Speed 3 bridle stretching how to

[direnc]

Once there was a thread on foilzone about stretching flysurfer bridles so they are back to their original lengths. Specific weights and stretch times were mentioned. Anyone know how it's best done? I have an old Speed 3 DLX 12m that could use some maintainance.

[foilholio]

Hang a pulley like from a tree. Run a rope thru the pulley. On one end attach the rope to a weight on the ground beneath the pulley on the other end attach the rope to all the ELCs or pigtails. From the kite lift to weight with both left and right bridles in pairs, slack the left holding the right, then slack the right holding the left both while holding the weight up. You can start in the middle and work you way out to the tips on one bridle row like all A then B. You should feel the bridle stretch out when you apply tension to one only. After you have stretched both quickly compare them and if they are not even jerk the shorter one a bit to get it to stretch more.

How much weight to use? Well that is a bit tricky. It will depend how you lift the weight. If you use 25-30kg and you lift in pairs and just swap the tension you should get good stretching results. If you try lifting 30kg with a single bridle quickly it will probably break. If you use something like 15kg you can probably bounce the weight on the bridle and it won't break, but merely tensioning with such little weight may not fully stretch the bridle. Another thing is try keep the line holding the pulley as short as possible as a long line will swing out and change the dynamics of how the load is distributed.

How you hold the bridle. I like to apply tension to some of the kite fabric and some of the bridle, both in the one hand. Like this it is a bit more comfortable and the LCLs can break before the bridle does. You may find gloves useful as it can still get painful.

[direnc]

Exactly what I was looking for. Thank you so much!

[Henk]

I would recommend not to stretch, but to enlarger or shorten the affected bridle lines by adding loops to lengthen the bridle at the LCL. This is also the practice in paragliding.

The problem with stretching is that it will always move back after a while.

[foilholio]

But the time and effort to measure the full bridle and make the loops, I have been down that road and it is a waste of time. However I have had great success modifying kites with loops, so maybe. The point I realized with the measuring that if you pull even just 1-2kg on some Z bridles they stretch out, which makes measuring shrunk bridles difficult or impossible.

[Horst Sergio]

Henk is right,

from my experience nobody stretches paraglider bridles as the result did not last for long and the bridle shape is not just about performance, but about safety reasons where nobody would accept a bad maintenance. Within paraglider bridles the exact shape is measured and than the less shrinked bridles will be looped to shorten.
With flying lines it is the same: Stretching doesn't solve problems for long in my experience.

But as foilholio says 2 kg on a small bridle line can already be much, so I think better go with around 1 kg.

But the best way is: handle your lines with care, don't sharp bend it anywhere, but wind all lines up on your bar also the biggest part of the bridle.
And never scratch out flying lines as most kiter do, but use clips to sort them on the end when disconnected from the kite.

[merl]

Comments from paraglider world seem to confirm my own suspicion - that stretching works but once lines have shrunk, they re-shrink quite quickly. \

If one wants to lengthen some bridles what is a good way? Extra long LCLs? Or shorten the As a bit by an extra loop at the lark's head knot?

[merl]

Just found the related thread about adjusting the ozone bridle by extending at the other end of the bridle - which is not idea since the outside of the bridle shrinks differently to the middle.

It sounds like nobody makes extensions to the bridle at the kite end - either stretching or extending at the line end.

[foilholio]

I offer some more info. I started the stretching thing because of a paraglider pilot. He stated that they do it regularly, particular the brake lines and competition gliders will do it during competition sometimes multiple times in one comp. It does work and I can think of no easier way to get unsymmetrical shrink out.

That said if the kite has some continual problem where one part is too long or short, then making pigtails and other permanent adjustments are excellent. As I have used pigtails extensively on Pansh kites to change how they fly they are a extremely simply effective tool. Merely get some spectra/dyneema fishing line and make large loops with figure eight knot on one end. Now don't forget that the mixers have their own problems and adjustments, and many things can be solved there.

[merl]

Interesting. Yes, I have restretched my bridle so I know that it works, but it seemed to work for quite a short time. Don't you find that restretched lines shrink again more quickly? I remember someone on foilzone arguing that extensions (to pully lines in that case) would last longer but did understand the point at the time. I noticed this with flying lines from a 2010 Cabrinha kite which had shrunk badly. It was easy to restretch them but they shrunk again in just a couple of sessions.