Line Stretch: How it affects your kite.

Nak · Since 19 May 2005 4316 Posts Camas Site Lackey **CGKA Member**

OK, long story how & why I got into this situation so I'll skip that. The main thing is how BIG an effect line stretch has on kite handling.

11m REV. Stock line on the right, 600# Spectra line (pre-stretched by me to 350#) on the left. (Unknown brand on the 600# spectra.)

The kite flew normally turning right, however it felt like a 19m fuel turning to the left.

After a bit of research I figured out it was because the no-name spectra line had a couple of inches more give--like a bungee--than the stock line. At normal pull, the stock line stretched about 2 inches and then felt pretty solid. The other line stretched maybe 3 o4 4 inches and still felt like a bungee.

Bottom line: A VERY SMALL difference in lines can make a HUGE difference in kite handling. Also, all spectra lines are not created equal.

Why this matters: Check your lines to see how much stretch they have. A small investment in better lines might have a huge benefit to you. I'll try and post some exact numbers later...

tstansbury · Since 06 Jun 2006 649 Posts Rowena and P.C Addicted

also check the lengths every now and then. A friend reminded me to check my lengths last year on a rev bar with stock lines with a seasons use. One line was an inch and a half longer than the others. needless to say the kite flew instantly better. It is weird that I had not noticed it but I guees it happened slowly.

ryan800 · Since 09 Dec 2007 64 Posts Seattle

Thanks for the post, that makes a lot of sense. I've been tempted to unload my 11 rev because I couldn't figure out what was causing it to do exactly what you describe.

Chooch · Wed Aug 12, 09 9:08 am

Be sure to check your lines right after your session. Don't bother checking them after they have been sitting for a while. They need the load of the kite on them to see the actual amount of strech on the lines.

Gman · Since 11 Feb 2006 4911 Posts Portland Unstrapped

Also double check the pulleys (they can get jammed with sand) and the lenghths of the bridle running through the outside pulleys (like anything they can wear out and stretch or contract)

Always good to attach your lines to a caribner and pull tight (sheet out completely) to see if all the lines are equal every so often

Nak · Wed Aug 12, 09 9:30 am

Definitely good points. In case there's some confusion though what I'm talking about isn't the tune of the bar, but the stretchiness of the line. (Is that a word? Very Happy

) The bar, lines & bridle were in near perfect tune and yet the kite flew like crap. The one line I replaced was just more elastic--despite being pre-stretched--than the other line. Why? I have no idea. The braid looked identical, but who knows. There must be a difference in the braid that isn't readily apparent.

I was just absolutely amazed at what a difference a slight variation in elasticity made in kite performance. When you check the tune of your lines, check that the elasticity of the left & right steering lines seems equal. If there's more than an inch or two of stretch with normal control pressures, consider upgrading to better lines.

I'll take some measurements under known load conditions soon. I have one line that I know is crap, I'll measure that for a reference point. I have one standard line that I know is good, another reference point.

Gman · Since 11 Feb 2006 4911 Posts Portland Unstrapped

thats what happens when you roll your own...
http://www.hempmuseum.org/ROOMS/ARM%20ROPE%20&%20TWINE.htm

eli_anderson · Since 04 Jun 2007 507 Posts Addicted

out of 4 if 1 line is elastic the core of that line has snapped,

out of 4 lines the center is likely to stretch, so re stretch the steering lines.

When I roll my own, tie 2 overhand or figure 8 loops, but melt the end closed and sleeve in through the sides.

pre-stretched doesn't mean much. You'll need to check for equal line length if you suspect a change.

Nak · Wed Aug 12, 09 10:23 am

eli_anderson · Since 04 Jun 2007 507 Posts Addicted

totally agreed.
BUT I never take pre-stretched for granted. I always stretch them myself.

I run 1,100lb on my center lines anyways, and 660lb on my steering lines.

Great thread! Very nice discussion about line.

Nak · Wed Aug 12, 09 10:49 am

Ditto, first thing I do with new lines--stock or otherwise--is pre-stretch them.

Where do you get your lines? You mentioned the core snapping so I'm guessing your lines aren't hollow? 1100 is pretty hefty line! You might consider hollow 800# line. Spliced 800# line will be as strong or stronger than 1100# line with knots in it.

eli_anderson · Since 04 Jun 2007 507 Posts Addicted

Ozone line sets are made from the highest quality Eurocord SK 75 Dyneema. Woven with a tight, square braid and treated with a special heating process, this line is highly resistant to abrasion, water absorption and stretching. -flyozone.com

when I tie knots it line, I re sleeve it with, and have never noticed a difference in strength. But there are many ways to mess it up if your knots are crossed up.

I really don't mess with spectra anymore. Innovative textiles was our source, now I leave it up to ozone stock sets.

I have some line from Germany, I use it for landkiting. But it looks like thread, micro line at 600lbs test the size of dental floss, and no stretch. but it allows the kites to fly with less drag from lines

I have tons of line sets for all different things. But generally messing around in the Ocean, with my 230lbs frame, 1,100 doesn't ware out.

mschulz · Since 29 May 2007 530 Posts Reno, NV Addicted

Nak - I love your other thread on making line sets http://nwkite.com/forums/t-11649.html&highlight=line+sets , but I still have one question before I go off and make a set of lines.

When using the 880# hallow line, when you splice the line, you are making the larks head to attach to the kite and bar correct?

Nak · Wed Aug 12, 09 6:48 pm

Correct, the lines attach just like any other line. If you haven't bought your line yet--and you aren't in a hurry--you might want to hold off a bit. I'm going o compare the elasticity in a couple of different lines and post it here. Right off the bat I can tell you to avoid the 500# spectra line from "Catch The Wind". Confused

The Jerry brown line is cheaper anyway here: http://www.thefishingreels.com/inc/sdetail/12587 I'm hoping that the Jerry Brown line, being a quality name brand, will be better stuff.