Sunday, July 18, 2010

Not Ready For Prime Time; Foil Kites

I had a great windsurfing session early today, blasting around the Indian River Lagoon on my cool-looking black and red slalom board with its matching red and black 8.4 meters squared sail. I felt pretty "dialed in", and enjoyed passing my kite friend John like he was standing still. Heh heh. I quit, contented, around 2pm.

Unfortunately, I got a "second wind" after a refreshing fast-food lunch of fat, sugar, and caffeine, and decided to join a different set of buddies at the same spot for a kiteboarding session. I have a love-hate relationship with kiteboarding. The act is beautiful when it works out, but the gear is horrendously finicky and unreliable. If you use an inflatable kite, your bladders and valves are likely to malfunction, or at least weigh your kite down in light winds, and if you use a foil kite, the bridles are likely to tangle, the fabric to wick wetness, and the chambers to fill with water such that you can't relaunch it if it crashes. Basically, all kite gear SUCKS in one way or another.

There's a diehard camp of foil-kite advocates, however, who will tirelessly espouse the flawless wonders of foil kites. Here are their common claims, with my critical evaluations of those claims based on my preliminary experiences with a foil kite.

Claim #1- "Foil kites are more powerful and efficient and fly better in lighter winds than inflatable kites."
Status = Partially true. If it is tuned correctly and flown skillfully, a foil kite will fly and stay aloft in wind slightly lighter than what it takes to keep a bladder-inflated kite in the air. And because it weighs less, it will rise faster and give more power on the "upstroke" when you are getting going. Once you're up to speed, the 3d airfoil shape of a foil kite pulls more for its size and goes upwind at a better angle than an inflatable kite. But foil kites have a tendency to "overfly" the wind window, "front-stall", and collapse, especially if the wind is gusty or shifting in direction, whereas bladder-inflated kites hold their shape much better and respond to wind changes better.

Claim #2- "Foil kites are more convenient and less of a hassle than inflatable kites."
Status = Partially true. It is definitely nice not having to pump up your kite and worry about bladders and valves leaking. Also, the foil kites pack up nice and small and you don't have to lug a pump around. However, it takes a longer for a foil kite to recover from a crash, because it gets really heavy with wetness and sand and there are complex bridles that take a long time to get untangled. Further, foil kites require "tuning" to keep them performing properly after their lines stretch with use. You need a PhD in aerodynamics and fluency in German to figure out how to tune them in a way that will make them fly better and not worse.

Claim #3- "Modern, closed-cell foil kites relaunch from the water as well, if not better, than inflatable kites."
Status = Total bullshit. IF you are standing in shallow water, and IF there is lots of good wind, and IF your foil kite just happened to crash in the perfect, untangled position at the center of the wind window, then it will relaunch about as easily as an inflatable kite... except that it will yank you downwind with crazy force because you're relaunching it in the "hot zone" instead of at the edge of the wind window. Of course, if your foil kite crashes anywhere other than at the center of the wind window, if it does any folds or inversions when it's falling out of the sky (which it will), if you're in water where you can't touch, if the wind is less than a steady 12 knots, if your feet are in a floaty directional board that doesn't provide much resistance against the kite, if the kite happens to get a little water in it when it crashes, or if a wave washes over the kite, it will be next to impossible to relaunch. I have only been able to do a deep water relaunch 1 out of the 5 times I have accidentally crashed my Flysurfer Speed 2 in deep water. And I ain't no kite kook, neither.

Claim #4- " Foil kites let you jump high and get major airtime in relatively light winds."
Status- True. I am not a very good jumper, but I have had some really nice, floaty airs while riding my foil kite. The only thing is that jumping makes you susceptible to getting in a position relative to the kite and the wind wherein the kite will collapse on itself and crash out of the sky. The difficulty and hassle of relaunching a crashed foil kite tends to make one more conservative about jumping.

Claim #5- "Foil kites turn fast."
Status- Not mine. My 12 meter Flysurfer Speed 2 foil kite turns at about the same speed as my 14 meter inflatable kite, if not slightly slower. When I have to turn the kite for jumps and transitions I need to plan ahead and get the timing right so I don't sink while waiting for the kite to turn. At least the bar pressure required to turn the kite is relatively light.

Claim #6- "Foil kites are safe and easy, especially for self-launching and landing"
Status- Mostly false. It's easy to self-launch a foil kite in most winds, and it's easy to self-land a foil kite in light wind, but it's extremely sketchy to self-land a foil kite in strong wind. Also, because of their powerful, lofty pull, their propensity to fold, tangle, and re-power in gusts and wind shifts, mediocre de-power systems, and their sometimes sluggish steering responses, they probably increase you're likelihood of having a serious accident. I chose not to fly my inflatable kite in wind over 20 mph, and I'll definitely excercise the same caution with my foil kite.

Conclusion- Foil kites may be better now than when they were first invented, and maybe even a little better than my 2-year old Flysurfer Speed 2, but they still have a long way to go before they are as safe, convenient, and dependable as inflatable kites for use on the water by average kiters. I would say that at this point in time, foil kites are most appropriate for good, technically-minded kiters who rarely crash the kite and who sail "door" style twintips close to shore in flat, shallow water and steady, light to moderate winds.

Specific areas for improvement- My Flysurfer Speed 2 would be improved if: 1) It flew with more stability slightly further back in the wind window, 2) It didn't have so many long, fine bridle lines, 3) It had water-repellent fabric and didn't get water in it so easily, 4) It had one-way drains all along the trailing edge that would let the water out when you were trying to relaunch it, 5) It had a users' manual with better pictures and better English translation, 6) The bar had bigger scoops for winding up the lines and stronger bungees on each end that would really lash the line-bundles down well, 7) The chicken loop line and emergency depower line were made of strong spectra or something that wouldn't get moldy and wear through and have to be waxed with a candle and stuff, 8) It had the ability to relaunch at the edge of the wind window like an inflatable kite.

That was a lot of words, now here's the video. The main words it has are angry swear words coming from me when the kite is resisting my attempts to relaunch it. The swear words are pretty bad, aggressive, blasphemous and scatological, so if you don't want to see that ugly, bad-tempered side of your favorite blogger / son / nephew / friend / whatever then turn the video off right after I crash the kite.

Losing my temper with a foil kite, 7-18-10 from James Douglass on Vimeo.

6 comments:

tbuckee said...

Good gravy! What if there had been young children in vicinity? The questions they would ask their parents!
I'm a windsurfer who has not tried kiting. I've always thought it took up too much space and your assessment of the whole sport doesn't make me anymore pumped to give it a try. Great blog, by the way.

Tom said...

Great video, great honesty about foil kites, very refreshing to hear from such a creditable source.

NC Paddle Surfer said...

Been there done that dozens of times back in 1999-2000. Inflatables saved the sport.

JSW225 said...

Never before has such a group of hobbyists been so creatively blasphemous as in Windsurfing and Kitesurfing. When shit's not going the way it's supposed to, vile words come out of my mouth that I wasn't even aware that I knew.

Atte said...

Hi.

About the water relaunch.

1. I newer see you pull both back lines at the same time (when the kite first go down), that almost always do the trick for me.

2. when you pull the front lines (the part when you have water in the left side) you have to make sure that you are holding one hand on the 2nd ball on the (in this case) green steering line to pull, that prevent the kite to "fly over" and land on its LE.

If there is wind I usually get the kite up without any problem. the problem is always when you are alone on the water because there is no LEIs ho can even fly (around 6-8 knots) then it could be tricky to get it up if it lands the way yours did.

The way your kite fell from the sky tells me to shorten the c line in the mixer, makes the kite more stable but also a little slow to turn. I prefer a little bit slower turning kite that stays up in the air.

This mess got to dam loooong.

/Atte

James Douglass said...

Hey Atte- Thanks for the relaunch tips! Since I posted this video I have shortened the B and C mixer lines and the kite has been behaving significantly better.