The set up I have on my wide tail quad is epic. Front 35mm from rail with 4mm toe over the length of the shapers mark
Rear 45 mm in and 2 mm toe.
8 degree in front
4 degree in rear.
I can’t remember how far from tail.
If I remember I will try to find where I put the piece of paper. And let you know.
For regular boards I swear by robin mair’s placements. If you message me I can send you a pdf with them on it.
http://www.gearbox.surf/resources/PDF_Files/GB-Quad-Fin-Layout-2015.pdf
Robin mair’s placements.
On a short wide board I would move them closer to the tail by at least half an inch.
I’m no expert but this works for me. And as for my mix of metric and inch measurements.
Sorry
Here’s Jamie’s recomendations with Chrisp’s added suggestions. I have personally decided to stick to an old forum labeled “Larry’s probox” where he recomended the toe to remain the same for both front and rear.
Definitley looks better with the cluster pushed back. Is it just me, or do the fin boxes still look a bit clustered like my last diagram? Keep in mind this diagram is accurate to the representing numbers.
ON A SIDE NOTE: When you talk about distance from the rail, you are referring to the rear base of the fin, and not the outline of the box, correct? Stupid question, but want to make sure lol
Chris - I’m sure I’m just clumsier than you. So much of this stuff is subjective, and then you can play with different foils etc too. I don’t think less cant made it looser, so much as having different cants did. At first I found quads intimidating, but they kinda grow on you. Lots of room for experimenting!
I love the Robin Mair inspired set up, with the trailing edge of the front fin 7/8" - 1 3/8" in front of the front edge of the rear fin.
I was fortunate to use RedX boxes at the time, and experimented with the fore/aft spread, and the biggest thing I noticed, which Robin had said would be noticeable, was the drag the came into play once the spread got beyond 1 1/2". The two fins stopped acting “as one,” and not only was the drag noticeable, but the beginnings of stalling (less/reduced “sharpness” of turn) at high angles of attack too.
Reminded of the fin box thread… It’s good to have options/the ability to make adjustments.
Not unlike the potential fallacy of “secret sauce,” the above is simply my personal experience.
Yes, when talking distance from the rail I am talking trailing edge of the fin itself, not the box. Honestly I haven’t really seen the rear fins closer to the rail than the front fins. I would move your rear fins further away from the rail (more than the front 1.125). This will also help with your perception that the fins are too close together (because they are in this case).
I have agonized over this fin placement stuff in the past, but have gotten over it. Some basic rules apply: Tighter cluster-looser, more pivoty. Spread cluster-more drive less pivoty. Rears closer to the stringer: more like a thruster. Rears closer to the rail: more like a twin. Try to position the fins so that your back foot is placed somewhere in the middle of the fins, this way your input from your foot goes straight down to the fins. That’s why clusters are further back on shorter boards: because your back foot is also usually a bit further back.
There is no right answer, just go with these basic principles and don’t sweat it too much. You can always change fins, or move them in the boxes if you use fusions or two-tab fins in FCS2 boxes.
The fin placement and toe look good to me.
For quads likd this the trailers and lead fins
should be assymetrically foiled IMHO.
One could do a Twinzer type set-up with the boxes
placed as show. Certainly experimenting with fin combos
will be a good idea here.
bigger fins up front will make for a quicker turning moment,
and bigger ones in the rear will give more holding power and
will support large wave performance better.
Stay Stoked, Rich
Rich… I have been thinking for a while about something.
A center fin is double foiled.
Side fins are single.
If you split the center fin in two and move them out towards the rail, the foil bias should grow as they move closer to the rail.
Yes?
Is that where 80/20 or 70/30 foils come in to play?
Maybe some of the issues that folks have had with quads not working is that they were using flat sided fins in a McKee setup or double foiled fins in a rail finned quad setup?
When you say trailing edge of the fin, are you referring to the trailing edge of the base, or the rake?
With a quad set-up having the both lead and trailing fins placed close to the rail, whether it be
a standard quad or twinzer. The fins should be foiled with a flat side or a helically foiled side
and a convex outer foil. This type of set up has the fins more toward the tail block as this
provide a better turning moment and directional stability.
With a McKee or Stretch quad set-up the lead fins are placed similarly to a truster
and the trailers more inboard and a little forward of where a thruster center would be placed.
All placements vary with board tail width. This type of fin set-up does better with 50/50,
70/30, or 80/20 foils as flat sided or helically foiled high pressure sided fins make the board
sticky particularly off the top-turn. I’ve found that that these fins with dissimilar concave
surfaces as trailer offer very nice performance and do well in big surf. Nathan Fletcher
asked Stretch to foil a set for him a while back. He was quite pleased with them.
Stay Stoked, Rich
The thing that intrigues me about quads is that there is no generally agreed way to set them out. Pretty much every aspect from cant, fin size, toe in, distance from tail and rail etc is up for discussion. This compares to the thruster set-up which has remained basically unchanged since Simon Anderson came up with it in 1981.
From a board designer’s point of view the scope for experimentation in quads is exciting. There is a local shaper round here who’s been exclusively making quads for years now. He’s surfing really short boards as well: 5’4" for example. He also happens to be one of the best surfers round here which makes people even more curious as to what he’s doing with his boards. The other day we were surfing one of the local spots and he let me have a try on the board he was riding. The board was so radically different from what I’m used to surfing that at one stage I actually fell off while I was going in a straight line! It was a great experience, as I like nothing more than having a new avenue for improvement in my surfing opened up for me.
Anyway, I have enjoyed reading about people’s thoughts on quads on this site. Keep 'em coming!
My outline continues to change the more I read about wide tailed boards. I gave it an arc tail to help the transistion from rail to rail. I made the nose and tail slightly narrower, but increased the length from 5’6 to a 5’9 to compensate for the lost volume. The quad fin placement remains the same, 5" and 10.75" up from tail. My next challenge is deciding on the bottom contours.
This board is designed for small summer days anywhere from waist to head high (maybe slight overhead). I was thinking spiral V from about 27" up from the tail. Deepest part of the V beginning at the leading edge of front fin (what are your thoughts on that).
That’s where I’m at up to this point, I dont have much shaping experience, any guidance is greatly appreciated.
Should I incorporate single/ double concave?
What do you suggest I do for the nose contours??
I am on same design principle for my next board, i think i will go with a massive concave vee, start in front off middle and increase to Max at tail. For my Quad set up i will start with a standard front fins placement and i go with no toe no cant for rear fins, i put them in the deep part off concave, and use 50/50 fins. I ever do this with success for me. Play with fins size to change board feel, from big front and extra small rear for small fast waves to same size in slow waves. I surf with a front foot stance, that is to say i don’t use my back foot as it need to be.
I like the looks of that one Pendulum
Pendulum, you are fast approaching the “overthinking it” stage. (Don’t worry, many of us are equally guilty of this). You say you are new to the game, so keep it simple and get to mowing foam. Your outline looks great. Keep your bottom contours simple. Ride it, make another…it’s a never-ending process.
