A Collection of Useful Resources
This page contains a collection of resources, such as fin layout guides for different types of boards and fin setups. These guides can be freely downloaded to serve for a hardcopy reference.
The layout guides provide information on the positioning of fins for various types of fin setups. They are not specific to any given board length as they are only intended to serve as a starting point. It is left to the builder to determine their preferred layout.
Additionally, there are also various guides detailing the GEARBOX system fin base and layout options. All are available as downloadable PDF files.
A Fin Setup Primer is also presented on this page, it should help to build a better understanding of fin layout in general. A downloadable version is also provided.
Finally, there is a new TIPS & TRICKS section that provides some ideas for improving either the strength or quality of an installation, or to gain a better understanding of the process. As new ideas arise they will be added to this section. COMING SOON!
Below is a page navigation option that makes it easier to jump to a section of interest.
TWIN FIN LAYOUT
KNEEBOARD TWINZER LAYOUT
KNEEBOARD QUAD LAYOUT
KNEEBOARD 5FIN LAYOUT
KNEEBOARD THRUSTER LAYOUT
KEEL FIN BASE
KEEL FIN ADJUSTMENT
STD INSTALL GUIDE
1ROUT INSTALL GUIDE
FIN SETUP PRIMER
A Guide to FIN SETUP and TERMINOLOGY
At best this is more art than science, but well worth experimenting!
The beauty of an adjustable fin system is that you can go out and experiment for yourself to verify what effect a change in fin placement can have on the overall performance of a board.
This primer will use some terminology that is best explained up front so that we are all speaking the same language.
fin triangle or CLUSTER
this is the grouping of the fins, whether it be a thruster, quad, or 2+1, it refers to the entire fin layout.
this is position of the entire fin cluster as a unit, either all forward all back, spread apart, grouped together, etc.
also referred to as fin angle, is the amount by which the side fins are leaning out from the centerline of the surfboard, bottom up.
this is the amount that the front of the fin boxes are pointed in (toed in) from the centerline of the box towards the stringer.
fore ’n’ aft
this is the position of the fin in the box forward or backwards along the length of the board.
spread fin CLUSTER
this is where all the fins in the cluster are spread as far apart as possible, side fins all the way forward, center fin all the way back, this generally makes the board stiffer. For quads the fins are spread as far apparent as the box adjustment will allow.
tight fin CLUSTER
the opposite of the spread fin cluster, typically side fins all the way back and center fin all the way forward, makes the board looser and more pivotal. For quads the fins are pushed as close together as the box adjustments will allow, front fins all the way back, back fins all the way forward.
a thruster setup consists of a set of side fins and a center fin, with the most common setup featuring fins that are all the same height.
a quad setup consists of a two sets of side fins, with the most common setup featuring a larger set of fins in front of a smaller set. The placement of these two sets relative to each other can vary widely, but our preference is for them to be close together.
reverse QUAD setup
a reverse quad setup consists of two sets of side fins, with the smaller set of fins in front of a larger set. The placement of these two sets relative to each other can vary widely, but our preference is for them to be close together. This is a term we coined to describe this setup arrangement.
a twinzer setup consists of a two sets of side fins, with a small set of canard-style fins in front of a much larger set. The placement of these two sets relative to each other is typically very tight to allow the canard fin to serve as a transition fin to the larger fin. The canard fins typically have additional cant built into the base in order to have more cant than the boxes typically provide.
a 5FIN setup is simply a quad setup with the addition of a center box, this allows the board to be ridden as either a quad or a thruster, or with all five fins.
a 2+1 setup consists of a set of side fins, and a much larger center fin, most commonly placed in a regular longboard center box. The side fins are commonly very small in relationship to the size of the center fin, but the heights can vary.
SINGLE fin setup
single fins are either setup in a regular longboard center box, or glassed on to the bottom of the board. One fin setup on the board centerline.
FIN SETUP TRAITS
spread fin CLUSTER
longer turning arc, more common on longer boards or guns
larger faster waves, situations where a gun would more likely be used.
tight fin CLUSTER
shorter turning arc, the common setup for smaller thrusters
wide range, depending on skill and the shape of the board.
fin CLUSTER forward
looser, shortest arc, less hold
pivotal surfing on small to medium waves.
fin CLUSTER normal
loose with control, typically the position designed by the shaper
versatile wide range of conditions.
fin CLUSTER back
more control, more projection, bigger, tube/pocket waves
once again typical for situations for a gun.
more fin CANT
looser with less drive, requires more turning to generate speed
small to medium surf.
less fin CANT
stiffer with more drive, bigger, faster hollow surf
commonly used in twin fins, guns or tow-in boards.
Above is just a small sampling of the more obvious combinations, there are many more in between or with subtle variations. The intent has been to provide a little insight into the more general characteristics of fin placement.
Obviously, the position and cant of the fins are very important and greatly affect the performance of a surfboard. The smallest change can sometimes have a dramatic effect on the board, but it is not a magic bullet, sometimes the opposite effect can occur. Fin setup is just one piece in a complex dynamic system of shapes and curves that make up a surfboard.
Each board is different, as is each surfer, so any changes could have different results depending on the board and the surfer!
The information provided above is applicable to a 2+1 fin setup, except in that type of setup the size of the center fin has a more heavily weighted effect on the cluster. The smaller the center fin the more it will perform like a thruster. Placement of the center fin is going to be by far the more controlling aspect of the performance of a 2+1 setup.
Of course there are other factors that can affect fin setup, the size and shape of the fin, even the foiling of the fin. Whether all of the fins in the cluster are the same size, or not. We believe the beauty of an adjustable system is that it allows the surfer to experiment for themselves to determine what works for them and to help them learn the significance of being able to adjust the fin setup on a surfboard.
Our system was designed to provide some adjustability, making it easier to experiment hands on with fin adjustment.
The renderings in this section show illustrations for some of the terms used in the fin setup discussion.
Hopefully, these will provide a visual guide to some of the terminology.
Shows what is referred to as a fin cluster, which is the combination of all of the fins in the layout.
Cluster Rear View
Another view of the fin cluster from the rear of the board, showing the cant angles of the fins in the cluster. When talking about fins this is the most common view used to refer to the left and right fins.
Shows how the cant angle is measured. With the GEARBOX fin system the cant angle is built into the box. The correct cant angle needs to be selected before installation.
Toe-in of the boxes, is another critical value, shown in this drawing.
This is the distance that the boxes are pointed in towards the stringer, from the box centerline. In quad setups this can vary from the front to the back fins.
Spread Fin Cluster
A spread fin cluster is where the fins are spread as far apart from each other as possible. For a thruster this means the side fins are as far forward as possible and the center fin as far back as possible. For quads the front fins are as far forward as possible, and the back fins as far back as possible.
Tight Fin Cluster
A tight fin cluster is where the fins are pushed as close together as possible. For a thruster this means the side fins are as far back as possible and the center fin as far forward as possible. For quads the front fins are as far back as possible, and the back fins as far forward as possible.
THINGS WE HAVE LEARNT THAT MIGHT BE HELPFUL WHEN INSTALLING THE SYSTEM, OR TO GAIN A BETTER UNDERSTANDING!
While the STANDARD and 1ROUT installs work perfectly there are still tricks, or slightly different approaches, that can be used to enhance an install.
We will share some of these thoughts here as they could be useful, either as an adjunct to the normal install or a revised approach.
Bear in mind, as with any install methodology, it really helps to run a few test installs before adopting any changes. This will provide a better feel for the process and help boost confidence that the right choice was made.
We will also go into more detail regarding the setting of the router bit depth to deal with deep concaves.
As always if there are any questions CONTACT us, we are here to help.
Section through center of 4º GEARBOX and foam cavity
When performing a typical install using the STANDARD router depth setting the illustration above shows how the box would sit in the cavity. Optimally, it should be slightly below the bottom of the board. More on this later!
The motive for pre-gluing the boxes into the cavity is twofold. First, it is a lot less stressful and gives you the time to get everything setup perfectly (for those that prefer to have a fin in the box to check cant angle, it makes that easier). Second, it means a coat of resin can be applied over the top of the cover filling in the hex grooves and creating small curved ramps against the dam and outer edge of the cavity. See detail image below.
To pre-glue the boxes, the routed cavity is covered with resin as is the underside of the box. Then insert the box into the cavity and allow any excess resin to squeeze out. Using a brush spread resin over the cover and the lower edge of the dam. Due to the nature of the resin it will create a small fillet at the dam and the outer edge of the cavity. This makes it a lot easier for the cloth to drape over the box. This is one of the main reasons the box should sit slightly below the lip of the cavity.
Section showing resin coating over cover and fillets at dam and cavity edge
Section showing main layer of fiberglass applied over box
Section showing final layer of fiberglass reinforcement applied
Section showing hot coat applied to board and box
Section showing box and dam sanded down after hot coatnig
The illustrations above shows step-by-step how this works.
Another reason for setting the box slightly below the cavity edge When using this technique it allows the bottom lamination and reinforcement layers to drape down over the box cover more easily.
This is important because if the box were flush with the bottom of the board there is a greater risk of sanding through the lamination, or at the very least sanding away the second reinforcement layer. By lowering the box the cloth ends up slightly below the bottom of the board making it a lot harder to sand through the layers.
Once the boxes have been glued in lamination can proceed, or if it is a post lam install the reinforcement layers can be applied. The gelled resin that was applied during the gluing process makes it very easy to press the cloth tight against the box as the resin will still be tacking. This will help hold the cloth in place while laminating.
It is important to always place the SECOND reinforcement layer ON TOP of the bottom (or first) layer. The reason being that there is less risk of sanding through the bottom layer, which would be very easy at the edges of the reinforcement layer if it was underneath the main layer.
With the new shape of the dam you will find that this process makes for a very clean install with little to no air around the base of the dam.
Look at the image below and you can see just how tight this process allows the glass to be around the dam after it has been sanded down, this makes for a much stronger install.
This photo shows just how tight the glass can be made to fit around the dam. This is a box sanded down before glossing, showing the two layers of glass.
DEEP CONCAVE INSTALLS
Base jig setup on a deep concave
When performing an install in a board with deep double concaves there is an extra precaution that needs to be taken to ensure the boxes install cleanly.
End view shows how the base jig spans the concave
When the base jig is placed on a deep concave it can bridge the concave, as shown in the illustration above. When this happens and the STANDARD router depth is utilized the box will not sit flush.
After routing the box would end up sitting slightly above the lip of the cavity
Normal rout would leave the box sitting above the lip of the cavity
For this reason the depth gauge provides a CONCAVE depth that sets the cavity deeper. The aim here is to get the box to sit slightly below the lowest part of the concave. In some cases the depth gauge might not provide enough depth due to the severity of the concave. Always do a test run to check that there is enough depth.
Box positioned slightly below the lowest lip of the cavity, by doing a deeper rout
Using the CONCAVE depth on the gauge the box should end up slightly below the lowest lip of the concave. As shown in the above illustration.
Final routed cavity