Swapping fins on a surf sup

Swapping fins on any sup board can make a difference but none more so than on a surf sup that is ridden off the fins and performs its job powered up on the plane.

Surfing has seen so many fads, trends and styles of fins come and go in its time so as sup surfers we need to understand and recognise how and why some of these have worked or failed to help improve our own boards and style of riding.

A Thruster setup

A basic 2+1 fin system found on many surf and all round sups.   Very versatile and delivering control and speed across a really wide wave range of anything from small mushy to big a hollow.

1 centre fin and 2 smaller side biters.

Changing the 2 side biters can loosen or stiffen the board.

Changing the centre fin for bigger or smaller can increase drive but also loosen the board.   A larger fin can increase stability, but in turn it becomes less manouverable.

A Quad setup

The quad gives a real skaty feel to a boards ride with extreme speed but this is coupled by exceptional grip from the 2 rear fins biting in.   The space between the fins allow the board to explode down the line, and this really suits smaller, mushier waves.

Quads are loose as the usual mid fin is missing compared to a tri.   Putting in smaller fins may increase speed but can you react in time.  It’s already quick.

Quads are so versatile that I could ride it in anything but the way to look at it is that the board is fast, grippy and controllable so anything from mushy to get teh speed or big to control the speed is its place. Jimmy Lewis Supertech and Worldwide and Stun Gun have Quad and Tri fin options.

A Single fin setup

A single fin is the classical setup.  Boards like noseriders – Jimmy Lewis Black and Blue – have a large singlefin to help lock down the tail and reduce manouverability, but it increases lift .

Reducing the size of the fin will make the board turn easier so will feel looser on a wave.  Reducing size too much may see the tail slipping out as you ride right off the back, but I wouldn’t worry too much about that unless you go crazy small.

A classic dolphin style swept back fin is a great starting point especially for classic old school sup surfing or when the waves are smaller and lacking in guts.

fin-setup-chart

Position of fins

If we refer to a single fin board, the further back you have the fin the more straight line and less squirrely it will feel.   That said, having a slightly smaller fin will also give that looser feel.  In my own noserider sup I have the fin 3/4 of the way back and I have changed down in size slightly from teh original that just too big and rigid for my riding style.

Fin shape and size

The larger centre fins could be effectively classified as Stable, Noserider or Looseness.

A basic rule of thumb is that a larger fin with greater surface area will be harder to turn, but super stable. Obviously going the other way creates a looser feel, but this has to be likened to the board size.