C-Quad Information

Peter Lynn Web Site Description from 2002

(https://web.archive.org/web/20021205094657/http://www.peterlynnkites.com/web/3power/page.htm#cquad )

USER INFORMATION for C Quad four line traction kites. Version 12, February 1999.

Type. These kites are neither soft kites nor framed kites but are of an entirely new hybrid arrangement using single skins with flexible f.r.p (fiber reinforced plastic) stiffeners.

History. Developed to be suitable for re-launching from water (hence the single skin and minimal structure) for kitesailing and kitesurfing, C Quads have proven to be devastatingly competitive for other traction kite uses also (like winning national buggy titles within months of initial release).

Shape. Their basic layout is "C" shaped with a small diameter fiber reinforced plastic (fiberglass or carbon) rod holding the curve of the "C" which is the leading edge and from one to 6 or more similar rods arranged as spines to provide some form to the skin and trailing edge.

The c-quad is unique in its abilities and performance. With an extremely high lift to drag ratio, it is able to perform at an upwind angle not possible with any other form of power kite. This ability gives buggiers and surfers a much improved range of wind/terrain conditions that can be surfed. Gone are the days of waiting for a perfect on shore breeze to surf or buggy a piece of beach.

Although a performance kite with improved power and abilities over other traction kites it is also a kite that can be flown an mastered by anyone wishing to own a power kite.

Fabric. All standard C Quads are made in Toray Chikara. The 4.2, 6.3 and 8.5 are also available in PC Icarex.

Current products (as at March 2000)

• 1.4m2 (2 spine) Chikara
• 2.2m2 (3 spine) Chikara
• 3.2m2 (3 spine) Chikara
• 4.2m2 (4 Spine) Chikara
• 6.3m2 (4 spine)Chikara
• 8.3m2 (5 spine) Chikara
• 10.5m2 (5 spine) Chikara

Additions

• Special colours
• Bent Spines
• Any of the above C Quads made in PC Icarex,
• C Quad foam inserts
• Noodles each
• Quad Bar
• C Quad Alloy 4 Line Handles (long or short - please specify)

These are the canard additions to a 6.3 c-quad as mentioned in the january 2000 newsletter. They prevent the kite luffing completely and can be retrofitted to existing c-quads.

rec.kites Google Group post about C-Quads

(original post by Bernhard Malle can be found >>here<<.

User information for C-Quad four line traction kites

Design, shape and history: Their basic layout is "C"-shaped with a small diameter fiber reinforced plastic (fibreglass or carbon) rod holding the curve of the "C" which is the leading edge and from one to 6 or more similar rods arranged as spines to provide some form to the skin and trailing edge. These kites are neither soft kites nor framed kites but are of an entirely new hybrid arrangement using single skins with flexible f.r.p.(fibre reinforced plastic) stiffeners. Developed to be suitable for re-launching from water (hence the single skin and minmal structure) for use with our new monohull kitesailing boat (the KiteBoard) and the FoilBoard, our new "snow board for the water", these kites are proving to be very competitive by performance and price for buggying and other traction kite uses.

Other sizes, up to 6.3sqm, are now being developed and already being used by a selected group of testers in buggy-racing and kite-boarding. Rip-stop nylon (Toray "Chikara") is used for all C-quads.

Performance:

The shaped skins and multiple bridle lines to the leading edge and spine rods create curved airfoil shapes which give good L/D (lift to drag ratio- the determinant of upwind performance) and excellent lift coefficients (the measure of power for size). These kites are powerful and easy to use with performance matching and bettering the very best traction kites in the world.

Rod Stiffness: as frame material. We are testing

Currently C Quads are supplied with fiberglass rods or hybrid rod of 25% carbon in the leading edge which provides excellent performance in the air (more power and easier flying in light winds) but it does require more care when packing the kite in its bag because the carbon is more brittle and could break when the kite is packed wrong!) Generally our experience is that there are few valid requirements in traction kiting for pull of much above the fliers body weight hence rod diameters are set for each kite size so that compressive distortions don't occur until the pull is greater than about 100kgms. Larger diameter stiffer rods can be fitted during the manufacture or at any later stage. Small increases in rod diameter result in gains in stiffness but there is still significant weight and packing disadvantages to doing this.

C-Quad Tuning:

As with other forms of four line kite, the main tuning is to set the relative brake line lengths to suit the wind and your flying style. Although we have experimented with many rigging systems, in their current form C-Quads have only the brake lines (no main bridling) to the trailing edges. This results in some flapping in light winds when the brakes are let fully off but facilitates maximum power control and als, at this stage of development, appears to be the most luff resistant arrangement.

C-Quad Flying:

Some over steering can occur coming out of stalls but handling is generally highly acceptable. When introducing new users to C-Quads, shortening the brake lines by a 100mm or so facilitates quicker adaption but experienced C-Quad users are now adopting a very different flying style than for conventional ram-air 4 line traction kites. The developing technique is to set the relative brake line length such that the handles are gripped little below the main lines rather than at the main lines with one finger above as is usual for conventional 4 line traction kites. A "Neutral" wrist position then sets the kite for maximum power while pulling on the brakes stalls the C-Quad as for conventional flying but releasing the brake lines a little de-powers the kite (without losing L/D but requiring some vigilance against luffing). It is this last technique, which conventional 4 line traction kites can't accept without collapsing, that is probably the main reason for their starting performance in buggy racing and on the water. New users tend to oversteer C-Quads by applying too much "2 Line" control and insufficient "brake" steering. In extreme cases this can cause collapsing.

Design Protection:

Peter Lynn Ltd. employs two graduate engineers plus support staff full time for traction kite product development and is only able to cover the cost of this if the breakthroughs we do make are not immediately copied by others freeloading on our work. Fortunately we have been able to file for a comprehensive patent to protect the C-Wing and the C-Quad designs and will vigorously pursue copiers. The patent covers not only specific aspects but also the combination of features we have used. Kite graphics are protected by copyright.

Water re-launching:

Being single skin, C-Quads do not hold water so have a natural advantage over ram air traction kites in their re-launch ability. In 1999 we expect to be offering special C-Quads with molded foam pads fitted to the wing tip leading edges to further facilitate water re-launching. For standard C-Quads flotation can be retro-fitted by sticking pieces of 5mm to 8mm thick polyethylene foam (eg, from Hiker Pads") to the wing tip leading edge areas using double sided tape. The more flotation that is added the easier water re-launching becomes but if more than approx. 0.3kgm of foam is added to the 4.2 C-Quad, light wind handling deteriorates, proportionally for other sizes.

Water re-launching is easiest in stronger winds and is facilitated by wave action but is not possible unless at least one of the kite's flying lines is tight.

Handlebars.

Normally C-Quads are flown with the usual 4-line kite handles (not included in the kite package). Contrary to our previous beliefs it has proved to be possible to make a bar, of cunning shape, but without swivels or pivots, that permits the full range of 4 line kite control. Comprimising a short central straight section that bends down and then out at reach end, in conjunction with a hip harness, these allow very easy one hand flying. - especially useful when a spare hand (or even two for short times) is required while getting back on the boat or refitting FoilBoard footstraps etc.. Handlebars do take a little time to adapt but then offer C-Quad control which can be more reliable than by individual handles in many circumstances. These bars will become available in 1999.

C-Quad are copyrighted names and registered trade marks for Peter Lynn Ltd

Traction kite products. All rights reserved. Patent filing number: 330489.