hey whats happen i have a 6’4" rusty catfish great board i would like to set up a quad fin system it is 14 1/2" wide at the tail fins are 11" from the tail to the trailing edge with a 5 deg. cant any sugustion on measurements for the back fins
Pedro,
It’s been my experience that quads don’t work all that well on shortboards with tails under 15.5" wide. The quad setup makes them track like crazy and the position of your front fins are pretty far back for a quad…they should be around 11.5" - 12" up.
With that said, if you’re set on doing it, I would start with the rear fins at 5.5" - 6" up from the tail and 1.5" inboard from the rail. Keep the cant angle the same as the front fins or a degree less.
If the board tracks too much, use a larger front fin/smaller rear fin combo.
HTH
Also , would you consider using fin boxes , so you can move the fins foreward or back in differing conditions too , perhaps ?
And a fifth fin ?
cheers
ben
Check out www.mckeesurf.com, there you will find heaps of info on multi fin placement in fine detail, well worth a look.