Power Kite Forum

Kite Size Equivalencies?

macboy - 18-1-2008 at 10:47 AM

I wonder if there are some general rules of thumb when it comes to kite size equivalencies? IE: A 7M foil is roughly the same in terms of overall power as a Xm LEI Arc and a Xm LEI Bow and a Xm LEI C kite.

Of course this is regardless of lift, handling etc - strictly power. Is this a fair assessment of the kites?

I guess what I'm getting at is if I'm flying 7's and feeling good pull and confidence, what size LEI arc, c or bow should I consider toying with - and will said size be enough to get a 170 pounder going on water? Can't afford to experiment with Peter Lynn of FlySurfer......

NPWfever - 18-1-2008 at 11:03 AM

Well if you are going to get a water kite you probably don't want to go C-kite your gonna want a bow. If you are looking at a bow, a PL arc is probably going to wind up cheaper. Or possibly a good deal on flysurfer. :D

DenisLaMenace - 18-1-2008 at 12:20 PM

i don't mean to have a scientific rule for computing this but from what people say, a rule of thumb could be

fixed bridle open cell kite

has more power than

depower open cell kite

which has a bit more power than

depower closed cell kite

which has more power than

depower bow kite

which has a bit more power than

depower hybrid LEI kite

which has a bit more power than

depower C-Shaphe LEI kiet

fot the same surface with aspect ratio abstraction

Then I dont know where to fit Peter Lynn in here
:puzzled:

I tend to beleive that my Flysurfer Psycho3 10m is roughly equivalent to a 12m hybrid LEI.

BeamerBob - 18-1-2008 at 12:41 PM

OK, this is a great start! This would be even more helpful if someone with hands on each of these or at least some of these could equate the differences in equivalent square meter kite sizes. I really would like to know what the relative power of these 19m flysurfers are when I have trouble holding down a 5m Crossfire. I'm not interested in these specific comparisons but if we could establish a reference kite and then work up and down the spectrum I bet it would be enlightening to many of us that only have fixed bridle foils. For simplicity we could pick a constant wind speed but talk about limits and ranges. I know this info is languishing in several heads out there. Share it with us up and comers.

Thanks

DenisLaMenace - 18-1-2008 at 12:52 PM

good idea Bob

the one thing for sure is trying to compare the fixed brdile with depower, is tough because different depower kites (brands and models) are not made with all the same depower range.

But we could pick few models that are popular.

powerzone - 18-1-2008 at 01:15 PM

snowbird or pablo already did this comparison in earlier threads.. i'll try to find it

one tricky part about a "rule of thumb" is the AR of kites vs apparent power. IE a 5m Samauri vs a 5m Blade or something.

awindofchange - 18-1-2008 at 01:20 PM

Generally speaking - an LEI C-Kite will have about the same power as a fixed bridled foil that is 40% less in size. So a 16m C kite will have the same power as a 9.6 meter bridled ram air foil.

Again this is a Generalization as most people know that one style foil will have different power than another style foil (compare an ozone Quattro to the Yakuza as an example). So you do have to take this into consideration.

The biggest problem with comparing a true depowerable to a fixed bridle foil is that the Depowerable will have different power depending on how it is depowered at the time. If you fully depower a 12 meter SLE in 10-12 mph winds you will have nearly zero pull where a 3-5 meter bridled foil could start pulling you fairly decent. Put the depower on full power and you may match the power that the foil puts out. Now put both kites in 20-25 mph winds. With the depowerable kite on full depower you may have solid controllable power but still be able to hold ground, the bridled foil will be rock solid and pulling very hard. Now power up the depowerable to full power and you are creating much more power than the bridled foil. So how do you compare this? Very difficult to do.

If you go full power to full power then I would estimate that the SLE/Bow style kites will still be about 40% less power than the same sized fixed bridled kite but you don't have anywhere near the usable range that you do on the depowereable kite (thinking of 12 meter Caution Answer to a 12 meter fixed bridled foil). Basically the SLE kite will be able to deliver the same power output without increase (as you depower it) from 12-14 mph winds all the way up to 30+ mph winds. A fixed bridled kite will automatically increase power as the winds increase to the point where you can non longer hold the kite down.

The Peter Lynn's are usually slightly underpowered per size than the C-shaped kites are but have much more depower ability and range. So a 14 meter C-shape kite would be about the same power as a 15-16 meter Peter Lynn. The newer PL kites such as the Venom II and the new Synergy close this gap so that power output is pretty equal to c-shaped kites. SLE/Bows still generate more power than C-shape kites.

Because of designs and also because of different manufacturers it is very difficult to make a comparison from one style kite to another. There are just too many variables to try and compare to. Even SLE/Bow's will produce different power per style so saying kite A is X amount more powerful than kite B is nearly impossible. There are too many types of kite A and kite B to get an accurate comparison.

Anyways, hope this helps some.

krumly - 22-1-2008 at 06:10 PM

Kent -

I do not own and have not flown a Bow or SLE, but they are the norm in Minnesota winter or summer. The guys who use them have mostly migrated from LEI C's and figure they use bows that are about 75% the size of the C's they used to use, and still get more range than the C would have (i.e, one 12m bow in lieu of 2 -3 C's in the 10-18m range).

I've often been moving fine with my 4 m Brooza when I see others using an 8-10 m Access or a 10 m bow. But then I bet my 127 lbs is more likely up against somebody @ 175 -200 lbs.

I agree about the PL Arcs. My Guerilla II 9m is less powerful than my older Slingshot Fuel 8M C, but a lot friendlier in gusty winds (the extensive depower range and autozenith really help).

krumly

Baluk - 22-1-2008 at 06:45 PM

My 12m Phantom ARC is used in the same winds I would use my 3.6m Beamer or 5m Ace. Which is a lot less than 50% The low end isn't better than the Ace from what I can recall... When you get it in the mid range winds.. the phantom is an awesome kite though.

When you compare, take a look at Projected Area as well. Something like a C Kite or Arc, compared to a Bow or Foil shows this quite easily. The amount of area of the sail that actually hits straight on with the wind and 'catches' teh wind.

take a look at this photo:

http://img145.imageshack.us/img145/2491/kitend8.gif

Not how the C kite on the left doesn't 'catch' all four 'arrows with plentiful wind' ? While the Bow kite on the right, catches a lot more, even though but lines that make the kite are the same size.

A fixed-bridle kite compared to a depower kite loses power due to the inefficiency of the wing. Too lazy to get into it though :p But to be able to accept the changes in AOA, the wing needs to be less efficient to be able to tolerate the changes and therefore not as strong as a same sized fixed bridle. Foil Depower kites (and as a whole) in general do not work too well in winds below 10mph because of several factors.

w00t

Pdxnebula - 22-1-2008 at 07:48 PM

I'v been curious myself over the last months, I'd like to know where Pro Foil's & a few others fit into the whole equation & I think it'd be a good topic to add to the Forum... Kite Comparisons...(or is it can of worms)???

speleopower - 23-1-2008 at 04:26 PM

I've noticed I am usually on an open cell foil about 1/2 the size of a LEI kite i.e. if I'm on a 5 meter foil then depowerable bow kite riders are on typically 9-12 meter kites. If I'm using my 10meter then people are on 16+ meter LEI's or no LEI kites are out.

I think the high end foil kites are typically about 40% smaller.

It's not a hard and fast rule just a starting point.

Hope this helps.
Scott

Bladerunner - 23-1-2008 at 05:00 PM

Quote:
Originally posted by speleopower
I've noticed I am usually on an open cell foil about 1/2 the size of a LEI kite i.e. if I'm on a 5 meter foil then depowerable bow kite riders are on typically 9-12 meter kites.
Scott


I'm so glad to here that I thought. I was a total wimp ! :lol:

I'm often amazed at how I'm struggling with my 3m and folks are having a grand time on 8 and 7 m depower.

Did I mention I want a 5 or 7m Pulse :?::!:

speleopower - 23-1-2008 at 07:05 PM

I've found if I have to kitesurf with less than a 5 meter foil kite it is better to goto a LEI type kite. I have a 6 meter North Rhino and a 4 meter North Toro for high wind.

See ya-Scott