When you template , size and place these 3 fins at their optimum they assist the board in everything including planing with no feeling of drag, just pure Where Do You Want To Go Energy .
This is not possible with off the shelf fins and few have worked with custom made fins to seek this like some did in the very early 70's with single fins and boxes for placement changes .
Its a lost art :-(
Totally agree, this has been a great read, so much food for thought.
Yeah George thanks I copy on the double inside single radial concave for shorter quads, but how soft/subtle are the invees on that gun, I could barley make out any crisp shadow lines across the bottom. And whats the concept and how does it play off of adjacent rail foil?
.....Also earlier you spoke of board asymmetry and rider toe/heel bio-mechanics, are there any rider bio-metrics, aside from obvious rider wt./ board volume that you incorporate in custom design.
I've worked with and spokento a lot of guys in the industry, but you really distill and deliver potency.
Sorry I wrote so much I didn't see the question in time. The InVee is distinct and strong. It runs under a quarter inch deep at max for the doubles, the single up front is around 1/8+
By the way, I'm stoked as I got the message today the board was shake down tested in smaller (15ft Ocean Beach, SF) today. They were impressed by how well it rolled over on rail (what the guys look for) because heavy boards like that usually are resistant to going into a turn. It's working, so Mav's tomorrow, hoping for more positive feedback.
Here's a ghetto screen shot of the contours and another shot of the rail slice of InVee:
Hi Bernie! I think the 40+ boards Ryan did were a snapshot in time. He had a budget and was consigned to build anything he could think of, then test the boards in surf venues throughout the world. "Snapshot" meaning, he built those boards for himself in the space of ONE month, by himself. That is one way to hammer out designs. I had a design course long ago and I recall the professor saying, "Fill the room full of typewriters and put monkeys at each one, eventually one will type out some Shakespeare..." (I am NOT saying in any way that Ryan is a simeon, focus on the approach.) If I presented a blank check to you, saying "Come up with boards of your own design" it would be a reflection of what you were into at that moment in your journey. If I presented the same offer 3 years prior (or ahead,) we know you would have different boards laid out, thus the "Snapshot." BTW, that is one HECK of a surfboard building feat- staying creative, building in unconventional ways, hats off to him!
Regarding what I think about what Ryan is doing, you are seeing a lot of background pulled from a lot of different places, with a VERY short development phase. I think it would have been really cool if he had a shaping/building area right at the venue (G-land, Chile, wherever...) and build 4 boards. Then use them. Then build 4 more (unfettered with outside concerns, like people/money/time/etc.) and so on until at the end of 5 or 6 "cycles" the designs become mutate closer to perfection. Even BETTER would be to share the info, rather than keep us guessing (NOT just dimensions, not enough, sorry,) and STILL EVEN BETTER YET share the experience of many Surfer/Shaper/Builders in a collective forum... ...oh wait, that's Swaylock's, or potentially anyways... ...as you've said, there are those who do not seek credit, so logically there are others who do. Stan Pleskunas and George Greenough said it best when I asked them if I could build a "Half Pipe" Sailboard like they were ripping on one afternoon in the mid-1980's, "Sure!" he quipped, "That's what it's for" said Stanley. That stuck with me for decades now. They didn't give a shit, they were onto the next thing already...
"Absolutely nailing down why quads are inherently faster then tri's." You know what? my guess is the quad rear fins are in the shadows of the front fins, racers call it "drafting" but I cannot say for sure, there is only theory no direct supporting data. I did one time address the "shadow" thing when I was working on the Titan IVB Project where the nose cone created a shock wave (called "the Bell") inside of which the entire 200 ft long vehicle "rode" inside. With the Quad set-up, there is a good chance this shadowing is happening (at times,) and the benefit is less drag. I should say that the effort to create the initial shockwave at the front fins increases a bit but not as much as the fins individually. *"Shock Wave" is a pretty harsh term but is accurate, there's NO sonic boom here, basically the water is being struck, and like ripples in a pond (shockwaves,) those ripples travel/propagate out from the source, and into other objects (fins.)
Thanks for posting that video! VERY revealing, note how much accelerating he's getting, clearly an octave (or two) faster than conventional boards.
"There's got to be some form of flex and bottom action going there especially since the boards seem long and thin in comparison to what the other pros are riding. Plus when you look at his snapped board it looks really thin and flimsy. I'm guessing he's pushing boundries but I'd like to hear George's take on it all."
I said before, "EVERYTHING'S a spring" even the water. The board is for sure bending and more importantly, rebounding in near perfect sync in most of those edited shots (they are NOT going to show you a "low lights reel" of all the shitty boards that didn't work, which is actually a shame, "Dead Ends are learning" one of Larry Gephardt's sayings.) Ryan's boards are light, they are chattering on the surface. Not sure that they are undulating too much, maybe they are (check out Dragon Boat racing in Thailand on YouTube some time, watch the Bow Man, ha ha.) I haven't met much success with perimeter stiffening, like parabolic stringers, or carbon rails. The boards, especially those without center stringers exhibit "frame roll" which is the twisting of the rigid rails inward when the feet press down hard on them. That's a good example of Lateral Bending, visualize the board as an aerobic trampoline, the frame being the rigid rails of the board. If you have a concave bottom contour under your front foot, and you spike a turn real hard, the board bends slightly rail-to-rail, turning that concave into a flat area or even belly, which can either be bad or good. For me it was never too good. I think I see some frame roll a couple times in that video. Water is also acting like a spring, MOVING water is "harder" and rebounds quicker. Almost like there's a "ball of water" under Ryan and he springboards off of it. Further the fins act like "fences" and contain some of the spill to keep that ball of water momentarily under him a little longer to exploit. Again, just some thoughts, not sure if they make any sense... ...flexy fins would aid or hinder in this effort. Also, the length of the fin base can be relevant. Ryan is using a type of lollipop fin on most of his boards. Some are like standard thruster fins but with a large tip. Greenough did a lot of work with those.
Hi Yorky! Good timing! Nice to have a positive environment to come back to. That's the way I remember how Swaylock's was like, there's plenty of other forums where those types can hide behind their keyboard and try to compensate for their own shortcomings. They can have it! ha!
Hate a machine? interesting. Door planers are machines. I'd shape a board using a seashell if that's all I had. Anyways, a good reason to use a maching is repeatability. Using CNC has allowed me to change ONE little thing in a shape, like "50 thousandths more tuck behind the wide point" with everything else equal to the previous shape. Literally isolating shaping elements. Plus the programs are getting better. Overall, it has changed how we've learned how boards work. In the last 8-9 years, I've found out what little increments of change can do to how a board feels. BUT the software allows us to create "fresh slate" designs as well, as mutations are the big jumps, the big gains, in board design. I should mention that I've "hand shaped" well over 6,000 surfboards (using an electric planer) and I don't miss the sweat labor, yet still there is an appeal to hand shaping (with an electric planer,) and I still will do a shape now and then. If I had 50 iFoam SUPS to shape in a rush, I'd think otherwise, but I don't do large numbers of anything, not even with the machine. We own our machine free and clear.
Changing the fins on a symmetric shape makes a HUGE difference. If you haven't tried it, I strongly suggest you do. Where to start? Hmmm, depends upon how/where/what you surf. No be-all answer there. More vertical fins are more pivoty, and fins with rake provide more spring, so match that to how you want to surf going from Heel-side to Toe-side. (I'm talking TURNS, and NOT just "going left" or "only rights," though that works too.) Again, "Nothing ventured, nothing gained..."
Yes, the "+" in my fin nomenclature refers to the "Toe" (reflected as distance out from the nose, so +2 is a long straigh stick, starting at the fin dot for the rear edge of the fin and pointing forward out toward the nose, but NOT right to the tip, but 2" away from the tip.) So, 11-1/4 x 1-1/8 + 3, is 11.25" up from the tail block, 1.125" IN from the rail, pointed 3" off the nose, this positions the REAR of ANY fin, I call it the Fin Dot.
Thanks, glad you appreciate it, at the least it's entertaining, but there might be a spark in that ^^^ 4,000 word pontification which may inspire someone, someday to build a bitchin' board! Thanks for chiming in!
"Why use a middle fin in your asymms?" Funny, I've been into my twin keeled fish lately, I think I've come across an ideal rocker or something, it seems that it can do no wrong. That said, the original push was that the most "vert" set up has been thruster, meaning vertical surfing vs horizontal, off-the-lips, up the face, combos like that. Quads and twins can be made to do the same, but the three fin goes right into the moves. (long explanation as to why, counter-intuitive, as it involves an actual "stalling" of the fins/board, or at least a slide of the rear end. Picture an old "Hook and Ladder" firetruck with the steering up front AND in the back (the Tiller.) That "rear steer" sets up a better trajectory to hit the lip vertically. The original push we wanted to make was to pursue vert surfing. NOT all the designs we've done are exclusive to this.
Hi Greg! Not sure which 3 fins, do you mean the 3 rear fins I've seen in your set-ups? Every bit of feedback I've heard of that set up has been positive, obviously you've tapped into something that works, and is VERY DIALED IN! Bigger guys really like the hold, you've distributed the fins to share that load, versus pegging it all onto one fin. Very smart because no particular fin will come close to its' stall limit and produce drag. I need to think more about that as I don't know much about it. Larry Gephardt tells me how he will "hand plane" his fish and put it up on rail. The fin actually promotes lift, and supports the board whilst on edge. Do you foil your own fins? I ask because at that level, the fins have to be perfect. Up close, Geppy's personal fins are works of art.
Right on! Good food! Stay tuned!
I was speaking of Thrusters , the same can be achieved with 4 fins , my 5 fin , twin fins ,and my tri fin and all came from finding this during single fins .
It has been neccessary to make and foil my own fins to create this effect , hopefully I will be able have them made some day .
Only problem is I have too many sizes to cover the range of boards I make ;-(
I will make you a set to try if you like in any of these types , could be fun ! :-)
Precision is the beauty of CNC. For example, the same rail profile shape can be accurately reproduced and/or proportionally re-sized repeatedly. As you say, this allows one to credibly vary one aspect of a design at a time.
Rail profile shape seems to be relegated to some mystical realm.
Regarding rails, do you use science/math/engineering to design your (specific) rail profile shapes? If so, which principles?
Could you discuss and elaborate about the performance effects of various rail profile shapes?
Good stuff in this thread, some nice pearls. Thanks for your consideration...
Swaylocks Surfboard Design Forum: thoughts & theories ... practical & theoretical
RAIL PROFILE http://bgboard.blogspot.com/2014/03/march-82014-afterr-seeing-recent.html
Thank you for sharing so much. I'm editing and re-phrasing my question.
I'd like to know where you stand on stringerless construction. Have you explored it very much? Do you see any potential advantages it could have over conventional (stringered) construction? Would you have any particular suggestions for someone building a stringerless shortboard? Let's say, for the sake of a generic baseline example, a standard 6'0" x 2.25" thick shortboard.
What does it take to make such a shape structurally viable or comparable in feel to a stringered board of the same shape?
Thank you again for all that you have already shared.
I was reading through your posts and the the discussion on fins and thought it would be too out-there to ask about your ideas on fnless boards, then saw your response to riding a Mentawi wave and that you've ridden mats. I ride paipo boards/bellyboards - both finless and finned but am wanting to get another finless board. I have three ideas - a 1" thick or so version of an alaia (for speed with control coming from the rails) with a virtually flat bottom, a board with a single deep concave or thirdly a board which utilises bottom ridges and contours. What direction would you go? The other consideration is that I love the capacity to really duckdive/glide underwater that a Paipo Nui/alaia/Galera NoFin offers so don't want something that has too much volume. My experience is that finless boards handle steep/hollow conditions well but can have problems in fuller sections/around whitewater.
Thanks for for your time.
Not only is George a mad surfboard scientist, he is a great surfer. About 25 years ago he busted an air over me on a twin fin, on a shalow reef!