Power Kite Forum

Bungee strop?

ssayre - 27-1-2016 at 11:16 AM

While driving for work, a had an idea strike me. I've been "street kiting" for awhile unhooked with the nasa stars and have never had a problem until recently. While riding toeside my right hand will start to shake and lose grip. Not sure what's happening except riding often seems to make it worse. Anyway, the stars are fixed bridle and I don't hook in on asphalt because gusts are not able to be buffered with my arms. However, I use bungees at work frequently and am well aware of stretch and strength. The round ones with braided on outside. I'm thinking of making a strop with qr using a bungee. This would react instantly to buffer gusts. I would need to experiment with length and stretch distance to dial it in.

So boneheaded idea or not?

abkayak - 27-1-2016 at 11:41 AM

sucks getting old...you lose your mind and your muscles...but it is better than the option
but yea go ahead im all for you trying this...im sure you wont be the first

BeamerBob - 27-1-2016 at 01:11 PM

You might have better results with a bungee between your hook and a pulley. Having a bungee on your strop could cause control issues.

Feyd - 27-1-2016 at 03:03 PM

2nd Bobs thought.

In climbing shops there are bungees materials with some amazing load ratings. Essentially webbing with bungee core.

Feyd - 27-1-2016 at 03:04 PM

Essentially kite suspension.

ssayre - 27-1-2016 at 03:15 PM

Hadnt thought of a pulley. I don't use a pulley now. It's basically a trainer kite with a harness loop currently. I was thinking of still flying unhooked more or less with bungee assist.

ssayre - 27-1-2016 at 03:17 PM

However, this has me thinking about using the standard harness loop with bungee between.

skimtwashington - 27-1-2016 at 03:20 PM

I'm thinking the bungee will be fairly stretched already if you are using a harness and are fairly well powered and using arms just to steer. At this point not much, if any stretch left to travel and absorb. I guess a little might be better than none.

The rate of stretch under increasing lbs per sq. in.....until maximum will be important. Typical camping bungees would stretch too quickly to it's limit, but there's better quality out there..

ssayre - 27-1-2016 at 05:21 PM

Quote: Originally posted by skimtwashington  
I'm thinking the bungee will be fairly stretched already if you are using a harness and are fairly well powered and using arms just to steer. At this point not much, if any stretch left to travel and absorb. I guess a little might be better than none.

The rate of stretch under increasing lbs per sq. in.....until maximum will be important. Typical camping bungees would stretch too quickly to it's limit, but there's better quality out there..


There are many types of bungee available. I'll probably use the type that is 1/2" in diameter with braided outer and cut to length. im not sure how I'm going to do it exactly but I'll probably start out very simply until I figure out what length and if I want to single or double it for added resistance. In theory it will bear some of the load and buy enough time to react to a gust.

B-Roc - 28-1-2016 at 07:35 AM

Why don't you put a limiter on it? For instance, you take a 10" bungee and alongside it you have a 12" piece of 2mm climbing rope. The climbing rope probably has some absurd 600-1100# breaking strain but that way you can allow the bungee to flex but you limit the amount of throw. Something to consider if you don't want to fiddle with stretch per pound of strain.

pi_r_squared - 28-1-2016 at 09:10 AM

It brings to mind the bungee "snatch straps" for extracting a stuck vehicle, being able to apply a steady (ish) pull for a longer duration. Bear in mind we're talking about stored energy in a spring (1/2 k x^2), so while you might get a larger force for the pre-load wiht a heavier bungee, the stored energy will be greater for a bungee with 1/2 the stiffness, stretching twice as much (within the safe working load limit of the bungee).

Now my morning is completely consumed with trying to picture how to splice a loop in the end of a bungee, thanks alot :P

pi_r_squared - 28-1-2016 at 09:12 AM

sorry, duplicate post and it doesn't want to "delete".
[shrug]

Prussik - 28-1-2016 at 10:23 AM

The idea is not new and we experimented with "speed control" in Wind Propulsion Institute about 15 years ago. The simplest, effective way was to have the stretch incorporated into the power lines. Though it is not as simple as it sounds if you want some preload and adjustability. Worked quite well but winding the lines was PITA.

ssayre - 28-1-2016 at 06:02 PM

Lots of good ideas. I'll play around with it and see what happens.

Hit the longboard tonight and only lasted 30 seconds one handed flying toeside. I do fine front side with both hands. It's like I've just worn out my right arm or something. I may have to make up a short line bar for the peak as I only have 1 spot to use it on asphalt and long lines.