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Line sets?

Blitzhound - 3-4-2016 at 01:37 PM

I want to make up a new set of dyneema lines for my PL V16

But I can't seem to find any info on the proper strength to use.

I'd like to use the lightest line possible. In an attempt to optimize light wind ability. I don't see any reason why I couldn't go lighter on the steering lines. Anyway. What's the suggested line strength for the main flying lines?
The kites main purpose is as a buggy engine. I tip the scale at about 300lbs. I'm a beach rider. Normal wind use 10-20mph

ssayre - 3-4-2016 at 03:02 PM

being a heavy rider myself, I wouldn't go lighter on the line then what they come stock with for a couple reasons. 1. If there is enough wind to get you cruising, your still going to load the lines pretty good especially on transitions. 2. light line can be more unruly than heavier line. You want to be able to unwind and fly not fiddle fart with little tangles that happen more easily in light line. 3. in the event of a lofting, i would rather the line hold me.

595 lbs on the power lines and I wouldn't go less than 300 on steering just for line management sake

PistolPete - 3-4-2016 at 08:38 PM

For FB Kites I use 500# center & 200# steering lines. For DP Kites I use 800# center & 500# steering lines.

Under 30m/100ft 800# braded spectra or 600# QPower lines no problem. Over 30m/100ft for DP foil for light winds, then I would take my chances with 500# center lines because the drag/weight becomes noticeable and I'm not expecting big gusts in light winds anyhow. However, for my big 19m foil long line 32m set used on the water I do use 800# center lines just fine.

I use Jerry Brown Hollow Spectra Lines on 300yd/900ft spools and have had great service from this seller for 200# , 500# , 800# .

Some good DIY info here: <nwkite> . The 200# and 500# lines I can get enough pre-stretch my hand but I use the car to carefully pull the 800# lines.

sendit - 3-4-2016 at 10:20 PM

You can't go wrong with Q-line with your Venom and you will need the strength for the occasional times when the kite luffs-then-powers-up, especially with buggy weight.

The Q-line is bullet proof, lasts for years (I have yet to wear out a set), and you can adjust/tune line length when ever you need to simply by changing knots. I use a 20m base set, then add 5 or 10m extensions (or combine) for different conditions, which gives me more range and performance from my kites in many ways.

Kent sells custom colored, pre-made sets from bulk spools (a real service and value to the kite community).

http://www.awindofchange.com/product/qpowerlineset.html
http://www.awindofchange.com/product/qpower-ext.html

Cheers,

Dave

Memopad - 4-4-2016 at 09:03 AM

Some of you guys seem to be using line strength interchangeably with line diameter. In that article that describes making your own lines anyway.

The Jerry Brown spectra doesn't give much info on fiber type or weave, but it's specs suggest it isn't something designed for high strength or low stretch. I'm not sure what characteristics fishing demands of it's line, but that's what the Jerry Brown rope is made for.

When you look at "proper" dyneema (spectra) rope, you'll find it's fibers advertised as sk75, sk78, sk90, etc. These all describe it's strength/stretch/creep characteristics. Sk75 has been almost completely phased out by sk78, and sk90 is currently some of the best as far as stretch and creep are concerned. On our kites, we're not really concerned about stretch, we're concerned about creep, which is the permanent elongation of the fibers over time.

Marlow has some pretty decent kite line, and their 1.8mm line from sk78 fibers is 990lb rope. The Jerry Brown 800lb stuff is 1.85mm diameter. Marlow race line is only 1.4mm diameter, but since it's made from sk90 fibers it's still a 715lb rope.

Just pointing out that not all spectra is created equal

I make sailboat rigging and sell a lot of rope as a side job/hobby, so I enjoy the subject. I stock a lot of dyneema that we use on sailboats, but mostly in the 2-6mm range, nothing as small as kite line yet. I am a Marlow retailer though so I might pick up some kiteline spools to play with.

PistolPete - 4-4-2016 at 12:04 PM

like the option of making and modifying my lines sets, and have used homemade q-power, spectra line sets, and OEM line sets. Just sharing what has worked for me. Attached is a good read translated from http://www.liros.com/fileadmin/user_upload/dateien/Aktuelles/News/Zerreissprobe.pdf

Memopad - 4-4-2016 at 12:20 PM

THanks for sharing that link.

I'm still intrigued by the shortening lines thing, that problem does not exist in the sailing world. The concern with us is stretch when using a line, and creep when a line is left tensioned over time (mostly a problem when using synthetic fibers as standing rigging to hold a mast up). But we don't have complex tuned bridle systems on a sailboat either :p

Blitzhound - 4-4-2016 at 09:11 PM

I'm not a sailor. But I am a merchant mariner. So while I'm not completely savoy on a sail boat. I have almost 20 years sailing ships all over the world.

So I have to ask. Other then weight. Why in the world would you ever use synthetic line for a mast stay? While you might save weight. You're going to deal with stretch and fatigue or creep as you call it. You're also going to have to contend with degradation from exposure to UV and salt. Unless you sleeve the entire stay. But then you're going to have to worry about rot. I suppose in an emergency it would be fine. But at that point as long as it holds. I don't give a #@%$#! about fatigue. Haha! Anyhow...if you read my original post I was asking for suggested strength. I.E. SWL (Safe Workload). Or I guess B.S. (Breaking Strain) since that is how spectra is rated. There is always going to be a quantifiable correlation between strength and diameter.

FYI in the sailing world there is no such thing as "rope"

Memopad - 5-4-2016 at 05:08 AM

Quote: Originally posted by Blitzhound

I'm not a sailor. But I am a merchant mariner. So while I'm not completely savoy on a sail boat. I have almost 20 years sailing ships all over the world.

So I have to ask. Other then weight. Why in the world would you ever use synthetic line for a mast stay? While you might save weight. You're going to deal with stretch and fatigue or creep as you call it. You're also going to have to contend with degradation from exposure to UV and salt. Unless you sleeve the entire stay. But then you're going to have to worry about rot. I suppose in an emergency it would be fine. But at that point as long as it holds. I don't give a #@%$#! about fatigue. Haha! Anyhow...if you read my original post I was asking for suggested strength. I.E. SWL (Safe Workload). Or I guess B.S. (Breaking Strain) since that is how spectra is rated. There is always going to be a quantifiable correlation between strength and diameter.

FYI in the sailing world there is no such thing as "rope"

You really want to get into the rope vs line argument? IMO it's a pointless thing to argue about, and if anyone doesn't understand what you're talking about when you say rope or line or string or whatever the hell else you want to call it probably isn't worth talking to :thumbup:

Anyway, synthetic stays actually do have some advantages over wire. Stainless steel wire still has a recommended service life around 10 years in a saltwater environment, depending on who you ask. Synthetics are a bit untested but the current accepted number is around 6-8 years life for that. You actually size synthetic rigging for stretch, not strength. A synthetic rig with acceptable stretch characteristics ends up being far stronger than the steel it's replacing. Creep is static elongation of the fibers and is non-reversible, but newer materials has cut this down a lot. If you tried to use sk75 dyneema as standing rigging it would go slack all the time and you'd have to tighten turnbuckles constantly to keep it under tension. UV stability is the current limiting factor to synthetic rigging, and that's improving all the time as well.

Racers like it because it reduces weight aloft, considerably. Cruisers like it because it's easy to splice in a new stay if you need a replacement while underway. No specialized swaging machines required. Initial cost is probably comparable, but each future replacement is quite a bit less than wire. Pros/cons to everything.

PHREERIDER - 5-4-2016 at 05:22 AM

Man this is good stuff.

Q line, I assume 300kg+, and SS sets are the only ones that have not failed .

2-3 times "load " hard to call in buggy esp. Without lift element.

300kg front , no smaller than 200kg rear.

I used 25-27m on most of my venom seems the sweet spot on them for max power with good speed and handling

Cerebite - 5-4-2016 at 08:09 AM

Quote: Originally posted by Memopad

Quote: Originally posted by Blitzhound

You actually size synthetic rigging for stretch, not strength. A synthetic rig with acceptable stretch characteristics ends up being far stronger than the steel it's replacing. Creep is static elongation of the fibers and is non-reversible, but newer materials has cut this down a lot.

Another interesting factor in the steel versus synthetic discussion is failure mode. A synthetic line will "collapse" when it fails while a steel one will recoil which is why most 4x4 winch lines have gone to synthetic.

But we have gotten off of topic. As a variant of the usual sourcing for linesets I recently researched arborist throwing line. I found that comparable line diameters and often higher test strengths are available for 1/2 to 2/3 of the cost of dedicated kite lines and it is very conducive to splicing making a very clean set. I made a set of 22m lines with spliced ends, 1.5mm diameter, 600# test [I fly the same strength power and brake] for just over $50 and great "hand" particularly compared to Q Line which I have been using almost exclusively for 3 or 4 years [the Q line tends to kink and hold twists even when very broken in].

Blitzhound - 5-4-2016 at 08:39 AM

The line, rope comment isn't an argument. It's a statement of fact. If you are going to talk about the maritime world you need to use proper terminology. As a mariner myself I can tell you that you could be the smartest person in the world when it comes to spectra line. But Mariners won't take you seriously because you either don't know or don't care enough to use proper terminology. The fact that you use them interchangeably and get offended when someone questions it. Says you deal with mostly yachters. Which most are NOT sailors, IMHO (going out and buying a sailboat doesn't make you a sailor)

I'm not trying to argue with or insult anyone. You seem to have a lot of useful info on synthetic line. But...I was simply asking for suggestions on what strength I should use.

Memopad - 6-4-2016 at 04:45 AM

The point that seems to have offended you was in comment to the article pistol pete linked to. I was merely commenting on the authors complaint of lower test line cutting into his bridle points, because it had a smaller diameter than the higher strength line. The pointless point I was trying to make was that you can have line with higher breaking strength be even smaller diameter, so using strength as a point of reference to chafe is not necessarily accurate. Not all dyneema is the same, just be aware of what you're buying

I guess it's a good thing I'm dealing with sailors and not mariners then :p It's all rope when it's on the spool anyway. We're talking about rope to make kite line out of right? If interchanging two words with identical meaning toward the point of discussion makes you not take a person seriously, then yeah that's a little annoying. At the end of the day, none of it matters, go fly a kite :D

Blitzhound - 6-4-2016 at 08:04 AM

Yet again...you fail to offer any suggestion as to recommended line strength. If your not going to be helpful. Please go hijack someone else's thread. Preferably on another forum!

hiaguy - 6-4-2016 at 08:54 AM

peterlynn.com ships depower foils and arcs with: "350/350daN Dyneema flying lines".

hey, i don't know spectra from cotton, but if they're shipping it, they might know what's best.

awindofchange - 6-4-2016 at 04:57 PM

I would suggest going with 600# Q-Powerline. The thickness of the line and strength has very little to do with light wind performance (to a point anyways). The main factor that will effect the light wind performance as well as the high wind performance of kite line is the resonating frequency in which those lines put off while under tension. All lines/wires/ropes/twines etc... vibrate or oscilate at different frequencies, the frequency that the line oscilates is what will determine the parasitic drag of the line when moving through the air. Thinner lines may oscilate more than fatter lines. Just for simple terms and discussion - If a 1/16" diameter line is oscilating at say 3/4" in each direction, the parasitic drag of the 1/16" line would be 1 9/16" worth of drag. If another line at 1/8" diameter is only oscilating at 1/4" in each direction, the parasitic drag would only be 5/8" of an inch. The 1/8" line would have less parasitic drag than the 1/16" line. This is the same dynamic as a pipe of 6 inches diameter will have less parasitic drag than a rope at 3" diameter. The reason is that the line will oscilate giving off a wide parasitic drag as well as disrupt the flowing air over the line and the pipe will be perfectly smooth, creating a smooth transition as it passes through the air.

Q-Powerline is the only 100% spectra kite line on the market (that I know of) that utilizes a specialized sleeve that is braided in with the spectra core in a linear wrap. This gives two main benefits, one is that you do not have to sleeve the line to maintain the strength of the line. The linear wrap has a very high melting point, allowing you to simply knot the ends of the line without loss fo strength. The second benefit is the linear wrap actually reduces the oscilating of the line and helps channel the air flow over the line smoothly so that it reduces parasitic drag. Q-power line actually oscilates at a very high frequency which is a much smaller sine wave than other lines which oscilate at a very low frequency putting of a very large sine wave. This has been tested and verified through actual documented wind tunnel testing. Q-Power also uses a 45-50% load rating while most other kite line manufactures will use a 80% load rating. This means that it is most likely that a 600% Q-Power line will be stronger than an 800# dyneema kite line made by some of the name brand kite manufacturers. It also means that a 600# Q-power line will have less drag on your kite in light winds than a 300# line from another manufacturer - making it easier to fly in lighter winds even though the Q-power line may be a bit heavier in weight.

Add that info to the fact that I have my personal Q-Power linesets that are going on over 10 years of hard lakebed and beach use. Q-Powerline may be the last line you will ever need to buy.

Hope that helps.

PHREERIDER - 6-4-2016 at 06:40 PM

true dat ! dynamic fitness is enhanced! heard alot line sing and vibrate.

Q is the only one that ALWAYS feels new . crisp and smooth.

the SS sets are ultra tough but some rear line vibration that adds fatigue that's noticeable.

Q carries me thru brutal wind and usage no doubt.

Cerebite - 7-4-2016 at 09:19 AM

Quote: Originally posted by awindofchange

I would suggest going with 600# Q-Powerline.... ...Q-Powerline may be the last line you will ever need to buy.

Hope that helps.

Agreed, I have been using it almost exclusively for the last 3 or 4 years and have loved it.
Last line you will ever need unless you run into a snot nosed brat and his dad who decide to fly in the designated kite buggy field at the kite festival. His $5 KMart kite on cotton string cut through 2 of my 4 lines like a hot knife through butter severely compromising my $100 lineset. They then had the audacity to say it was my fault [sorry, rant over

]

Blitzhound - 7-4-2016 at 02:36 PM

Thanks for the suggestions guys. I'll definitely look at Q-powerline. I was guessing around 500# so 600 sounds good to me. I didn't give much thought to vibration. As usual you guys are full of great info. Thank you!