How to check your lines length balance?

[kitesurfvoilier]

Hi Bushflyr,
I totally agree with you, may be not perfect but just check that your low tension situation is balanced and correct it is easy! And with the Kitecleat, you don't want to attach your lines to anything! So one more time, quicker!

[foilholio]

Hi Foilholio,
Thanks for your point of view, I was not talking about race world championship settings
Just visually adjust a +/-10mm difference between lines with no real tension on it and I still think it could just help your kite to fly better!

10mm makes a difference, having a kite fly neutral is great for tricks. Often the kite has a bias so, lines can be out to correct it somewhat.

Foil,

You have 100x more experience than me, but I've always had success putting all my pigtails on a line attached to a post, then having a look at my bar holding it. First thing is you check your center lines vs outside lines....that is easy to figure out if they are off. On my setup, I have a swivel, so I can tell if it is not parallel to my eyeline, if not I grab the swivel and pull the center lines and can tell which is longer by a small amount by seeing the amount of tension on each line. Then you can pinch off the two connection points of the steering lines to the bar outside lines to feel out if there is a differing amount of tension in each of those.

I'm actually able to find a 3-6mm difference by just starting with a full spectrum analysis then honing in on the center vs outside lines all while being by the bar.

You can do it with a rod of some sort and see how they balance. I.e. a line on each end and you pull in the center, it'll then tilt like your swivel. The problem you get is when your lines ain't free like on a pulley to "find" there own length but are solidly connected at both ends, then the shorter one will just end up stretching to match the longer one. A bit of riding later and they'll be uneven again. Now if they were made accurately you can generally just stretch them and then they will match up again. But most lines are not so accurate.

Actually, yes, it is completely possible and even easy to check your line length with a post and a hook or whatever. Tie lines to solid object, pull bar, observe sag. Give a little tug on chicken loop to confirm that tension and sag are still equal. Done. It's simple physics and bit of common sense vector analysis that nobody needs to calculate but can easily observe.

The observe sag method is not accurate. I have used it on lines and they bend 99% even i.e. my eyes could not tell a difference. Onto the pulley and they are 20-40mm out. The thing is you can't measure a line accurately at all with out putting tension on it. Sag=no tension. You want to know the length that the lines are under tension anyway, because that is what the conditions are when using the kite.

[edt]

there is tension when the line sags that comes from the weight of the line not much but it's not no tension. It's good enough for me and is the method most kiters use. As far as I know only foilholio uses the system that he describes, it is interesting to be sure but he is the only one that uses it.

[foilholio]

I wonder why I get so much skepticism sometimes. Anyway it's a simple enough device, some rope and a pulley. It's the physic of the 2 lines reaching equilibrium through a pulley and you observe the length difference over a less than 10cm width VS observe the slight subtleties of two sags matching over 20meters plus. Do you really think your eyes have the accuracy to detect those sag difference that equate to line length differences of less than 1mm? because the pulley can do that, the same as anyone can measure anything with a small ruler. Add even a slight wind and the sag method is horrible. The pulley is fine in any weather, 40knot wind no problem

[Bushflyr]

Actually, yes, it is completely possible and even easy to check your line length with a post and a hook or whatever. Tie lines to solid object, pull bar, observe sag. Give a little tug on chicken loop to confirm that tension and sag are still equal. Done. It's simple physics and bit of common sense vector analysis that nobody needs to calculate but can easily observe.

The observe sag method is not accurate. I have used it on lines and they bend 99% even i.e. my eyes could not tell a difference. Onto the pulley and they are 20-40mm out. The thing is you can't measure a line accurately at all with out putting tension on it. Sag=no tension. You want to know the length that the lines are under tension anyway, because that is what the conditions are when using the kite.

Completely untrue. A line will sag no matter how hard you pull it. It's simple physics. If you wind up with "20-40mm" of difference you're just doing it wrong. I put a good 50 lbs or so of force on my bar when I check lines. Grab the center with one hand and lean back hard. Pull the CL with the other hand to make sure the tension is even. 1mm of difference in line length will translate to something like 10mm more sag in the middle. Way easier to see the difference in sag than try to measure 1mm at the end of a line.

[foilholio]

Saying something is untrue does not so make it. You obviously have never tried my method or you would not jump so quick to attack me. If you use 50lbs of force on two lines in unison
then all that is going to happen is you stretch the shorter of the two and end up with more even lines, which may be all you needed to do. But that is not a method of accurately comparing the lengths of the two lines, to do so they need to be individually tensioned with the same force each!. Maybe it is something beyond most, but coming from foil kites I can tell you that your method of measuring needs to involve a constant force or your measurements are worthless.

[edt]

getting a constant force is pretty hard how about this. Get four 5 pound weights hook them to middle of each 4 lines tension them and then look at the sag. You should need somewhere around 200-300 pounds pressure to even lift up the weights and then you wouldn't need anything complicated, just look for the sag and pull by hand.