Fin Guide : How To Choose The Right Fins For You and Your Board

Fins are fundamental to your surfboard set-up and how your board performs in different swell conditions. Choosing the right fins to optimise your boards performance depends on a range of variables; fin box, size of the board and you. Below is a simple guide to help you under stand your board, the way it was meant to be ridden. 

 

Fixed fins or Glass-on fins are laminated into the board. These are chosen by the shaper and can not be changed.

Boards that permit interchangeable fins have boxes, in which fins are screwed into. Interchangeable fins can be secured in the box or removed by using a fin key. The specialised key allows adjustment of the small inset grub screws.

 

There are two main fins boxes systems that allow interchangeable fins; FCS and Futures. The box system thus determines the type of base of the interchangeable fin that can be inserted into your board's box. 

 

The size of the fin plays a big difference in your performance and of the board in the water.

Taking in consideration your weight and surfing style,

a bigger fin will have more hold and more control in bigger surf.

A smaller fin will have a more loose feeling and be more forgiving. However in bigger surf, will lack drive and control. 

A medium sized fin will provide optimum performance all-around surf.

 

It's essential to understand your board's fin set-up to best suit your surf conditions.

Flip your board over and look at the tail of your board. The number of fin boxes you see, is the fin set-up and typically range from 1-5.

The most common surfboard fin setups are Single,  2 +1, Twin, Thruster, Quad and 5-Fin.

The traditional surfboard fin set-up is the single fin box, commonly used in longboards. Single fins will provide stability, control, and predictability to your board.

 Single fin boxes are longer to allow you to move the fin forward for a looser feel, or further back for more control *nose ride.

Tip: When first trying a new single fin, place the fin in the center of box for a couple surfs and accordingly move the fin forward or backward to find its sweet spot to suit your surfing style.

 

2+1 configurations have a longboard single fin box in the middle, with 2 side fin boxes to each side AKA side bites.

Most commons in performance longboards , eggs and SUPs

 

 

Twin fins or twinny set-up will make your surfboard fun, and manoeuvrable.

Two fin setups are not ideal for big-wave riding and are commonly featured on fish shapes and fun boards.

Twin fins offer a skate feel and longer, more drawn out turns.

 

 

Thruster is the most common set-up these days.

Thruster performs well because it adds stability, control, and manoeuvrability from beginners to pros surfers.

The front fins are angled towards the board’s stringer and are flat foiled to increase adding hold. The center fin is symmetric on both sides (50/50 Foil) for stability.

 

 

Quad fin set-up delivers speed in smaller surf by channeling the water to the end of the surfboard and out the tail for acceleration.

The two fins near the rails of the board will also add stability and hold in big-wave surfing. Quad fins are great for generating drive through turns.

 

5-fin set-up allows mixing and matching fins depending on preference and the surf conditions.

Change it from the freedom of a twin fin, to the traction of a thruster, to the speed of a quad without changing boards.

 

Getting Technical

 

The height also referred to as the depth, is measured from the base of the fin to the highest point of the fin.

The deeper the fin the more hold, the shorter the depth the less hold. Shorter fins will have a loose feeling and will make turns easier.

 

 

The base length of the fin is the widest point of the fin, the part of the fin that it’s contact with the board. Longer fin bases allow more water through allowing the board to move faster. A shorter fin base will allow making sharp turns.

 

 

The rake of a fin is defined as how far the front edge of a fin arcs backwards. The rake or sweep angle is a measurement that determines how far back the fin curves in relation to its base.

 

 The toe or splay is defined as the angle of the side fins in relation to the board’s stringer. Side fins normally angle inwards to create pressure on the outside foil. This creates a more responsive feel.

 

Fin Cant is the degree of outward angle a fin has in relation to the bottom of your surfboard. If a fin has zero cant its position straight up and down at a right angle to your board. This is going to be fast in a straight line, but it will not give as much response through turns. If the cant of fin is larger, it allows having more response through the turns. It means it can maintain some more drive when the board is tilted on the rail.

 

The flex of a fin determines projection, and is versatile in that it can be utilised in a range of different boards, including short performance boards to long boards and nose riders. Generally, flex fins have a wide base, which reduce down to a narrow tip.

 

 

Foil refers to the shape and geometry of the inside and outside faces of the fin. Foils directly affect the flow of water over the surface of the fin.

 Here are some of the details on the main types of foil.

Flat: A flat inside face combined with a convex outside face.

Inside: Consites of a convex outside foil, and a concave inside foil.

50/50 (symmetrical): A symmetrical foil used on all center fins where both sides are convex. Even water flow on both sides creating stability and control.

80/20: Combines the performance of a center and side fin offering increased speed, smooth rail-to-rail transitions and a consistent feel in a variety of conditions. Normally used as trailers for Quad fins set-up.

 

 

Helpful Tips:

• Boards with a smaller and stiffer fin set-up will be more responsive.

• When riding a shorter board in bigger surf, you will want a larger, more raked fin.

• Normally Larger surfers will need larger fins same goes to smaller surfers having smaller fins.

• Single fin placement in relation to the tail, will change your board feel. Set the fin forward to create a looser feel or set the fin further back to create more hold and control.

The best way to find out what fins will suits you best is to try different sets/templates in different conditions. 

 The goal of having the right fin set-up is to increase performance and ultimately have fun.