A while back there was talk about the virtues of thick vs. thin fins. Below are some snapshots of an article that appeared in SURFER p.83; June/July Vol.14 No.2 1973.
Tom Morey’s articles on air injection and flexible structures now this…
Boy we sure were alot smarter back then…
Too bad we didn’t realize it at the time…
Love your MVGs
wish I had some of the Spitzers
Always good to try and learn about new things
I had not seen that article before. It is basicaly correct, though somewhat simplified. In my own experience I made fins in the 3/4, 7/8, and one inch thick range, with excellent results in performance. Was there a question, or did you post the article as an information service?
Hey Bill,
Mainly information service for younger guys. And your reply gives it depth and meaning.
I posted it so anyone to see how far back the idea goes not just alone as an idea, but as an idea printed in SURFER, which also shows how progressive SURFER was in back in the day.
You were obviously completely aware yourself. Which helps bring it into perspective. There is NO substitute for your experience. You are one of the guys who helped create the sport. YOU thought up ideas and tested them until they worked.
Yes the terms have changed though I love the simplicity. And without easy access to NACA or NASA research or info, and based on observation alone, it’s very good. The term Drag inserted where today we label that part of separated flow the Turbulent Bubble. Makes the point, and that is the point. Why complicate things?
The Bahne’s were paying attention, too, as can be seen in the ad printed a year or so later. See attached, or inline if I can get it to work. Mark
Much Mahalo, Oneula.
YOU said it. There currently seems to be a stranglehold on the past, technologically speaking. But the past I remember was creative not static. At least from what was coming out of creative centers like HI, OZ, and later FL. As for Tom Morey I lived for his articles. He totally maximized the flexible structure and got the removable fin and permanent box ideas firmly planted. They thrive today in many forms which all trace back to Morey. We can see the proof of that in the list of prior art in any of the current fin system patents. The Bahne’s were right on his heels. But since then what?
I ran across an observation by Warren Bolster in an interview in a later SURFER* mag where he voiced his concerns about what he saw as the increasing localization and isolation of the individual Cali surf scenes. (If it doesn’t show in line check the link at the bottom of the post to read it.)
I wonder how much effect, if any, this kind of thing may have had, or may have influenced, the current state of affairs? Given that the stifling of creativity may be based on the lack of freedom as described by Mr. Bolster it would seem to be almost institutionalized in and marketed by the industry and media today.
Has the Spicoli thing become total reality, ie. wear this brand and ride that board, or risk the wrath of Spicoli as when he said, “Those guys are a bunch of fags.” LMAO for sure, but isn’t that attitude holding back progress in the face of increasingly outdated materials, boards and maneuvers? Heck the aerial movement started 30 years ago in FL where nurture was cultivated.
Swaylocks is great for teaching everything to the next guys from how to make a swirl in both poly and epoxy, to the latest blank, fiber, and resin materials, but is Swaylocks the only source for progress? For freedom? If so what can we learn from the past to keep it that way and help it grow beyond this forum? So we aren’t doomed to repeat the same stagnation problems. I think I already said it, nurture.
The FL guys nurtured each other for the most part from Tabling (who still runs a surf school) on and propped each other in the mags. Bolster was there back then for some of it, so he knew the alternative. I talked with Greg Loehr a couple hours ago and he was telling me about Tabling taking him to Sebastian Inlet for the first time when he was 15, with Warren Bolster. And Greg repeated that kind of thing with the team of Bruce Walker and Lewis Graves at Ocean Ave. That is where Kech learned it and he still does it to this day to his credit. One of his proteges is Kelly. Now, is it any wonder Greg, or Kech or Kelly exist coming from that kind of background? Greg nurtured MVGs, too, so I know how important it is to have that kind of support. We see some of that today, but there could be more of it across the board. Most of it is concentrated here, at Sways, though, there could be more here, too.
We need to look to the past more to remember and learn to lighten up, loosen up, free up, and move forward rather than see the past as something static.
*Reprinted here without written permission, but with full credit to SURFER pg. 79, Vol. 18, No. 3, August/September 1977.
I believe that there is a place for fins in a range thicknesses relative to their horizontal cord. I’ll leave assymetrical fins out of the picture for the sake of keeping things simple. Thicker fins are make changing the angle of attack easier. They are more sensitive to directional change. Two fins of the same template will act very differently depending on their thickness and the position of the vertical cord but we’re only talking thickness right now so I won’t introduce much on that variable here except to say that as you move the vertical cord forward and increase thickness break from one direction to another more easily.
In cross sectional picture at the top of the post the thin fin is given a raw deal because the foil on it stinks but then so does the foil on lots of fins. The picture is a better example of a good foil and a bad one then how a thick and thin fin perform differently IMHO.
Thin fins may not change direction as easily as thicker ones but I agree with George Greenough when he says that they are faster. I’ve had a chance to get some direct feed back from a top surfer who drops by this forum occasionally that rides single almost exclusively and when he wants to go really fast he wants a very thin fin.
Foiling thin fins with no flat spots is a real challenge but the results a clearly worth the effort when speed is essential.
On boards that travel more slowly, particularly single fined longboards, relatively thicker fins work better because they make the board more manueverable.
Fins with flat spots, like surfboards, do a bad job of directing water flow naturally. Any fin template regardless of how thick or thin it is will get a bad rap simply because it is foiled poorly.
Good waves, Rich
That’s a good article. Thankyou Mark. Halcyon, single finned longboards can be devilishly fast. Thick fins can be fast.
Mark,
My earliest exposure to the thick fin concept, dates from a discussion about it with Phil Edwards in 1960. Phil was fully into thick foils, and could discuss the subject in very technical and correct terms. It was obvious that he had done considerable homework on the subject. You just had to pay attention to a man of his surfing skill, and stature in the sport. I think your post is quite timely. There seems to be a stagnation of either design, or thinking, currently. I hope this stimulates an exploration of thick fins in conjunction with current high performance short board design, as well as revisiting it relative to “modern” longboarding.
on it …
thickness is 13.5 % of chord length , positive bouyancy , rear fin is 15 % of chord , built in 96 , first national title in 99 , 4 all up since then …
this is just part of the package …started in this direction in the mid 80s with foam sided fin panels …much to the dismay of every other board builder …
bringing this down to modern times and in line with some earlier comments …
i recently presented a board to 2 different pro surfers and got 2 totally different responses …
one has never won a world title , but everyone wonders why he hasnt , and years back it was predicted he would win many world titles …
the other has done pretty well …
the first guy zoned in on the fins and said there to fat , never even rode the board …
the second guy zoned in on the fins and a few other points and said yea unreal , before he even rode it , then came back with feedback consistent with my own …
guess the difference between good and better is an intuative understanding of what actually works , not what looks cool …
winning world titles and performing at elite levels requires way more than just good surfing skills, riding average equipment is the biggest handicap …
its little wonder that in the past those who stood out and carved reputations for themselves that have lasted to this day , were willing to use what would be considered unconventional or uncool curves , but the bottom line is they had an advantage others couldnt understand and didnt seem logical …
seems nothing has changed …
but hey if others cant see it , im not really fussed …
the longer boards continue to stagnate , the better off my own team guys are …
weve even been locked out of some competitions , because there sick of the same guys winning all the time …
even talking about having boards built to a certain standard so the competition is fairer …
now that makes sense doesnt it ??? sounds pretty progressive to me ???
it all comes down to economics …
whatever wins on sunday sells on monday …
as long as theres a dollar to be made , it will be an influential factor …
the masses dont have a clue , they just buy what wins …
coming back to simple fins again ,
thin fins are cheaper and easier to produce , so its uneconomical to promote something that functions better …
that separates board builders into 2 classes , the ones who dont give a rats , and the ones who do …
regards
BERT passionate about fins …
o and thrailkill , that last comment of yours made my day , but its just like the greek mathmatician (cant remember his name ) he discovered 2500 years ago the world was round and worked out its exact size using simple geometry , he was only 40 kms out on the actual circumference of the globe coz he didnt consider the equatorial bulge due to the rotational speed of the earth creating centrifugal force …
but that knowledge was locked away for 2000 years before it became mainstream …it was something that the mainstream just couldnt except until it was proven beyond doubt …
so i guess we wait …
What do you think the chances are of Surfer mag running that exact same article today? Zip to none would be my guess. Just goes to show, nothing about building surfboards is revolutionary. All the information is/has been out there for a LONG time. It’s just a matter of applying it in the relevant areas.
Theoretical question on thick fins: Can you decrease the overall fin area with a fatter fin? Say, decrease the overall chord and depth for a given outline based on the thickness relative to chord? Granted if you shorten the chord the thickness relative to the chord length will be greater but overall, would it be prudent to lessent the suface area going with a thicker foil?
I once had a Surfer Mag editor back in the 80’s tell me, “I don’t think Surfer is the right forum for articles on board design.” … ??.. ??.. … ??.. ??.. ??.. ??.. Well then… what the F#&K is???
…SWAYLOCKS RULES!! …
IMHO thicker fins provide a smoother, more powerful ride while thinner fins, popular today, offer the promise of more speed but rarely pony up. In windsurfing we did a lot of work on this and the only point of sail that was faster with a thin fin was broad reach. Every other point of sail was faster with a 12%+ foil section. And yes, we could reduce the size of the plan shape with a thicker foil. Also, the thinner fins we tested had to be produced with 100% carbon or aluminum or they were useless. This all doesn’t apply directly to surfboards but it’s certainly close enough that the findings have merit.
In the real world of hydrodynamics you’ll never find a foil of less than 8% which is thicker than almost all surfboard fins made today.
OK you have me now. I’ve taken a templet off one of my fins and I’m haveing one made that is between 7/8 and 1 inch thick, it will have a foam core to keep the weight down. The fin is 11 inchs long and had a base that is 8 3/4, it is not a pivot fin but does not have a lot of rake. I will let you all know how it works like for me.
Bill,
Seems you are a better place to start than the article I posted.
To me designing and revisiting designs can not proceed without you.
Can you recall your first and any later conversations you may have had with Mr. Edwards? How did he approach designing and what were these conversations like.
And or can you describe how he inflenced your
fin and board designs and ideas? And vice versa.
I dont know exactly what I’m looking for, but I will know it when I see it.
Mark
“guess the difference between good and better is an intuative understanding of what actually works , not what looks cool …”
Interesting observation, Bert. I think that however well intentioned a surfer, subsconscious preconceptions and preconceived notions can foul up a test. How can I or anyone prove that? I can’t.
MY examples:
I gave MVGs to a former top womens world champ. Hand full of world titles. In her 40’s and she rips like you would not believe. She said she didn’t feel anything. I gave MVGs to a mens pro who was top five last year. He said he didn’t feel anything. I gave MVGs to a multi time world champ, and his brother told me he said the same thing. He didn’t feel anything. But he said he liked them, until his brother or someone influenced him.
I gave them to a commer and he said he won’t tell anyone about them because he doesn’t want to give away his advantage.
I gave MVGs to the current longboard champ. He called me right after his session to tell me he was stoked. Said they gave him more speed and drive on his single fin egg with tuna fin. More speed and more control.
Question, how can anyone stick something as big as that on the bottom of their board and not feel something? Anything?
Maybe it’s all in the mind? And being open to the possibilities allows one to push the limits of their abilities towards them. IN other words surfing past their known ability. Isn’t that after all where new moves are found?
What does this tell us? Where does it leave us?
There is safety in numbers not in creativity?
Testing is inconclusive?
The whole experience leaves me confounded.
Back to thick vs thin.
You have to trust your riders…
Could have to do with a wide number of uncontrolled variables…board type, speed of waves ridden that day, fin on which the MVG was used, rider style, etc.
Given the circumstances I’ll take a zero over a negative number anyday.
Based on that I have some ideas.
I think it has something to do with level of expectations. I suspect drag is easier to feel than a small increase in speed or control. That is probably what most people look for first in a test. Drag and resistance or tracking of any kind. If they were looking for drag and resistence first and they didn’t find any, then a zero is a very good first result. The best possible in fact.
If any of them had said it slowed them down I would have quit.
After that a new mind set and a new test is required. I don’t know if anyone of the above mentioned pros took it that far. They all had things of their own to promote.
This is not so much about MVGs, other than that is where I have my experinece testing, but I’m actually wondering how to test fins in actual field trials and lower or at least control for the subjectivity of the rider. That is in the broadest terms I can think of right now.
I’m thinking if I had a questionaire with a testing parameter and introduction so I can either program the rider in a way as to standardize the test or establish a baseline of some sort first. Or establish the rider’s mindset prior to testing. Mood is important. Attitude towards the board they are using too. One former world champ said he tried them on a board that was a known dog and it didn’t make it magic. What does that tell me? If I was a big fin company I’d have my doubts about tests like that.
It may sound jaded, but if I put $50 bills in the bags maybe I would have gotten different results. But that’s not my style. I have too much respect for and belief in the integrity of the individuals to do that. So we can eliminate that variable. They can take money for board shorts all they want and not affect their integrity one iota. But taking money for testing a performance product like mine never happened to me. I can say absolutely no one ever asked and I never offered. In that respect my test results are pure.
In my experience we have very ethical pros and shapers. So be stoked about that.
Great article and drawing. Maybe, aside from a lack on understanding by most of us, it is a cost consideration. We looked into having a 1/2 panel laid up(i think it would give us around 25 10 inch fins) and it was a lot more than a 3/8. By the time we would have them foiled and all it was going to cost close to $50 per fin. If the panel was 3/4…wow I think it might be $75 or more per fin. Well worth the money for all the advantages that a proper foil will deliver, but not what the masses will pay in most cases.
Roger
thick fins cost too much? like, 75 cents worth of 3/4" plywood…
I am a great believer in full foiled fins. I find they work smoother and are probably the most underated aspect of board design at the moment.
Mark, I did spend some time with Phil when he was in Australia filming Surfing Hollow Days, and all these years later I guess he could still be considered my own biggest design influence. I was a 15 year old kid at the time, and the way I got it from Phil is that ‘foils have their thickest point a third from the front and a fin’s trailing edge should be blunt’.
Nowadays, I have my own small fin company and Phil’s ‘rules’ still stand true as ever…
Thick foiled fins. Good. Here are some of my prototypes that I had laying on my desk. None of my boards are with me right now- maybe I’ll take some pictures of what’s on my boards later. Enjoy. I find that the thicker fins have a smoother- less draggy feeling to them. These fins pictured are only for my noseriders. I have only recently started messing with them on my performance boards. So I won’t get into that… But I find that about a thickness of about 10% of the chord length is perfect for my noseriders. I don’t have much time to ramble right now, Maybe later. (oh that thick ass foam fin is something like 17% of chord) …and there is a reason why the fins are shaped like airplane wings. Guess why? Enjoy! -Carl
