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 Post subject: Re: Strutless kite RRD
PostPosted: Mon Apr 21, 2014 6:53 pm 
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Posts: 2372
Cool, there is a big one from rrd too!
---
And yes those "toast" loops were kinda scary, did not seem like the kite was going to head back to zenith! So, go hard but be careful to not go too big/high I guess.
Not really my thing but I'd choose an easier "parachute" I think.


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 Post subject: Re: Strutless kite RRD
PostPosted: Mon Apr 21, 2014 7:42 pm 
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Location: shallow sea
BWD wrote:
Quote:
i bet rrd didn't make bigger sizes because they couldn't manage heavy fluttering and impossible waterlaunch...
it's a lot more likely that their LE and canopy shaping strategies didn't scale easily to 15m+.
Look at what the rrd and the trip have in common, contrast against the cloud and airush zero:
AR and canopy shape, LE size, bridle configuration tell the story.

By the way, if your kite is flapping, sheet in.
If you are a flyweight you don't need a 17 anyway (over 10 knots).
Or to put it another way, grow a pair or rig down to the appropriate size kite.
Riding all the time with a sheeted out kite is like riding the clutch in a car, it doesn't smell right after a while, struts or no struts!

well BWD, i see it again, if you don't understand your opponent try to discredit him. this was seen too many times here on the forum. mostly from the brand affiliated posters, but sometimes from ordinary posters too. i'd like to call them the stockholm syndrome kite owners. it is when you bought the kite, and even if you are not totally satisfied with it, you are still keeping to praise it! but whatever...
if you are out of sales arguments, please don't use the "beginner" or "stupid" kiter arguments. because you just don't really know who you are talking with.

since i'm 109kg of deadweight now i don't need to grow anything else to use the biggest size of BRM or RRD or Airush etc. it is vice versa, if you are the manufacturer of the big litewind kites, make sure it is for the real life user. strutless kites are impossible to make with high enough wing shape to make sufficient lift without distorting the kite canopy. that is why all strutless kites are very low profile wings not suitable for low wind riding for heavy riders. flapping or not! strutless kites in bigger sizes have very limited usage in terms of kiters weight and riding conditions.
same conditions were true to first generation of the switchkites product. now they learned their lessons - their newer kites have more wing profile (even if they previously tried to accuse everyone of not knowing what they are doing)

personally i can not understand why to manufacture those kind of kites at all:
-same low profile wing race kites are made with the weight close to the same size strutless kite, but without the distortion of the wing and much easier relaunch
-smaller sizes of strutless kites are only good for flyweight kiter for travel option, other wise it would be a disaster waiting to happen
-only advantage for strutless kite under 12sqm is the travel weight and nothing else!

as i see it only field of use for strutless kites is the kite schools in some really poor wind condition regions e.g. Egypt


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 Post subject: Re: Strutless kite RRD
PostPosted: Mon Apr 21, 2014 11:59 pm 
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well put............


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 Post subject: Re: Strutless kite RRD
PostPosted: Tue Apr 22, 2014 12:46 am 
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Eree sorry not trying to offend but I do disagree with what you wrote.
You might remember I also disagree with some (negative) stuff you wrote about other kites.
For me the relaunch on the clouds is no problem, like I said, and the videos show.
fly one if you don't believe it.
If you weigh 109 I am sure you would not have a lot of fluttering - you could hold the power. And I guess you know how to sheet in and fly a kite properly.
If you try, with your size you might distort the canopy, but I think 109 kg could distort almost any kite - if you try.
There is a different person - who trolls the strut less threads- I think maybe doesn't weigh so much - that is who might be Flyweight.

Anyway most of what I write is intended to be mainly topical not about another forum poster.
I am not calling you beginner or expert or kite designers buddy, and no I don't know who passes you kites to see if you can buckle them, if anybody, but that's your business not mine.

About weight and the strutless kites: I think being too small for the kite is a bigger problem, at least the cloud because it has a limited top end compared to other same size kites.
I don't have any syndrome about kites, I just like trying different ones. I have written about what I think is good and bad about strutless. It's true I do argue with those who just diss them and say things I think aren't true though.
Maybe I will try another brm or rrd strutless or maybe next time I'll try something else.
I might not try a 9m c kite in 33 knots again soon, that is what I tried last week and I would rather have a delta or some smaller SLE next time it is 30+ . On the other hand a 5m cloud might have been fun but a 7 with struts and bridle is what I wanted for that session. Getting old maybe.

So one more thing, might as well say it here as any related thread, exception to what I rather write about, this is about forum members:

It's funny that the other "strutless hater" and now also eree, are guys who both seem to have dropped hints that they are connected and have flown lots of kites and maybe prototypes. could be BS but maybe they really are affiliated to some designers, some of the ones that have not been able to make a decent strutless kite yet.


And no paff that post by eree was not so well put.


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 Post subject: Re: Strutless kite RRD
PostPosted: Fri May 09, 2014 7:26 pm 
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Joined: Fri Dec 12, 2008 2:46 am
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Location: San Diego
Anybody get a chance to try it at the Pismo demo or anywhere else?


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 Post subject: Re: Strutless kite RRD
PostPosted: Fri May 09, 2014 8:36 pm 
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Joined: Mon Aug 18, 2003 9:10 pm
Posts: 139
I've had the chance to try the RRD strutless kite
I was underpowered on my RRD religion 8m, onshore conditions on waveboard. Then switched to 10m emotion. Putting up the kite I felt immediately the power of the kite, this thing has some serious power. So I probably should have been on the 8. Being a little overpowered I tried to get some waves and I noticed that the kite doesn't turn good with de powered lines, which for me is quit essential on a good wave kite. But this could have been better on the smaller 8, don't know.
It also flutters a lot when powering and depowering, something to get used to maybe, but I don't like.
For me it can not match the performance of kites with struts.

Are you going on holiday and want to cut back on travel expenses, then this kite maybe your solution. It packs down really small, one kite will be enough to cover most conditions. Good for freeride, general use, mowing the lawn, etc.

Being so light, it drifts really well. So I you kite in a place with good groundswell (not wind swell), this could have some potential to park the kite overhead and really focus on surfing the wave.

This is my view on it....and yes I'm sponsored by RRD


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 Post subject: Re: Strutless kite RRD
PostPosted: Sat May 10, 2014 7:19 am 
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Joined: Wed Jan 12, 2005 7:23 pm
Posts: 445
Location: drtuba.eu, kite-stuff.org, eXtremist.si, kajtar.si
I actually like the RRD strutless, it is so close to my idea some years back,


I've also posted some analysis on VS. subject with no much interest on it (I wonder why... :D ), but which I think reflects in real life quite well...
Image

Anyway, readable here:
viewtopic.php?p=788376#p788376

Nowdays I'm perfectly happy to be on 2 strutted kites ;)




BWD wrote:
Eree sorry not trying to offend but I do disagree with what you wrote.
You might remember I also disagree with some (negative) stuff you wrote about other kites.
For me the relaunch on the clouds is no problem, like I said, and the videos show.
fly one if you don't believe it.
If you weigh 109 I am sure you would not have a lot of fluttering - you could hold the power. And I guess you know how to sheet in and fly a kite properly.
If you try, with your size you might distort the canopy, but I think 109 kg could distort almost any kite - if you try.
There is a different person - who trolls the strut less threads- I think maybe doesn't weigh so much - that is who might be Flyweight.

Anyway most of what I write is intended to be mainly topical not about another forum poster.
I am not calling you beginner or expert or kite designers buddy, and no I don't know who passes you kites to see if you can buckle them, if anybody, but that's your business not mine.

About weight and the strutless kites: I think being too small for the kite is a bigger problem, at least the cloud because it has a limited top end compared to other same size kites.
I don't have any syndrome about kites, I just like trying different ones. I have written about what I think is good and bad about strutless. It's true I do argue with those who just diss them and say things I think aren't true though.
Maybe I will try another brm or rrd strutless or maybe next time I'll try something else.
I might not try a 9m c kite in 33 knots again soon, that is what I tried last week and I would rather have a delta or some smaller SLE next time it is 30+ . On the other hand a 5m cloud might have been fun but a 7 with struts and bridle is what I wanted for that session. Getting old maybe.

So one more thing, might as well say it here as any related thread, exception to what I rather write about, this is about forum members:

It's funny that the other "strutless hater" and now also eree, are guys who both seem to have dropped hints that they are connected and have flown lots of kites and maybe prototypes. could be BS but maybe they really are affiliated to some designers, some of the ones that have not been able to make a decent strutless kite yet.


And no paff that post by eree was not so well put.


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 Post subject: Re: Strutless kite RRD
PostPosted: Sat May 10, 2014 2:01 pm 
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Well, I thought your post was interesting Gigi but had no comment.
I don't really study aerodynamics in detail with computer analysis, so no feedback on that side of things from me! Until now...
So, I have to raise the question though, does the computer model a kite flying around the window and turning, or just in a steady state like "parked" in a wind tunnel?
I suspect the analysis is more of a simple steady state but maybe I'm wrong?
Not only changing AOA but also twist and yaw may be important in seeing how kites really work.
Also to consider struts, how does the computer consider the disturbances of air under the intrados by the struts as the kite yaws, turns and twists?
My guess is that maybe it doesn't, unless it is a very nice computer model that has routines developed from empirical live measurement of kites flying and turning.
The other thing I wonder if normal aerodynamic modeling accounts for is canopy luffing. This seems like a complicated relationship of mechanics and aero depending on profile, velocity, kite materials, Reynolds numbers and spring constants, etc.
Does the model automatically move the kite back in the window at low AOA for luffing strut less? Because that is what happens as you know I guess from your experience, and it's opposite for strutted kites. Or if you have to place it in the window manually, how to you know you are placing it correctly? How else might this violate assumptions of the model?
How do you consider the time element in how long it takes any disturbance created by struts to resolve as kites turn and twist? Do kites underperform the models' predictions? Could it be because of factors such as this?
There could be a millionth technical questions about modeling kite performance, maybe some have answers already?
Sorry if the questions I mention are silly...

What I am most curious to ask though, is how are your current 2 strut kites?
Would you like to show pictures or videos somewhere?
I always like to see the videos and things you post here, when you have time, it can be educational!

By the way sorry to OP and rrd guys for being way OT


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 Post subject: Re: Strutless kite RRD
PostPosted: Sat May 10, 2014 6:42 pm 
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Joined: Wed Jan 12, 2005 7:23 pm
Posts: 445
Location: drtuba.eu, kite-stuff.org, eXtremist.si, kajtar.si
Hi BWD, I'm sure that you also read the notice I've put at the end of that post...?

For the things XFLR can do for you pls search google... I did not find any SW yet which can predict the, say, advanced things you asks so far. I doubt there will be one in short future...

Theory may sometimes be very different than real life experience, BUT in time you can learn by comparing both. As you wrote there are many variables to consider.

Did not do much media materials for the public recenty, sorry, but here's a preview of what I've been designing recently:
Click here

or one of them in action


(sorry RRD I'm not using intentionally this thread)

:bye:

BWD wrote:
Well, I thought your post was interesting Gigi but had no comment.
I don't really study aerodynamics in detail with computer analysis, so no feedback on that side of things from me! Until now...
So, I have to raise the question though, does the computer model a kite flying around the window and turning, or just in a steady state like "parked" in a wind tunnel?
I suspect the analysis is more of a simple steady state but maybe I'm wrong?
Not only changing AOA but also twist and yaw may be important in seeing how kites really work.
Also to consider struts, how does the computer consider the disturbances of air under the intrados by the struts as the kite yaws, turns and twists?
My guess is that maybe it doesn't, unless it is a very nice computer model that has routines developed from empirical live measurement of kites flying and turning.
The other thing I wonder if normal aerodynamic modeling accounts for is canopy luffing. This seems like a complicated relationship of mechanics and aero depending on profile, velocity, kite materials, Reynolds numbers and spring constants, etc.
Does the model automatically move the kite back in the window at low AOA for luffing strut less? Because that is what happens as you know I guess from your experience, and it's opposite for strutted kites. Or if you have to place it in the window manually, how to you know you are placing it correctly? How else might this violate assumptions of the model?
How do you consider the time element in how long it takes any disturbance created by struts to resolve as kites turn and twist? Do kites underperform the models' predictions? Could it be because of factors such as this?
There could be a millionth technical questions about modeling kite performance, maybe some have answers already?
Sorry if the questions I mention are silly...

What I am most curious to ask though, is how are your current 2 strut kites?
Would you like to show pictures or videos somewhere?
I always like to see the videos and things you post here, when you have time, it can be educational!

By the way sorry to OP and rrd guys for being way OT


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 Post subject: Re: Strutless kite RRD
PostPosted: Sun May 11, 2014 10:01 am 
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Joined: Wed Jul 12, 2006 1:22 pm
Posts: 235
Location: south london
In 7/8m weather you could put a shopping bag up and it would fly. That RRD video of the 8m looks like an awful kite, the canopy is all over the place. All for R&D but when you go and see the price of an board go over £800 and kites for £1200 then maybe that R&D should be put in refining existing gear.

For heavier guys and bigger kites the market is already well developed. Raises the question whats the point?


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