I need some test pilots.
There is some debate on the effectiveness of BIG vs. SMALL stabilizers. I just took my stabilizer off and the rig still flew.
A little pitchy BUT IT FLEW!
I even attempt a few pumps at the end.
PS: Remember I was a TOTAL BEGINNER ON THIS THING WITH NO TAIL
PSS: Removing the Tailwing made the board more sensitive than my 3 ft 3 inch foil board aka made my longboard fell like a shortboard INSTANTLY.
Stabilizers are most important at slow speeds and for STABLE FLIGHT. This would apply when LEARNING. This may also apply when starting, or (maybe) when slowing down in a turn.
Unlike anything artificial that flies we are using Weight-Shift Control. Hang gliders are the exception and have no tail. Birds use weight shift control and wing warping and have very little tail. Every single modern airplane with a tail uses control services.
Check out where my front foot had to be to fly ~ 8 inches behind the front strap. This is a huge revelation because it shows how much DOWN FORCE the tail wing is producing. My CG (center of gravity) has moved on average 4 inches backward to fly in a stable configuration. More math and pictures to come.
1) Down Force = Drag
2) Down Force becomes overwhelming front foot pressure in big waves
3) Any potential benefit of Downforce may be unnecessary at high speeds or with better skill
4) The flying wing is the most efficient and maneuverable configuration
PS: I also posted this on the StandupZone.com but you guys tend to have a different perspective and more experience on the foils.
There was mention of Rear Stabilizers in the thread below:
www.seabreeze.com.au/forums/Stand-Up-Paddle/Foiling/Stabaliser-wing-which-way-up?page=1#15
Then back and forth about what led to better pumping Big or Small Stabilizer. I ask "Is it the equipment or the rider?"
At the very least we could afford to fly with smaller stabilizers and or eliminate the camber on the stabilizer e.g. make the stabilizer symmetric.
Here Tony Logosz discusses the influence of stabilizers. His experience stems from Kites and Windsurfers. There may be a need for a vertical stabilizer in those contexts that we surf foilers do not need (as much).
--> 2:13 for his Comments of the Stabilizer:
The GoFoil design has changed VERY LITTLE since Kai first flew on an ELONGATED DOWNWIND board.
There was in incredible cantilevered weight in the form of 10 Feet of Nose. Without the huge downforce on the tail he may never have flown.
Since then the 'designers' just made bigger wings. There was little attention paid to the physics of what was going on underwater for the tailwing. Empirically they worked in small to medium sized waves. Anyone who has ever tried to take off on a steep 8 to 10 foot +++ face knows that the current configuration is compromised. The overwhelming front foot pressure is barely controllable I call it "Over-Foiling."
***This may not be true for all designs - Colas has suggested the Gong foils do NOT do this.
The dream is to pump up onto a non-breaking 15+ foot face and then race down the line, away from the death zone, flying free.
Here is the video of Kai's progression.
Are we be putting Race Car bodies on Cadillac chassis?
PS: Weekend coming up in Australia
I don't expect answers to come quickly BUT 'If' (???) my SPIDY-sense is correct then Stabilizers are like training wheels on performance. This observation could result in:
1) Redesigned Foils
2) Modular Tailwings, provided by Manufacturer or Homebuilt, for Beginners vs. Advanced riders
3) Redesign of Boards requiring Boxes further forward and / or Win-Win for Track box design
Your photo in 10:07 post, about change of stance when balance point shifted, given how much drag your back wing was providing ... have you experimented yet with the canard concept? The stabilizer adds lift, not drag, so not only do you not a detriment but you add a positive effect: which means you can get same lift with smaller wings, or can increase lift with same size wings. But maintain the stability that comes with a 2nd wing.
More discussion here: www.seabreeze.com.au/forums/Stand-Up-Paddle/Foiling/Canard-SUP-Surf-foil-video
Would be cool to try it out! Though I suspect your rig won't allow it, with how the big wings connect to the fuselage. I am going to DIY one this fall/winter.
Hey Beasho let me take you back 10 or 15 years. Got my hands on this relic last night a good mate gave it to me plus I'm getting a hold of one of the original Rush Randels aluminium tow foil boards same as the ones Laird made famous tow foiling on those big waves ( still the largest BTW)
Have a look at rear wing one this one , super small compared to the front wing , this particular foil used to cavitate and blow out around 20 knots the RR is heaps better. We will test them both this weekend side by side. It'll be interesting to comparing over decade old gear to the new stuff and might give some insight to your questions on small rear wings.
Something that I have noticed here with my local foil crew is that the demand for more higher performance foils is getting larger and I'm seeing guys absolutely ripping on small foils , Naish medium is classic example. Companies like Signature are now only producing high aspect high performance foils , Lift & MFC are the same. The downwind crew are learning on the biggest possible foil like the GF 280 but they are starting to drop back to the 200 once their skill set lifts giving them more speed and control. I don't think we will see rear wingless foils but definitely the aspect ratio will be higher. However when i was in New Caledonia at the beginning of the year some of the the kite foilers rear wings were so small they were no bigger than a mustache . 
Select to expand quotePiros said..
Something that I have noticed here with my local foil crew is that the demand for more higher performance foils is getting larger and I'm seeing guys absolutely ripping on small foils , Naish medium is classic example.
That's funny....exact opposite in kite foiling world. 5 years ago you were an ultra kook if on anything other than a super high aspect race wing. Now half the kiters are switching over to big sup foil wings, to slow down and be able to actually ride the waves independent of kite's power.
Feels like some kind of convergence going on!
Yeah that is funny , we are all now kiting on our Sup/Surf foils and the kite foils are now being used as tow in foils in the bigger waves because they can handle the speed better. Complete polar opposite in the two sports .
Select to expand quoteBeasho said..
The overwhelming front foot pressure is barely controllable I call it "Over-Foiling."
***This may not be true for all designs - Colas has suggested the Gong foils do NOT do this.
Very interesting Beasho! I love this kind of wild experimentation.
On the Gong foil, it was true of the first design (The "Hellvator", full carbon). The faster you went, the more it seemed to "lock" itself on a stable flying height. I guess because the designer (Patrice Guenole) was really put off by slow foils, and the focus on this first design was on being able to go fast.
However, after seeing how "real" people actually use foils, the new Gong foil ("Allvator", 399 euros, alu+carbon) has a more common handling now: it has much more lift, so you can foil more easily in crappy slow small wind waves(*), and it is easier to pump... but you then get over foiling as you say: you do not get this "autopilot" effect at high speeds. I must say that, altough I miss this feeling, it is globally better, as most foiling is done at low speeds, and if waves are powerful, most people will SUP or surf anyways. Foiling on powerful waves is for now a niche market I guess... at least for Gong that tries to keep prices low by selling in volume.
But maybe designs will advance - with your kind of experiments? - to foils that can be fun in slow waves but not overfoil at speed?
(*) such as these mediteranean 4s period "waves":
www.facebook.com/sylvain.roux2/videos/10156843937129883/
Select to expand quotemkat said..
Hey,Beasho ,are in Melbourne?
Half Moon Bay- could be Black Rock.
Chrz
Half Moon Bay, CA USA
South of San Francisco.
Pity...would have been 5 km from Elwood beach.
Quote: "need a test pilot"- experimenting with tailless foil.
Why not test myself?
you look more experienced with foils (tailless for sure
)
I need to drive for 4 hours to get a friend with the boat
need to see it real time and make adjustments
more fun to do it with a similar minded madman
here is a proof that we all need some help: my patented "releasing boots"- kited them for a year- still around...
www.dropbox.com/sh/5pe8wis1gl8h6rx/AADXybsNl9ulzp8EfVT1xWMua?dl=0
From DW (FoilSurfMachines) on the Zone.
The kite gives a huge advantage on lift and control BUT this is encouraging and super nimble:
