WHY use kites at all? The efficiency of conventional sails is such that they can go faster, have better upwind performance and can "sheet out" to spill the wind giving a wide usable wind range per square metre of sail.
Where as kites gain unspillable lift as the wind increases so have a much smaller wind range per square metre of sail. They are also subject to loss of control and "loft" in lulls.
On the positive side, the fact that lines are used means that we can use "clean air" (laminar flow) avoiding "messy" ground winds (turbulent flow). Also in light or off shore winds we can make full use of the wind gradient. (This is the effect that increases in height from the ground are often accompanied with an increase in wind strength.) This gives us traction potential when Land Yachts and Speed Sailors might be becalmed.
Large buggies that cannot breakdown and masses of kites that cannot possibly all be carried at one time, negate our sports main viability. SPIDER offers the World's most compact, complete and practical traction system, covering the widest wind range in one portable package. IT'S IN THE BAG!!
The key to practical kite traction is in the use of parafoils - where the stored weight and volume is so low. Shown here, and covering a wind range of 3mph to 60mph, is everything you need contained in a LAZY SACK":
A complete 3 wheeled SPIDERKART, MODULUS traction system, Storm rig, Ultralight, Spingback, helmet, motorcycle suit, boots, harness, tools and spares. THAT'S A TOTAL OF 13 SQ METRES AND 16 KITE SIZES!!!
A parafoil is a fully soft inflatable wing. People are already familiar with their use in the sports of hang gliding and parachuting. For kite traction the design is modified somewhat but the principles of using air inflated wings are similar. There are no spars or solid cross members which means that the weight and storage volume can be kept to a minimum. One of the most notable factors in the use of parafoils for traction is their exceptional power potential for their given weight and durability.
SPIDER Parafoils are not toys but tools. They offer traction across a very wide wind range in a remarkably small and light package. They can be used on land, sand, snow and ice. On skis or in a kart it is possible to gybe and tack, make upwind, cross wind, and downwind courses.
All SPIDER parafoils have the following characteristics:
4 liners. As a kite they are controlled by the Pilot by 4 lines, 2 power lines and 2 brake lines. With these it is possible to launch, land and position the parafoil anywhere in the "wind window". This is an area defined by the furthermost point it can fly to the extreme left, right and overhead. These positions are referred to as the "edges of the wind window", or just "edge". By positioning the kite in various areas, traction, speed control and lift can be induced.
Low pressure. The way a parafoil inflates will dictate its handling in various conditions. If the air can fill and empty the cells easily, the result is a low pressure design. The advantages are easy inflation when collapsed, wet, or snow bound. It is also possible to drive all the air from the cells in a controlled manner by over braking, which "kills" the kite instantly. This is a crucial safety feature in dangerous situations, such as sudden squalls etc.
High aspect ratio. This is the ratio of the span of the leading edge to the chord (depth) of the parafoil. The high aspect design results in several important characteristics. A maneuverable and responsive kite with a high spin rate, fast traction speed with superior upwind performance and the ability to be "killed". They will also remain parked and stable when anchored, even in squally conditions.
Durability. Because of the way and situations in which they are used, the canopies can received considerable shock loading. All SPIDER parafoils are based on a reinforced substructure whereby the point loading of the "bridling" is spread along the wall. This results in a very robust "bulletproof" canopy.
Options. The material used for the canopy can vary. The "standard" materials, ripstop nylon (K 42) coupled with polyester bridling offer the best in terms of durability. They have a high degree of "give" - and from our experience we KNOW it's necessary! There are lighter and high performance alternatives, which we offer as "Specials". But there is a trade off between performance and durability/cost.