kites and equipment for zerowind
synergetic kites

fluelastrasse 54
8047 zurich

++41 44 401 56 60

urban ninja kites with numbers

read the last paragraph for informations about the weight of the kite and how to get the good lightweight materials


1 mm = 0.0394 inch
1 inch = 25.4 mm
or 2.54 cm,
1 m (meter) = 39.4 inches
10 newton = 1 da'n
= 1 kp = 2.2 pounds [lb],
1 newton = 0.22 lb (#)
our 320 n bridle line equals a 70 lb bridle line in usa (such a sleeved line is 1 mm = 0.04 inch in diameter, and 0.6 mm = 0.02 inch when pressed with the gauge or in a tighten knot), this will be the lightest bridle line you can get.
ergo.260 (n) spectra line is a test #50 or #60 kite line (e.g. laser pro gold 50 ore something slightly heavier for better grip).

ext. link please read the attribution-noncommercial-no-derivative-works license under creative commons

an urban ninja with 3m 6 mm reflex tapes    © jürg iten ch 2007
neu: lesen sie die komplette bauanleitung für diesen drachen in deutsch!

make a kite: this instructable: intro, specs, variations, bill of materials
  1. cutting and assembling the sail
  2. sewing the sail
  3. the leading edges
  4. the tail of the kite
  5. the nose of the kite
  6. flanges and the pen loops
  7. assembly
  8. typography
  9. flight and setup, movies
  10. about the weight, how to get the materials

build your own zero or lightwind single line kite and fly with it in horizontal gliding, flatspin or diving mode. this kite is designed for active flights in the most gentle of breezes or without any wind in confined urban areas like parking lots, courtyards, parks and indoor. in normal to stronger winds it just hangs up there, cool for kids too:

the urban ninja

a synergetic low wind kite project

this plan is for non commercial use only. © ch 2006

when the winds are becoming too gentle for a rokkaku battle, take your ninjas and enjoy them dancing together in the sky!

choose your weapon:


see dimensions and span of the urban ninja kite in comparison with the synergetic wing-kites.

the urban ninja kite is a current product of the swiss kite lab:, and this article reflects precisely our urban ninja, manufactured at our atelier in switzerland and commercially distributed by us.
should we be able, after more than 2 dozens of prototypes, to refine its flying characteristics or to simplify parts of the product, we will show the results highlighted in rose for a couple of days in this original plan.

the smooth, the bad and the ugly

smoother and harder variants of the original ninja kite:
for now: the smooth ones and new: the bad with a short clip . . . . .

parts for making a kite

the carbon tubes used in the kite are avia.125 - 3.1 mm, 7.5 g/m. they come mostly in lengths of 1 m or 2 m, that's roughly 40 inches or 80 inches.

and now to the kite making: please read this kite building turorial and plan completely, then start preparing all the parts shown on the bill of material.

when done, print the ninja-stencils.pdf plan. it's 800 mm x 420 mm. check the 500 mm bar to make shure your print is properly scaled. cut away the part left of the center fold of the panels. punch 3 mm holes at the corners, spine and leading edge marks.

or download the plan in dxf format, set the dimensions probably to cm, import text as text, preseve faces, the file is a 2d plan.

the pictures in this kite building plan are often showing details quite big, taken from a short distance. as a clue, you can watch the squares in the icarex cloth to determine the scale of a pic: they are around 10 mm, or two and a half of them are an inch.
western kite builders, making designs such as rokkakus, deltas, genkis or codys etc. may be surprised how small and accurate the details of an urban ninja are formed. on the other hand, people involved in indian fighters or north american fighter kites, will have to imagine the kite and its details in double size.

1   the sail

icarex with template
fold icarex sharply, lay the template on top of it and align the left edges of both.

the holes for marking the kite shape
mark all the points through the holes, including the bridle and leading edge marks for the upper black panel. remove the template, then cut the still folded panels with a straightedge and a sharp cutter.

mark at the spreader position
for the leading edge marks of the upper black panel cut a small wedge as guide for drawing the marks on both left and right sides of the panel.

here are the measurements for direct drafting onto the sail, again folded first. the units are in mm, millimeters.
plan of the upper black panel of the kite
plan of the center white panel of the kite
plan for the lower black panel of the kite

layout of the sail
press transfer adhesive tape, 6 mm or 1/4 inch wide, to the back side of the black panels, leaving a few millimeters free at the center fold. place one half of the white panel over the highly visible tape liner and roll it back. remove the liner slowly and let the white icarex drop back onto theadhesive tape.

taping the first seam of the sail
lay the left side of the white panel on to its right side, adjust the position for a good symmetry. remove 1/2 inch of the tape liner at the center and fold it tightly up at 90°

taping the second seam of the sail
lay the left side of the black panel on to the white panel, adjust the position accurately and lock it with weights. pull out the liner very slowly, be careful not to displace the panels. press the black icarex to the tape with the fingers, do not rub to avoid distortion of the seam.

the assembled sail, three panels of icarex
the assembled sail of the kite with the profiled keel: last chance to check for perfect symmetry!
should your finished flying kite lean to one side later in the sky, you can correct this by moving the y-line along the x-line.

2   sewing the sail

reinforcements for the sail of the kite
before sewing, make compound patches of an adhesive dacron 12 x 20 mm and two adhesive icarex pieces 9 x 40 mm. place the compound patches for the bridle and the z-line attachement exactly at the center fold. two of them start on the white panel, this will make three layers at this tension loaded point.
the upper bridle attachment is centered at 110 mm above the end of the black panel or 104 mm from the end of the white panel. that is 245 mm from the nose tip. then triple zig zag the panels together, 4 mm wide and 3 mm long is a nice stitch. at the center you may shorten the stitches to 1.5 mm to improve resistance.

sewing the trailing edge
sew first the folded icarex trailing edges, avoid tensions as much as possible. maybe a long double zig zag, reduced upper and lower thread tension and a double fabric transport will help. then sew the leading edges with a narrow medium length triple zig zag.

3   the leading edges

the sewn leading edge at the wingtip
for the wingtip cut pieces of icarex-coated kevlar 6 x 16 mm and self-adhesive icarex 10 x 10 mm and 16 x 40 mm. stick the small adhesive icarex patch at the outer end of the leading edge.

sticking the reinforcements at the wingtip
fold the icarex piece sharply, fold the paper liner back and place the kevlar or dacron reinforcement onto the adhesive

the finished leading edge wingtip detail
stick half of the icarex piece to the leading edge using the fold as a positioning guide, turn the sail and press the second half down to the back side. punch a hole, diameter 5 mm.

finishing the leading edge with cutouts and patches
place the leading edge spar reinfocement patch. temporarily you may stick an additional layer here to protect this exposed point of the leading edge in hard city-flights on asphalt. then cut out the leading edge: the opening is 9 mm deep and 80 mm long, the lower end at 20 mm, the upper end at 60 mm from the silver mark.

4  the tail

the reinforcemant compound for the tail section
make a compound of adhesive dacron 20 x 50 mm folded at 30 mm and a piece of dacron 10 x 40 mm for the spine end pocket. stick it accuratly aligned with the center fold of the kite and sew it to the sail with two straight stitches.

tail section of the kite sewn
front side of the spine end: melt the thread ends down and press them to the fabric.

tail section of the kite finished with two holes
back side of the spine end: punch or melt with a soldering bit two holes, diameter 3mm.

5   the nose of the kite

the nose piece made of dacron
make a piece of adhesive coated dacron 25 x 50 mm with two beveled corners and two cuts 5 mm long and 5 mm from the center fold.

nose piece sticked to the kite sail
fold half of the paper liner sharply back and stick the nose piece to the sail, the sharp folds will help in positioning and centering accurately.

bungi through 4 holes of the dacron nose
sew the nose to the sail, seal the front tip with a lighter, and punch 3 mm holes. prepare a 85 mm long 1.8 mm bungi cord with good flanges at both ends.

square knot in the bungi, loose
try to make a square knot or reef knot, called the samariter- knoten in switzerland. use the pliers to arrange it and tighten it with a continuous pull.

square knot at the nose of the kite, tightened
voila!  the accurately placed holes and the bungi will hold the spine exactly at the center of the kite.

6   the pen-loops

bridle line in the pliers
to make a flange: let 4 mm line out of the pliers. all given lengths of lines include this allowance: the z-line is 130 mm when cut, with the two flanges melted down it will be 122 mm, ready for the loop.

pressed to the plyers to form a flange
for a nice, compact flange: melt the bridle line and press it even and gently to the pliers with the plastic part of the lighter.

the simple loop, loose
make a loose loop like this: the line shown is the z-line which will pull down the spine to the spreader.

the loop laid around the pen
lay the loop around a slightly conical pen and pull the line until the flange stops at the knot.

the tightened bridle line loop
tighten the loop around the pen to proof the strength of the knot. these loops are made directly on both ends of the x-line, at one end of the y-line and at one end of the z-line.

7   assembly of the kite

the sail of the kite and the parts for making the kite ready to fly
punch or melt with a soldering bit two holes, diameter 3mm, at the three reinforcements along the spine. we use to fold the sail to make each pair of the holes in one step, good for symmetry too.

tie the z-line and the two legs of the bridle to the sail and tighten the knots carefully, again with the pen, but leave the loops open for inserting the spine later.

the leader line has an overhand knot, stopped with a flange at each end. larkshead the bridle around a knot of the leader line.

use the lightest bridle line you can find. we like our all black 320 n spectra core bridle line, which equals a 70 lb bridle line (such a sleeved line is 1 mm = 0.04 inch in diameter, and 0.6 mm = 0.02 inch when pressed in the tighten knot). all lenghts given are for this line, if you are using heavyer stuff, add a few millimeters at each end. see more unit conversions at the top of the left column.

the x-line and the y-line, back of the kite
insert the spine through the loops of the z-line and the bridle and into the tail pocket. shown here the loop of the z-line near the seam and the upper bridle loop bottom right. tighten the three loops. in the upper left shown the x-line with the attached y-line, the kite is assemembled on this photo.

nose of the kite with jaco rubber piece
tension the bungi at the nose, putting first the knot into the jaco, then the second loop. the jaco is cut at the ring and shortened by 12 mm.

the second bungi loop goes into the nose piece too
the pic is showing the second diagonal loop of the bungi, which is pulled into the nose piece of the kite.
you may shorten the 995 mm spine a little bit, depending on the strength of the bungi line and the strain and stretch in the fabric used. most sail fabric will get longer under tension over time, so let a couple of mm space between the jaco and the tip of the nose, especially if the sail is nylon spinaker. but better use icarex.

the leading edge carbon tube and the apa connector
make the upper ends of the leading edge tubes as round and smooth as possible by sanding them. the backside of the kite is shown. the upper end of the stopper is 138 mm from the top of the avia.125 3.1 mm carbon le-tube.

pushing the carbon spar into the leading edge pocket
insert the leading edge tubes fitted with the vinyl stoppers from top through the cutout into the leading edge and through the holes at the wingtip out again until the upper end is at the cutout. place first the loop of the x-line above the stopper, then the apa connector . . .

spreader to leading edge connection assembled
. . . and push the tube up into the leading edge. move the x-line and the apa down to the stopper

the carbon spreader is placed into the apa connector
when assembled, the loop of the x-line should align with the silver mark on the sail. shown here the front side of the kite.

the z-line for different zero or light wind adjustments
attaching the spreader: extend the loop of the z-line to form a double loop around the spreader. this is the neutral standard setup for all of our kites and wings. with a single loop, the z-line will be longer, with three loops it will pull and bend the spine closer down to the spreader.
when flying in the city, protect the double loop with a tape or two small vinyl or teflon tubes around the spreader beside the bridle line. this will prevent erosion of the z-line loops at take-offs and landings on asphalt.

now the kite is ready to beeing built up: bend the spreader by holding both ends firmly and use the thumbs to place it into the apas. the x-line will be probably a little bit loose or a little bit tight, this will be adjusted with the y-line.

two half hitches in the y-line at the stern of the kite
first setup of the y-line: at the tail use two half hitches (zwei halbe schläge) to tie the y-line around the spine. the x-line line should get a considerable tension and the sail should be rather slack.

different flying characteristics by tensioning the y-line
shown here the front side view of the kite, now ready to fly ! ! !
for flights in the city protect the short section of the exposed y-line with tape, or go with the line through a short vinyl or teflon tube, which will contact the asphalt at take-offs.

8   typo

front projection view of the flying kite     side projection view of the flying kite     flat projection view of the flying kite

draw the numbers onto both faces, the front side and the back side of the sail with a black marker pen. stick a sample to the window to test the effects from an appropriate distance. we use comics-like wide fonts of course, like this one called "field day filter" and numbers, which clearly indicate the orientation of the ninja on its wild flights, also from the back side.
fredi haller, switzerland, is applying highly pigmented acrylic resin calligraphy ink 29700 from rohrer-klingler for the graphic-design on his urban ninjas. he's painting with aquarel brushes on either one or both sides of the sail. after a short drying period the lightfast paint is resistant to water and abrasion. it doesnt break off when folding the kite down. the black ink is darker than that of a marker pen and looks a bit more even.

here's a real scale pdf of this cool font designed by ray larabie. you can print it on a4 sheets. your name is to identify your personal kite on a crowded field, all urban ninjas look the same after all. we would be delighted about a mentioning like "powered by" as well, thanks.

9   flights without wind

the following pics show the urban ninja with the standard setup: it will park at 60 m in medium to stronger winds. in zero or very gentle breezes it has a light, but responsive pull. the short fly aways or dives will show an extreme nose up tendency, so you will be able to turn back the kite towards you anytime. the urban ninja rolls backwards gladly and recovers to a nice short horizontal glide within a few meters. slacken the line instantly after the impulsive pull to fly this and most other moves.

dihedral adjustment for flying in zero winds

the dihedral can be adjusted with the length of the z-line to vary the yaw stability in glides. as an additional effect of a shorter z-line the spine bend increases and flatspins become tighter.

main view of the zero wind kite

back view with x-line and y-line

the most important adjustment is the tension of the whole sail. shorten or lenghten the y-line on the field to adjust the effective span of the spreader. this affects directly the span of the kite and the slack in the sail.

stern of the kite: the two half hitches in the y-line
the first half hitch of the y-line at the keel . . . and the second half hitch. the line goes around the carbon spine as well.

the urban ninja flies best with a very very slack sail, resulting in a deep billow and an accented keel area. a slack sail slows this fast little kite down. the airflow will pass a softer, flexible surface, especially if the icarex is somewhat crinkly, hence adjust the y-line at will. the pictures show a rather tight sail.

light and heavy setup of the bridle

with a lighter bridle setting, the kite will fly more agile and respond to light, but sharp pulls on the flying line. this is good for the urban ninja flying style. shown here the aggressive 580 mm bridle, or 600 mm using heavier bridle line.

attaching the flying line to the kite with a larkshead knot
lay 50 m of spectra line (called dyneema in europe) to the ground, attach it with a larkshead loop to the leader line and fly!

never fly:

the flight card shows the flying style of our kites. the movie of the urban ninja is showing the rather fast freestyle moves. to compare with the single line gliders, here is a movie of a flight with the long way home or a short indoor session with the c'est la vie gran turismo. these clips are in .mov format, on the photos and movies page you find also .wmv encoded clips.

find more information on light materials for kite building, such as measured weights on our kite building page.

have marvelous flights !

thomas k. horvath, zurich switzerland, summer 2006

if you find out any improvement on the kite design itself or some details or want to help us in correcting our clumsy english in this tutorial, feel free to send an e-mail to us. thank you!

zero wind flying at a kite festival: 5 urban ninjas
ninjas at the donaueschingen kite festival 2007. there was too little wind for kites other than synergetic zerowind ones to lift off.    picture © markus egger ch 2007

10   materials and weight . . .

never ever build your urban ninja kite heavier than indicated in the specs of this plan, it would be definitely too jumpy and less fun to control. using icarex, the sound would also be much crisper than with soft fabrics like chikara, good for locating the kite in the dark. if it's impossible for you to find the adequate light materials for making this kite, we can offer:

ninja kit netto

the fast and save way to kite building, for kids and teens too: a complete construction kit with pre cut carbon spars for inexpensive shipping, the icarex panels are not precut, all materials and parts, including the non-precut adhesive fabrics to build your own perfect urban ninja. choose one of our five standard colors for the bright center panel.
without 9460 6-mm-tape, without flying line.
buy now: 48.00 euro

ninja kit brutto

a complete construction kit for making this kite, with pre cut carbon spars for inexpensive shipping, the icarex panels are not precut, all materials and parts, including the non-precut adhesive fabrics to build your own perfect urban ninja. choose one of our five standard colors for the bright center panel.
including 6 mm x 55 m 9460 tape (for 26 ninjas or many other kites) and 100 m ergo.260 line on a 105 mm halo-spool.
buy now: 98.00 euro

the urban ninja

the production kite with kidif you prefer to fly instead of building this single line freestyle kite you can order a finished urban ninja. choose one of our five standard colors for the center panel. comes in a black tube, flying lines are not included.
buy now: euro 148.00

for further infos on ordering materials for ultralight kite making at our kite-lab please visit our contact and shopping page.

this kite plan is for non commercial use only.
© ch 2006


this kite making plan is licensed under a
ext. link creative commons attribution-noncommercial-no-derivative-works license.

neu: der komplette deutsche bauplan für diesen drachen!