Nice to meet you all ! Excited to put my first post ! Love this forum, tones of great insights.
I have a question on fin. I shaped a single fin 6’0 x 20" x 2 3/4
I mostly ride it in beach breaks in San Francisco area. I have a Captain fin dyer arrow 8’.
I like this fin but I doesn’t give me that much drive so I’m looking for another fin with a wider bade. I would like to keep the tighter turn possibilities. I’m looking at the Futures Machado 8.5", have you guys tried it ? I’m pretty open to other recommendations too.
Here is a picture of the board to give you an idea.
You’re basically going from one extreme to another, there being a ~1.5" difference in base chord between them. Have you looked at the Parrish single fin? (not the 2+1, but the full base single). Or maybe the Dobson fin in that size? Those fins are closer to the middle of that range.
I just glassed a 7.5" fin into an old shortboard of mine. A bit of an experiment. I got the fin template from Blending Curves. It’s the top row, fourth from the left in the fin section. I’ll probably take it for a spin today or tomorrow. I can report back if you like.
Dimensions are as follows: 6’1" X 19" X 14.5" X 11.25"X 2.5" Flat bottom. I set the fin 12.25" from the tail to the leading edge. The fin is just under six inches at the base. The board was originaly a thruster. I never really liked it that much. I have to work tomorrow now so it might be a few days yet before I get to take this puppy for a spin.
The flex fins with the narrow tips go back to longboards and the transition era before boards dropped below 7ft in length. You would move up on the board to put it in trim and to use the long rail line to get your drive, and either turn the board from the middle or step back to get more of a pivot.
The fins that came after that and which went with the shorter lengths had stiffer layups, which made them hold better in faster conditions.
Your board has a short rail line with relatively more curve in the template when compared to a longer board with the same widths. That means you probably won’t be engaging as much rail line at any given time and will need to get more of your drive out of your fin(s). TO ME, that means you’d want a stiffer fin with comparatively more surface area. Less rake for slower conditions and more pivoting, and more rake for bigger conditions and the longer carve.
I’ve tried the short single fin designs several times and I have ALWAYS gone back to adding sides later on in order to get more versatility out of the board.
You might check our Geoff McCoy’s website because he has done a lot of work with singles on shortboard lengths that have lots of surface area. I did a McCoy-inspired design and ran it as a single for several months, but I eventually ended up adding side boxes and I now run the board as a quad - which works way better for me in the conditions in which I surf that board. I still use singlefin designs a lot, but only on boards that are at least 6-10 in length and which are aimed specifically at weak/slow conditions.
I managed to sneak out for a quick surf after work today. It was about head height. There was a fairly fat peak on the bank at the beach running quickly into a sucky little bowling shorebreak.
The single goes fine. It has a nice pivoty feel to it. I got a couple of cheaky little cover-ups on the inside and the board performed well. It was quite easy to wash speed off, and then the board seemed to be happy to take a nice high line. I didn’t really get a chance to do any turns as such so that’ll have to wait for another day.
The only thing was that the fin buzzes a bit. I’m pretty sure I know how I can fix it as there’s a slight kink in the fin in the last couple of inches. I’ll just straighten it out.
I went straight from the single to a quad which was interesting. Two completely different experiences!
