Where in the world do you guys get off saying that’s a reverse fin?
So what if the leading edge is straight and the trailing edge is curved?
CoE of fin is still behind chord base, so it’s a normal fin!!!
A reverse fin has it’s fin area in front of the base center, like those forward swept wings in the AirForce’s experimental computer guide plane.
So what are the physics of the reverse fin and why did it go away?
Why did it go away? Who can say for sure. In my case I’d been working with boards designed around the “reverse” fin since 1960. By 1967 the “short board revolution” was underway. It was a time of change! At that time any board under 9’ 0" was referred to as a Mini Board. I think we all just moved in that direction. I dropped from 10’ 7" to 8’ 8" in one step. It may not sound very dramatic now, but it felt like a quantum leap at the time. I shifted my focus to high aspect ratio fins in conjunction with the “new” board and performance concepts. As to the physics, three elements combined to make the reverse fin superior to other fins in use at that time. Hydrodynamic foil, thick chord, and high angle of attack leading edge. If the fin was constructed with these elements in place, all went well. If not you could look forward to fin stall, digging rail on cutbacks, and spinouts. Not rocket science, just attention to detail. Most of the industry at that time didn’t have much understanding of fin dynamics.
LeeDD, you state your case in a most adamant way. The style of fin under discussion has for over forty (40) years been referred to as a “reverse fin” throughout the industry. You seem to want to redefine the term to suit your opinion. I for one don’t give much weight to the opinion of someone who will not identify themselves to this forum. I like to know who I am having a dialoge with. I’ve agreed with many of your past posts. Not this one however. What the Air Force is up to has nothing to do with surfing terminology, or concepts. Please fill us all in on your background and experience, it would add considerable value to what you have to offer. Thank you.
Bill, Richard. Are these fins closer to the ones you talked about / used?
The fin on the steptail was shot at a bit of an angle so it appeares a bid distorted. I think I have a more straight on photo somewhere. I will find it and post it later.platty.
Platty, yes, the red fin you attached is very close, especially the base/ height ratio. The leading edge angle is within a degree or two of being the same, but with a straighter line. Thanks for the input.
Guys,
The reason why these fins and all the other barn door rudder fins lost stature in the surf world was because people started to design surfboards that could drive, turn and project on waves. In the late 60’s we needed something more than a rudder. Let those fins rest where they belong…in museums. If your building a really old school log, then cool, put the barn door or reverse fin, or a sheet of unfoiled plywood on, it really won’t matter much, it will still be a pig. Now let’s all kneel down and pray to George G, and Simon A. Now give me 15 hail Marys to the foiled fin technology gods.
-Jay
Hey don’t get me wrong, i got a whole house, backyard and garage full of boards from 59-67. I think they are great, and some almost ride well, but i would have loved to see Greg Noll at the Pt, or the Bay on a modern Gun in 1965. Just picture Peter Cole towing in to (fill in the blank)
Jay, I think you miss the spirit of this ongoing discussion. I think that people who were not there " in the day" would like to have a more in depth understanding of one of the many steps on the path to what many call modern surfing technology. In thier day the reverse fin was modern technology. As to the hail Mary’s, only one is needed. Phil Edwards was the first person that I’m aware of to advocate, and put into practice the true foiling of surfboard fins. All of us who embraced the concept and put it into practice, were simply going through a door that was opened by Mr. Edwards. Thanks Phil.
Bill thanks,
For some reason I thought this discussion was an attempt to resurrect the weed cutter? My misunderstanding. I get frustrated…sometimes when we try to rehash old designs with the intentions of making them hi-performance, yes the weedcutter was hi-performance in the day. But it is like the on-going attempt with the fish design, we shape them true to the day of the 70’s then we complain why they track etc, etc. So we end up putting in fin toe and cant, less tail width, concaves, wings, cannard fins, tail kick, and were back to the hi-performance fun board.
I’m a firm believer in grasp and respect for the past, but constantly looking ahead for the successes of the future.
-Jay
If application of terminology is WRONG, then I say…put a semi colon to bracket the mis phrase.
If you don’t, you are leading towards a misdirection!!
A true reverse fin, pointing towards the front of the board, has been used since the late '60’s by SOMEONE!
I even bothered to cut one out of glass stock and fit it into a FU finbox, but the box was too far forwards on the board.
Saw it at some surf mag, around end of '60’s.
I said the same thing about “reverse pointer” windsurfing fins when they first got popular around '90. All it was, was a switch of the leading and trailing edges, just like the original one’s you are talking about.
Just calling a spade a spade, whether it’s 1962 or 2005, a spade is a spade!
Jay, your post speaks to the same frustrations I experience. You are right on point! Thank you for such clarity.
Hey guys,
Reason for the ititial post wasn’t to imply that we should all go back to “the good ole days” or to bring back the dead, just researching a bit of fun history. If the “reverse fin” wasn’t just someone’s cynical idea for humor, then it’s interesting to know how it evolved and for what reasons. Thanks to Bill for sharing some of the early wisdom. A lot of the young guys don’t care, but as an old guy I get a kick out of some of the younger studs who seem eager to know about surfing’s roots and how it all evolved. Many of today’s surfers weren’t around when we knee paddled or surfed without a leash, and though they don’t want to go back to “the day”, they’re eager to understand and connect with the past. Thanks to all for your input!
…What the Air Force is up to has nothing to do with surfing terminology, or concepts…
Conversely, it’s also worth noting that the surfing community often has a propensity to adopt established terms in marine architecture, fluid mechanics, etc. but use them in an entirely different context. The term “chimes”, instead of the marine architectural term “chines” being a prime example. Another example is the occasional use (including in print by a popular surf magazine) of an established term for a totally different meaning. An example being “aspect ratio” to (incorrectly) mean the ratio of thickness to chord length of a fin/foil, rather than the ratio of the foil span divided by the mean chord length. There are many other examples as well.
This practice of applying different meanings to previously established practice can easily lead to misconceptions and bad physics when exploring/researching technical articles in fields/interests other than surfing…and can lead to inadvertent (and sometimes) heated discussions between parties who are using the same term for different meanings.
mtb
AMEN!
Speaking of Phil Edwards and fins… he once said they “are one of, if not THE most important aspects of design. If you don’t believe it, try your board with no fin.”
Go down to the Takayama shop. Donald basically scaled down the Phil Edwards reverse fin to fit a fish surfboard or side fins or side bites and also added the template to a longboard fin… AND HERE IS THE SHADY PART… HE HAS HIS PATENT LAWYERS ON IT TRYING TO PATENT IT! I wonder what Phil or L.J. would say about that crap??? Oooh… change it 10% and it is your idea, huh? Wow.
Isn’t the Spitfire wing inspired fin, sold by Solosurfer, pretty much in principle a reverse fin? By all user accounts in the following thread it still seems to be a valid design: