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 Post subject: Re: Do Kites Fly Better with Strut Vavles Closed?
PostPosted: Fri Sep 27, 2013 8:15 am 
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It is something I have never thought of before.

But thinking about it. It is conceivable that during twisting forces of powered turning there will be high pressure and low pressure sections of the kite. That in turn could squeeze air from the high pressure section to the low pressure.

Closing the valves off would counteract this issue buy keeping the strut pressure even an not allowing the LE to as much internal volume to squeeze differential pressure zones?!


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 Post subject: Re: Do Kites Fly Better with Strut Vavles Closed?
PostPosted: Fri Sep 27, 2013 12:17 pm 
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I also heard that if you apply a teflon coating to the bottom if your board, it will go faster.


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 Post subject: Re: Do Kites Fly Better with Strut Vavles Closed?
PostPosted: Fri Sep 27, 2013 10:28 pm 
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How about putting more air pressure in struts than leading edge with a one pump

Pump the kite to10 PSI then clip close all struts
Bleed 2 PSI from leading edge

LE= 8........STRUTS= 10

Would it fly even better then ?


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 Post subject: Re: Do Kites Fly Better with Strut Vavles Closed?
PostPosted: Sun Sep 29, 2013 1:49 am 
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it is a safety feature, so when you blow your LE you still have something floaty to help you swim in.


no performance difference, i think those guys that think so were (and probably are) a little hi.


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 Post subject: Re: Do Kites Fly Better with Strut Vavles Closed?
PostPosted: Sun Sep 29, 2013 7:42 am 
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Quote:
By the way, when I pinch one strut, I will pinch either the left or the right. If the theory is correct, then the kite will turn faster in the pinched direction. Nope. Still turns the same.


I don't think that's the theory and I don't think that's the right experiment. My idea of what's happening is that if pressure is being applied to the LE, air flows into any or all struts that are open and as pressure comes off the LE it will lag momentarily before regaining it's rigidity. When I was having the problems I described in my other post the kite was cupping as it stalled, then springing back and flying fine at the edge of the window.

I'm all for someone other than me doing a controlled experiment (season is wrapping up, I'm not going to fool around while there's wind). Blind, all the valves open or closed.

Here's another factor in this though - like I said, I always use a gauge when pumping up. That kite that I noticed this with was used and I didn't pump it as hard as I would have with a new one - I'm guessing I would have kept it between 6 and 7 psi. I think that if a kite was inflated properly it would be harder to notice- it's way easier to get air into a strut at 6.5 than if it's already at 8+.

Also - Peter Frank - WTF? You always seem pretty thoughtful - but this is a safety issue that you are falling on the wrong side of so that you can keep your kite pretty? Have you ever had a bladder burst while you are riding? It's very nice to keep some flotation with you, especially in the cold water we both have.


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 Post subject: Re: Do Kites Fly Better with Strut Vavles Closed?
PostPosted: Sun Sep 29, 2013 10:29 am 
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geopeck wrote:
Quote:
Snip...

Also - Peter Frank - WTF? You always seem pretty thoughtful - but this is a safety issue that you are falling on the wrong side of so that you can keep your kite pretty? Have you ever had a bladder burst while you are riding? It's very nice to keep some flotation with you, especially in the cold water we both have.


?

I dont get what you mean by "keeping your kite pretty" ?

Anyways, I choose NOT to close and open my clips every single time I rig/derig my kites - because I ride A LOT !

What a waste of time in my eyes :-?

And on the big kite I have taken the clips off, as it will be lighter, and they wont rub against something (destroy the kite), nor need help when inflating.
As big kites are often packed really hard in the bag, both because of their size, and because you typically only use limited amount of time when rigging down.
So only advantages by NOT having clips on those IMO (except for the rare rainy days where they are practical).


Yes, you can have a bladder failure - I've had one in 14 years, so yes, it can happen - and it could happen tomorrow.

It is my choice though - just like I often ride without safety leash too, because it is faster and easier sometimes - if sideon and waves and alone or just a few out, where I just want to get rid of the kite if it goes into the rolling waves.

The risk that I am really far out, and the wind changes 90 to 180 percent, and that I can not ditch the kite and swim ashore on my board (or without), is 1 out of a million in my eyes.
You also got a downside, if you try to rescue your kite - as you will get dragged out so far and fast (as we agree that the only scenario where it could have an impact, is if wind oddly changes to offshore, right ?) that you might not be able to swim ashore no more - and then you are in REAL trouble !
Water can be cold, and darkness could be approaching - and if out alone or if noone sees you - you could be worse off than if you go for the swim ashore :o

There is a risk in both scenarios - but it is just my choice to do like I do.

Just like some are using impact vest, flotation vest, helmet, knife, whistle, GPS transponders etc etc.
Others are not, or just using some of the add-on gear.

Personal choices, and depending on WHAT you are doing, as if going for a long distance ride far out, you choose differently of course.
Just like I wear a helmet sometimes, other times not.

So I choose not to close the valves, as it is a PITA to do both before you go out, and to open afterwards, besides it makes derigging MUCH slower.


And evaluating the risk and any situation I could think of on a given day - I typically make my choice.

You choose to close/open your clips every time - I do not :naughty:

Off topic, I know, but would just respond !

8) Peter


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 Post subject: Re: Do Kites Fly Better with Strut Vavles Closed?
PostPosted: Sun Sep 29, 2013 11:58 am 
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Peter_Frank wrote:
Anyways, I choose NOT to close and open my clips every single time I rig/derig my kites - because I ride A LOT !

What a waste of time in my eyes :-?


Hi,

I agree 100% with Peter here.

Someone mentioned they need floatation when a bladder bursts. I will tell you that the chance of bursting a bladder is reduced if you keep your struts open because if you smash your kite hard onto the water (while having the struts open), there is additional volume where the air can escape into.

Cheers
Caesar 8)


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 Post subject: Re: Do Kites Fly Better with Strut Vavles Closed?
PostPosted: Sun Sep 29, 2013 1:35 pm 
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Peter_Frank wrote:

Anyways, I choose NOT to close and open my clips every single time I rig/derig my kites - because I ride A LOT !

What a waste of time in my eyes :-?

And on the big kite I have taken the clips off, as it will be lighter

Yes, you can have a bladder failure - I've had one in 14 years

8) Peter


Me too Peter 14.5 years and only one failure...but i always clip them..just in case..1 in a million
You may ride a lot ...but i doubt more than me...in the water year long
Really...a waste of time ....10 seconds rigging....de-rigging...with 5 struts and 6 seconds with 3 !!

Much more waste of time putting lines on and off every time going out...like majority of people do
Do you take your lines on and off Peter...if so that is a waste of time in my eyes :wink:

You have a big kite...yes...what size?
Hand pumping my 19 with lines on + clip 5 struts...i am "in the water" without rushing in 5 minutes

Have you calculated your "total time" to get in the water when you do not clip or have no clips :?:
How about weight saving taking off clips altogether on big kite..how many grams..0.05% saving :?:

I am of course messing with you a little bit
I hope you see a bit of humor in it
I do respect your experience......Mr. strapped transition man :thumb:
By the way today ......the sun sets 20 minutes later than you...more time possible on the water

:pump: :surf: :sun: :cheers:


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 Post subject: Re: Do Kites Fly Better with Strut Vavles Closed?
PostPosted: Sun Sep 29, 2013 2:36 pm 
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I think it might depend on how you ride, I slam the kite a lot, pop valves, snap lines. Seems like I swim back to shore once a month. You don't have to pinch every single strut. Just a single strut makes the difference between a two hour swim back to shore and a 15 minute swim.


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 Post subject: Re: Do Kites Fly Better with Strut Vavles Closed?
PostPosted: Sun Sep 29, 2013 3:44 pm 
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Quote:
Do kites fly better with strut inflation valves closed on a one pump system? It really seems that my Ozone Zephyr shows a difference when flying between all valves open and all valves closed. It seems to go upwind better with the strut valves closed. Maybe if the valves are all open the air in the bladders is moving around from chamber to chamber too much, and this causes some losses?

That is a very good question Mr. alden. Personally I never lock my "One pump" valves. I always leave them unlock so the air can flow freely between the LE and the other struts so my kites are balanced especially the SCREAMER models because of their performance. But I do lock the middle strut of my RENEGADE models in case something happens and I need floatation when I venture in the ocean since I use the Renegade model as my wave kites . And if it is a big day with big waves then I always make sure to lock all 3 struts on my RENEGADE or the SURF models for more floatation in case I get eaten or destroyed.
But again for safety reasons, it's always good to lock all your struts up. It doesn't matter what kite you are on that day. It's more safe.


Attachments:
PERFORMANCE with Screamer kite.jpg
PERFORMANCE with Screamer kite.jpg [ 130.55 KIB | Viewed 262 times ]
OCEAN with Renegade kite.jpg
OCEAN with Renegade kite.jpg [ 214.68 KIB | Viewed 262 times ]
RENEGADE model.jpg
RENEGADE model.jpg [ 320.16 KIB | Viewed 262 times ]
RENEGADE 3 STRUTS.jpg
RENEGADE 3 STRUTS.jpg [ 281.38 KIB | Viewed 262 times ]
The SURF models.jpg
The SURF models.jpg [ 210.28 KIB | Viewed 262 times ]
SCREAMER model.jpg
SCREAMER model.jpg [ 301.95 KIB | Viewed 262 times ]
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