Dynamic Bridles for Box of Tricks et al.

Subject Dynamic Bridles for Box of Tricks et al.
From abw@peritas.com (Andy Wardley)
Date Wed, 5 Jun 1996 07:47:25 -1000
Newsgroups rec.kites

[ Note: check out the Dynamic Bridle page for more detail and diagrams. ]

Some of you may remember me mentioning a cunning plan I had to create dynamic bridles for the Box of Tricks, Reflex and Fusion without the aid of a safety net. In fact, my method requires only the original bridle, tied with a single knot and the trick is done. If you don't like the way it flies, you can shift the knot down a bit or simply untie it to revert to the original bridle.

As with any of the Fizz kites, the bridle consists of a piece of line which is attached at the T-Piece (T) and has a tow point loop at the other end (P). Onto this is lark's headed the outer bridle line which connects the upper spreader/LE point (U) to the lower spreader/LE point (L). The bad ASCII-art diagram shows this for the right wing.

               U               (one piece of line T<->P, 
              /                    another piece U<->L)
             /                               
            /                         
T----------@- - - - -L     
          P|

Simply slip the outer (U<->L) line off the tow point:

                   U
                  /
                 /                               
                /                         
T----------+    - - - - -L     
          P|

and tie an overhand knot joining the upper and lower LE bridle sections together. Keep the line folded over at the original bridle point (marked with a white dot on a newer kite)

                    U
                    |
                    |                             
                    |                         
T----------+    ====@ - -L     
          P|

Then lark's head the U<->L line back onto the tow point and voila, one dynamic bridle.

                U
                |
                |                             
                |                         
T----------@====@ - -L     
          P|

It's really a lot easier if you try it rather than trying to visualise quite what my crap ASCII art represents.

As for how far in the knot should go, the Fusion and Box of Tricks are fairly simple. Just pull the outer bridle line (U<->L)down and towards the T-Piece until it is taut. The knot should be placed so that it is at the same height as the lower spreader. You will find that the angle from point L -> knot -> point U is roughly 90 degrees.

            U
            |
            |                             
            |                         
T__         @ - -L
   \__     /
      \__ /
         @
        P|

If you find the action of the bridle too extreme, try moving the knot further down towards the tow point. If you're feeling a little crazy, move the knot up and away from the tow point. For the Box and the Fusion, a knot in line with the spreader is about as far up as you can go without the kite getting very "rocky". That is, the nose of the kite tends to rock forwards, particularly when coming out of a turn. With the Reflex, a knot at the spreader will be fairly tame. Try moving it an inch or two *above* the "spreader line" to see the effect.

The general effect of the bridle is to make the kite a little more extreme. If you're a trick flier looking for an extra something and don't mind sacrificing a little precision, then you might want to give it a try. The kite tends to turn faster, Axel flatter and respond slightly smoother to input. The downside is that it can take a little getting used to, especially in lighter winds where the nose rocking forwards can be a problem. The great thing is that if you don't like it, just untie the knot and in a matter of seconds, you're back to the original bridle.

Now is that clever or what?

The only downside of tieing a knot in the bridle is that it makes it difficult to adjust the bridle for different windspeeds. Having said that, I rarely adjust the bridles on the BOT, Reflex or Fusion but your mileage may vary.

I've done something similar to the Phantom Elite with some excellent results, but it was far from a simple matter. The same trick simply didn't work, pulling the bridle point too far down and shrinking the bridle size in general up to frame stressing point.

A