It appears as though that board is not set up with the McKee placement specs from the photo, so don't let that influence your decision.
If you put keels in and another set of smaller fins, that board will be over-finned, IMO. By the look of it, I'd say putting keels alone in either spot would not be ideal... they'd be either too far forward, or to far back. I guess what I'm saying is that board is not set up for keels.
I'd also suggest that you don't need bigger fins.... you need stiffer fins. The other option would be fins with more tip and/or more height, but not necessarily more area.
I'm a big fan of the epoxy performance core fins, like some of the other guys have suggested. I have those green Simons, too, and like them, but I've never put them in a quad. But I think the flex, foil, and template (particularly the sweep) make them an excellent choice, and might solve your problem.
Good info here...
Correct me if I'm wrong, but the whole idea of the quad is essentially splitting the fins from a fish in two. So, if you use keels plus trailers you'd def. have too much fin.
I also like the idea of a possibly stiffer fin. And, something with more height (depth)
You could take the front fins of your standard thruster set-up (you've got FCS's own template with the graphic that is similar to the infinity symbol right?) and add the G-1000 or Q-1000 as the rear fins. I think one of them has a 50/50 foil while the other is flat. They've got more depth and a pinch more sweep than the rear fins in the M4 set.
The Lost Mayhem template Quad fin is big. I told my shaper I wasnt digging my new stick's drive, he asked me what fin i was running when i told him he siad that the wider tail needs big fins, I switched out my old G4 FCS and put in the Merrick template in Galss flex, huge difference! So much more drive. For that board you want flat foil on the inside of the fin. No insdie foil crap.
I agree with some of the others, keels up front with trailers will probably be too stiff feeling.
I have a rount tailed fish, and I'm running a slightly odd setup that seems to be working. I have MRtx twins up front, and little GX double foiled rears (their the center fins).
I tried this setup mainly because I read some reviews about how it worked well on the Proctor little rascal, which has a template similar to your fish (and mine). In any event, I've been pleased. Had it out in the last two swells we got, which together ranged from chest to just overhead, and not soft by any means, and they held well, heaps of speed, and I didn't think it felt to stiff either. Then again I'm about 220 lbs and used to riding twin keels, so I need a fair amount of fin.
I've also heard good things about those GAM fins. If your smaller they might be good as fronts with some small rears (GX, G1000 etc...)
Also, I thought those FCS keels were the ones designed for smaller surfers. I thought they put three plugs on their full size keels, but I could be wrong. Strong surfers have ben know to pull out plugs using keels in standard FCS plugs....Fusion plugs are supposed to help prevent this.
A few guys I've talked to, and this has been my experience as well, agree that fins with a foiled inside surface (meaning the ones that have a concaved surface on the inside) work best in better surf. Fins with flat inner surfaces work better in weaker surf. The only explanation I can think of for this is that while an inside foiled fin is designed to create less drag, there is minimal turbulence and better laminar flow at lower speeds, and you can't really feel any effect from the inside foil. But at higher speeds, where a greater degree of turbulence is created, and flow tends to become detached easier, the drag-reducing effects of the inside foil are greater... great enough to feel a difference. In other words, the faster you go, and the harder you turn, the better they work. That's why pros love 'em, and joes can't usually tell the difference... they generally surf better waves, go faster, and turn harder then the rest of us.
However... since I don't like to spend a lot of money on fins, most of my shortboards have inside foil fins, because when the surf is good, I want them to work good. When the surf is bad, who cares.
great info guys. I agree that the wider tail and fish shape are mostly the issue on the steeper faces, but im not talking inverted beach break drops. My only complaint, is that when you initiate a deep bottom turn on a faster hollower wave that requires a more vertical approach back up the lip, the board hesitates. It initiates the turn very well, with good drive, but the lack of the center pivot fins creates an exagerated turn for me. I can feel the two heel side fins release and it makes my ascent back up the wave not as steep as I would like. There is a similar effect off the top which requires me to initiate a hard top turn a bit early so I dont get caught up on the top.... The side fins releasing at the top actually help. I love that feeling. It lets you swing the board around...
Most of the trouble, although the rails and wide tail dont help, are the loss of torque and sharp turning in a hard bottom turn... So the idea that I may want longer fins with more sweep makes sense as apposed to the wider, keel style...
The physics of it make sense to me, that some added length will create a slightly deeper fin path in the water, thus making up a little bit for the lack of center pivot, with a stronger hold between the 2 side fins...
Its a shame, I have those Merrick Fins, but they are futures!!!
Im just going to go down to the shop, cause they have like 100 demo fins. I just wanted to narrow down a few that I should try...
I will start with some longer fins and go from there...
All my other FCS' arent any bigger than the m4s. All my shortboard fins are 4s or below for better release.
The infinity fins I have are actually the g3s, so they are smaller, so that wouldnt help. I used to have the g4 and 5s but boke them over the years...
So, I am going to have to hit the shop for some demos...
I will try the keel, with small trailors as the last setup and let you guys know how it works out...
The board performs like a BEAST when it was like waist to chest one day, but im just having trouble with the performance on slightly bigger, faster stuff... But these are conditions that arent that supreme, or I would have taken my shortboards out anyway... So, im riding head high+ waves on this board, but not huge barrel sections. Ive actually been on the cliffs for a week or so on it.
It kicks as$ once you get it going and get some speed, but those initial bottom turns are losing power.
I've been using Pavel's Speed Dialer (Canard Quad) setup for a few years now, and I'm very happy with the results. The setup is basically a Geppy fin cut in half and split up to accommodate a quad setup (but it's a bit more complicated than my simplistic example).
Another consideration may be to put the smaller fins in front and the larger fins in back, creating a "Twinzer" a la Larry Mabile. But I'm sold on the Pavel system.