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Monofoil or "riding stabless", setup and riding

Posted: Sat Sep 17, 2016 10:10 pm
by Horst Sergio
Thanks to Master Phil's video:

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we all know that it is possible to go without stabi, but what are the needs for an easy to ride monofoil and what can we expect from it?

I can't already answer all questions, but trying to share what I know.

About one thing I am already pretty sure, monofoil is not just something to try 5 minutes and done, but can be a very funny own riding style that earns its own topic and discussion about foil setup. Maybe more than all that twin(tip)foils, already been discussed and constructed.

Therefore today I finished my "zero fuselage" upgrade for my LEVITAZ Element foil. Till now I tried a LEVITAZ Aspect, a ZEEKO Makaira Freeride and an AIRUSH ALU Foil going stabless and the Element was far the easiest wing to go. So I think low chamber and low aspect might be good for monofoils.

So this is my new baby :D :
To make sure the monofoil does not feel to much solo, I put an other new toy beside, hope it will help me to bridge the time when I am not in the water :wink: .

For the first try,
for sure there is no need to cut the fuselage, just dismount the stabi as Phil.
But make sure you are prepared with the same conditions as a foil beginner should be:
Perfect spot conditions with about 12-16 knt of wind, very small waves, well powered kite, and a big board with a long nose and front and back straps.
And the same is for beginning: First don't try to start flying but just riding on the board and just if everything is perfect carefully try to lift. In the first times, as a beginner, you will meet the kangaroo, so if it starts to get out of control try to come back to surface to save time for riding not for falling.

As a beginner you will first find the upwind leg easier but, after short you might also be able to go down wind, and much faster than in your foil history, you might do nearly everything you have been able with stabi till then.

Happy monofoiling


And tell me if you find a foil that works even better than the Element.

Re: Monofoil or "riding stabless", setup and riding

Posted: Sat Sep 17, 2016 10:50 pm
by ronnie
One wing has potential because the rear wing pushes down on a normal foil.

With one wing you can reduce drag and have the same amount of lift from a smaller wing.


Re: Monofoil or "riding stabless", setup and riding

Posted: Sat Sep 17, 2016 11:16 pm
by alexrider
In order to restore some of the lost stability on a monofoil, reflex could be given to the wing, alternatively have a swept wing with washout (twist). An underwater flying wing would certainly look cool.

Re: Monofoil or "riding stabless", setup and riding

Posted: Sat Sep 17, 2016 11:50 pm
by Horst Sergio
ronnie wrote:One wing has potential because the rear wing pushes down on a normal foil.

With one wing you can reduce drag and have the same amount of lift from a smaller wing.

In fact one early feeling was: The low aspect Element wing without stabi has about the same low drag as the high Aspect with stabi. And additionally the last time I was riding in pretty bad low wind, the advantage of the lower drag maybe was already more helpful to keep going, than the disadvantage of the lower pitch stability. It was incredible how low the wind was. I think with that condition it would have been possible to ride my freerace Aspect, but maybe not the Element with stabi.

For sure there are many possibilities as you mentioned to make a monofoil even more pitch stable. I want to motivate some of the shapers to try something more in this direction. For example, maybe Levitaz is interested to offer at least the zero fuselage I build. But on the end you have to try the hole setup. When I was looking on the wing of the Airush (which is a nice foil, shape from "radical" from france) I was hoping it could be good for monofoil as the wing is bow shaped with maybe some twist, but on the end it doesn't feel stable when I tried.

Re: Monofoil or "riding stabless", setup and riding

Posted: Sun Sep 18, 2016 12:39 am
by ronnie
A lot of the pitch instability comes from the wing being swung forward and back to change the AOA, while you want the C of Gravity to stay in the same place.

That's why the hinged wing is worth considering.
The board can be kept at the level position, so less wind resistance.
The wing stays under the CofG.
All the wing does is provide lift upwards, with minimum drag.
It may crash better, because the CoG is more above the centre of the wing, and there is less rotational force involved.

There has been a foil that was depth-controlled by pressure of the depth of water, but that might not be reliable enough.
There are several hinged foils or hinged flap foils in use on yachts - controlled by surface-following wands.

It would be possible to alter just the AOA by foot positioning&pressure.

Re: Monofoil or "riding stabless", setup and riding

Posted: Sun Sep 18, 2016 8:51 am
by Peter_Frank
Interesting and certainly fun trying and exploring :D

Three ways you can make a single wing ("Flying wing" in aircraft/glider terms) more stable:

1. Use, on a normal not swept wing, a special camber that is like a normal profile at the front, and then got an "S" at the last part. Also called "reflex".
These can have positive pitching moment thus be self stable, and are used for aircraft that need a reasonably performance without having a tail.

2. Use a swept back wing with lower aoa at the tips (called washout in flying terms).
These will have a softer stall, and not prone to tip-stalling, but most importantly they also get a more stable (= less) pitching moment.

3. Use a swept back wing with low AR, as the bigger tip vortices will reduce the aoa at the tips, and in general be more stable and less pitch sensitive overall.

These are 3 classic ways I know of and have been using:

The disadvantage of all of them though, is that they are not as performing nor low drag nor high L/D as a classic wing with a rear small stabilizer.

So using a long fuselage and a small stabilizer is no doubt the most performing and lowest drag, giving the same stability is desired.
But then there are so many other things to consider, namely that a longer fuselage is more drag and difficult to make light and strong/stiff.

Finally, the dynamics, which IMO is the most important aspect - will be really different, and maybe the "surfing wing" with no rear stabilizer has some advantages ?

Just like we have loads of fun with flying wings for R/C combat or fun aerobatics as an example, easy/fast to make and very agile, eventhough they perform like crap - but that is a very secondary priority.

8) PF

Re: Monofoil or "riding stabless", setup and riding

Posted: Sun Sep 18, 2016 9:21 am
by Horst Sergio
Just dismount your stabi and try it yourself and then decide if you still see some profit from a version with mechanic.

The biggest problem is to keep the monofoil in line with the vectors of gravity and kiteforce. This is just possible if you don't do too much movement at all. So there is not too much movement of the mast to control height. I see your points, but a mechanic will increase thickness of the mast and add drag on further parts, so drag for sure won't be smaller and I think to link the mechanic to the regulation loop of your brain, will be a lot work.

Keep it simple,
is also the idea of my next project: A travel board with volume and less than 1 m, that works as a box for the foil and other stuff, fits together with a kite into normal flight luggage. This is how the first simple prototype will look like to check the dimensions and concept. ... I know the scoop is not so elegant yet :oops:
For travel and long distance ride I will for sure use a stabi in the future. The advantage of the monofoil is apart from the funny and free feeling (you may also drift it a bit) that you save also much weight (ca. 0,7 kg) on the most critical position for jumping. I now have the lightest and cheapest Levitaz, which is still as bomb proved as before. Great for freestyle. :D

Think you are completely right. I never expect the worldcup going on monofoils due to lower drag in the future. I am far away from pressing the monofoil hard to go fast upwind or downwind as on my freerace. Also for the monofoil performance was secondary, but funny that it is not that bad at all.

Re: Monofoil or "riding stabless", setup and riding

Posted: Mon Sep 19, 2016 1:10 pm
by jaros
Very interesting! Thank you for that report. Until now I tought that only masters like the Horue guy can manage to ride without rear wing... I am looking forward to hearing more test reports from you and also from other riders. I will try that for sure and write here how it went.

Re: Monofoil or "riding stabless", setup and riding

Posted: Tue Sep 20, 2016 3:00 pm
by Horst Sergio
Hi Jaros, on the end it is not so easy at all and everybody starting with monofoil should be very safe with normal foil as doing flying jibes and tacks and landing jumps.

But if this requirements are fulfilled and you have a useful monofoil as described, the learning curve is very high: First hour I was happy to foil some 100 m in perfect condition and yesterday when I had to try my new zero fuselage the condition was pretty terrible with loads of rain in my foil kite, gusty wind, small short waves but I was going everywhere I want without to much touchdown or falling and started to try the first time seriously changing foot position in flight. Didn't get it but not too far away. And the zero fuselage felt great for backflips. Also started to play with the small wave and it's a very cool feeling that you can nearly (maybe with more experience) drift the foil, when you ride high. :D Will try to do a linecam video in the next days.

That's how the darkness, all the rain and my new baby looked complete after the first test 8) ... and it all has this great starting a new sport feeling :rollgrin: (nearly the same as when started foiling)
But still respect to Phil, haven't tried a flying tack jet and I also think his wing is more difficult to ride. I have just tried the H13 with stabi one year ago.

Re: Monofoil or "riding stabless", setup and riding

Posted: Fri Sep 23, 2016 11:39 pm
by Horst Sergio
Some eye candy :rollgrin:

For Freestyle now just monofoil :thumb:
Short video will be at the next days :bye: