The weight of material and kite
Kite fabrics, films, laminates etc. can show very different properties; carbon tubes and rods for the frame of a kite as well.
Manufacturer specs rarely correspond to the practically measured weights.
The weight of a normal kite
The weight of a kite, whether it's a light wind, standard or even a strong wind kite, plays a relevant role for the flying characteristics like stability or the useable wind range. In general, it's quite obvious:
The lighter a kite and this is true for the rather heavy box kites too, the less it will be exposed to undesired phenomenons like oscillations or even resonance in flight. The air should hold the kite, not its mass.
The ideal no or low wind kite is extremely light, with sturdy details and highly warp resistant in stronger winds.
Synergetic zero wind kites
The lighter a Horvath kite is constructed, the slower are all movements, those of the kite as well as of the pilot. The effects of air increase in relation to those of the involved mass.
The flight characteristic e.g. of the i'll be back spectra laminate urban flow edition, at a weight of 11 grams, is very slow and calm. The kite performs a 360° flatspin slowly on its own while the pilot has plenty of time watching what his device does.
At the other end of the range is Urban ninja: the numbers: With a similar size, it has more mass and the effects of the air are less. This kite performs, with impulsive inputs, several flatspins in series, upwards when in thermals. Everything is getting a bit faster and livelier, there is more energy involved in the system. But a zero wind kite must not be heavier than this one.
Whether, here and now, I start a kinetically rather active kite or a slow-moving one is a situative decision. If there's some wind and I'm rather in a playful mood, I fly a highly reactive synergetic kite. When I'm looking for the quiet moment – just doing nothing – I float with an ultralight or hyperlight kite.
Weight and Quality
About the profane technics behind it: We place everything we use in production onto the precision scales and check sporadically whether the specs of a material or a component are still within the tolerance, which is tight in our atelier.
Often we can see it immediately by eye or feel it in the hand when something is wrong. Warped cast parts, out-of-round carbon tubes, inaccurate holes and other strange things that deviate from the standard: sorting out and disposing.
Fabric like Icarex
Normally the weight of the kite cloth icarex pc31 is declared as 31g/m2, that's because of the measurement methods and used units of the textile industry, where e.g. the sailmaker ounce is used commonly. Such specifications are related often to the gross weight of the fabric, that is before the coating process. Icarex is a sail cloth coated with polycarbonate on both sides, resulting in a measured weight per unit area of around 36g/m2.
Film, laminate, Dyneema
After real-life tests, not every light-wind-kite flies better with expensive ultralight materials.
If suppliers offer kites made of so-called indoor mylar laminates, which are indicated with 21g/m2, their sails will effectively weigh between 25 and 38 g/m2, net. Icarex is definitely the better choice for the production of light kites, which are also resistant in everyday life.
White matte translucent hdpe-film weighing 20 g/m2 is made in Switzerland according to our specs. This hdpe-film is convenient to stick and fold when building small kites. It behaves soft and floaty in the air. That's why we use it for the Sticky 3.7 and the Sticky wing in kite building workshops at our studio in Zurich or at your company.
The expensive spectra laminate film is used for the sail of the I'll be back editions and C'est la vie, darling. Some other special editions are available, called Hyperlights. They are larger and the laminate is one gradation stronger. This light material has been called "Dyneema Composite Fabric" for some time now, formerly "cuben fiber". If not the whole sail is made of this material, there are essential reinforcements made of it on all our kites. Lightness counts in every smallest detail.
Carbon tubes
Due to the piece by piece production technique using prepreg sheets, tapered carbon tubes as e.g. the Skyshark 2pt may show considerable differences up to plus-minus 10% in weight. Therefore we use Skysharks weighed in pairs for the production of The long way home.
Apparently it's easier to manufacture pultruded carbon tubes within smaller tolerances. But we noticed that this is only true within the same production series. There are similar tolerances between different production lots as with the wrapped tubes or spars.
Cheap pultruded carbon tubes show an additional unpleasant effect: They have the tendency to be out of round, which results in different stiffness and mechanical stability depending on the direction it is turned. This makes them weak and vulnerable. That's why on our kites we use special high quality carbon tubes, which are round.
Carbon rods
Carbon rods (technically: round rods, solid material) are mechanically much more resilient than tubes. Their ideally exact round cross-section hardly deforms and is dimensionally stable. Rods can be bent at a smaller radius and exposed to greater lateral loads, even brutal forces.
On our small kites like I'll be back or The numbers often solid ø 1.5 mm carbon rods form the structure. They are hardly heavier than tubes of the same diameter, but more practical, i.e. virtually unbreakable and almost impossible to crush. We can grind and polish the ends to a nice special profile, because there is enough solid material.
Tubes could be filled (epoxy, telescopically inserted solid rods, etc.) at moment peaks or mechanically stressed sections such as the ends . On our kites, however, this would be too expensive and especially: heavier. In addition, we like to rely on statically balanced synergetic constructions without extreme load peaks. Rather not add anything.
Keep it light and smooth.