Finally got to try different boards, what a revelation!

[manuel]

Completely agree on changing the board's feel, I understand that shape is shape.

After the session, it could certainly take advantage of side fins. The board has tremendous acceleration out of the wave and therefore is a bit technical to position the body over the board. Basically there's a slippery feel.

I used to sheet in to give my Acid a kick in the butt to go both at the jibe and the surf. Now if I do this the board slip under my feet and I find myself leaning too far back. So I have to be more over the board and not sheet in, let it use the power of the wave and slide down.

I found it much more stable over white water because of the extra volume under feet. It planed out clew-first switch-stance very well a bit too well, I need to get used to this.

I'm riding a 19cm fin right now quite powerful kinda freestyle type with a wide base. It wasn't bad but spun out quite suddenly and lacked a bit of drive.

So now onto grocery shopping for a tri-fin conversion.
I was thinking slot boxes since I can't adjust the rear fin?
Depending on complexity I may use some local help to get it done.
But I would like to come up with detailed instructions for the job.

[isobars]

Wouldn't it be infinitely easier, much quicker, and maybe just as effective to just use an adult-sized fin? 19 cm is microscopic, intended for slidey tricks more than traction, unless you have two of them.

[adywind]

Ha ha I was wondering the same thing. Why would you go wave riding with s freestyle fin?! Freestyle fins are like undersized slalom fins-hard and straight not meant for carving. Loosing grip easily at the same time kills your confidence and makes you sail defensively. This board comes with a 23cm stock fin, put one this big and meant for waves and see how it feels.
The conversion on the other hand is a fun project that also may be beneficial.

[manuel]

I ride small fins for the same exact reason that we have multi fins out there.
To increase looseness/reduce lift, have more rail in the water at the surf, easier top turn, more control of the board trim.

The stock fin is a freewave, really stiff, good for bigger sails, jumping, not as good for wave riding.

I just happened to run into that odd fin and since it was smaller, I gave it a shot, it turned out better than the stock fin for my application.

[adywind]

[isobars]

[manuel]

[U2U2U2]

I would not call that a Freestyle fin. Size is rather small, but depends on sail and how powered up you are..more...more

To convert the Goya to a tri fin, Boards UK has 'many' threads that involve adding fin boxes. It get rather complicated if you consider toe in, and fin shape if symmetrical or asymmetrical.

Slotbox you can get from Matt Prichard, not cheap. You would have some fore aft movement with smaller fins. Other options on box are mini tuttle, shortened USBox, cheap and available . For this application I would use ProBox, cost $8 or so a box, these accept ProBox fins OR FCS with the 2 tabs, nice fins for the money and any surf shop will have them.

Placement of the box : copy a similar board, something like 4.5cm from rail to REAR BOX center , align the center of the box, OR slightly forward, 1 1.5cm
WITH the rear footstrap ::FRONT screw.

the box itself should have some additional material, CMat, divnycell, and inserted in carbon and or SGlass, with 2 stage epoxy.

depending on your skills and equipment, sanders, router this is all pretty easy stuff to do.

[manuel]

Thanks for the great info. I will dig into it.
Sourcing boxes is the first problem, $8 for the proboxes does sound nice so long as they can take the stress.
How much adjustment can we have from them?

Some other folks are saying I should add rear boxes too to have the quad option. Sounds like shortened US boxes would work well. Although I may want to try bigger fins up front.

My experience is car body work and fiberglass work (car parts).
I have only non-powered tools.

[U2U2U2]

I have ProBox in a few boards, I tested the strength and feel that when installed with additional support are up to the task, the task being small fins
I have used 15cm, and have them as rears on a quad. It will be extremely difficult to find fins over that length that will fit anyway.

Range of adjustment is small 1--2cm, depends on what size fin base and which fin. the box length is 90mm.

for your Goya, I would consider side fins 8/12cm . If you wanted to use all 3 fins the same size, 13-14 cm , my guess .

A tri fin is pretty straightforward to make, options are , box, toein, and fin foil , again I am not keen on powerbox,but have done 2.

QUAD brings up 2 more finboxes and IMO the quad is more sensitive on fins, sizes and shape.

slotbox are nice, some are now making their own, cost to purchase $35 EACH