I do this all the time to adjust lines.
Anyone see a problem, as I have had queries about this on a bar I,m selling.
He was concerned the knot in the sleeve would weaken the line.
Have done this for 10 years with no problem.

Yeah would weaken lines for sure. Probably not as disastrous as non sleeved lines tho.

It's not the end of the world. Just get them shortened and re sleeved. 10cms wont make any difference.

But what I really want to know is why are you shortening your lines anyway?

Since shortening 2 lines is effectively lengthening the other two lines.

Perhaps use longer pig tails.

That's a common issue with single front line safety systems. Eventually, your front lines will become uneven, I have yet to see a brand of kite on single front line flagging that doesn't do that over time.

Good on you for noticing it and tuning your lines, most wouldn't even notice or think back lines are the issue.

As for your question, no, I don't see any issue doing what you're doing, I would do the same thing. As long as you don't do a knot on the line itself it's all good. Alternatively, you could also do another pig tail at the kite's connection, but no good if you use the same bar on multiple kites.

Another option for such a short length difference, it to stretch the shorter line a bit. Lines actually shrink over time so by stretching it you're actually putting it back closer to its default factory length.

From my experience, that's probably your safety line that is shorter than the other front line and you must've done that knot on the fixed front line to make it even with the safety line. So if you undid that knot and stretched the other line a bit it should make it even and look more neat, without a knot.

In extreme cases I've used pigtail extensions to correct bigger length difference as I wouldn't recommend stretching lines more than a few cm, but when you get to that stage lines are probably due to be changed

Christian

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Underoath said...
Yeah would weaken lines for sure. Probably not as disastrous as non sleeved lines tho.

It's not the end of the world. Just get them shortened and re sleeved. 10cms wont make any difference.

But what I really want to know is why are you shortening your lines anyway?

Since shortening 2 lines is effectively lengthening the other two lines.

Perhaps use longer pig tails.

Knots on one front line to even them up.
I usually hook my lines up every couple of months to make them even.]

I reckon its fine but would be a different story if you had that knot in the line.

Hey Peeps,

@underoath The knot won't weaken the lines significantly because the sleeve buffs out the bends withing the knot so it doesn't draw to tightly. There is also little tension on the knot as its used as a stopper rather than a knot in a flying line itself.

Tying a knot like that will easily rectify the line length issue and it isn't really a problem. This works well for small line length discrepancies. We manufacture Spectra pig tails to adjust longer problems in store which is a more permanent fix and looks neater.

Bouncing or stretching the shorter line by attaching a single line to a tree and hauling it tight does not fix the issue permanently. It will work for a session or maybe two but will quickly return back to it's state.

The problem is less of the one line stretching and more of the other line under less tension shortening. As the resins break down over time, the prestretched lines revert back to their unstretched length. "Bouncing" the lines back to the stretched length only works very temporarily. It seems that the safety flagging line gets stretched more often than the other of the pair and so appears to get longer.

The biggest difference is usually between fronts and backs. We have always thought of the lines stretching on the front as they carry the most load compared to the rear or back lines. Evidence suggests the back lines shrink anywhere from 2-8 inches in length. This can't be fixed apart from shortening the front lines by adding a knot in the sleeved pigtail, or by adding an extension to the back lines.

Hope this makes sense.

DM

I just tuned up a few of my bars and I adjust line lengths a bit differently.

At the bottom of the line where it is looped onto a stailess ring I put a small pigtail of dyeema in as a spacer, making the larks head go around a larger diameter and having the effect of shortening the line. You could use anything as it is only a spacer. This lets me adjust lengths without any knots in the lines and is easy to remove.

A picture would make the explanation clearer, but it works for me and as far as I know is safe.

I bet there are a lot of different ways that work, but that is how I figured out to do it.

Defo not a issue , Ive had kitelines that i've resleeved and tied knots to complete the sleeving , that have had 100's of sessions on them. Infact thats that way that all kitelines where sleeve in the past with two overhand knots inline.

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windywander said..
I just tuned up a few of my bars and I adjust line lengths a bit differently.

At the bottom of the line where it is looped onto a stailess ring I put a small pigtail of dyeema in as a spacer, making the larks head go around a larger diameter and having the effect of shortening the line. You could use anything as it is only a spacer. This lets me adjust lengths without any knots in the lines and is easy to remove.

A picture would make the explanation clearer, but it works for me and as far as I know is safe.

I bet there are a lot of different ways that work, but that is how I figured out to do it.

Hi Windywander,
Thats a good idea, will do that tommorow.
Would look better from a buyers perspective.
Now who wants to buy a 2013 50cm bar?

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yendor said...

Underoath said...
Yeah would weaken lines for sure. Probably not as disastrous as non sleeved lines tho.

It's not the end of the world. Just get them shortened and re sleeved. 10cms wont make any difference.

But what I really want to know is why are you shortening your lines anyway?

Since shortening 2 lines is effectively lengthening the other two lines.

Perhaps use longer pig tails.

Knots on one front line to even them up.
I usually hook my lines up every couple of months to make them even.]

You have motivated me to check the lengths of my lines!

Can't be an issue if Ozone bars come with three of those knots already tied on the end of the steering lines :)

That will never break, normal line will break before that does.

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dafish said..
Can't be an issue if Ozone bars come with three of those knots already tied on the end of the steering lines :)

Bingo, you win dafish! There is no problem with the overhand knot in the sleeved section. Prior to kitesurfing all power kite lines where hand made, hand sleeved and hand knotted. Personally, I've made thousands of pairs and quad sets of lines, for dual line and 4 line power kites. I still use a 200kg spectra line set I made 20 years ago, they still work fine and are remarkably even and in good condition, although the braid is coarser that what is sold as kite line these days.

The idea that lines shrink over time, has always puzzled me because it contradicts my own experience. The article below explains a property of synthetic and natural fibre ropes, but specifically, mentions dyneema SK75 and SK78, which are used for most kitesurfing lines.

Dyneema and Spectra are trade names, for chemically identical or extremely similar synthetic fibres. Spectra is owned by DuPont and Dyneema is owned by DSM, and now I think there is Chinese made stuff too.

The fibres of these lines cannot be coloured because they are so smooth and chemically inert, so the manufacturers colour the lines with coloured resins, you will see it on your hands on new line sets when you run your lines out. Even white slingshot lines have clear waxy resin coatings. My theory like Darren hinted at above is that these resins wear off over time and sand/grit/salt and other contaminants get inside the line braid and enlarge it causing this shrinkage phenomenon, which goes against the scientifically proven evidence that these fibres elongate over time and load.

Increasing the radius of bends in line using larger knots and/or sleeving greatly reduces the weakening effect of knots or a spacer as "windywander" recommends has no weakening effect.


www.samsonrope.com/Documents/Technical Bulletins/TB_Understanding Creep_MAR2012_WEB.pdf

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Ozone Kites Aus said..

dafish said..
Can't be an issue if Ozone bars come with three of those knots already tied on the end of the steering lines :)

and now I think there is Chinese made stuff too.


dont forget german liros and some italian lines aswell steve

... line shrinkage is real. Maybe it only happens more in certain brands like the lines North use but I did have it happen to a Core bar I owned too, it's lines shrunk about 20cm from memory.

Years ago, I was doing a bit of maintenance on my gear and decided to check all of my bars including the missus and sons bars, three different weights and styles of use. I had bars that were 2 years old with heavy use to a bar only used once, so essentially brand new spare bar I hadn't used.

I had the most used bar and the near new bar run out and with the lines attached to the same pole, I noticed, about 25cm difference. Hmmm, the bars were from the same year length etc and yet, the old heavily used bar was overall shorter. Both bars were trimmed evenly too ie front/back lines same.

I decided to see if I could work out why so I grabbed the tape measure, measuring the lines, writing down to the mm what I found.

The results were almost linear shrinkage with age of bar.

Of course the older bars have more use, so session times vs amount of shrinkage was pretty predictable. The more the bar was used, the shorter the lines got. I would regularly check them over time, re-adjust and trim where necessary but, still, the older lines were always shorter with the biggest difference of nearly 30cm.

I believe that when the lines are being made, only so much tension is used in the machinery process and once they finish, they stretch and treat them and the 'kite brand' makes the lines. We use them in a relatively uneven tension-ed way as we load and unload them constantly while kiting so we kind of pulse them and 'work' them until the pre-stretching comes out,,,,, they go back the their natural state,,, which of course is shorter.

Maybe it goes against what the manufactures say but I know I measured it so yes, lines do shrink. Bridles too by the way.

It's no biggie at the end of the day, so long as they are all even, kite is trimmed,,,, we're happy.

cheers,

Robbie :)

what he said above...found the same.

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Ozone Kites Aus said..

dafish said..
Can't be an issue if Ozone bars come with three of those knots already tied on the end of the steering lines :)

Bingo, you win dafish! There is no problem with the overhand knot in the sleeved section. Prior to kitesurfing all power kite lines where hand made, hand sleeved and hand knotted. Personally, I've made thousands of pairs and quad sets of lines, for dual line and 4 line power kites. I still use a 200kg spectra line set I made 20 years ago, they still work fine and are remarkably even and in good condition, although the braid is coarser that what is sold as kite line these days.

The idea that lines shrink over time, has always puzzled me because it contradicts my own experience. The article below explains a property of synthetic and natural fibre ropes, but specifically, mentions dyneema SK75 and SK78, which are used for most kitesurfing lines.

Hey Ozone.

If you don't wash your lines with fresh water, will salt crystals will build on a microscopic level and slowly damage the lines over time.

Or is it just BS?

Probably already mentioned but can't be ****ed reading. But why don't you stretch out the shorter line by hand and then trim the back lines?

I regularly have to stretch one back line by hand if Iv been looping the same direction for a wile!

You are cutting line strength down buy 40% .

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Ozone Kites Aus said..

dafish said..
Can't be an issue if Ozone bars come with three of those knots already tied on the end of the steering lines :)

Bingo, you win dafish! There is no problem with the overhand knot in the sleeved section. Prior to kitesurfing all power kite lines where hand made, hand sleeved and hand knotted. Personally, I've made thousands of pairs and quad sets of lines, for dual line and 4 line power kites. I still use a 200kg spectra line set I made 20 years ago, they still work fine and are remarkably even and in good condition, although the braid is coarser that what is sold as kite line these days.

The idea that lines shrink over time, has always puzzled me because it contradicts my own experience. The article below explains a property of synthetic and natural fibre ropes, but specifically, mentions dyneema SK75 and SK78, which are used for most kitesurfing lines.

Dyneema and Spectra are trade names, for chemically identical or extremely similar synthetic fibres. Spectra is owned by DuPont and Dyneema is owned by DSM, and now I think there is Chinese made stuff too.

The fibres of these lines cannot be coloured because they are so smooth and chemically inert, so the manufacturers colour the lines with coloured resins, you will see it on your hands on new line sets when you run your lines out. Even white slingshot lines have clear waxy resin coatings. My theory like Darren hinted at above is that these resins wear off over time and sand/grit/salt and other contaminants get inside the line braid and enlarge it causing this shrinkage phenomenon, which goes against the scientifically proven evidence that these fibres elongate over time and load.

Increasing the radius of bends in line using larger knots and/or sleeving greatly reduces the weakening effect of knots or a spacer as "windywander" recommends has no weakening effect.


www.samsonrope.com/Documents/Technical Bulletins/TB_Understanding Creep_MAR2012_WEB.pdf

Loads of experience there Ozone, great. I was about to throw in my own 5 cents worth and say Kevlar, Dyneema and Spectra are all the same man made fibre, namely Aramid. Lucky I checked 1st. Dyneema & Spectra are a different material, and 40% stronger than Kevlar. WOW! nothing but the best for our gear.

As has been said, it's unlikely those knots will cause a problem.

But ... most bars have built in features to allow you to adjust line length, specifically, knots in the pig tails and leaders. Why not use them for their intended purpose? It's easier to do. It's stronger. It looks better. It's neater and cleaner. You have almost infinite adjustment.

At the very least, stray knots in the lines are going to cause tangle points when you're rigging up. Why not put the adjustment knots out of the way where they belong?

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gdownie said..
You are cutting line strength down buy 40% .

Here's what I did after my last set of North Lines broke 3 years ago. Rather than paying North's outrageous price for a replacement set of lines (with their different lengths for front and back lines), I bought a 500ft spool of ancient Dyneema line from kite-line.com (www.kite-line.com/kiteboarding-gear/accessories/kite-lines/q-power-600lb-500ft-spool) for less than half the price and made my own line set. I doubled up the lines before I knotted it so the "single" line goes straight through and doesn't suffer the strength degradation due to the "bend" of a hard knot.

I've run this for 3 seasons now, often in crazy gusty 5m conditions in the Gorge and the lines have held up fine. Is it weaker than a properly made set of lines? Possibly. But it has lasted 3 seasons in some pretty intense conditions so that works for me. YMMV. BTW, Dyneema is a bit of a pig compared to normal lines - it whistles and it sucks to untangle but it's better than worrying about North's average line life and my bank balance. The Trust Bar itself is great.

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Underoath said..

Hey Ozone.

If you don't wash your lines with fresh water, will salt crystals will build on a microscopic level and slowly damage the lines over time.

Or is it just BS?

Bit of both IMO. If you used your gear and got it thoroughly wet, then never used it for long enough for it to dry out enough to form crystals, and then you used it without it getting wet again, I think the salt crystals would damage the line fibres if this cycle was repeated over time.
I rinse my bar and lines after each use if there is fresh water at the spot, if not, it goes in the back of the ute till next time. Once you wet the bar and lines even in salt water any crystals will begin to dissolve.
The best thing to do is to put your bar and lines in a tub of water for 10 mins then let it dry, soaking will dissolve any crystals, even on bars that have not been getting a regular rinse.

I never wash my kites, or brush sand off them, both of those things will do more harm than good.

@Peutz, I definitely believe that what you believe is true, for you :-) Same for everyone, however for your experiment to have real validity the bars would need to be measured when new, then compared with one of the bars that remains unused, over time. I also think that you are probably correct to some degree about some line brands pre-stretching and coating techniques and materials. Some brands definitely seem to exhibit this shrinking issue more than others. I think brands that combine different fibres into their lines have almost all had issues too, although I'm not up to speed on what the latest North lines you use are made from.

@Fishoutofwater - you have Q-Power line, its 100% spectra, they use a special layup linear fibre inner core with a mega tight outer braid, makes the line stiff and strong, and round, thats why they whistle. Q-Power line is very low stretch too, but it is a bit of a pain to use, and the knots you need to tie present problems for safety flag out systems to function properly. Definitely a good product, more for the person that knows what they are doing.

This is that 20+ year old line set, i made the lines and the winder/handles back in Geelong around 1994/95 - I've no idea if the lines have shrunk, but I doubt it, my money would be on that that have elongated.



Regards

Steve

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@Fishoutofwater - you have Q-Power line, its 100% spectra, they use a special layup linear fibre inner core with a mega tight outer braid, makes the line stiff and strong, and round, thats why they whistle. Q-Power line is very low stretch too, but it is a bit of a pain to use, and the knots you need to tie present problems for safety flag out systems to function properly. Definitely a good product, more for the person that knows what they are doing.

Thanks for the background Steve - most informative. The spool I bought from kite-line has a graphic of a guy riding a pickle-fork on the front so there's a good chance they're pretty old stock :). Even though they're a bit of a PITA at times they're totally bomber and I've got enough extra on the 500ft spool for one replacement line.

Can you explain how the knots I need to tie present problems for safety flag out systems? In my specific case I'm using the 4-line North Trust bar so the de-power mechanism is the bar traveling up the single thick centre line before it reaches the Y where the centre lines start. That flag-out system doesn't interact with any lines I fabricated. I'd like to know if I'm missing something though. While I don't think there's a problem with North 4 and 5 line Trust Bars (and similar designs) it would be helpful if you had an example of another depower system where the custom lines would present a problem.

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Ozone Kites Aus said..
.
.
I never wash my kites, or brush sand off them, both of those things will do more harm than good.

.
.
Steve

Ouch...."The best thing to do is to put your bar and lines in a tub of water for 10 mins then let it dry, soaking will dissolve any crystals" - and yet somehow the above will do more harm?

Using a washing machine maybe yes.

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dbabicwa said..

Ozone Kites Aus said..
.
.
I never wash my kites, or brush sand off them, both of those things will do more harm than good.

.
.
Steve

Ouch...."The best thing to do is to put your bar and lines in a tub of water for 10 mins then let it dry, soaking will dissolve any crystals" - and yet somehow the above will do more harm?

Using a washing machine maybe yes.

Brushing sand off scratches the surface coatings of the kite cloth. Leave the sand where it is, it will fall off next time you pump up and go kiting, in the meantime it does no harm.
Washing in fresh water introduces chlorine to your kites, then you leave them inflated somewhere to dry here they could get damaged, unless you have a way of keeping them still and out of the wind. Packing them up damp after washing with freshwater will create an ideal climate for mould to develop, salty kite fabric does not seem to be something that mould will grow on in my experience. The canopy cloth is sealed really well these days especially the Teijin D2 cloth, the yarns themselves are coated, then once they are woven into the cloth, the cloth is then coated again, so they are double sealed and salt water does not penetrate the cloth. Stitching and threads yeah, but its all designed for a life in or near the sea. Worth thing is washing in fresh water and then drying in the sun or leaving kites inflated on the beach and flapping in the wind, exposed to UV and heat.

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dbabicwa said..

Ozone Kites Aus said..
.
.
I never wash my kites, or brush sand off them, both of those things will do more harm than good.

.
.
Steve

Ouch...."The best thing to do is to put your bar and lines in a tub of water for 10 mins then let it dry, soaking will dissolve any crystals" - and yet somehow the above will do more harm?

Using a washing machine maybe yes.

Yeah not really familiar with the North flag out systems, but I am with Ozone and thats one that could have an issue. If you can safely flag out your kite when self landing and you are sure the system works as it is designed then there is no problem with your setup.

Q-Power came out when standard kite lines were lower rated, and less tech. The latest Dyneema version and fine braiding machines deliver outstanding quality lines and all the top brands use this sort of quality kite line now.

Never thought about the impact of brushing sand off your kites, might be something there.

But whTs the impact of rolling up your kite with sand on it, tightly enough to get it in the bag? Wouldn't that also create friction to take away the coating?

Imo I use big XL duffel bag things for my kites for that reason, the kite bags just sit in my Shed...stupidly small buggers.

Couple of weeks ago we kited in the rain, and when we came in we just rolled up on the wet sand, when I got home I unrolled the kite in my garage left it overnight, gave it a quick shake and rolled it up on the floor it still had sand on it, but it was now dry. Then I got the leaf blower and got ride of the sand.
If you just fold your kite tip to tip and then roll it up to the middle, fold in 3 it will fit into any of the bags I see at the beach.

Minimal brushing, minimal folding is the go. I like the idea of the oversize duffle bags.

I don't know if I agree with don't remove sand from kites or don't wash bars theory. To be fair I don't brush it off. but do the whack and shake method to remove sand.

If the kite goes away to sandy (and it could be sitting in the bag for a month or so) gosling around in the bag for a month or so could lead to abrasion.

As for not rinsing bars. I don't think ozone kites aus use any bars long enough to see the long term effect of not washing salt off the stainless parts.

All Ozone stainless parts corrosion and fail if not constantly washed. They are obviously not using a high enough grade of stainless to prevent corrosion.
My advice to ozone. Specify all stainless as 316L, Particularly parts that are welded.

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FishOutOfWater said...

gdownie said..
You are cutting line strength down buy 40% .

Here's what I did after my last set of North Lines broke 3 years ago. Rather than paying North's outrageous price for a replacement set of lines (with their different lengths for front and back lines), I bought a 500ft spool of ancient Dyneema line from kite-line.com (www.kite-line.com/kiteboarding-gear/accessories/kite-lines/q-power-600lb-500ft-spool) for less than half the price and made my own line set. I doubled up the lines before I knotted it so the "single" line goes straight through and doesn't suffer the strength degradation due to the "bend" of a hard knot.

I've run this for 3 seasons now, often in crazy gusty 5m conditions in the Gorge and the lines have held up fine. Is it weaker than a properly made set of lines? Possibly. But it has lasted 3 seasons in some pretty intense conditions so that works for me. YMMV. BTW, Dyneema is a bit of a pig compared to normal lines - it whistles and it sucks to untangle but it's better than worrying about North's average line life and my bank balance. The Trust Bar itself is great.

It won't matter if you double the lines, any knot, bend or even a splice will weaken a line/rope (different materials/lays will weaken differently to each knot/bend/splice.)
Assuming the lines are in good condition, I'd dare say that the force they are experiencing is waaaaaaaay under its breaking strain, so the small % loss due to the knot is negligible. So long story short, everyone is kinda correct in Thai thread!
Out of curiosity, does anyone know what the breaking strain of modern kite lines is?