Power Kite Forum

Troubleshooting NPW lift on long lines vs short lines

FiniteState - 12-2-2016 at 05:53 PM

Hey there. My 3m NPW9 works pretty well (according to my n00b interpretation) on my short 10ft lines, but I'm having issues when I hook up my 100ft lines. With my short lines, it rises up to zenith with hardly any effort. When I launch it with my long lines, it stalls out barely above the ground. This is with as much pull only on the power lines as possible.

Attached is a pic of it stalling out with the long lines -- and a pic of it doing just fine with short lines.

Thoughts?

Thanks in advance!
-DL

long.jpg - 114kB short.jpg - 176kB

John Holgate - 12-2-2016 at 06:08 PM

Sounds like the weight of the 100ft of brake lines are causing some brake to be applied? I had this happen once when I converted one of my NS2's to a fourline system and at speed in the buggy, the wind resistance on the brake line caused the kite to go in full reverse at 40kph. I fixed that by using a Z bridle and using a bit of extra slack in the brake lines but I could still pull the brakes if I needed to. If a Z bridle won't work for you, can you use much lighter lines for the brake lines?

skimtwashington - 12-2-2016 at 08:42 PM

You flying it on 2 handles or on bar set up?

Did you check the lines to see if all 4 lines are equal length?
( See if power lines had stretched and are now too much longer than the brake lines?)

What type of lines are you using?

FiniteState - 13-2-2016 at 10:24 AM

Thanks for the replies. I'm using handles, with 300lb dyneema. This is my first set of proper lines - probably overkill strength for my size kite, but my thinking was that I could use it for this and any larger kites. My 10' tester handles are just PVC with fairly heavy rope (stuff I had lying around).

I'll double-check the line lengths...

Prussik - 13-2-2016 at 10:41 AM

If an excessive brake line pull is a problem (certainly looks like it is) then z-bridle is not a solution. The function of z-bridle is to transfer brake line pull to the power lines - NOT reducing it. That's the advantage of z-bridles - braking function is not affected. And I don't think the weight of 100 ft line is a problem though, in small measure, contributes to the effect. Brake lines are simply too short. If z-bridles are used then the appropriate leaders have to be sufficiently long, otherwise the effect will be identical to lines being too short.

Windstruck - 13-2-2016 at 11:10 AM

All this perfectly appropriate talk about line lengths and bridling going on. Did anybody else take note what a FANTASTIC looking kite he's got there? DL, that's a beauty! :thumbup:

Bladerunner - 13-2-2016 at 02:13 PM

Quote: Originally posted by Prussik  
If an excessive brake line pull is a problem (certainly looks like it is) then z-bridle is not a solution. The function of z-bridle is to transfer brake line pull to the power lines - NOT reducing it. That's the advantage of z-bridles - braking function is not affected. And I don't think the weight of 100 ft line is a problem though, in small measure, contributes to the effect. Brake lines are simply too short. If z-bridles are used then the appropriate leaders have to be sufficiently long, otherwise the effect will be identical to lines being too short.


This is exactly what I was thinking. Quick and easy to prove. Use the knots on your leader lines to make your back lines longer. ( front lines shorter ) If it will fly to zenith on the short lines and not long then the problem is most likely in the lines.

FiniteState - 13-2-2016 at 09:01 PM

Quote: Originally posted by Windstruck  
All this perfectly appropriate talk about line lengths and bridling going on. Did anybody else take note what a FANTASTIC looking kite he's got there? DL, that's a beauty! :thumbup:


Oh, thanks so much! :) (fyi, "*she's got there")

Quote: Originally posted by Bladerunner  
Quote: Originally posted by Prussik  
If an excessive brake line pull is a problem (certainly looks like it is) then z-bridle is not a solution. The function of z-bridle is to transfer brake line pull to the power lines - NOT reducing it. That's the advantage of z-bridles - braking function is not affected. And I don't think the weight of 100 ft line is a problem though, in small measure, contributes to the effect. Brake lines are simply too short. If z-bridles are used then the appropriate leaders have to be sufficiently long, otherwise the effect will be identical to lines being too short.


This is exactly what I was thinking. Quick and easy to prove. Use the knots on your leader lines to make your back lines longer. ( front lines shorter ) If it will fly to zenith on the short lines and not long then the problem is most likely in the lines.


Cool, will try. Any suggestion for the kind of knot for hiking up the leader lines? I'd like to be able to re/move them easily. Not sure if the pull of the kite will be too much to cinch down a basic double overhand.

skimtwashington - 14-2-2016 at 05:32 AM


Again...the most likely scenario is the power lines have stretched and are longer than brake lines.

So...

If you measure all 4 lines first, you will know if that's the problem and EXACTLY how much length to compensate w/ leader lines. Will save trial and error guessing where to move knot.

I use a simple overhand knot and it stays put.

If for some reason the amount you have to compensate is longer than the handle's leader line allows, you can add a piece of leader line to the present leader line.