TLDR: Can I install a new fin box in front of the existing fin box, or do I really need to replace the old fin box? That is, how bad would it be to have a new fin box about 8 inches forward on the board?
Hi. I have a 2019 iRocker and a new board, which I love on lakes. Since I can use my new board on anything deeper than 9 inches of water, I plan to turn my old iRocker into a river board.
I got the 5" river center fin from iRocker but even that is too long for some of the rivers I go down. And the side fins are also 5" with no other options. I’ve been going finless, but that is no different than going on a pool float with an oar.
I don’t think there are any third-party compatible 3" fins. I guess, does anyone know of any third-party compatible fin makers?
If not, my plan is to customize my board. I am planning on removing the center fin box and replacing it with an Air 7 that can hold a 3" center fin. If 5’s will work, I can just use the existing side fins, so no need to replace those. My question is, can I install the new fin box in front of the existing fin box, or do I really need to replace the old fin box? That is, how bad would it be to have the new fin box about 8 inches forward on the board?
For reference it’s a 10 ft board and I am 5 feet tall.
A 3" fin on a 10 ft board wide enough to use as a river board is not going to do much of anything. If you want the fin to help with tracking you don’t want to move the position forward for a slow speed board. If you are surfing moving the fin box forward makes the board very “loose”. If you really want a 3" fin, buy a plastic low cost 5" fin and cut it down with a hack saw or jig saw and shape it to give the right leading edges and foil shape with a file, finish with sand paper, a small orbital sander and a dremel tool are great for fin shaping. Installing a fin box properly can be a bit of a problem on SUP boards because the outer skin layer may be some sort of plastic ABS polymer and not fiberglass, carbon and epoxy or polyester resin based. It’s doable but you don’t want to take on a fin box for the first time you cut into your board.
Would it be better to cut the side fins down and have two 3" fins and no center fin? I agree that I won’t get much traction with a single 3" fin, but having nothing is kind of miserable.
Do you know what kind of fin boxes you have for the side bites? You can easily buy cheap 3" side bite thruster fins, and see if it works. My guess is it’s not going to do much for tracking when paddling. I went through a phase of just using 3" thrusters on my Aquarius surf kayak, and it was really loose at high speed and not noticeably different than finless when paddling.
I have iRocker side fins. Here’s the link. iROCKER Flip Lock Side Fin I can’t tell if any third-party fins fit because iRocker just HAD to be different.
There are for an inflatable? They seem to be really inexpensive, I would just buy a center fin and cut it down.