Postby jumptheshark » Tue Apr 21, 2020 2:05 pm
I've stacked arcs. I had a 16 a 13 and a 10 Venom3 for ages. It was tricky to do well, and even at its best, it is not something I would do again.
In todays state of the art where the biggest kite most recreational foilers are ever going to need is between 11 and 15m it's just not worth it. Maybe as an experiment with Peaks, but it will be just that.
Two kites together really negatively impact the flying performance of each other so neither actually ends up producing any where near the power per meter they do on their own.
This is one of those situations where the performance of the whole is well less than the sum of the component parts! The big kite slows the whole system down, but much slower than it would be on its own, because your input to it is all third party translated through the first kite. The small kite is held back by the big one and tends to wobble between getting ahead and then falling back when its stalled back by the big kite. Until you get the distance and trim just right between kites, you will have a oscillating system that is hard to control and correct. Even when you get it all just right, you have much lower stall resistance of both kites, virtually no relaunch, very limited ability to work or recover the kites in the window because they are so much slower, they pull each other out of shape and they sit so deep the overall window is significantly smaller. This translates into glacial turning speed, lack lustre power and piss poor upwind while occasionally falling back to produce loads of static power you can't shed.
It takes a bit of time to get the system working as a unit, and there is a relative sheeting difference between the kites where that big one has to be sheeted out compared to the small one, to speed it up and stop it from stalling, so you never really get to capitalize on its power. It really just ends up being a wet noodle that kills all the joy in the smaller kite.
I spent some time on it, and eventually got the 10/13 stack to fly pretty well together, but it was never even close to more utility than the 16m on its own.
Still a decent learning experience, but with things like hydrofoils, we are at the stage where kite size is at its all time lowest, and there are people who can get out and ride in ridiculously low wind speed without going bigger than 13m.