Surfboard Fin Guide
What is there to know about a surfboard fin?, or more importantly your fins.
Before the removable fin systems were introduced and glass on fins were basically your only option for a thruster, the “Everyday Surfer” probably didn’t pay that much attention to the design elements of a surfboard fin.
You got what you got and that was it.
Now the possibilities are almost limitless, a different type of fin will alter a surfboards performance and directly affect the way you surf, for example- if the fin is to big, does not have enough flex or the sweep is to much can effect a surfboards performance positively or negatively.
So with all the options How to know which is best fin for you and the waves you surf?
Follow these basics of fin design and at least you can set yourself on the right track.
Fin Design Basics
The Area or Outline of the fin is determined by the
This refers to the front and back part of the fin that comes into contact with bottom deck of the surfboard.
Base determines the amount of drive you have. More base more drive, less base less drive.
This refers to the height or how far the the fin goes into the water.
Depth determines how much hold or grip a surfboard will have. The taller the surfboard fin the more hold and stability it will have while a shorter fin wont grip as much and release easier.
This refers to to how much of the fins outline is curved backward. It is also known as the Rake.
Sweep determines the turning radius of a surfboard. The more sweep a fin has the longer the turning radius, while surfboard fins with less sweep will produce tighter turns.
Now consider these characteristics of Fin and Fin placement.
This refers to the amount a fin flexes from left to right.
A surfboard fin flexibility determines the amount of drive and responsiveness you will feel while surfing. Fins with little flex (stiff) are more responsive and faster while a fin with more flex are more forgiving and easier to use.
This refers to the angle of the fin leaning out in relation to the bottom of the surfboard.
A fin that is straight up and down has no cant. The less cant a fin has the more drive and acceleration a board will have but will also produce a stiffer feeling. More cant a fin has the looser a board will feel and be more maneuverable.
This refers to the angle of the fin box in relation to the stringer of the surfboard.
The toe is not a fin design and is determined by the shaper, a fin that runs parallel with the stringer has zero degrees toe. The side fins will generally have some sort of Toe-In-meaning angled towards the stringer
Toe-in causes the water to pressure the outside of the fins, which in turn makes the board more responsive to rider input.
This refers to the thickness of the fin and how it is dispersed throughout the fin, whether it be thickest in the middle and thinnest on the edges or some variation of that.
Foils can create and affect projection, torque, speed, maneuverability and release.
Okay so the basic terms are down now what?
Guidelines On How To Use Your Fins
- If your board is a bit stiff, use some smaller fins or fins with less sweep or more flex.
- If your board is too loose and lacking drive, try a bigger set of fins, a stiffer flex fin or a fin with more sweep.
- Generally a lighter person requires less fin area to provide enough hold on a wave and a heavier person will need more fin area to not slide out.
- Boards with a lot of rail (ie guns) require less fin area.
- Boards with a lot of rocker may require fins with greater area, more depth or sweep.
- Boards with wider tails require more fin area than those with narrower tails.
- If you are using a small board in big or powerful waves use larger or more swept fins.
A few pointers on fin placement.
- Fin placement/cluster refers how spread out or how close together a set fins are in relation to each other.
- A Fin setup with a spread out cluster results in more control and longer drawn out turns .
- A Fin cluster that is close together will result in being able to turn the board faster but a bit harder to control.
- How far up or back the fins are in relation to the tail will also create different performance characteristics.
- Fin clusters set forward creates a looser board
- Fin clusters set further back provides more hold and control, good for days when the waves are big.
To Truly know what fin is best for you and the waves you surf on a daily basis, you got to try out different sets, borrow some from your mates or often surfshops will let you test drive different sets.