Power Kite Forum

Arc vs. foil size/performance equivalents

lad - 2-8-2009 at 07:04 PM

Let's see if I can articulate this right :smug:

We all know how you have to step up a few sizes to equivocate a typical depower to a FB.

I'm trying to compare arc sizes to foil ones (DEPOWER foils, that is) to see what would fit in my foil gaps if I get an arc.

I see where the Lynn arc models are rated by the flat surface area - and provided charts also give the (much less) projected area.

While the shape obviously makes them have less wind area then a foil with the same total area, is there a formula for arc efficiency?

It other words, it would seem the touted higher lift/efficiency, inflated/stable surface, and, (not the least), absence of full bridle drag, would compensate for the smaller projected area. Wouldn't this give an actual foil square meter equivalency somewhere between the flat and projected area numbers? (Such as an 18m Phantom has only 11.5 projected area, but would lift n' pull more like, say, a conventional 15m foil?)

Or is it all actually about apple and oranges?

Bladerunner - 2-8-2009 at 07:26 PM

Using my 15 Syn as the best example I have this is my feeling.

It says the projected area is 9m and I think a 9m ( or 10 ) depower mayyy be a good equal size ???? It is hard to quantify because they both fly a bit different.

What I have found very odd is setting up the 15 when people are overpowered on 4m Fixed Bridles and having fun on 2's. Turns out that is when it's at it's best!

Today I was out in about 8 knott winds and it was frustrating. I got a much needed fix but not enough wind for jumping. Not even enough for auto zenith to kick in but enough to work for a ride. ( I should have let the straps a bit more loose ).

FloRider - 2-8-2009 at 07:28 PM

Great question Lad. I'll be watching this thread responses closely for my future quiver additions.

lad - 2-8-2009 at 07:32 PM

bladerunner,

Are you saying....that at least in some ways...a 15m Syn can be like a 2m FB?!?!?!

:eekdrull:

snobdr - 3-8-2009 at 05:13 AM

Just look at the kites windrange. Compairing one to the other dosent really work as there is so many differences between specific kites.

Drewculous - 3-8-2009 at 06:56 AM

my 15 phantom seems to do best in the same winds i like my 5.6m FB in... as far as arc vs. depower foil... no clue, sorry

PHREERIDER - 3-8-2009 at 06:57 AM

http://www.kite-fantastic.co.uk/articles/mx5alan/arc-wind-ra...

windrange indeed is the best way to look for application and comparison

this is a great resource for arcs with the weight feature it really gives usable info .

FB is a diverse group form entry level to race only experience can really help there although FLysurfer , HQ , flexifoil and Peter lynn have OME charts for most of there stuff. it can be really hard to tell on info alone

kinda like wine, cars and women.

Bladerunner - 3-8-2009 at 08:23 AM

YES I am saying that a have had a couple of days now when 2m kites were doing the job and my 15m Syn wasn't overpowered.

The 1st time TDMC was giving tandem runs in His buggy with a 2m Ace while I was Flyng the Syn.

The Next time. TDMC was having a hoot with the 2m Ace, Scudley got supermaned like never before on His 4m Reflex and I wasn't overpowered. On that day I started with a 2m and was amazed how much more safe I felt flying the big arc ? I think my 15 starts to do what it should at about the same wind that the fixed bridle people are enjoying 5's and 4's.

The top end of my Syn is amazing. It is the bottom end I am disappointed with on an all too often basis. It needs more wind than my 13m Phsycho III did.

I am not big and definately not all that brave but I will take the 15 out in wind up to the high 20's.

USA_Eli_A - 3-8-2009 at 08:36 AM

there is no such thing as Arc vs. Foil sizes. you can search in on the SEARCH function of this forum so that REDUNDANT and very pointless threads can be avoided....:evil:

EXAMPLE: FIXED VS. DEPOWER = 2 COMPLETELY DIFFERENT STYLES. HMM...


Arc vs. foil size/performance equivalents......RRRRR

Drewculous - 3-8-2009 at 03:44 PM

Quote:
Originally posted by USA_Eli_A
there is no such thing as Arc vs. Foil sizes. you can search in on the SEARCH function of this forum so that REDUNDANT and very pointless threads can be avoided....:evil:

EXAMPLE: FIXED VS. DEPOWER = 2 COMPLETELY DIFFERENT STYLES. HMM...


Arc vs. foil size/performance equivalents......RRRRR


I searched arc vs. foil, and got 0 results...hmm

instead of slamming someone for asking a question they dont know the answer to, just keep quiet... your post adds nothing to the conversation other than to basically vent some anger on someone for asking a question.... everyone knows they (arcs & foils) are two different kinds of kites.... but hes just looking for advice on a kite to add to his stash, making sure he doesnt get one that wouldnt fit in his line-up... and trying to learn something, and help others down the line! I apologize if i missed your intent Eli, but this seemed a little uncalled for

I took from this, that he's looking for a comparison between like a 10m depower foil, and a 10m arc... wind range, power, useability... I'm not sure, only having flown FB foils and arcs... maybe some of the arc and depower-foil gurus can chime in (hmm hmm Angus)

lad - 3-8-2009 at 04:00 PM

Wellll folks...I can easily imagine the topic has been covered here before (and I'm normally a duteous searcher).

But I, too, wasn't sure what search terms to use - hence my own uncertain questioning (and, er, furtherhence, my ending "apples and oranges" escape clause - a conclusion forcefully confirmed by one Mr. Eli.)

I think the simplest way to put it is:

Arcs have no bridling and other said performance qualities over foils > so, when only comparing an arc's actual "projected" area dimension number to a depower's given/actual/projected dimension number > will the arc still, generally, have more pull, speed or lift etc. ? (more stability is a given in any case)

Is this performance gap even greater that when comparing same sized FBs w/ Depowers? (or is it kiwis and kumquats all over again?)

Some of us can only consider coming over to D'ARC SIDE gradually, and it would make more sense to start with filling gaps in the foil quiver.

Just thinkin' practical here, folks.
That's all...

rudeboysaude - 3-8-2009 at 04:55 PM

Lad.

Candian Windrider page has a FAQ page that attempts to address this. How accurate is it? I don't know, it's not super current. Check it out near the bottom of the page here:

http://canadianwindrider.com/faqs/kites.html

Looking at what kites you have, it seems like you have most wind range covered for snowkiting. But you could sell all of those and have 2 ARCs, like a 10M and 15M Synergy and ride it all. Snow, water, and in any wind. I'd say that one ARC would overlap at least 2 of your kites in any size you went. They just have a great wind range.

I'm not sure you really have a gap in your quiver, but I think once you get an ARC you'll make one when you sell your other kites to buy another ARC. Get a 15-16M Arc, See which kites it replaces for you, then you'll know. In the summer I fly my Syn19 almost entirely. Up to 25 mph and then I ride a 13M V2. In the winter I can drop down to a 15M Syn and and 10M Venom.

Comparing pull and performance is really subjective. Windrange really is the best measure for looking for a kite that fits a quiver gap as all kites fly different. Variety is the spice of life!

A.

awindofchange - 3-8-2009 at 05:27 PM

One of the difficult things about this question is that the arc's, like all depowerable kites, have a huge wind range so it is difficult to place one kite inside of your already existing quiver.

Example is that if you have a 2m FB and a 5m FB and are looking to add in an ARC to use along side of the two kites you have, then you are pretty limited to either a 15m or 19m as the two kites you have should cover the ultra high wind ranges and the ARC will cover the lower wind ranges....except the ARC's (like ALL depowerable kites) don't have very good low wind power (under 8-10 mph winds) as compared to fixed bridled foils which can rip a tree stump out of the ground in 5-8 mph winds.

One ARC will usually cover the same wind range of 2 or even 3 fixed bridled kites. This is the reason that some people will say an 8 meter Synergy will cover the same as a 2, 3, 4, and 5m fixed bridled kite (all depending on the riders skill, terrain they are riding on, weight, etc... etc...)

Rudeboy pretty much summed it up for you on which kite I too would recommend. If you are looking for something to fit in with your current quiver, I would say 15 or 19 meter for your lighter wind days. You seem to have all the heavier wind days covered. Even with one of those two, you would probably find one or two of your kites not being used anymore.

Hope that helps. It really is like comparing apples to bricks. :)

lad - 3-8-2009 at 05:31 PM

"...but I think once you get an ARC you'll...sell your other kites to buy another ARC..."

Aw jeesh...that's just what I was afraid you'd say....



(Warning: this kind of foolishness is what bored graphic artists do when sitting home unemployed!)

Drewculous - 4-8-2009 at 07:09 AM

lmao! Thats a great pic! hahaha

lad - 4-8-2009 at 07:13 AM

The poor young Miss is clearly just trying to inflate her quiver...:wink2: