Dan's Safe Kite Control Bar Experiments
I am experimenting with kite control bars for kiteboarding.
Click on images for blow-ups.
Bar 1 - 2003/04/15 - "Clunker"
This bar has two experiments: a release-under-load shackle with
custom trigger in the chicken loop and a clamcleat for locking the power
Design notes (see diagram):
- Clamcleat: this is attached at about a 90 degree angle to the
bullseye, the idea is to rotate the bar when you want to engage
it. It worked ok but required a quick glance to engage it to
ensure the rope was in the cleat.
- Part 1: this was machined out of aluminum, it is one main bar
plus a small endcap for the tylaska shackle which screws on.
- Part 2: this was machined out of delrin (acetal). it is a
tube with a taper at one end. a rope goes through it to hold the
tie ball on the end. the tapered design is critical, it allows the
tylaska shackle to be released by pulling the tie ball in addition to
moving it away or towards the rider. Make the trigger out of
plastic for smoothest action.
- Tylaska T5 Shackle (regular bail size): this is the best
release-under-load shackle, and its trigger mechanism is the easiest to
work with for adding the custom trigger.
- U-Shackle: standard sailing part, must be large enough to not
snag the tylaska shackle when released. Here I used a Wichard 1402
3/16", a smaller U shackle does not release well. Later i switched to a
Wichard 1241 5/32" bow shackle since it is smaller but still releases
- The Tylaska shackle with custom trigger works really well.
- Chicken loop assembly is a bit clunky and complicated.
- Clamcleat worked well on the beach for launching and
landing. You can't fly hooked in with it, because the rope can
pull out of the cleat unexpectedly when you turn the kite.
Bar 2 - 2003/05/01 - "Power Cleat"
This bar improves the quick-release chicken loop and the cleating
concepts of Bar 1. It also has a nice secondary power adjustment
Design notes (see diagram):
- SpinLock Powercleat PX0812: this is a cleating device which
locks/unlocks by rotating the bar 30 degrees when the line is
tensioned. It replaces the normal bullseye. You can reverse
the direction of the cleat depending on how you plan to use it. As
shown it is useful for launching and landing the kite depowered, but
duplicates the function of the secondary power adjuster. If you
reverse it you can lock any power level on the water so the rear-line
load is carried on your harness instead of your arms.
- Tylaska shackle with custom trigger (part 2) is unchanged from
Bar 1. See bar 1 design notes.
- Both ends of the chicken loop are hooked through the tylaska
shackle. One end has the U-shackle, the other end is tied to the
top of the tylaska shackle so it does not go anywhere.
- The Green tie balls are the endpoints for chicken-loop motion.
- The Clamcleat is screwed to a loop of 1-inch webbing. Use
fender washers on the backside.
- It is not shown here, but put a piece of velcro on the rope next
to the red ball and stick it onto the bar. This makes it easy to
grab the ball at any time and prevents it from flopping around.
- This bar is better than Bar 1 in every way.
- The SpinLock Powercleat works well. I found it easy to keep in
either locked or unlocked mode while riding, and it is just as
smooth as a basic bullseye when unlocked. It does have problems with
sand, after dragging my bar across the beach it jammed up and i had to
spend a minute flushing it out. I used the larger powercleat model for
now since I was not sure it would be strong enough, but I will test the
smaller one in the future.
- The chicken loop assembly works well.
- The 'full circle' chicken loop is slightly harder to unhook than
the 'half-circle' design in bar 1 because the loop stretches more when
you are hooked in. Most riders probably will prefer this.
- You MUST TEST the release mechanism, as it is sensitive to the
exact parts you have used. Once you find the right parts it will work
100%, but if you for example use the wrong U shackle it will not work
well. See Bar 1 notes. Test the mechanism by hanging your body off
it, add additional weights if desired.
- The secondary power adjustment shown here is not an original
idea, but I showed it since many folks are liking it more than the
common commercial designs.
3 - 2003/06/08 - "Super Pulley"
This bar improves upon the standard pulley-bar. The pulley range
is adjustable, and counters the natural tendency of the kite to steer
slower with less power. When you depower the kite the pulley setup
causes the center lines to move more on the pulley, and when you power
up the center lines move less on the pulley. In addition the need
for an extra power adjuster strap is eliminated, making this a very
converient bar to use. Chicken loop is optional.
- 3 pulleys are used, here I used Ronstan RF185.
- Pulley 3 has two bolts, locking its angle. It is mounted as
close to the cleat as possible with shims so that the rope is directly
in line with the cleat opening.
- Pulley 2 has only one bolt, but 2 bolts may turn out to be better.
- Spinlock Powercleat PX0308. I used the smaller model this
time, it is easier to mount.
- I lathed the wood part from a 2x2 block of white ash I found at
home depot (28" table leg: $6.00). This was convenient since I
could leave the bar square at the points where I needed to attach stuff.
- The plastic parts are 1/4" x 2" delrin (acetal). The
winders are 5" long.
The Spinlock cleat works really well - it has improved ergonomics
compared to a clamcleat (of course, it is $30 instead of $5). For
riders who want a fixed harness line, using the spinlock cleat mounted
on the bar as the secondary power adjuster should work really well.
- Usa a fixed harness line as shown, or you could connect a chicken
loop with 2:1 mechanical advantage.
- Secondary power adjustment using spinlock cleat mounted on the
bar - very convenient and easy!
- Pulley-bar setup increases steering response.
- Adjustable pulley-rope increases steering response at low power
when kite naturally steers slowly.
- Put the tie-ball on the rope at the maximum-power setting, that
way you can instantly go right to maximum power by unlocking the cleat
and just letting the rope go.