Converting a 2+1 into quad this weekend. Any suggestions on rear fin placement? Front trailing edge is at 12" Board is 6’ disc- rather wide @ 20" and tail @ 15". My searching in the archives has given me an info overload. Any recomendations would be greatly appreciated. I’m leaning toward 5.5" for the rear fins approx. with a 7" separation- is all hope lost or should I give it a go?
The 5.5" up from the tail sounds good, however, the spacing between them is relative to the width of the tail at the 5.5" mark. Personally, I would set them an inch or so in from the rail with approx. 1/8" of toe-in. I doubt that there’s a magic number that works for every board, but that’s a pretty good starting point.
Hey Landlord,
Abandon numbers long enough to hold the fins your planning on using as trailers in the board and scoping how they look on it. More inboard will give more directional stability less drive. More aft will give more drive and make the board stiffer. Separating the cluster will make the board stiffer. double foiled fins will be smooth. More cant releases better. Less cant engages earily and is stiffer. If you want the surf smaller waves with the board hold the trailers further forward. If you want more drive hole the trailer more toward the rail. If you extend a line to the nose from the lead fins and aim the trailers at the same point that this line ends on the board you’ll have a very good approximation of where you want your trailer aimed.
What looks right generally is right.
Look at some web site and see how the fin placement looks on the professionally placed quad set-ups then do your best immitation of the one that appeals to you most.
Mahalo, Rich
Thanks to all for the input. I have scoured Mckee’s site- this has a bounty of helpful info. I’ll try to report back as to the progress.