Multi Fin Conversion using 4WFS

Multi fins are everywhere and I was interested if conversion were feasible, so I decided to convert my Starboard Evo 70 to be a multi fin board. The result turned out great, so I'm now offering a service of installing 4WFS boxes on your board.  

I started to research fin sysyems and came across the four way fins system (4WFS). I was struck by the ease of adjustment available from the system, so decided to give it a try.  I installed the fins so I could run the board as a quad, thruster or single. This is the result:

The fins I had available are:

  • 24cm mcf
  • 21cm mcf
  • 17.5 from a mistral twinser
  • 2 x 14.5cm side fins (4wfs)
  • 2 x 11cm side fins (4wfs)
  • 2 x 11cm center fins (4wfs) 

 

 

 

My observation after using for a week on Tiree:

General: 

  • Multi fins turn better.
  • Quad more draggy than thruster or single.
  • Quad more secure when stacked.
  • I think with smaller fins, drag from the quad could be reduced, but still have sufficent area.
  • The toe in angle is critical. I installed the boxes with no toe, they are adjustable 2.5 deg both directions.
  • Front fins toed out 2.5 deg - the board wouldn't plane.
  • front fins toed in 2.5 deg - front fins ventilated but board sailed ok. More draggy, no turning benefit.
  • Straight performed best. Note this is for the evo that is a double concave shape in the rear, a board with V may require more toe. Next time i'm sailing I plan trying both front and rear fins toed in 1 degree.

Quad setup:

  • Quad fins feel a little more draggy
  • 4 x 11cm fins fine for sails smaller than 5.3m
  • 2 x 11 rear and 2 x 14.5cm fins better for sails up to 5.6m or when under powered on 5.3
  • Very dependable when stacked, but still turned very well. Preference when well powered. Smaller  fins should be tried next.

Tri Setup

  • Performed very well, good for more marginal conditions. Very adjustable.
  • Setup with 2 x 11cm front 17.5 rear
  • rear fin position had massive effect, could transform board from exceptionally loose, almost uncontrollable to very secure.

 

Single fin

  • Felt more locked in like a freeride board after using multi fins, evon on an EVO!
 Want Multi Fins on your board?

Prices for a conversion are available here. Get in contact to discuss your requirements as there are loads of options.
 
Installation Video

I've used a gopro to produce a time lapse video of two fin boxes being installed on a RRD cult wave.