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Dyneema safety check

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Created by Greenarrowz > 9 months ago, 18 May 2016
Greenarrowz
NSW, 301 posts
18 May 2016 5:17PM
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Winter winds are upon us so those who use dynabar may want to replace before your next session.
Mine was cactus after 6 months.



Replaced with SK75 2000kg 4mm in around 1hr.
Worth the effort.



Kozzie
QLD, 1451 posts
19 May 2016 10:19AM
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compressed and thin is not the same as having them broken.
but nothing wrong with replacing either. remember to check your straps to they tend to wear behind the buckles so just completely remove all the parts. has caught me out a couple times.

love seeing that offcut piece of pvc plumbers pipe sticking out from that ****ty switch leash in last photo

Greenarrowz
NSW, 301 posts
19 May 2016 5:40PM
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Yes very industrial....lol

chalks
10 posts
19 May 2016 5:16PM
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Greenarrowz,

Good advice. See you use a Brummel splice at one end. What do you do at the other? The problem with knots, even figure of eights, is that I find they stretch. Was wondering whether using a stopper ball might help.

Greenarrowz
NSW, 301 posts
19 May 2016 8:30PM
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I hear you....you could use another brummel...and run a stitch along the dyneema...but then you cant adjust at will.
I found that in the life of that rope i adjusted it around 3 times.
If you pre-stretch your dyneema after splicing you can minimise stretch to an insignificant amount.

So i been using a figure 8 knot and when it cones time to adjust...be patient undoing that figure 8.... its under alot of boosting tension and can be near impossible to undo.

If you use SK75 Dyneema the stretch is very munimal....and it IS stronger than wire rope.

@ $3.70 a meter the price is right to replace it when ever the wind changes...lol
1 session on new rope...25 knots...stretch is minimal.





chalks
10 posts
19 May 2016 7:16PM
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Greenarrowz,

Thanks that's very helpful. Agree with you about replacing the rope, which I have just done. As a matter of interest I don't use a Dynabar but a Da Kine spreader bar with the hook cut off. I then thread the rope through the clip attachment point on the bar on one end, do a Brummel splice and then through the other end and tie off with a figure of eight and a stopper.

Looks as if Dynabar have adopted your system for the attachment- respect!

Mark50
NSW, 166 posts
20 May 2016 6:47AM
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Stick with Dyneema produced by one of the recognized rope manufacturers. There is some "no name" unbranded lookalike rubbish out there that is pretty low quality and seems to wear very quickly. Might be cheap, but will probably let you down. BTW another knot site worth looking up is Grogs Knots. They have animated step by step video on how to tie all sorts of knots. They also have an App for your phone for a couple of bucks.

Jedibrad
NSW, 527 posts
20 May 2016 8:17AM
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Please forgive me if i'm wrong, but have you replaced your old line which had a core to a non cored line??

The 3 tones breaking strain means jack as you abrade your way through it.

For what it's worth i use the dakine shorts, threw out the spreader bar and put in a loop of rope through and put both knotted ends on the right side as i'm a natural footer, this gets the chicken loop out to my left hip. I don't think too many people ride toeside switch??

Loftywinds
QLD, 2060 posts
20 May 2016 11:07AM
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Thank God, kite lines & ropes last longer than the kite itself. And the concept of a "disposable kite" has not been developed yet.

www.alibaba.com/product-detail/disposable-kite-prices_60400589438.html

Greenarrowz
NSW, 301 posts
20 May 2016 2:27PM
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Jedibrad said...
Please forgive me if i'm wrong, but have you replaced your old line which had a core to a non cored line??


No...Your forgiven....
What do you think that core is....lol

I think Donaghys 4mm Dyneema Ocean 12 Rope (R) is extremely high quality SK75/90 and speaks for itself..and cheap @$3.70 p/meter.www.donaghys.com/leaving-donaghys?redirect=/

Kamikuza
QLD, 6493 posts
20 May 2016 6:16PM
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SonnyRider said..
I use this for mine
http://www.liros.com/en/products/productfinder/details/detail/liros-d-pro.html
I used the 4mm first and found it pretty good. I recently changed to the 6mm. I splice both ends. But like Greenroom says, no room for adjustment when it stretch's.


Um, it's a single eye splice with the bury being the whole length. You're not using a single length, are you?

SonnyRider
92 posts
21 May 2016 6:20PM
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Kamikuza said..

SonnyRider said..
I use this for mine
http://www.liros.com/en/products/productfinder/details/detail/liros-d-pro.html
I used the 4mm first and found it pretty good. I recently changed to the 6mm. I splice both ends. But like Greenroom says, no room for adjustment when it stretch's.



Um, it's a single eye splice with the bury being the whole length. You're not using a single length, are you?


The line that comes with the Jaybar is buried the full length and tied off at the end.

I've done a brummel splice both ends, tapering off to the middle of the 300mm line, so each has a bury of 150mm. It kind'a helps to centralise the block I use as well. I also soak the line in melted wax to help resist wear.

I CBA to take pictures of mine but I have fitted a 6mm stainless eye nut in the holes on the bar and looped the line through them. Because I don't have access to cutting down a shackle bolt & drilling a new hole to fit the bow shackle like Greenroom has. If I could I would go down this route. Now Jay has them listed on the website But the cost of delivery is more than the item cost. So until someone stocks them in the UK, I'm not buying them.

The 6mm line I use has a breaking strength of 4300kgs. The 4mm line I used has a breaking strength of 1300kgs. The 4mm I used for several months and has no real signs of any wear. Running the block it is super smoooooth.
The 6mm was an experiment to see if I could use it or not. So far it's been on for 5 sessions.

Kamikuza
QLD, 6493 posts
21 May 2016 8:46PM
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SonnyRider said..

Kamikuza said..


SonnyRider said..
I use this for mine
http://www.liros.com/en/products/productfinder/details/detail/liros-d-pro.html
I used the 4mm first and found it pretty good. I recently changed to the 6mm. I splice both ends. But like Greenroom says, no room for adjustment when it stretch's.




Um, it's a single eye splice with the bury being the whole length. You're not using a single length, are you?



The line that comes with the Jaybar is buried the full length and tied off at the end.

I've done a brummel splice both ends, tapering off to the middle of the 300mm line, so each has a bury of 150mm. It kind'a helps to centralise the block I use as well. I also soak the line in melted wax to help resist wear.

I CBA to take pictures of mine but I have fitted a 6mm stainless eye nut in the holes on the bar and looped the line through them. Because I don't have access to cutting down a shackle bolt & drilling a new hole to fit the bow shackle like Greenroom has. If I could I would go down this route. Now Jay has them listed on the website But the cost of delivery is more than the item cost. So until someone stocks them in the UK, I'm not buying them.

The 6mm line I use has a breaking strength of 4300kgs. The 4mm line I used has a breaking strength of 1300kgs. The 4mm I used for several months and has no real signs of any wear. Running the block it is super smoooooth.
The 6mm was an experiment to see if I could use it or not. So far it's been on for 5 sessions.


I predict that'll break in the middle :D

Greenarrowz
NSW, 301 posts
21 May 2016 9:04PM
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I spliced a few of these today at slighly various lengths.
Started at a target of 19 - 20cm from eye to eye... 20cm is the distance on a 11 inch dyna v8 with swivel links.
The bottom 2 have a smaller eye on the right side...
Top one is larger...was my first go.


And you gain around 1 cm over if you prestretch..
This is my pre stretching method
P.s i dont know why the pics are off rotation.




SonnyRider
92 posts
21 May 2016 7:26PM
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Select to expand quote
Greenarrowz said..
I spliced a few of these today at slighly various lengths.
Started at a target of 19 - 20cm from eye to eye... 20cm is the distance on a 11 inch dyna v8 with swivel links.
The bottom 2 have a smaller eye on the right side...
Top one is larger...was my first go.


And you gain around 1 cm over if you prestretch..
This is my pre stretching method
P.s i dont know why the pics are off rotation.






Interesting, how or what is the top line you spliced?

I like your pre-stretching technique :) Shame I don't have big old battery kicking around

Kam. I couldn't agree more. I keep an eye on the line, hence why I chose the 6mm to give me some more time ;)
I might just go back to the bury the entire length until I can get my hands on the swivel links Greenroom has.

Greenarrowz
NSW, 301 posts
21 May 2016 10:09PM
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The left is a long bury and the right side is simular to 5 or 6 tuck brummel with a buried end.
4mm SK75.

Kamikuza
QLD, 6493 posts
21 May 2016 11:35PM
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Stitching and brummels are to stop the tail coming out when the line is unloaded. That's it. When the splice is loaded, the tension on the line clamps the buried tail in place. The recommended amount is 72x the diameter of the line for dyneema . . .

If you're going to stitch, you may as well do a simple eye splice with a decent tail and taper, and leave it at that.

The problem with eye splices on both ends is what happens to the middle.

You're not "pre-stretching" the rope, you're resetting the fibers after you've meddled with it ;)

Greenarrowz
NSW, 301 posts
22 May 2016 3:58PM
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I know this is rough , but while we on the subject.
Its a 360° long bury and sew up across the rear 20 cm.
Pulley would have to be removed and replaced to install.
Oh and the pre stretching or de"meddeling" teqnique was applied also Kam..




Jedibrad
NSW, 527 posts
22 May 2016 4:56PM
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Whilst i enjoy fiddle as much of the next guy... you can see from the first photo the only reason u had to replace the line was due to abrasion.
I'm no expert with the aramids but i've had quite a few failures due to abrasion both sailing and kiting and it can really ruin your day
And whilst you may be happy with yours... for the benefit of other readers... this application is better suited to cordage with an abrasion resistant jacket

Kamikuza
QLD, 6493 posts
22 May 2016 6:18PM
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Select to expand quote
Greenarrowz said..
I know this is rough , but while we on the subject.
Its a 360° long bury and sew up across the rear 20 cm.
Pulley would have to be removed and replaced to install.
Oh and the pre stretching or de"meddeling" teqnique was applied also Kam..






What's it for? I played with that kind of thing for ****s n' giggles. If it's for your pulley line, the problem is still that you're left with a "void" where the tails meet. That's a danger zone for wear.

Manufacturers prestretch the the rope with a lot more wright than an old battery ;)

Jono77
WA, 356 posts
23 May 2016 4:35PM
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I just made up a few spare ones the same as the original, one loop on one end, double for the length. I made one just a tiny bit too short for my 13 inch bar and can't quite squeeze the figure 8 knot on the end. It will probably fit 11 inch bar.

If you are in Perth and want it, PM me and you can have it. I'm in the Scarborough area.



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"Dyneema safety check" started by Greenarrowz