Size, Aspect Ratio, and Brand - How They Relate to the Pull of the Kite

Chalk and cheese... I love it,... must be an Aussie-ism...

Flight characteristic is a culmination of many factors. I would presume that the 2 kites will likely perform relatively similar in most conditions. To the best of my understanding, how strong a kite pulls and where a kite pulls is a function of the combination of Aspect Ratio, profile and angle of attack.

Your Quattro is designed to be a tame all-around beginner style kite. But the Twister is designed for lift and speed. The Twister's AR I believe is around 3.6-3.7 ish, combined with its specific AoA and profile, it is designed for LIFT... It's a jump-kite for sure (in the bigger sizes) (DO NOT JUMP WITH A 3M KITE). Typically higher AR kites have a stronger pull. The Quattro likely has an AR around 3.4 ish.

What you find with AR is that as the AR goes up, strength and speed increase, but stability decreases. Twisters are very stable as their AR is still low enough that stability as not really effected. But hen the AR gets over 4, then you start to notice the difference in stability.

So, given that, it IS likely that the 2 will perform the same in most conditions, but don't be surprised if your Twister out-performs the Quattro, because as the speed increases, apparent wind increases and might give you even more oomph. Conversely, if the wind is very unstable, you might find the Quattro performing better, at least in the department of stability and ease of use.

so theres a nice muddles answer for you, hope it helped

Makes sense, and thanks for all the input everyone. I suppose it's about what I expected - there is some theory to it but it'll be understandable after experience.

Soliver, don't worry, I have no intention of breaking my legs and am not even considering jumping right now, or any time soon. I'm focusing on basic landboarding right now, will try out snow kiting this winter if we get any snow here, and then will look to try the water out next year, where falling after a jump seems a lot less painful .

Well that's definitely NOT your average first post... :o welcome Ian...

True Cheezy, though it is pretty typical for forum newbies to pull out old threads to comment on

Welcome to PKF Ian, sounds like you bring a wealth of knowledge!

Soliver be pimpin' yo!

Where you from Ian?

Quote: Originally posted by RedSky

Another aussie :D Welcome. I'm a pommie myself. Just to pick up on your post regarding High AR kites, particularly their acceleration and pull. Although a high AR is faster with its more efficient wing, it's initial acceleration is slower than that of a kite with a low AR, with all things being equal. This is because there is less power the further forward a kite sits in the wind window. A low AR kite will sit further back closer to the optimum zone of power generating more pull to out accelerate a high AR kite, initially anyway, to a point.

Redsky, I think he means the kite's apparent wind speed. I have noticed this in practice. I have flown some lower aspect kites, and still own a pretty low aspect Tensor. The difference between that and my Reactors or when I owned the big black Toxic is pretty huge. When the reactors hit an air pocket while flying through the window, they will sometimes get this quick surge. You don't really see low aspect stuff do that.

I think this is attributed to a higher volume of air passing over the high AR airfoil from LE to TE. The air makes that trip faster, because the total distance is shorter. Along with the air making the trip faster, it is a wider wing, allowing more air to pass at the same time. Imagine a two-lane road, with a 55mph speed limit, that is 5 miles from start to finish. Now imagine a four lane road, with the same speed limit of 55mph, but the length of this road is only 2.5 miles. You will be able to get way more cars from start to finish on the four-lane road. The cars are air molecules

Quote: Originally posted by Demoknight

Quote: Originally posted by RedSky   Another aussie :D Welcome. I'm a pommie myself. Just to pick up on your post regarding High AR kites, particularly their acceleration and pull. Although a high AR is faster with its more efficient wing, it's initial acceleration is slower than that of a kite with a low AR, with all things being equal. This is because there is less power the further forward a kite sits in the wind window. A low AR kite will sit further back closer to the optimum zone of power generating more pull to out accelerate a high AR kite, initially anyway, to a point. Redsky, I think he means the kite's apparent wind speed. I have noticed this in practice. I have flown some lower aspect kites, and still own a pretty low aspect Tensor. The difference between that and my Reactors or when I owned the big black Toxic is pretty huge. When the reactors hit an air pocket while flying through the window, they will sometimes get this quick surge. You don't really see low aspect stuff do that. I think this is attributed to a higher volume of air passing over the high AR airfoil from LE to TE. The air makes that trip faster, because the total distance is shorter. Along with the air making the trip faster, it is a wider wing, allowing more air to pass at the same time. Imagine a two-lane road, with a 55mph speed limit, that is 5 miles from start to finish. Now imagine a four lane road, with the same speed limit of 55mph, but the length of this road is only 2.5 miles. You will be able to get way more cars from start to finish on the four-lane road. The cars are air molecules

Interesting post.

You're right of course and I think PHREE hinted at it, it's a dynamic system with kites being more akin to sailing than flight. Your high AR kites may well surge to produce more power but this is normally a single event that cannot be easily and reliably replicated, in fact a trick to give a high AR kite more power is to limit their efficiency by applying some brake input.

When Ian mentioned acceleration I immediately and perhaps wrongly thought about acceleration from a standing start and not as perhaps you and most people thought, when a kite is already in motion. That's where our ideas might be conflicting. I've put it down to me watching too much Top Gear on TV.

If a kite is already at speed and able to take advantage of its efficiency and to build on apparent wind then you are correct.

However I stick by my guns :frog:, that a low AR kite will out accelerate a high AR kite with all other things being equal from a standing start to some low initial low speed, say 20mph, if only to prove the theory that a low AR kite that sits further back produces more initial power.

My foil experience isn't up to date however. My experience is coming from LEI's. Whereas kite buggying normally concerns itself with upwind efficiency and top speed, kitesurfing kites are perhaps more clearly defined with less efficient kites that pull strongly downwind being more desirable for extreme and powerful riding.

Actually the AR on Toxic and Reactor are the same ... Both at 4.5 on all sizes except the 8m Toxic is 4.8, whereas the Reactor 8.6m is still 4.5. The differences discussed in the marketing jargon of the 2 kites may be notable though. Reactor is marketed as a "low lift" kite very specific to buggying. Toxic is marketed as a buggy kite as well, however they say it's also a good jump kite.... With that said, maybe it is a function of of the Angle of Attack (AoA) or the profile of Reactor, or perhaps the happy culmination of all of the above.

Just in case you may have it backwards lower AR = a MORE stable but SLOWER kite whereas higher AR = a LESS stable but FASTER kite (usually with more LIFT)... That's why most beginner kites are low AR.

I would say (based on my limited experience in comparison and things I've read other people say) Reactor is one of the more stable kites in this "class" (4.5-ish AR Intermediate level), from what I've read, the Flexifoil Blurr is really good too, but I've only flown one of those for a few minutes and can't tell you how they compare.

Do be aware though that even though Reactor is marketed as "low lift" it will still lift you, just ask the 2 titanium plates in my heel

Quote: Originally posted by Ian D

Is a high A/R, race-type kite like a Vapor, Prodigy, etc, going to be worth putting up with lower stability and other handling problems when used in a general buggying situation? I love the look of a high A/R kite and their higher performance, but read some bad things about abrupt power deliveries, overflying and lifting OBE's. Thanks for the info. Cheers, Ian

It really depends on your wind conditions. If typically your winds are clean and stable then a race kite might give better performance but not always. The stability of a lower AR kite can move you on.

I'd be inclined to avoid flying race kites in anything less than ideal conditions and unless you're actually competing in a race and are aiming specifically for a maker then for the rest of us a lower or just slightler AR kite is going to be a more fun kite to fly in less than ideal conditions, and anyway let's face it, riding upwind is the slow boring bit, it's the pedaling uphill on a bike before turning around and heading back downhill again and even the very best performing kites on the market aren't going to make it any less boring. Sure you might make one or two less tacks upwind but really?

If you're short on experience then a race kite is sure to slow your progression. There's nothing more testing or infuriating than having to stop every two minutes to untangle your kite and lines, to constantly shake out wing tuck and bow ties. Trust me I know. I flew almost every make of race kite inland for a decade, convinced that my next purchase would be better.

Looking back now, the problem is clear to me. Here's what you really need to know, it's not all about your choice of kite. You need to bring the buggy into the equation here too, as one affects the other more than you may think.

Take me, back in the early days I was using a very lightweight 14Kg buggy, when really for my conditions I should have been riding a heavier bug whilst flying a larger kite to match.

Buying a heavier bug was a great improvement all round. It was faster, more stable, it was able to hold much more power that resulted in faster, more direct upwind travel.

Sometimes for fun, my friend would jump on the back axle to catch a ride. Providing there was good supply of wind, the extra weight on the rear axle together with the bugs momentum would point the kite upwind to almost ridiculous angles.

Obviously for practically reasons you wouldn't want a teenager hanging off the rear axle, for one thing, with all that weight over the back your ability to slide to a stop is all but gone but the point is made. Anyway, I'm rambling on. I guess what I'm saying is, consider the buggy in regards to performance. Kite and buggy have a direct relationship to one another. A lower AR kite in a heavier bug may result in better all round performance than a high AR kite in a lighter bug. Something to consider maybe.

VERY WELL SAID RED!

What's under you can be as important as what's above.

Quote: Originally posted by Demoknight

Ian: I have the most modern versions of the Reactor(2013) 3.5, 5.5, and 8.6. I also owned the 8.0m Toxic for nearly a year. I really enjoyed the Toxic. That kite was the kite that made me fall in love with big fixed bridle kites. That being said; it is not a jumping kite any more than the Reactor is. I have no clue why they market it that way. I have jumped twice the height with my 8.6m Reactor. The Reactor is in my opinion a beginner kite, not intermediate. I say this for one main reason. You cannot overfly this kite unless you are a skilled pilot and know how to purposely overfly any kite. The way that the Reactor is bridled, once you bring it to zenith, or to the side of the window it has a rocker effect that rolls the whole kite back a few degrees. Anyone with a Reactor will confirm this. If you do not keep enough tension on the lines, the kite rocks back and drifts back into the window where it pulls the lines taught again and changes its AoA back to the normal angle. The bridle almost works as a hinge for this to happen every time. I think this is most likely by design to aid in stability. The most difficult part of flying higher aspect "intermediate" to "advanced" kites is that they fly so well they will fly to the edge of the window and just keep going until they get negative AoA and collapse and often invert from the pressure being reversed suddenly. My 8m Toxic would do this every time if you let your attention lapse for a moment. Overall, to be honest, I like my Reactors better than the Toxic. Keep in mind that my 8.6m Reactor cost about $200 more than the Toxic 8.0m. That is not a negligible price difference. I can honestly say, because of the Toxic quirks i.e. overflying ( I cannot speak to the instability of the smaller sizes because I only owned and flew the 8.0 and it tracked like it was on rails ) I became a better pilot than if I had gotten a Reactor first and never had to deal with overfly issues. If you are not concerned with the price difference, go for the Reactor. If you want 90% of the performance, at 25% less cost, get the Toxic. The Toxic will teach you more anyway.

I have 4 and 5m Toxics and they are both as steady and stable as any kite I've ever flown. Wide wind range as well. If a Toxic is overflying the edge, especially in the larger sizes, then it needs a little bridle tweak. A tiny adjustment can make a huge difference in the enjoyment of flying a misbehaving kite.

Quote: Originally posted by BeamerBob

I have 4 and 5m Toxics and they are both as steady and stable as any kite I've ever flown. Wide wind range as well. If a Toxic is overflying the edge, especially in the larger sizes, then it needs a little bridle tweak. A tiny adjustment can make a huge difference in the enjoyment of flying a misbehaving kite.

This is just static flying that the 8m likes to overfly. In motion on the buggy, it will happily park and ride with or without brakes.