Fin Tech Talk - Single fins

There is a lot of choice out there when it comes to fins, how do we know which is the right fin for the surfing we want to do?

Most single fins have a standard box fitment so are universal. You drop a little tab into the box, slot the fin in the centre, side it to where you want and tighten the bolt onto the little tab you dropped in. You can move fins forwards and backwards in the box.

Moving your fin around in the box is a huge deal. It can totally change the way your board feels and surfs. Further back in the box and you will have more hold and down the line speed. If you have the fin further forward, your board will become loser, easier to turn and more lively. This is to do with the relationship between the position of your feet and the placement of the fin and the angle of the pivot that comes from that.

The biggest factors in choosing a fin are as follows…

BASE LENGTH

The wider your fin is at the base, the wider the base of the fin, the more your board will want to go in one direction. It’s harder to turn a really wide fin, but great for trim and stability on the nose. A wide based fin will create more drag which is good for staying in the pocket on the nose. A narrow fin will allow you to turn more easily.

HEIGHT

This is relative to the size and width of your surfboard. A longer fin gives you more stability and drive and will sit deeper in the water and will remain in there as you put the surfboard onto a rail. Your fin and your rail work in harmony with each other. People say to match the fin height and board length roughly, it’s a good guide. A 9’6 log will like a 9.5-10” fin. The only exception to this is shorter boards that you are hoping to surf more radically on the rail. I’d keep with a 7-7.5” fin for a board in the low to mid 6’ range. For a 7’ board I would go up to 8”.

This is a great option for all-round longboarding. Blending tip-time with turns.

RAKE

This is how much a fin sweeps backwards from tip to base. The more curve backwards your fin has, the more stability and down-the-line feeling it will have. The more upright your fin is, the more sharply and loose it will want to turn.

More of a traditional template, hold on the nose and stiffer turning.

FLEX

This affects how ‘lively’ your board feels under foot. A fin with lots of flex with load up under pressure and store energy that is released at the end of a turn, this is fun and suits some surfers and boards well. A stiffer fin will be more predictable and stable.

A great Midlength template

SINGLE VS 2+1

Some of you may have two fin boxes as well as a singlefin box. Adding ‘sidebites’ brings the boards closer to a thruster feeling. If you want more of a ‘single fin’ feeling, up the size of the centre fin, drop the sidebite size and vice versa.

3..25 and 3.75” sidebites inFCS twin tab. These fit FCSii boxes fine.