Just shaped and glassed a board intended to be a quad, and have become overwhelmed by divergent formulas and ideas for placement.
The board a 5’10’’ 22’‘wide square tail with a 16.5’’ tail, hard rails, deep single into a concave vee. I purchased a set of Probox production quads and am trying to figure out where to place them.
The board will be mostly surfed in smaller under head high surf, beaches and points in Nh and Maine.
Thinking
Front; cant 8, 1.125 from rail(or1) toe 0.25 ? distance from tail
Rear; cant 6 1.125 or 1’’ from rail toe 3/16 ? distance from tail ???
I have a board with similar dims and I put mine at the distances on the Mckee site but put them both 1.25" off rail with a .25" toe and cants of 5 degrees and 0 degrees and I’ve been very happy with that set up from hip to overhead
I haven't built a quad yet, but I'm working on one now, and hope to build a midsized-simmons quad soon. I saved this thread, because it has some quad info on it...http://www2.swaylocks.com/forums/imput-quad-fin-placement
This one was super loose. I used the McKee placement and the biggest future set I could get, the Simon Anderson set. 6’0"X22-7/8’X3"
I like the McKee placement because he put the back fins in what he call’s the “happy medium” possition as far as distance from the rail (or distance between the fins). He did the years of groundwork trying every combination for every size board. So if it’s your first board of any type then using his placement will give you a, not to loose, not to tight, type of ride and that’s a good place to start.
wondering how he trailing fins being down in the bottom of the deepish double concave vee will effect the ride and if i ran with mckee, and how pushing them out towards the rail would effect things
Obviously the more towards the rail the more of a twin fin like ride, but the main thing I have found (because I have boards with both set ups) is that with all 4 fins out on the rail I have a hard time in any kind of bumpy conditions. They don’t handle bumpy bottom turns as well as with the McKee set up. So if your surfing lots of small, clean waves then put all 4 fins out on the rail, you’ll get faster cutbacks on faster off the tops. But if you want an all around board that can handle some size and some less than ideal conditions better to put those back fins closer together like McKee does. (in my opinion:)
yeah, would like to be able to push the size it would handle and will be surfing some chop and slop. so maybe a more center orientated back fin mckee system is the idea.
jj
Funny, i have that thread open on the computer. That is an AWESOME info filled thread. Quote
I don’t know if this is really the case or not but I have felt myself that some of that conception of quads as not being able to get on edge probably has more to do with poorly designed quads than the fact that theyare quads… maybe the misconception that quads should have wide wide tails and not compensation for that width with some vee…? Or simply from ineffectively placed quad setups…? I have heard more complaints of trackiness from the McKee setup than from the speed dialer or Robin’s setup. I don’t know I don’t have that much experience with production quads though, so who knows. It’s a different beast than a thruster though for sure. I had a shortboard quad made for me by a local shaper and it had that kind of a feel to it. I salvaged it by squeezing the cluster as close together as I could with the FCS fusion plugs it came with; you only get a small adjustment range with them though. Still, I can honestly say that my homemade shortboard with Robin’s placement surfs twice as well, without any of that trackiness.
Aloha TaylorO:
This is one of the reasons I prefer the fins closer to the rail as that really helps the board get up on the rail, and once up they really hold. I have done quads with extremely wide tails that have absolutely no problem getting on edge. In fact my experience with quads (when placed closer to the rail) is that they excel at doing this and is one of the main reasons I like them so much. So for me the closeness to the rail was the key to enhancing this capability.
If a quad is having problems getting on edge it is more likely to be the placement of the fins relative to the rail (possibly also a combination of toe-in and cant), but more importantly the fin template (to much base length) and the size of the fins. If there is to much fin on the rail there could be problems, so getting the right amount of fin area is really important as far as I'm concerned. I'm always looking to get by with the least amount of fin area possible without sacrificing drive and hold.
i think trackiness comes from parallel fins like keels on a true fish. i have a waide fat fish i made 22 1/2, 3, 6’4" and 17nose 17tail 5"crack 11" tip to tip with the mckee and i’m 106 kg and it goes well, turns on a 6 pence,holds on the wall. maybe the best way though is to put fin boxes/plugs for mckee and on the rail and see which is best; i’m gonna do it on the next board. also what about canards on a speed dialer setup? a proven setup/layout and fin style combo.
Robin told me the same thing. He said having the back fins closer to the center will make the board feel like a thruster. I have 2 very different boards with Robins setup using different fins and it works great. My older quads were using a setup similar to McKee’s. I agree that having the fins closer to the center makes the board feel more like a thruster. Putting them closer to the rail seems to free up the board without giving up hold. End result is a loose board has also holds in really well and loves to run. No bogging down after turns. But it could be the fins, I’m using these.
I use the mckee for distance from tail,then place the back shapers dot on the front and rear jigs 1.25" from the rail and toe them both in 1/8-1/4" depending on the design of the board.I also try to keep the same angle of cant on the front and back fins,for the first few surfs I place the fins where they would be in the box if they were not adjustable.You have plenty of options for adjustability so you can really fine tune the board to your style of surfing.Check out the thread"how I probox" it has tons of neat tricks to help avoid disaster durring the install.
im wondering how the McKee and Robins systems work on the turn after you have gone from the trough to the lip and are initiating the turn back down the wave. Today, a local shaper whos personal preference was for thrusters, stated that while quads drive fast down the line, that type of off the lip redirectioning was made more difficult with quads. Wondering if pulling the rear fins towards center like the mckee system, making it more like thruster, rectifys this possibility.
the “How I probox” thread is awesome, just stumbled across it today. Glad there has been a bit of swell in the water all day or i probably would have charged ahead and wasted a lot of time.
I can say that my 6-6 round pin quad will turn hard off the bottom then hard off the top and want to keep going, so slowing down at all. If I place my foot right above the fins, I can make square turns that throw tons of spray.
The first day I rode the board I fell off the back twice seeing how hard I could push it. Once off the bottom and once on a hard cutback. Every turn adds speed even if it’s 180 degrees. The only other board I have that can do that is my Griffin 5-fin fish, and his side fins are all close to the rail.
I haven’t been on my older quads for over a year, so I can’t give you a really good comparison. I never felt the way this setup does with the boards that have the rear fins closer to the stringer. Note that Robins fins are closer together was well. Look up my thread on single fin to quad it has the layout for a board 6-6 long. Other sizes may need adjustments, but just ask Robin, he posts as hand-shaper.
