Zero Cant & Toe Fins on a Sup

[Piros]

First up please don't take this as a JP plug but I get so bashed on my straight fin theory I want to explain how it works and post a couple of videos to prove my point. I have my flame suit on so fire away. So here goes it  I know there are new boxes on the market that let you adjust the fins but this post relates to production Sups.

The theory behind the straight zero cant & toe fins is speed and power return from your turns. It's been used for years in Windsurfers & Kite boards nothing new. Have a look at your rear fins in your quad set they are zero cant and reduced or no toe. Tow boards are the same with minimal cant and toe. Another thing is FCS have zero 5 & 9 degree cant boxes so the FCS fins are straight except for ones like the H2's. Unless you get a custom board and specify cant boxes you get straight like all the Sup production boards , that means you are already riding zero cant but didn't realise like the rears in your quads.

Future boxes are all straight so the cant is built into the fins but even Futures are now offering reduced cant fins. I have taken it a step further with my VP fins and you can now buy zero cant with a future base. I've had heaps of emails from shapers of 30+ years saying it can't work , my reply is what happened when you tried it ? answer "I never have"...Boom I rest my case.

[ninja tuna]

Piros,

Your videos inspired  me to have my  pro-boxes installed on my custom Bill Foote with no toe and no cant and the board is awesome.  All my future custom SUS boards will have the boxes installed this way. 

[Dwight (DW)]

It's all about choosing your compromises. These explain what it all does when you change fin setups

[Beasho]

Piros:  I am 100% with you on this one. 

I have just installed 5 ProBoxes in 3 boards.  My big wave gun may be next.  Because:

Futures boxes SUCK.  They are not designed for the rigor of SUP's.  3 of my boxes have mysteriously ripped out.  Having wondered why I read this post from ProBox Larry which explained:

"This is the beauty of the Standup World where fins are one of the main point of power and drive that you cannot cheat with because they are under continuous load due to the fact that your standup board rides higher on the water. Not like surfing where the board foil line and simi sinker design of the surfboard in the water makes up for the lack of relying on the fins." Larry's Facebook page

A snowboard, or a ski do not need fins because they generate enough "lift" using rocker against a harder surface with the help of an edge.  An Alaia board also turns without a fin largely relying on holding its edge and its rocker.  What we are experiencing with SUP is the LACK of penetration because we have so much float.  Therefore the fins are being more heavily taxed to provide lateral resistance. 

Its like the early days of windsurfing when (my) finboxes were continuously ripping out until (I went with) Tuttle fin boxes fixed it all by connecting to the top and bottom of the board.

[Beasho]

I have a handful of session with ZERO cant.  (I didn't have the stones to go ZERO tow yet) 

The boards are FAST, FAST, FAST.

My initial take was that my short board yawed like crazy.  3 strokes and I would have to switch hands.  Odd!  But it turned outrageously well.  Drive, power whatever the heck that means ?

I was out several days in bigger stuff 10 - 12 feet on my 10' 6" PSH gun and the 10' Jeff Clark (pictured above).  I was making sections that I didn't used to be able to make.   Did I mention FAST.  My 10' 6" PSH used to be stiff at speed it now can turn at speed.  This seemed odd until I realized that Tow + Cant = MORE DRAG.  Cant with  tow is like adding huge tail feathers to an arrow slowing it down but making sure it will go straight.  I took away a great deal of the drag (and my fins were actually whistling).  This explained the speed.  The turning?

With all due respect the video of the "surfer guy" has no (very little) relevance to SUP.  I have an aerospace engineering degree and have caught ~ 11,405 waves on an SUP ranging from 2 to 25 feet and am still baffled by what drive and looseness means (grip and slide?).  His demonstration was with a 6 ft shortboard.  Our boards are more like big wave guns, or extremely long, long boards.  I also learned in engineering school not to go overboard with the theory rather to let reality set the context for the (next) theory.  I don't doubt that Tow and Cant work but maybe they are suited to zippy 6 foot beach breaks and shorter boards.  I think we are doing something VERY different but our hardware is rooted in the 'Zonky' hybrid genetics of shortboards, long boards and windsurfers to name a few.

I love is that no one really knows what is going on meaning that we are on the verge of great discovery.

Piros & JP keep driving and I will keep pushing. 

Next question: Why have single foils on the front fins?  Single foils create lift.  Lift = DRAG.  If you really want LOW DRAG then:  Zero Toe + Zero Cant & why not Double Foils?

[standuped]

Coming up on 2 years on this program.  JP for me!

[supsurf-tw]

Next question: Why have single foils on the front fins?  Single foils create lift.  Lift = DRAG.  If you really want LOW DRAG then:  Zero Toe + Zero Cant & why not Double Foiled?

You can however remember fin setups are always just another design feature. One of many. It's how all the elements come together to achieve the desired result in a board.

[Beasho]

Maybe my problem is with the semantics.  I would re-define the video like this.  But  tough guy surfers wouldn't like the 2nd definition. 

Apparently JP discovered that you can have your speed and your turning too.  For some reason this is threatening to the knuckle-draggers who have never tried.

[K-541`]

 The surf industry has always been slow to change look at how long and hard they cried when Clark foam went down.How about epoxy, glass shops would not touch the stuff  but they eventually came around.Like Piros said 0 tow no cant its nothing new maybe just to sup.

[Piros]

Thanks for the positive feedback a change from my normal nay sayers 

The whole straight fin theory basically is a hydrodynamics thing , it's just faster. The fastest way forward in any vessel is to reduce drag. Toe just means drag and cant is supposed to produce lift but we don't need that as we have all that extra foam , we are already floating fine before we catch a wave so it's driving the water flow down and not letting it funnel past. Compared with a short board all that extra wetted area on Sups will always be slower than any other surf craft , so we need every bit of extra speed we can get and with speed everything else is easier. 

With all due respect the video of the "surfer guy" has no (very little) relevance to SUP.  I have an aerospace engineering degree and have caught ~ 11,405 waves on an SUP ranging from 2 to 25 feet and am still baffled by what drive and looseness means (grip and slide?).

Beasho drive and speed comes from your rails and fins , the more pressure you can put into your turn will create acceleration. This is where your fins are super important you need a solid base with controlled flexion on the the tips , if you load up a good fin it will flex at the tip under pressure and push back on the release pushing you forward. Link that up with a series of driving turns and you are flying down the line. A good fin holds it's shape right to the last second and if you want to blow the tail you can and it will bite again at the right time. Soft plastics fins will flex from the base and let go much earlier and flex again badly on the catch and just slide when you need your grip back. Any fins that whistles is not working.

Next question: Why have single foils on the front fins?  Single foils create lift.  Lift = DRAG.  If you really want LOW DRAG then:  Zero Toe + Zero Cant & why not Double Foiled?

Really good question : The twin foiled thing is again a knuckle dragger theory as you put it. It' from single fins mounted in the centre of the board. It's got me beat why quad fronts are single foiled and rears twin foiled but are mounted off centre ? Personally I think all fins should have the same flex pattern to work together a twin foiled fin will be much stiffer than the fin in front of it. To me it just doesn't make sense. My understanding is the only fin which should be twin foiled is the centre fin and that fin should still match the flex patterns of the others.

None of this is from the Surfers Bible it's all from my personal evolution experience. This is a video from the fins I have put out to support what I said above. Don't take this as a plug but it proves I have put my money where my mouth is.

[Dwight (DW)]

So as not to throw cant under the bus totally, here is a counter point on what cant can do for a SUP.

Increasing cant makes a board roll into a bottom turn easier. It feels very much like when you add vee to a bottom shape. But we all know vee is a displacement bottom. The opposite of where you want to go, if the particular board you're shaping is designed to plane up, instantly. Like say for that 6 foot fast beach break wave Beasho thinks nobody cares about  .

I submit more people surf fast beach breaks than Mavericks 

Honestly, there is no right answer for everyone. Every place different I surf, I think to myself, I could design a different board that would be ideal for THIS wave. You really can design the optimal board for each surf spot. That is the power you gain being a shaper and I absolutely love it.

[1tuberider]

I am seeing really talented surfers in the videos. I think they could make anything work well.

My starboard pro I set up as a twin with only the smallest of fins in the back boxes. It was extremely loose and with the back foot over the fins plenty of drive. You might give it a try because my board handled a lot like what you see in the video. It won't cost you a lot either. Of course I had nothing to do with it.

[Tom]

So what I am getting is that zero cant & toe creates a faster board going straight, which works good on a SUP because the paddle assists the turning along with shape and rocker of the board. If this is true, why have a quad or three fin set up, just go with a single fin. Seems a single fin will keep the board pointed down the wave and not create the drag you'd get from cant and toe. This seems to work well with windsurfers, all of my windsurf wave boards were rounded pin single fins.

[Beasho]

The fastest way forward in any vessel is to reduce drag. Toe just means drag and cant is supposed to produce lift but we don't need that as we have all that extra foam

I agree with Tom (above) but appreciate the 'turnability' offered by 3 and 4 fin systems.

Introducing TOE, Camber (e.g. single foil fins) or Multiple fins ADDS DRAG.  & Almost every 3 and 4 fin set up has 2 forward fins that are producing counter acting Asymetrical (single foils) and Angle of Attack (Toe) lift just adding more drag to more drag from fins fighting each other. 

WHY?                                 Does it have to be SLOWER to turn better?

The lowest drag, highest speed option would be a high aspect ratio single fin like on a slalom windsurfer. The majority of drag comes from the tip of the fin.  Long and skinny = Efficient.  Short and fat, or more fin tips = Less Efficient and SLOW.

That said I am re-posting something from last year: 

------------------------------------------------

Here is a little picture of what is going on.  A foil generates lift by what's called 'circulation.'  Circulation, in simple terms is fluid moving faster over one side of the object than the other.  Circulation can be induced two three ways (& more like spinning a cylinder/baseball)

1) By a symmetric foil
2) By Angle of attack
3) By Spinning an Object (e.g. curve ball)

The problem with a symmetric foil is you can't turn it off.  It is generating lift, 90 degrees to flow, 100% of the time and lift is 100% correlated to drag.
 
Angle of attack can be controlled.  This is why very fast aircraft use symmetric foils otherwise the lift and drag become excessive and somewhat unmanageable because lift & drag are also a function of Velocity^2.  Want to take off, going slow, angle the nose up.  Want to go supersonic juice the throttle and drop angle of attack to 0.000001. 

Then some rocket scientist goes and puts fins on a surfboard with the symmetric foil 'lift' designed to counter the angle of attack, Toe-In 'lift'.  Is this just to induce drag?  This is the type of thing that made NO sense until someone tried it.  It must work, better than not, because nearly every 3 fin board boasts this design (short of some of the recent JP boards). 

. . . .  I will add that on my biggest wave board (12' PSH gun) I ride it as a single fin to get rid of all these appendages to maximize board speed.   

PS:  What I love is the explanation "which in turn makes the board more responsive to rider input."  Typical surf mantra   
PSS:  That's it!  Now I am going to have to go buy one of those JP boards.
Schematic from here: http://www.tactics.com/info/guide-to-surfboard-fins

Originally here:
http://www.standupzone.com/forum/index.php/topic,20424.15.html

[Beasho]

On my biggest 12' gun I have pared it down to one large fin.  I added one small side-bite to prevent spin out.

PS: The funniest observation about surfing big (ger) waves was that "You just go straight" sending much of this hoopla out the window.