List of questions for Ken Winner

[cglazier]

Hey Ken
Can jou give us any idea how many kites are sold worldwide, or any other indication of how big our sport is.
...Just curious.

Thanks,
Chris G

[Foxi]

Is there a Toro 20 in the loop ?

[Dwight]

I can answer the question about the 20m Toro and I’ll bet I’m right-on too. I’ve had correspondence with Ken where he told me he didn’t agree with some of my opinions on the yahoo kite group. Big kites and aspect ratio was one such conversation. In every exchange will Ken, regardless of topic, he’s always been right. Sometimes it takes me awhile to figure it out, or figure out what he really meant, but he’s always turned out to be right. The man is just one heck of a smart techno geek. I’m one myself, just not that smart.

I’ve gone all high aspect, then all low aspect, then back to high aspect, but not freaky high aspect like I consider some kites. I’m riding Rhinos. Ken told me high aspect kites were actually easier to use in bigger sizes. I now agree. What I learned the hard way was, they are less critical of kite and jump timing. A lower aspect 20 m would have a narrower window of where it could be when you reverse it to jump. If you’re off in the kite placement, you will get thrown hard in a direction you don’t want to go. With a higher aspect 20 m, the kite is way more tolerant of where it can be in the window. The increased tolerance for error makes landing much easier too. I think it’s the better L/D of the higher aspect kite that allows it room for error from the pilot. Turning speed has no relevance in this conversation. The lower aspect kite can be made to appear to pivot about it’s tip quicker, but that won’t make you jump better because air speed is what you need most in real light wind.


<font size=-1>[ This Message was edited by: Dwight on 2002-08-08 16:57 ]</font>

[Toby]

I just retyped the info I got from North about the Rhino 2 and I noticed that they only want sizes 10-20 sqm.

Dwight, please ask Ken if this makes sense, since the 8 is an important size for riders worldwide (most common setup: 8-12-16), also for the ladies.

Thx
Toby

[Dwight]

He is making the 8m too. The team riders wanted the 10 and 8. I wanted a 9, but that size is not planned for now.

[Tony]

What makes for a good minimalist quiver to cover most conditions ... considering the range of these new kites? Say 3 kites.
How about a mixed quiver of Toro's and Rhino II's ?
Toro 8m, Toro/RhinoII 12m, RhinoII 18m ??

[Guest]

>what was the benchmark in the design of the Rhino 2? <

We started off working to make improvements on the Rhino. We wanted to go slightly

higher in AR since the Toro covers the mid-AR range and since higher AR has the

potential for certain performance advantages.

Once the X2 came out we used that as a guide in the sense that we knew we had to

come up with something at least as good.

>How does it compare with existing kites (i.e. where do you see improvements)? <

We think we kept the stability of the Rhino -- ie. it doesn't jellyfish or luff too easily --

and improved the lift, hangtime, turning speed and relaunch.

Compared to the X2, we think the Rhino2 has a bit more power. This is something

that's easily controlled and adjusted in the basic geometry of the kite. Our riders

preferred the gutsier option.

We're pleased with our new ribs -- hexribs, we call them. The name comes from the

fact that the patterns derive from ribs modeled on the computer with a hexagonal cross

section -- which for a number of reasons and for this application is a good

approximation of a circular cross section. The result is a rib that is quite stiff (virtually

no wrinkling), accurate (no shrinking), and aerodynamically clean. It's a true 3D shape,

much like segmented ribs in that respect.

We've added some durability details, such as Ballistic Duck (used in bullet proof vests)

in the rib ends for abrasion resistance, and scuff pads at the corners of the kites.


>When are we going to see improvements in kite materials, especially the canopy?<

We can easily use a heavier ripstop. In fact, I've made prototypes with ripstop more

than than twice as tough. The problem is that such kites are heavier and more

expensive.

>I’d like to know more about what you think about the segmented rib idea. I know you

said it might create extra drag because the seams run opposite the direction of airflow.

<

I don't think I said exactly that. My point was to say that if one is going to split hairs,

one should give North credit for running seams in the more aerodynamic direction.


>I know from being in hang gliders, during the early years, that canopy collapse on the

top front of the leading edge was detrimental to performance. I thought the real idea

behind these ribs was to shore up that gap which allows the canopy to push in at the

rib and add a small amount of canopy stiffness in this area. I have seen photos on the

web of the X2 with the canopy collapsed at the rib. Maybe my thoughts are wrong, or

maybe the X2 rib doesn’t work to prevent this problem like they had hoped.<

You're right that this is an important area, but I don't think the X2 rib was intended to

support it. It's a very difficult area to support.

Ribs of traditional construction can be made quite stiff and can be made to fill the

space that's filled by the X2 ribs, so I don't think these functions are the main purposes

of the segmented ribs. Sure, a segmented rib of a given diameter is stiffer than a

conventional rib of given diameter, but rib stiffness isn't a huge performance factor. That

is, a wide range of stiffness values is acceptable.

I think the segmented ribs do two main things: (1) they ensure good thread alignment

and (2) they provide the designer with a more accurate rib. Since conventional ribs

shrink, wrinkle and change shape a lot when they're inflated (and go from 2d to 3d

creatures), making them fit the kite properly can be difficult. The segmented ribs can be

more accurately modeled on the computer and thus are easier to fit to the kite.


>What are your thoughts on the inflated tip ribs?<

Nicely executed on the X2. I don't think they inhibit vortices very much, but can't say I

have proof. The main thing I like about our solution, epoxy tip battens, is that they

permit a little more taper in the LE tip and offer a little less drag.


>I’ve heard users of the X2 describe it as being almost foil like in the fast way it zooms

across the wind window. I’ve heard the X2 described as a directional riders kite. Does

the Rhino II behave like this? I hope it’s more like the original Rhino, but with more top

end range. A strong steady puller with good range.<

We feel we're a little more toward the "strong steady puller" end of the spectrum with

the Rhino2. Huge range and steady pull, keep in mind, seem to be mutually exclusive

qualities to some extent. I've made protoypes with huge range but erratic pull (because

they fly too far to the edge), and 12-meter kites that pulled like a 16 but had lousy

range. It's one of those areas where we look for the right combination.

>Do you still ride a wakeboard and why don't kite manufacturers distinguish the

diference between a kite for wakeboarding and a kite for non wake?<

I no longer ride a wakeboard. I think some manufacturers do make kites for wakeboard

riders and do show this in their advertising. That said, most of the growth in

kiteboarding nowadays seems to be in the footstrap-twintip area.

>What warranty comes with a North Kite?<

Six months, materials and workmanship, I believe. So far we've had very few claims --

considering the thousands of kites out there.


>When I fly the Toro 16 and Rhino 16, the feel at the bar is identical. Can I expect the

same feel with the Rhino II 16m? I guess what I'm asking, will the bar and line length I

use now, be right for the Rhino II.<

Pretty much the same, except (1) the back leaders can be slightly shorter and (2)

there's less tension on the back lines.


>Where do you envisage kite design in the future? Do you see it mirroring windsufing

race sails in some way in that they will be able to build kites with greater and greater

top end limiting the need for smaller kites I feel this is happening already.<

This is happening and will probably continue, but don't forget that wave sails are still

about as big as they were ten years ago. Not sure what that tells us. Just thought I'd

mention it.

I think there are a heck of a lot of improvements to be made, but I'm not so sure steps

will be as big as the ones we've seen in the last two years.

People like to speculate about double-surface inflatables, but I tend to agree with those

who argue against it. Certain parts of the kite span could maybe benefit from double

surface, but it's very far from the sure and obvious improvement that some think it is.


>What is the difference between the new kite and an x2<

The Rhino2 seems to be a bit more powerful. There are other significant differences, but

to characterize them well we'd have to do side-by-side testing.

>I would like to know about the way of designing of a kite: do you start with an existing

kite, modify and adjust several parameters, build and test it several times (sort of trial &

error) or do you use CFD applications or maybe wind tunnel tests.<

In windsurfing we once saw a lot of sail design work that involved measuring loads on

sails and trying to model sail behavior on the computer. Designers eventually dropped

these efforts in favor of on-water testing exclusively. Why? A combination of two

factors: (1) windsurfing rigs are extremely complex, and difficult to analyze and model

correctly, (2) if modeling them is possible, the industry isn't big and profitable enough to

support the effort.

Interestingly, not only windsurfing sails have repeatedly frustrated ambitious graduate

students and experienced engineers, but so have windsurfing fins.

I think kiteboarding kites are a similar type of problem, though I suspect they aren't as

complex as windsurfing rigs. That said, I've used some foil analysis software and would

not be surprised if others have run their designs through CFD applications.

>What performance charateristic distinguish the Toro from the Current Rhino and the

New Rhino II? I am trying to decide on which one to get next. I currently fly the Rhinos

and have been happy with them. Some say the Toro is better for hang time, and more

stable in the smaller sizes for high wind kites i.e, not so jiteery and fast in higher winds

making them easier to control. <

The Toro is a bit rangier than the old Rhino. It jumps a little higher, has better hangtime

and relaunches more easily. The smaller sizes are slower to turn; the bigger sizes are

faster.

The Rhino2 turns quicker, jumps even higher and has even better hangtime. It's about

like the Rhino for relaunch and stability, though in the bigger sizes the Rhino2 is more

stable.


>What changes are present in the new bar "scepter". Where can we go on the net to

learn more about this bar, or other new products from North.

Some info about the bar should be available shortly. I think the web site will be updated

soon also.

>The Rhino seems to depower when I pull in while in the chicken loop on jumps.

Someone else addressed this issue very capably. I can add that a lot of people have

trouble with stuff like this on all different kites, so you're not alone.

> I hear that Wipika and North are made in the same factory in China. Is this true? If

so, it would seem that the two kites should be similiar in quality control and probably in

materials use, even though design may be different. I noticed that the material used in

the Wipika AB 10.0 leading edge that came out just after the rhino was very similarin

color and apearance and design, leading me to believe in the truth of this assertion. If

different brands of kites are made in the same factory, it would seem that "trade

sectets" and changes in design are short lived unless protected by patent.<

North kites are not all made at one factory, though many have been made in a factory

that has also made Wipika kites.

Materials and quality control standards are determined by each designer. While there

can be similarities, there are differences. For example, only North, as far as I know,

uses 3mm spectra line for pigtails even though anyone can buy that particular material.

The leading edge material that you mention in the Wipika AB10 was probably not the

same material that appeared in the Rhino, though it may have been from the same

company. It was some months before others started using Dacron, and when they did

it's true that they tended to use exactly the same stuff that we were using.

As for whether whether innovations can be easily copied: where a kite is built has little

to do with it. As soon as a kite is on the market, other designers can check it out.

>I was just told by my friend who rides on the Airsuh team, that Airush is sticking with

the same non-segmented leading edge design they had last year. Just small shaping

improvements. They claim their way is more expensive to produce because of material

fall-off cost. Labor is so cheap it's not a factor.<

Could be. I'm not an authority on that type of construction. The first production guys we

worked with complained that the segmented LEs were difficult and expensive to build.

Maybe they had that reaction because they were new to it.

>They say you did it to save money and so did Naish. Put this nonsence to bed.<

Segmented LEs offer better thread alignment, better aerodynamics in that there's no

seam on the bottom side, better aerodynamics in that they permit use of a smaller

diameter, and better relaunch in that they offer more stiffness for a given diameter.

Come to think of it, I believe we get better fidelity to design as well, because the leading

edge of the canopy and the line where it attaches to the LE tube can be more

accurately modeled on the computer when using segmented LE.


>I have a friend who weighs 100 kg. He has been bummed all summer because he

can't buy a 22.5 Rhino in the US. The distributor ran out of them mid-summer and won't

be getting any more until the Rhino II is released. This tells me North under estimated

the need for these kites.<

Another consideration: The Toro 18 is better than the Rhino 22.5. Turns faster, jumps

higher and is just as powerful. The 18 has higher AR than the other Toros, but it still

relaunches easily.



>I would like to add something to the wish list for the new kite:
- removable battens (easy packing!)
- Coloured lines like Naish (if you don't buy kite only, Dwight
- Expandable bag, of course
- Releasable chickenloop
- May be a cabrinha-style valve or a second dump valve on the main
- A better grip on the bar
- A better shaped bar <


The batten is removable.
The lines are set up so front and back can't be switched.
The bag has always been expandable.
Releasable chickenloop is pretty much done
All Rhino2 kites have two LE valves
We think the bar is a big improvement.


>Can jou give us any idea how many kites are sold worldwide, or any other indication of

how big our sport is. <

Not sure. Between 50,000 and 100,000 kites in 2002.



>Is there a Toro 20 in the loop ?<

No. The Toro 18 is as powerful as the Rhino 22.5 (or so close that the difference doesn't

matter).


>I just retyped the info I got from North about the Rhino 2 and I noticed that they only

want sizes 10-20 sqm. <

Team riders say they want an 8meter as well, so it could well happen.


>What makes for a good minimalist quiver to cover most conditions ... considering the

range of these new kites? Say 3 kites. <

Depends on where you ride and how much wind you like to ride in. 10, 14, 20 would

work for a lot of people.


>How about a mixed quiver of Toro's and Rhino II's ?
Toro 8m, Toro/RhinoII 12m, RhinoII 18m ??

If you're comfortable in the conditions you use a 12 or 16 in, the Rhino2 is probably the

call. If you find conditions in which you use 8 and 10-meter kites a little challenging, the

Toro could be the right option in those sizes.<

[Robert]

Ken,

Thank you for answering the questions.

Keep up the good work!

Greetzz...
Robert

[Johnny TBKS]

Hey Ken,
Thanks for your time here. Everyone appreciates word of wisdom from down inside the industry. I think that regardless of brand, as long as it is one of the top brands, people will have a huge interest in what you say. Though I personally asked no questions of you, I think you have done a great job at answering their questions in a timely and professional manner.

You are helping to educate the general public some about North kites, and I think LEI's in general to a point, and for this you deserve to be commended. It takes a big part of your time reading all these questions and then responding to them, this we know, so thanks again for taking some of your time to help everyone out.

Keep up the good work!

Johnny

<font size=-1>[ This Message was edited by: Johnny TBKS on 2002-08-10 06:11 ]</font>