G'day G'star
When I started in kites, kevlar lines were the high tech sh1t, they had to be sleeved because they cut themselves. They also cut all other kite lines, due to very high melting temp, and abrasive molecular structure (not slippery).
When Spectra came out it was only available in rolls, so I made up thousands of line sets to sell with every kite I sold, and now there are some knots I can do completely blindfolded, and I am sure I could make an even length line set, blindfolded too.
Not bragging just want to demonstrate there is some experience behind my advice. Spectra will break within a couple of inches of a knot (sleeved or unsleeved) every time it is loaded beyond its rated breaking strain.
Breakage does not happen because the knot melts the line, but because of the uneven load on the individual fibres of the line as they are stretched around the radius of the knot.
Sleeving increases the radius of the knot and increases the strength, slightly.
Sleeved and sewn lines - as in shameful store bought lines - hardly weaken the lines at all. The load is spread fairly evenly across all fibres in the line over the sewn area of the sleeve and the larks head knot, and using thicker pigtails decreases line strength even less, because the larks head is "bigger".
Sleeving was also used on spectra/dyneema lines to stop the knots used to make loops from running, or slipping. I have witnessed a knot run or slip inder load on spectra kite lines. Spectra/Dyneema is very slippery upon itself, so sleeving helps to locate the knots, thats was the main reason for sleeving the other being that it added a bit of strength, and tests have been done to prove these points.
If you were only using 150kg breaking strain lines G'star, then you are very light, and you must not jump or load the lines much.??
150kg/100kg 4 line sets used to be sold by some shops as standard on Blades, but we always sold 225kg/100kg as a minimum. The loads on land kites for buggying and land boarding are not as high as on kites used on the water.
Spectra and Dyneema are trade names, the product is gel spun polyethylene, and the latest higher modulus versions are approx 70 - 150% stronger than what I could buy and make lines from 15 years ago. I have some 500lb spectra in the shop that is nearly 3 times thicker than current kite surfing lines!!
Fibres of gel spun Polyethylene cannot be coloured, so modern kite line sets are treated with coloured synthetic resins, which have a twofold effect of colouring and protecting very fine sand/grit from getting inside the weave of the line.
GSP also has very little memory, and is prone to "creep", a term used to describe the process of stretching and not returning to original length when the line is held under high load for long periods - something heavy kiters do regularly and thats why front lines always get longer and will eventually break.
GSP is virtually unaffected by saltwater, UV light, or even the strongest acids or alkali's.
Its also true that spectra and dyneema (GSP) have low melthing points, approx 300c, so a little friction from rubbing along someone elses lines (or a tree branch, etc), and they can be ruined and break.
Bowski - just shorten all the lines by 2 feet, you will not feel any difference when riding.
If you can get down to Geelong, Goshen can show you how to do the shortening and which knots to use. He also has bulk sleeving in stock.
Cya and
Goodwinds
Steve Mcshameless
quote:
Originally posted by Gstar
Some people have more money than others.
$10 or $130, it's a no brainer.
See www.kiteworks.ca/tips/sleevingspectra.htm
[Quote]
Why we sleeve our lines.
Spectra lines must be sleeved when tying knots. Spectra line although extremely strong have a very low melting point, when tied in a knot the pressure will melt the lines. When a knot is tied in a line the breaking strength drops by up to 60%. Sleeving Spectra line will increase its knotted strength up to 60% of the line strength. This means you loose almost no line strength after sleeving.
I've used this type of set up for many years without a break ever.
The only break I've ever had was in the pigtail lines of the kite. At that time all four broke at the same time (6mm leader line, knoted but UNSLEEVED), YES ALL FOUR AT ONCE.
See ya later kite! Offshore woodies!
My point is, the lines I was using were 150KG rated and assembled as described in the link above.
I had also been using them for the previous 2 years on a 2 line set up (4.9 & 7.2 Flexifoil Blade) while kiting the channel in the UK.
More analogue than digital for sure but $120 cheaper and,
just as safe in my opinion
SHAMELESS ADD BY THE WAY .
ALL OUR LOCAL STORES SELL PRE MADE LINE SETS....DER!
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