Kite Stability

[jrjohnson1]

What characteristics determine a kite’s stability? I know some people would like to claim it’s brand based, but if we go beyond that, what do the kite designers & engineers do to enhance how smooth and stable a kite flies? I’m sure some of us have flown kites in the past that feel punchy or seem to have less wind range than others. Why did they feel less stable? What is it about the smoother flying kites that make them feel more stable? Is it kite design, such as a delta hybrid or an open-C platform (both claim rock solid stability)? Switchblades are notorious for being ultra smooth in gusty conditions and they’re a bow design, so it’s not easy to assume it’s a kite’s shape that’s a determining factor. A lot of kites have migrated towards fewer struts, but wouldn’t you think a 5 strut kite is going to be more stable in higher winds than a 3 strut kite? However I once owned a 7 strut kite and it definitely didn’t feel more smooth than 3 strut kites I own. Aerodynamics must play a role but I’ve also owned a kite with a small leading edge and it was one of the most punchy kites I’ve ever felt. One might think aspect ratio plays a big role but high aspect race kites are never recommended for beginners and you’d think with large sections of middle canopy exposed with the lower aspect ratio kites they'd be more sensitive to wind gusts. Without getting too brand specific, anybody have any theories on how kite designers enhance the wind range and smoothness of a kite while still maintaining aggressive performance characteristics? When I asked the most experienced kitesurfer I know this question of stability, his response was, “You're over thinking it Bro. Just go kite!” Hopefully other experienced kiters can address this question so those of us that are less experienced can be a bit wiser.

[Barry P]

Wow, even defining what 'stability' means is a can of worms all by itself.

Near the top on a gust my early kites would lurch forward right past zenith and tumble out of the sky. Arrrgh!!! I called that instability. Over then next few years that company made changes to produce a more stable and more agile kite. From what I could see they changed the location of the bridle attachments, increased amount of canopy in the wing tip, and deepened the canopy overall (lower aspect ratio). Maybe there was more to it that I did not detect, but it worked.

I remember a few other early kites I owned that required that you ride them 'sky anchor' style (as little movement as possible)... almost impossible to down loop through a turn without getting yanked off your edge because the amount of bar travel required to bleed off the power spike usually exceeded what the bar offered. They could also surge like crazy in a gust. Almost evil in behavior. Looking back, I wonder how much could have been corrected by a different bar arrangement. In those days 10 or 12 inches of travel was standard. Today bar travel is like 18" or more (some provide 28" and have eliminated the trim strap all together!).

Unfortunately for us, there are few (none perhaps) kite manufacturers that are located and test in inland conditions. 'Gusty' on the coast or in Hawaii isn't even close to what it means here. Gusty there is like a 'gusty' day on Mille Lacs where wind speed goes up and down by maybe 50% over a 2 or 3 minute period. On city lakes we often have days where wind speed will vary by 300% or more within a 2-10 second period (5-20 mph days are not uncommon, right? and we try to kite them).

In short... I guess I don't know, there's lots of factors. It seems kites are better behaved (more responsive to control inputs) than they used to be - and I happy to be off those old evil kites.

[MK]

I sent this inquiry out to my reps, along for their feedback. My Naish rep just responded:

"Hey Mike,



I think I got this one…



Stability is created by balancing the “tow point” which is the imaginary point at which the bridles create pull from. Keeping that aligned with the “center effort” of the kite (the point where the canopy pulls from) balances the kite since those forces aren’t fighting each other. This allows the kite to not fall out of the sky at 12 o’clock, sit nicely on its wingtip at the edge of the window and deliver smooth “linear” power while turning. It also creates a kite that can handle gusts and have positive bar feedback. The shape and diameter of the LE also play a large role in the feel and performance of the kite. For instance, swept wingtips like on a C-kite (like the Torch) allow for faster turns that create more power, whereas a rounded wingtip that has a consistent LE diameter creates more of an axial turn that delivers smoother power (like the Pivot). The engineering of it all is something that Naish’s kite designer Damien Giardin has really dialed and uses to create all these great kites!



Hopefully that makes sense and provides more clarification than confusion."

[jrjohnson1]

Wow!! Great explanation! Balancing the bridle’s tow point with the kite’s center effort, the right balance achieves kite stability. Fascinating stuff! Thanks Mike for reaching out to your reps. Please be sure to thank the Naish rep for providing this explanation, much appreciated. His answer definitely makes sense and eliminates a lot of the questions I’ve been asking myself for far too long. Thank you Barry for chiming in as well. We now have a better understanding of this beloved sport of ours.

[Dean Rizer]

Great topic! I've zeroed in on a couple of kites that don't surge and remain reasonably stable in 20-40 conditions. But I've yet to ride a kite that will keep me moving through those conditions without dropping my butt in the water then launching me on the next blast.
Recently I read a few reviews on the Ocean Rodeo Storm. It's a 5 strut 5 meter kite offered only in one size. It's made for people who "need to ride in extereme conditions". The designer walked through many of the design elements that make the kite stable, 5 struts, Balanced tow points, are comments that were also mentioned by the Naish rep.
The review mentions the Storm's ability to carry a rider through 20-40 knot conditions. For a 5 meter kite, that got my attention. Will someone out there please buy one, I'd love to try it.........so many kites!