Black Sheep said..
A large fin box in an SB Airborne 8.8, would that be a good idea?
I recently bought an SB AB 8.8 2015 second hand, I had already tried an SB WP 8.10 and that quad fin but I didn't really like it.
I now also experience that with the AB 8.8, hence the plan to build a large fin box in it.
It has already been mentioned more on the forum here, but never the findings with this.
I just want to place the box back more than in the picture, just over the fcs box.

I would be doing it,I don't surf any board without a fin box,as I tend to like 2/1 set ups with a tight cluster,I was considering that board but declined for that very reason.Make sure the box is reinforced as there won't be any h/density pvcin that area go for it! That box placement looks ok as it is around the quad rear mark,what works for me consistently is a formula... put a straight edge across the tips of front fins transfer vertically down mark board,then your critical measurement to the front of Finn in the box is around1/4--1-1/4 I never go for ward of the mark!.regardless of changing fin sizes you will find your happy place in there somewhere.In my younger days I worked with some high profile shapers on log boards and this formula was consistent with them all.Having said that there always exceptions to the formula !,good purchase and good luck

Sorry, the photo is an example of someone who has already done it. But in my opinion too much forward and too big fin box. I want to use a smaller one, like in the picture of my fin box.

justaddwater said..

Black Sheep said..
A large fin box in an SB Airborne 8.8, would that be a good idea?
I recently bought an SB AB 8.8 2015 second hand, I had already tried an SB WP 8.10 and that quad fin but I didn't really like it.
I now also experience that with the AB 8.8, hence the plan to build a large fin box in it.
It has already been mentioned more on the forum here, but never the findings with this.
I just want to place the box back more than in the picture, just over the fcs box.

I would be doing it,I don't surf any board without a fin box,as I tend to like 2/1 set ups with a tight cluster,I was considering that board but declined for that very reason.Make sure the box is reinforced as there won't be any h/density pvcin that area go for it! That box placement looks ok as it is around the quad rear mark,what works for me consistently is a formula... put a straight edge across the tips of front fins transfer vertically down mark board,then your critical measurement to the front of Finn in the box is around1/4--1-1/4 I never go for ward of the mark!.regardless of changing fin sizes you will find your happy place in there somewhere.In my younger days I worked with some high profile shapers on log boards and this formula was consistent with them all.Having said that there always exceptions to the formula !,good purchase and good luck

Can you draw what you mean by... put a straight edge across the tips of front fins transfer vertically down mark board,then your critical measurement to the front of Finn in the box is around1/4--1-1/4

Some time ago, I convinced Gong to put 2 FCS boxes inline (and some other brands even copied it). It acted as a poor man fin box:
pro:
- lightweight
- can use any FCS fins
- can use symmetrical big keel fins, interesting setup for longboard SUPs
- easier to put in thin tails
- 3 fin positions with only 2 boxes
cons:
- cannot be fine tuned: only 3 positions
- not worth the trouble with FCSII boxes, most people with FCSII boxes will not want to use screws again. Gong didn't use this after switching to FCSII boxes.



My experiment for noseriding:




Quobba has an interesting "slider" concept for the center fin, that can be moved tool-less in the water, but with a limited range, and is not yet available.