a little sluggish.
I really like the lines on this one, I pulled the tail in a bit more than usual and the end result is less drag on the turns.
I made the tail with a mini bat wing.
My idea is that the water needs an exit point, a focal exit point, and the bat wing provides the water’s energy to escape.
Surfboard Shaping Software. The AKU is a machine used to ‘machine shape’ a surfboard blank.
The AKU shaping software is the software that was developed to use with the AKU machine (but you can use it without buying the machine too).
It is really easy to use and lots of fun.
The software is made for both Mac and PC and provides a 3D environment to design surfboards.
You can download it here for free: http://www.akushaper.com/
It’s made to feed into a shaping machine but it can also help you with your custom shaping projects.
The AKU file is the file format read by the software, you have to have the program to open the file.
If you want to use the shaping machine then just take your file and locate the closest machine supplier and they’ll run the shapes for you. Check this map for the closest location. There is one in Ventura, California at IShapes.net
You can also output the AKU designs to PDF after you have customized them, here is a sample output from A Mini Simmons AKU file design.
I have been wondering about this a lot in Mini Simmons surfboard design (surfboard design in general)—what is a hull and how does it influence the board and the ride?
Two factors are at work when a planing surfboard is in motion:
When at rest, a surfers weight is borne entirely by the buoyant force (also depending on how much beer you drank the night before).
At low speeds every hull acts as a displacement hull, meaning that the buoyant force is mainly responsible for supporting the surfer.
As speed increases, hydrodynamic lift increases as well. Ok, you got to reach back to some physics for this one.
But check out this diagram which will help:
A fluid flowing (water) past the surface of a body (surfer + surfboard) exerts surface force on it. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the surface force parallel to the flow direction.
If the fluid is air, the force is called an aerodynamic force—if it’s water it’s called hydrodynamic force.
In contrast, the buoyant force decreases as the hull lifts out of the water decreasing the displaced volume.
This is the reason that surfboards with lots of rocker need more speed and their no rocker cousins scream across the water.
The major difference between a planing surfboard hull and a displacement hull is the way in which the surfboard travels through the water.
A displacement hull has a belly, or convex, bottom contour and planing surface. This design does not ride high on the water like a planing hull, instead plowing through and parting the water. Think of an ocean liner moving through the deep ocean versus a speed boat racing around a lake.
At high speeds a displacement hull’s tail will sink down lower and lower as a result of the “hole” created in the water as the surfboard moves forward.
A planing hull, on the other hand, will have a flat or concave bottom contour and plane up on top of the water.
The board will almost skim across the water’s surface.
Displacement hulls push through the water as they have no hydrodynamic lift, or the surfboard does not rise out of the water as speed increases.
Planing hulls are designed to run on top of the water at high speeds.
To achieve this they typically are very flat at the tail.
The hull design (shape) does not limit the maximum attainable speed but does affect the power required for it to get on plane (on top of the water).
Semi-displacement or semi-planing hulls have features of both planing and displacement hulls.
They have a maximum hull design speed. Exceeding this speed can result in erratic handling and unstable operation.
There is not one hull design characteristic that differentiates semi-displacement from semi-planing hull.
The greater the hydrodynamic lift and higher the hull design speed the more likely it will be referred to as a semi-planing hull.
I came across this blog post by Steven Mast of Mast Surfboards and it is an excellent discussion of the topic.
“Although the recent fascination with hulls has centered around the Greg Liddle “modified transitional displacement hulls”, any surfboard can be considered a hull. There are displacement hulls, planing hulls and as usually is the case, some variant of the two.
As soon as you put an edge at the tail of your board you have created a planing hull. The very nature of the release provided by that edge, by definition puts that board into planing mode. It the edge were left soft and round, you still have a displacement hull. Now whether it is a good one of either type is another matter.
Have you ever seen the old footage of guys towing behind motor boats on their logs? As soon as they get going, the tail end of the board starts submarining and they can literally walk to the nose and go. This demonstrates a the principle of displacement hull theory. A displacement hull has a theoretical hull speed, above which the water actually sucks the hull deeper into the water (I’m simplifying here). Take a sailboat or any other displacement hull and tow it. At anything above the theoretical hull speed, the boat begins to submarine, actually being pulled deeper into the water.
Old, soft edged boards are the same, as are any true displacement hulls being produced today. As soon as you put an edge at the tail, you release the water and the board begins to plane. The modern surfboard, most “hulls” included, balance these principles to achieve the desired effect or feel.
Now I’m sure I’ll get some flak for this, but displacement hulls, by their very nature, are not as fast as planing hulls (editors note: . They may “feel” faster in a section, but without the release, they are constantly dragging more than a sharp edged board would. Now this is not a bad thing. The feeling of a well balance hull is one of the great pleasures of surfing that most people fail to credit. Surfing one well takes a different approach, especially if you are stepping off a thruster. Single fin riders tend to have an easier time.
Another thing I’ll take flak for, and I’m saying it anyway, Greg Liddle did not invent the displacement hull surfboard. He refined it to an amazing degree, made it work in a short package, championing it when it was completely against the trends of the time, but have you ever seen a Weber Foil? Have you ever really looked at almost any board before the mid sixties?
All displacement hulls, although arguably not “modified transitional displacement hulls”, whatever that means. Please don’t take this as me dissing Greg Liddle. On the contrary, I think his boards are brilliant and have been a huge design influence for me. It’s just I get a little frustrated when I here people talk about hull this and hull that, without any understanding of what a hull is.”