Yup, agreed, the UK discussion and pictures add a different perspective on this (pasted below).

I don't think the kites need to be marked for their exact size, it's all how they fly relative to each other. That said, it would be nice if there was a standard measurement of size as I find my slingshots tend to be smaller than some of the other kites flown in my area. Somebody will lay out an 11 that looks bigger than my 14 and then brag about what a great low end the kite has! Then again, even with standard sizes it would be arbitrary due to what the company does with the canopy shape & bridle.

Here is what I have learned in my exhaustive 7 year kite study and personal demo quest.
Kites that have "a great high end" usually have a shitty low end.
Kites that have "a great low end" are usually scary when you depower them in high winds.
All fancy design attributes aside, more fabric = more power.
People that say "I only ride my 6M, bro." have a much bigger board than you, weigh as much as a squirrel, and live in a very windy place.

Per this UK thread, this is an 8/10/12 laid out flat;



Good discussion.

I have to say this reminds me of old days when, scaling or no scaling, the word to the wise was, if you want a good kite, get a 12.
This was because 12 was (is?) the most-used size world wide, so designers started designing a model around the 12 then built (or scaled) around that, and it was more likely to be "perfected" before production runs.
Regarding scaling, in fact, aside from fudge factors and empirically determined correction ratios from prior years' experience, (educated guesses in other words), kites must be scaled, and then the parameters tweaked away from the scaled dimensions through testing. With experience and some spreadsheets the process may be more sophisticated than a xerox reduction, but it still has a key role in design, even if you call it "modeling" or "art" instead of "scaling."

With the rpm the most likely explanation seems the 12 was designed to fit a range of use rather than a measurement, and other sizes followed. Whether a 10 or 12 was the original "proto-rpm" ancestor back in 2008 or so may be hard to guess, but I lean towards the 12 as the original, since the rpm model was meant to fit between the fuel and the turbodiesel, and the 10 and smaller rpms became more sporty, while the 12 and 14 rpm are definitely a little more boring (sorry!) than the equivalent-sized fuels.

The 10 was able to be made flatter and faster to make it more performance-oriented, since it didn't need to support the line's low end, and in fact, folks have said the 10 was more the "sweet" kite in the rpm line since it came out.

I've ridden with 14 and 12 rpm, and fuels 9m to 15m, and tested 12 rpm back to back with a 2009 11m fuel and can say 12 rpm is a sweet kite, hair more low end and depower than fuel but similar feel and reassuringly just a little softer. The 14 rpm on the other hand, is no more sporty and fun than my old (2005) 15m fuel, especially if I put the old 15 on 20 or 23m lines instead of the original 27s.
Your opinions may vary, but definitely try 'em before you buy.

I believe that SS is trying to maximize their profit in all ends.
Not supplying pumps with the new kites is one example.
They do a LOT of extra $ by making the best selling kite (RPM 12m) smaller and cheaper to produce but still follow the price ladder and charge full 12m price.

Opinions differ on this issue also, thats assuming it's an issue. The rider who posted this thread presumably has a pump for each kite, why ?

Right now I have seven pumps, I don't wear them out and don't leave them around to get stolen. What makes it worse is, no one wants to pay a decent/fair price for even a quality pump because courier costs have already taken a bite out of the deal.

Same with the supply of bars, it's a matter of opinion whether kites should be priced including a bar. Some riders would prefer to buy a bar from a different manufacturer because of the quality and some would like to save money at all costs.

That is the stupidest thing I've read on this forum in a long time.
You actually think SS made the kite smaller to save money on material?!?!
Damn, I bet that's why the 12M also comes with 25M lines instead of 27M! They're screwing us out of 8M of Firewire!!!

If the 12 really is the reference size for all kites, then it only makes sense that they'd put extra focus on that kite to get it delivering the right power for the size. Maybe they made the 10 too big? That blows out your theory...crap, they screwed up and have been giving us all extra 10M fabric for years! Idiots!

BWD's theory that this was the proto that other kites were scaled from makes the most sense of theories going around. Could be a screw-up, also, of course. But, if they made the perfect 12 and then scaled down all the other sizes proportionately...maybe the other sizes got too small for their expected power delivery. ? And since I haven't heard anyone complaining that the 14 is too small, then they could have beefed up the smaller sizes just a tad.

Anyway, again, interesting discussion. Sorry to lash out McAbe. Your theory struck me funny.

I know this isn't a pump thread, but what the heck...while I'm replying...

My pumps do wear out. That little o ring that goes along the shaft eventually breaks down from heat and sand abrasion, and the internal valves will eventually break so that they don't give two strong strokes. I maintain them and don't get them stolen, but by the end of the season even though they still work, they don't work well. I look forward to a tight efficient pump with each new kite.

You're right, though. Seems that someone could design a better pump instead of kite stores selling different colors of the same shitty pump for $50.

With bars, that has always been an option...you can get kite-only, or you get it complete. So, while people have that choice, these days you see a lot of manufacturers integrating their safety systems between their kite and bar. So, you can swap out, but you get the best relaunch, safety, depower on their kit. Not every setup, but some. I agree that it is nice to have the option. I happen to like SS bars and would consider them for use on other kites I flew.

Exactly my point, some bars are better than others and some that aren't so good are still suitable for some riders. The market is now split between few that price the package with the bar included, and others don't.

Let's have it one-way or the other Eh.

Regarding pumps, OK, you disagree with me. I must be a half-pint drinker because I never wore a pump out yet though I have started to cycle them.

I still think the 12 metre RPM is what it is, let's wait and see how many riders are happy owning both the 10 and 12 because the 12 performs. Or maybe not. Some bloody-minded-ness coming up on this thread and whilst I'm not suggesting Slingshot are faultless in all things they are an example of a quality design and manufacture.

If it helps, I don't fly Slingshot kites nor do I ride their boards and thats me getting flying and riding into the right order.

Maybe the reason behind the lack of a pump has more to do with shipping costs then the actual cost of the pump.

I've no idea how the 12 RPM performs - seems a lot of people like it -- however threads like this would end if they published data like this

http://www.flysurfer.com/en/produkte/kites/psycho4/

tells you all you need to know - don't know why other companies don't give data like this - it's not as if it's hard to find - just ask the designer

There is a significant difference in size between my original 2009 10 and 12m RPMs. I've always felt that the performance of the 12m was a little disappointing in terms of speed and upwind ability and the difference in low end was probably only 2 knots maximum. The leading edge diameter on the 12m is much larger which may have been necessary to maintain the structure of the kite. Maybe Slingshot redesigned the 12m and found that a kite with a smaller leading edge diameter out-performed a slightly bigger kite in all aspects?
You can also change the performance of of a kite significantly by changing the draft profile but the visual difference is not obvious to a casual observer. A deeper profile kite would have a slightly higher surface area but I suspect the difference would be less than a m².