High vs low Aspect kite understanding in terms of AirStyle..

[Imba]

Well, since i have no wind\only light wind season & im kinda stuck on Boracay... and sinca iu cant anyhow progress on AirStyle (which i start to do on Feb 2013)...

So all i can do is to work & to read "theory" about kites (+sometimes test some huge demo kites here rarely).

A lot of people discuss WHICH kite(s) is good or bad for AirStyle.
But ive decide to try to understand the laws, aerodinamic facts & "gliding logic" behind those talks.

Because (mostly) kites arent good or bad for AirStyle because of their weight\manufacturer\color\lines material. I believe that the grounbase here is the kite shape.

Sorry if its will sounds too "newbish" for some people here, but (at least for me its was a new small step in the global understanding of kiting: The "Aspect Ratio" of the kites and the "High\Low Aspect".
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But, im not as good writes as some people, so i just Copy&Past the ariginal article about those things. The original text is here: http://www.4kiteboarding.com/unasratosepr.html

And i really like hos "short" but very informative the guys wrote down everything there. After reading of that text i did finnaly "summarize" everything in my own hed.... everything that ive testes, tryed, FEELed on my kites & demo kites before (because some of them was High Aspect kites... and Some of them was "LA" (Low Aspect).

So, i hope someone will find its interesting to read. Now i have more or less clear idea whyu Zephyr, Dyno & Turbine is good for AirStyle. No i can drop the facts other than just "they are big, slow & that is what makes them good".
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Aspect ratio refers to the lift vs. drag of the kite. It is a measurement of the wingspan of the kite compared to the chord line(leading edge to trailing edge). Think of a moderate aspect ratio kite as slightly oval shaped and then a high aspect ratio kite a bit more rectangular in shape.

The trend has been to increase the aspect ratios of every kite offered across the board. Only a few years ago, we were flying 3.5 aspect ratio kites, where now we have 5.0 and higher aspect ratio kites!

In reality there are pros and cons to both high and low aspect ratio kites.

PROS for moderate aspect ratio kiteboarding kites:
The kite will not fly as far into the wind so the effective "edge of the window" is more in front of you. This creates a VERY steady constant pull from the kite and is often defined as "stable" What "stable" really means is the kite sits on the edge of the window without a tendancy to overfly the wind window, it is very predictable and can be managed easiest by a beginner.

Also, this makes it much easier to water relaunch from the water.

Also, it has more power in lighter winds for its size since it flys more downwind of the pilot.

More affordable.

Cons of a moderate aspect ratio kiteboarding kite:
The kiteboarding kite can produce more pressure on the bar, which is usually good for heavier stronger riders as they prefer the constant feedback. Lighter pilots without the weight have to work harder with this kite and can be fatigued easier without the weight for a ballast.

Jumps tend to pull you downwind rather than upward higher loftier jumps. The kite will provide more of a yank downwind rather than a upward lift straight up.

PROS of a high aspect ratio kiteboarding kite:
A high aspect ratio kiteboarding kite will fly far into the wind so the effective "edge of the window" is further upwind. This makes it easier to drive yourself upwind without having to edge so much with the board, typically this is more desirable with lighter pilots who have to work harder to edge the board..

It can also produce higher jumps as the kite is further upwind when you send it. It can also provide longer loft time during a jump.

Also, this makes the kite have lighter bar pressure.

Also, it slightly more manageable on the upper limit of its wind range than the Element as you can send the kite further upwind and thus reducing the kites power.

Cons of a high aspect ratio kiteboarding kite:
A high aspect ratio kiteboarding kite has less feedback(bar pressure), which is usually good for heavier stronger riders as they prefer the constant feedback. Because the kiteboarding kite can fly so far upwind it can create a varying amount of power, as you receive power from the kite, you edge the board more, thus forcing the kite further upwind, thus reducing the power of the kite and losing power, you then begin to sink on your board and have to move the kite up and down to create more power. This varying amount of power is what I refer to as "micro managing" the kite. Simply put, you will "fly" a higher aspect ratio kite more that a moderate aspect ratio kite that likes to just be "parked".

Harder to water relaunch.

More expensive.
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Imba

[Imba]

HIGH aspect sample pics:

Old 2011 DYNO...

http://farm6.static.flickr.com/5091/552 ... 8099_z.jpg
(long & thin)
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Ozone Zephyr "scheme" (also High Aspect machine):
http://a248.e.akamai.net/origin-cdn.vol ... 013--6.jpg
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Slingshot Turbine:
http://www.forcesix.com/uploads/2/8/8/6 ... 5_orig.jpg
http://www.forcesix.com/uploads/2/8/8/6 ... 6_orig.jpg
Very long...very "thin"...
===============

Low Aspect kites:
https://sphotos-a.xx.fbcdn.net/hphotos- ... 4052_n.jpg
Its shorter (from side-to-side) & its wider = low aspect.
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And comparing the Dyno 2011 with 2012\2013\(2014?) models (which Toby said suck comparing to 2011). Well.. its kinda easy answer "WHY".

Because if you check you will see (screenshots) that North re-design the angle of attack & aspect ration (lower it down substantially) on 2012 & 2013 DYNOs...


And the funny thing here. If you check the 2011-2012-2013 Slingshot Turbines... (17m Light Wind kite) each year they become more and more aggressive on High Aspect ration angle... Cant wait to test at the latest one.

Turbine review: http://www.forcesix.com/2013-slingshot- ... eview.html

Few possible cons which i see:
- 4 lines (hard to relaunch comparing to DYNO? And what about safety release on 25+ killer wind\storm coming?!).
- Bar without MicroLoop (Still need re-make\North bar?).
- 2013 Turbine is much much more expensive than 2012 used Dyno.
- U can get DYNO in 15-16-17-18m. While Turbine is only come in 17m size (not sure it a lot of people can handle it on 20+ knots gusts even on the small board).


Imba

[Imba]

Small update:

After searching & searching... i found out that the Aspect Ratio of 2011 DYNO is 5,2.
For those who dont understand still its the "aspect" ratio of Width to Length of the kite.
AR of 2013 Slingshot Turbine is 5,4

Funny thing that even on the official manufacturers web-site there is no such detailed info. Sigh...


AR of Bantits, Vegases, Chaos and stuf.. is somewhere around 2,9 - 4,0 mostly...

[Toby]

Thx for the insights imba, sounds interesting.

I am not a technical guy, that's why I also stopped course racing after 2007, since it was clear it will become a material war, which it did.

Turbine sounds indeed interesting. It should be available at the world cup in Germany for testing, will give it a spin.

Having a 5th line to relaunch is really good, works well on my 18.
I wonder how big 4 line kites relaunch these days?
But I am sure a 5th line could be attached in addition?

[Toby]

And yes, the problem with the microloop will always be present.
And for top level it is needed (competitions are not top level).

[foxzone]

thanks Imba for bringing up this info. Interesting. I am trying to get to airstyle myself. Still lots of to learn but I am looking/reading/trying equipment that will help do it better/easier.

I have north quad bar with ml but I converted it to a single line safety with lines and swivel from Liquid Force CPR bar. I want to be sure that it flags as I would use safety release as a last result. I had a situation that north default mini fifth didn't work. Two front lines ended up going over the top of the kite and kite was inverted pulling like hell. 5 line setup may be better but not too many kites use it.

Anyway, how about shape of a kite? flatter vs more "c"? dyno and vegas have both AR 5.2 but much different kites.

Liquid Force NRG is praised as a big boost and slow kite.
http://www.thekiteboarder.com/2013/04/2 ... te-review/
Would it be good? It is kinda heavy. Over 12 lb. Does weight matter?

Does anybody use famous Fat Lady for airstyle? reports say that jumps well but it's fast (that may not be good). It's also light, less than 9 lb. I have one but I am still learning to jump higher so cannot really comment.

What is a good jump height/flight time I should achieve to be ready for airstyle tricks?

[Imba]

Anyway, how about shape of a kite? flatter vs more "c"? dyno and vegas have both AR 5.2 but much different kites.

Wait, wait, wait. Hold on a sec! Right now in _not_ going to start a flame war on forum. But mate, you are so wrong in understanding the "Aspect Ratio" thingy.

2011 Dyno have AR 5,2.
Lets go to math again. AR 5,2 basiccaly means that the "width" equal to *5,2 of length.
Or visa versa: It 5,2 time LONGER... (from left to right wing) when its "widher" from baloon to wingtip.

Look at the DYNO screenshot here:

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Fuuny thing.... And i think you mate just fall as the victume of that inforamtion. If you google down "vegas Aspect Ratio" you get the 5,9 numbers. Which is a total bullshit. Because North Vegas is almost "square" kite with ratio of somewher arounf 3.0.



Anyway. I think the problem here is layd in the fact of "how exactly" you measure the "aspect ratio" itself. From which wingtip - to which wingtip? Internal? external? Pumped? Not pumped?


Anyway:
- The greatest DRAG power comes formtfrom the "square" (a.k.a. short & fat kites).
- The greatest LIFT power comes from "long (from left wing to right) & thin (from ballon to wingtip) kites.


PS: Nop. DYNO is not the same AR as VEGAS.

DYNO have the aerodinamis of Porsche.
Veras have the aerodynamic of Hammer.

[Imba]

thanks Imba for bringing up this info. Interesting. I am trying to get to airstyle myself. Still lots of to learn but I am looking/reading/trying equipment that will help do it better/easier.

Liquid Force NRG is praised as a big boost and slow kite.
http://www.thekiteboarder.com/2013/04/2 ... te-review/
What is a good jump height/flight time I should achieve to be ready for airstyle tricks?

Well, if you look on your own screenshot.
The kite is:
a)flat
b)wide
c)thin

So, seem like more or less its "perfect" for AirStyle (if there is at least such thing as "perfect" kite).


Its should be:
a)High AR (which Liquid Force NRG IS!)
b)It must big pretty BIG... ti sustain a lot of airlift\air pressure.
c)It must "land" you softly.


If we dont fall into the details that you dont have the bar with "MicrtoLoop" - oyu are seem pretty solid so far. And i dont think ML is so so nesessary on 1\2nd season of sessions.


You can have no ML ... but you can up-level your uplift jumps & landing s from 10-20meters to a level of pure perfection. And for doing that you dont need the ML or anyother special bar. You just need: Smallest possible board + biggest possible (High AR) kite.

my 2 cents.

[Toby]

and what about the diameter of the fronttube?

Small or big? What will be the difference?

[foxzone]

I was just reading off north website dyno and vegas specs.
http://www.northkites.com/products/kites/dyno/
http://www.northkites.com/products/kites/vegas/

You would think they measure them the same way.
Just trying to educate myself.
I've got the NRG few days ago so I will try how it works for me compared to Fat Lady when I have a chance.

16m NRG has huge tube and is heavy. How is Dyno? How much does it weight? Or does it matter? We want to be powered anyway.