adjustable fin systems just a gimmick ????

hello all…

I have been reading through a lot of discussions about fins and fin set up, and i know ye all are probably sick of discussing it, but where i come from (EIRE) you don’t see really any of these adjustable system.  

A bunch of us were discussing them over a few pints the other night and we came to the conclusion that they must really be for pro surfers, but yet most of them don’t seem to use them!!!

Form reading other discussions on this it seems they do change the feel of the board but are they used that much?  caus any off the rack boards i see tend to have the FCS or Future fin systems…

personally i dont think I would notice any difference but then again i tend to do a lot of my surfing in the wite-wash hahaha 

 

by the way folks take it easy on me virgin participant here!!

Fin position will make or break a board design.     The  difference between a ho-hum board, and a magic board!

does changing the length of a board make a difference? With out a doubt. I don’t know if you longboard but if you do take the fin and put it all the way forward. Try to nose ride. Put it all the way back, try and nose ride. Night and day. The fcs fusion plugs offer a tiny bit of adjustability and it is enough to make a noticeable difference.

A repost of an article I wrote years ago.

 

When you walk into your favorite surf shop and get all google eyed over the masterpieces in the racks, it’s not the fins you’re drooling over. Think about it for a minute though. What is a surfboard, but a summation of hydrodynamic surfaces. Just as an airplane generates lift from its wings and control from its tail; your board’s bottom generates lift and affects speed. But, it’s your fins working together with rail and bottom contour that most influence the feel of your board when turning. And let’s face it how many short boarders straight-line the waves they ride.

Few surfers really understand how fins affect the way their board rides and leave all the specifics to someone else. Rail and bottom contour assist fins in performing their function. But, what really influences the way your board turns is the combination of several important fin factors. No wonder so few surfers pay attention to the "Fin Affect". It’s f’n complicated!

But, today, as the form shape of surfboards goes through finer and finer adjustments, the biggest gains you can make to your board’s performance have to do with your fins. The predominant factors that influence your "Fin Affect" are:

1) Foil Shape- the curvature from leading edge to trailing edge as it changes from base to tip.

2) Template shape- The combination of depth, width, and rake that make up the profile outline of the fin.

3) Placement- which incorporates how far the fins are from the back of the board, how far apart they are from one another, toe and camber.

4) Stability and flex.

 

Let’s discuss each of these and how changing them will affect the way your board performs.

Foils are surfaces that affect lift and drag. If you notice an airplane wing has a flat side on the bottom and curved side on the top. The path of least resistance is the bottom side. It takes more effort (drag) to flow around the curved top surface, so more air flows under the wing than over. This creates high pressure under the wing. The air that does flow over the wing separates from the wing at the apex of the leading edge of the wing and creates a low-pressure area above the foil and a higher pressure area below. This difference in pressure forms the force (lift) that allows the wing to go up. The more curve a foil has the more drag it induces over the curved surface; which means that a foil with greater curvature will have more lift at lower speeds. The problem is that at higher speeds that additional drag will develop turbulence and stall the flow across the foil. The exact same scenario occurs under water with side fins. The big difference is that instead of lifting your tail out under water; Side fins orient the curved surface so that they actually pull your boards fin and rail down into the water. This gives you hold when cranking a nasty slash. Consequently, thicker more curvy foils for slow waves and flatter more fine foils for high-speed waves.

Template shape has to do with how the fin looks in profile. An over simplification would be deeper, rakier & wider fins provide more control. But, the more profile you have the more fin you drag around. So, you have to optimize the combination of the three so that it is loose enough for your conditions. Yet, it is also tight enough to not get too squirrelly on you. Other factors that figure into requiring more or less of these three variables are:

1) Type of wave: steep and heavy or slopey and fun.

2) Surface conditions: Choppy and irregular or clean and smooth.

3) Rider Size: Big and heavy or small and featherweight.

4) Rider Style: Subtle and flowing or Extreme and radical.

 


Each of the first considerations requires more fin template area and each of the second work better with less.

 

 

 

 

 

 

Placement has traditionally been left to convention. Simon Anderson set a benchmark twenty years ago for approximate location. Each shaper has their own personal preference for each of the "models" they make. But, there are subtle differences in most boards and in all riders. Otherwise why would custom boards be in such demand?

And remarkably as little as an 1/8" movement fore or aft in either or both the center fin or the side fins can have almost as much effect as going from a rakey 4 ¾" fin to a vertical 4 5/8" fin. If you move your fins closer together they act looser and if you spread them further apart they get tighter.

Toe is the amount of angle the base of your side fins are pointed in towards the center of the board relative to the leading edge and trailing edge at the base. Camber is the amount of angle the body of your fin is set at relative to an imaginary horizontal plane perpendicular to your stringer. Both affect the angle of attack that your fin foils experience as they flow through the water. More angle forces more water flow around the outside plane at lower speeds. The net affect is that it becomes easier to initiate turns on slower waves. To much angle at higher speeds increases turbulence and drag.

Finally, stability and flex are crucial to making this all click. If you have a deeper fin you can get away with more tip-flex and not wash out. The benefit of tip flex is that it dampens or smoothes out some of the bite in direction changes. The down side of tip flex is that if you get too much tip flex it will wash out. Base stability is crucial to a good set of fins. If a fin moves around at the base it will set up turbulence. Turbulence generates drag and disturbs the lift, which keeps you fins holding. So it is slow and out of control. If you like a more pivoty board you would do well to try a stiffer set of smaller more vertical fins.

Prior to eight years ago the only options a surfer had to muck with all these variables was to grind his glass-on fins off and install a slightly different set in a slightly different location and record the differences until they found the optimum. Not very likely. So, with the exception of a few elite pros, we all lived with what we were given. Now with the advent of removable fins (i.e. FCS, Future, Lock Box, OAM and O’Fish’l) you can at least muck with the first two "Fin affect factors". But, if you want the ability to dial in your board with all four factors you have got to try the newest competitor to the fin system market Red X.

Tom O’Keefe

 

Nice Tom - 

I’ve been amazed by the difference if feel and function in the edge finned quads I’ve been riding, by minute 1/8" changes, and, most importantly for me at this point, I found that I like my toe side fins closer together, 7/8", and further forward, and my heel side fins further apart, 1 3/8", and further back.  

It has been working great, but if I didn’t use RedX I wouldn’t have been able to work this stuff out, and I would not have been happy with the way the boards worked had I had to ride them with the fins set in the center of the boxes.

I also found moving the center fin on my tri’s to make a big difference - not so much the sides, which was far more subtle than the center, or the moving of the fins on the quads.

Now I’m working on turning with so much speed to burn…  Ha!

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hello all...

I have been reading through a lot of discussions about fins and fin set up, and i know ye all are probably sick of discussing it, but where i come from (EIRE) you don't see really any of these adjustable system.  

A bunch of us were discussing them over a few pints the other night and we came to the conclusion that they must really be for pro surfers, but yet most of them don't seem to use them!!!

Form reading other discussions on this it seems they do change the feel of the board but are they used that much?  caus any off the rack boards i see tend to have the FCS or Future fin systems...

personally i dont think I would notice any difference but then again i tend to do a lot of my surfing in the wite-wash hahaha 

 

by the way folks take it easy on me virgin participant here!!

[/quote]

 

Hi egg30, Fin systems that can install with ease in any bottom contour of a board which can have fiber glass fins made easily for so the board can perform is not a gimmick. A fin system designed only for shipping boards which makes alot of claims to performance and you have to shape the board around the finsystem, is a gimmick. Most fin systems that came out in the early to mid 90's were designed for shipping multiple boards to save shipping costs and all the board builders gave the molders their designs to make their fins out of plastic for costs. Once everybody had their fin designs made in plastic to cut costs the market stop focus on fins at that point, because all the focus switch to board designs and the molders now called themself fin companies. Coming into the 21 Century board designs changed so much that you had to focus on something esle that is related to performace of the board and well we know that would be fins, so now everybody wants to be a fin company.  

 

What I find is that the surfing industry seems to think that surfing started in the 90's, because alot of up coming finsystems are remakes of systems prior to the 90's which have come and gone. This is the reason you see mainly FCS and Future Fins in boards, because people are slow to change by habit in the surfing industry as a whole. And when you have large inventory of boards with a certain system in it the companies don't want to invest into change, it would kill the existing inventory and out date their boards. The funny thing is that will happen anyway because the consumer market will force the change and become smarter than the manufacture! I noticed that change in the last 3 years that the consumer is smarted in buying their boards. The excuse by the board manufactures that the systems are to complicated so they sell you on a shipping finsystem is coming to a end from what I can see.

 

In answer to your question why pros don't all use finsystems is simple, the boards are designed for them and that's one less thing for them to think about. Not to mention their boards are supplied by their sponsors. If they had to pay for their boards and buy them off a rack, I believe they would be more app to trying a board with a finsystem instead. Newer finsystems will change the way we buy boards in the future.

 

Mahalo,Larry

 

 

 

 

 

I’ve turned a dog of a board into a line driving turning machine by adjusting the cant and the distance for and aft of a quad setup.Look at the 10.5" longboard box,it’s adjustable.I know most boards and fin set ups are different,but it would be cool to have a small reference chart that tells you the different adjustability variations and the affect they have on the ride.

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,but it would be cool to have a small reference chart that tells you the different adjustability variations and the affect they have on the ride.

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Jesus, Hope you and the family are well my friend. I noticed your request and just wanted to let you know such a chart will be coming to light soon with that exact information for ProBox, since the ProBox Movement has grown in the past few years nicely. Will post it here first. Take care and keep up the stoke, always feel your positive energy when reading your threads. Mahalo, Larry

hi Egg30, welcome to Swaylocks…

IMHO, and from my experience, adjustable fins make a huge difference. adjusting fore/aft placement and cant can take a board from mediocre to great… as you progress and start to make turns out on the open face, try using a fin system that lets you adjust and just see for yourself. every surfer is different and what feels good to one might not feel good to the next. or maybe it feels good enough and that’s why people are ok with non-moveable fins. but, again IMHO, tuning a board to what feels good to you can have great results.

there is something to be said for a shaper that has done tens of thousands of boards and has a shape/fin placement dialed but still, i feel that any board could still be better tuned to the specific rider.

regarding the pros, they’ve gone through the fin adjustments and have the fin placements exactly where they want them. whether they use glass-ons or FCS or Futures, they’ve worked out what’s best for them. they’ve gone through many boards shaped off the same file and dialed it in. so, in a sense, they have adjustable fins, they just adjust them from board to board. you should ask surfding about how specific fin placement #'s are for pros.

regarding FCS and Future, you see more of them because they have more money for advertising. but, if you will notice, FCS is playing catch-up. they went from those plugs to boxes (fusion), and from no adjustability to some (fore/aft) adjustability.

you could look at a fin system that makes a board easier to ship or to keep more in your garage. or, you can look at a fin system that actually allows you to enhances the performance of a that board and allows you to taylor the ride to the conditions… your choice.

there are several quality fin systems out there that allow different adjustments… Lokbox, 4 Way Fin System, Probox, Fins Unlimited etc … personally, i like Probox for ease of installation and simplicity. and, even though i have yet to do it, making fins for Probox is really straight forward.

hi Egg30, welcome to Swaylocks... IMHO, and from my experience, adjustable fins make a huge difference. adjusting fore/aft placement and cant can take a board from mediocre to great... as you progress and start to make turns out on the open face, try using a fin system that lets you adjust and just see for yourself. every surfer is different and what feels good to one might not feel good to the next. or maybe it feels good enough and that's why people are ok with non-moveable fins. but, again IMHO, tuning a board to what feels good to you can have great results. there is something to be said for a shaper that has done tens of thousands of boards and has a shape/fin placement dialed but still, i feel that any board could still be better tuned to the specific rider. regarding the pros, they've gone through the fin adjustments and have the fin placements exactly where they want them. whether they use glass-ons or FCS or Futures, they've worked out what's best for them. they've gone through many boards shaped off the same file and dialed it in. so, in a sense, they have adjustable fins, they just adjust them from board to board. you should ask surfding about how specific fin placement #'s are for pros. regarding FCS and Future, you see more of them because they have more money for advertising. but, if you will notice, FCS is playing catch-up. they went from those plugs to boxes (fusion), and from no adjustability to some (fore/aft) adjustability. you could look at a fin system that makes a board easier to ship or to keep more in your garage. or, you can look at a fin system that actually allows you to enhances the performance of a that board and allows you to taylor the ride to the conditions... your choice. there are several quality fin systems out there that allow different adjustments... Lokbox, 4 Way Fin System, Probox, Fins Unlimited etc ... personally, i like Probox for ease of installation and simplicity. and, even though i have yet to do it, making fins for Probox is really straight forward.

I live in Ireland and my shed is full of adjustable fin systems. For thrusters it is less important as the fins are (Should be) layed out to one of a number of sets of well proven numbers. But in single or quad finned systems it’s essential.

There again, it you only surf top class surf, it’s less critical once you get something to work. In small, marginal, fat or junky waves, fin placement is everything.

IMHO Glassed on fins feel better under your feet when you get the positions dialled in. But a system like probox allows you to adjust so many variables it’s magic in the hands of someone who is meticulous enough to measure and document the positions, and who understands the fin/bottom interaction.

 

Thanks Larry,we are doing great,I hope you and yours are doing great also.I will be moving in a few weeks, we found a very nice house on 100 wooded acres with a 4 car garage and it’s close to my new job and about 15-20 minutes from my local break so I am stoked beyond repair.Once I get settled I will building boards in the garage so I will be placing an order for some more proboxes.It’s interesting because my go to “magic board” has glass on fins,even though it rides good it lacks the final adjustments for the type of surf I’m stuck with here in florida.My first project once moving will be giving said board a new look and and of course some proboxes

Isnt this exactly what you are looking for Jesus?  Straight from the ProBox website: http://proboxfinsystems.com/pages/technical/technical_primer.html

 

 

Thanks Durbs that is a good chart,I need to be more thorough when navigating certain websites!I can’t believe I missed that.

Thanks durbs, For posting the chart from the ProBox Website. Thought I would share a sneak pick to Jesus and my Swaylockian Friends about explaining the different ProBox adjustments in a segment coming out on ESP soon along with some other things from Fibre Glas Fin Co..

Mahalo, Larry

 

 

 

 

 

hi again folks, wow didn’t think i would get such a response!!!

I guess my original enquire was based on the short boards but now that i think about it the long boarders have been adjusting their settings for years… Thanks Tom for that very in-depth explanation must admit i hadn’t seen it before so my apologies for making you rehash it again 

also Chrisp, larry and Burnsie your knowlage on the subject dose kinda blow me away, I am as you guessed a novice to the sport so i am sure my post sounded a bit uneducated :) 

I have been reading over all the replies and it seems to me that wave conditions might have a lot to do with the way the board feel or at least the way the fins have been dialed in… or have I got this wrong? and by all accounts the wave are never really constance (Tide is pushing or going out) So if you set the fins for one condition could they end being a hinderance half way trough a session or would the wave ever really change that much???

Larry I had a look through your blog very cool :slight_smile: but I was wondering if your Probox works with hollow boards because i have built a surf board which uses a ribbing structure (I have attached pic) but is hollow I was thinking of glassing on fin but I would like to fit a system like your:) any toughs on the subject/project

With a good solid board that has a 2+1 fin system (box with side bites) you have the foundation for a daily rider that will handle a wide range of conditions.

 

 

 

Larry I had a look through your blog very cool :) but I was wondering if your Probox works with hollow boards because i have built a surf board which uses a ribbing structure (I have attached pic) but is hollow I was thinking of glassing on fin but I would like to fit a system like your:) any toughs on the subject/project

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Hi egg30, Thanks for checking the blogs out, still alot more to add which will be in the next few weeks before the season starts.

Your board concept is extremely cool(-: Do you have a website or blog where I can see closer to get a idea of the structure layout. The fins on the board in that pic are they a

finsystem of some sort?

Look forward to seeing more and share some ideas with you my friend.

Mahalo,Larry

Hi egg30, Thanks for checking the blogs out, still alot more to add which will be in the next few weeks before the season starts.

Your board concept is extremely cool(-: Do you have a website or blog where I can see closer to get a idea of the structure layout. The fins on the board in that pic are they a

finsystem of some sort?

Look forward to seeing more and share some ideas with you my friend.

Mahalo,Larry

hey Larry, check out this thread:

http://www2.swaylocks.com/forums/im-building-64-hollow-core-cardboard-fish

it looks like the same construction as the board above.

also check this link:

http://www.sheldrake.net/cardboards/

by the way, that is a sweet looking board Egg30