Power Kite Forum

pulley bars. what do they do

shortlineflyer - 31-5-2012 at 10:22 AM

I am thinking of making a pulley bar buy im not sure i understand what they do

does the bar make the kite turn faster, why?

Flyfish - 31-5-2012 at 10:34 AM

Hey shortline,
I have experience with depower pulley bars, but not the older non-depower ones.
Not sure which kites your thinking about trying them on, but my experience is I don't like them.
They make the kite turn faster by applying 2 times the force to the steering lines for any given imput that you make with the bar. But along with a 100% increase in steering imput comes 100% increase in bar tension. It gets really tiering. My thought is that if you have a kite that doesn't turn fast enough, don't try to fix it with a pulley bar. Solution: Get a new kite!
:wink2:

indigo_wolf - 31-5-2012 at 11:18 AM

Quote:
Originally posted by shortlineflyer
I am thinking of making a pulley bar buy im not sure i understand what they do

That made even the cat giggle a little bit.

Quote:
Originally posted by shortlineflyer
does the bar make the kite turn faster, why?

Yes... the setup is generally called a cross-over bar. When you apply power on one side, the crossover bar simultaneously applies the opposite brake. In effect, it recreates what happens when you perform a combination turn with control handles.

Applicable Threads & Videos

Thread: Converting a normal fixed bridle bar to crossover
Thread:Slingshot Turbo Bar!
Video: Home Made Turbo Bar

ATB,
Sam

Flyfish - 31-5-2012 at 12:20 PM

Oh...
Sorry, I thought he was talking about depower kites.

indigo_wolf - 31-5-2012 at 12:35 PM

Quote:
Originally posted by Flyfish
Oh...
Sorry, I thought he was talking about depower kites.


Nothing to be sorry about. The first post was a little vague. Either of our responses could apply depending on exactly what SLF was referring to.

ATB,
Sam

shortlineflyer - 31-5-2012 at 12:38 PM

I am interested in both actually

indigo_wolf - 31-5-2012 at 12:53 PM

One thing you might have to keep in mind is that John was using PVC and Jovver already has the Slingshot bar and various other required bits. If you start from scratch, the components may cost more than an off the shelf complete rig (if everything is bought new).

ATB,
Sam

shortlineflyer - 31-5-2012 at 01:10 PM

i already have a bar and some hardware

indigo_wolf - 31-5-2012 at 01:19 PM

Time to star burning the official "mad scientist midnight oil" then. :wee:

ATB,
Sam

John Holgate - 31-5-2012 at 02:42 PM

I just copied the Ozone Turbo Bar - all measurements were best guess from looking at a picture. It ended up working really well. Power lines (and 90% of the pull) goes through the center line to the harness. Brakes to the outside. Some of the turning input is applied back to the power lines through the pulleys. Providing your kite likes to be steered with the brakes - and not all kites do - the turbo bar works extremely well. I now fly all my fixed bridles from the turbo bar - except for the nasa wings which don't like the tb. My Century II was woeful on the bar as was a PL Reactor - simply too much brake input from the bar when steering.

A depower bar does not work well with FB's as it's ALL brake input which results in lots of stalling/spinning. May work well with some kites, but not worth the trouble imho.

There are quite a few different ways to rig up bars, I've only tried a couple. Ozone states 'depower through brakes' with the Turbo Bar, but I thinks that's misleading. Depower (as I accept the definition) is achieved through altering the angle of attack of the kite which is achieved through a combination of bridle and pulleys at the kite. All the turbo bar does is pull the brakes - not my idea of depower. Because of the mechanics/leverage of the bar, it gives you more brake for less effort resulting in a much faster turning kite. You can do exactly the same with handles, you would just have to be much more aggressive with them.

There are pro's and cons for the whole handle v bar debate. But you won't really know till you try it for yourself. Happy experimenting!

PistolPete - 31-5-2012 at 07:17 PM

Before Cabrinha went to IDS in 2009, in 2008 they had kites that could be rigged for 1:1 (no bar pulley) or 2:1 (with bar pulley). The attach points/bridals at the kite needed to be changed depending on the configuration used. Quick Turns -vs- Lighter Pull were the trade offs. The 2N1 bar would be rigged to match the kite rigging (pulley/no pulley).

Links:
http://www.cabrinhakites.com/powerdrive-2n1.html

http://www.kiteforum.com/wiki/index.php?title=Powerdrive_2N1_S_2008


Video



http://www.kiteforum.com/wiki/index.php?title=Powerdrive_2N1_S_2008

kitedelight - 31-5-2012 at 11:40 PM

my Naish Shockwave that had a 2:1 pulley bar than could also be turned into 1:1.
here is a similar manual with the bar images
http://www.endlesswind.com/download/f/3/naish-manual-27-sle

yup, it's pure physics...twice the line distance/bar movement at the cost of twice the load.
So, ya, faster turning/bar movement, but also twice the depower of the kite compared to the 1:1 bar movement. The relative powerband on the depower throw for the current winds is also 1/2 as small though, so it requires more precision with the bar movements.

I tried 2:1 a couple times landboarding...honestly, incredible depower and the bar wasn't too bad in lighter winds for landboarding. It was easy to dish too much power in the gusts, but was usable with practice. But, 1:1 was still my preference. Tried 2:1 on the snow, and it was lousy so used 1:1 all the time.

I wouldn't use 2:1 again, but hey, it's a neat experience, and if you've got the stuff and some time..why not.

snowspider - 1-6-2012 at 05:29 AM

I have a slingshot turbo kite with a 17"pulley bar , great match up, easy bar pressure ,kite turns fast. Setup the same bar on my 10m Scorpion and I could do chinups on the bar the pressure was brutal , switched to 1:1 ,eased the pressure and it worked great.

my 2 cents

Jason-G - 1-6-2012 at 05:57 AM

I got an airush pully bar for a depower kite cheap. I never used it on a DP kite though. In the video below, Top Hat (the guy wearing the hat) is using the same type of pulley bar. You fix the angle of the kite with a trim adjuster but there is no chicken loop. Just a fixed loop. There is a pulley that travels the length of the bar to make the kite turn really fast. They are old school and were recommended for advanced kiters. This is totally different than a turbo bar type setup.

Jason



http://www.youtube.com/watch?v=qCymH-9WCDw