I know I hear this "pinching" thing all the time but have yet to see any pictures or evidence that it actaully "pinches" the shape of the kite. I know it makes sense that "pinching" of the shape would occur, I guess I'd just like to see evidence of it.
How drastic is it if it happens? Does bridle length make a difference? etc.
Basically I have found I can use a low Y on a north kite (I do this on the dice, except in real windy or gusty conditions then it's back on the high Y, you can see the difference in profile really clearly when you tether launch it. The high Y creates a much tighter C arc and the low Y opens up the canopy for quicker turning, more direct feel and better jumping IMO). In the surf though I want it as c as possible and the high Y north bar comes out.
Putting a high Y on a kite designed for a low Y will pinch it as it is already designed for its maximum ....mm let's call it "openness".
So a low Y on a north kite, will certain advantages and disadvantages and no north bar on a low Y kite. It's already at it optimum pinch on a low Y if you know what I mean and looking at it from another perspective.
I have a low Y bar (4 line) a high Y north quad bar and a high Y five line north bar and I chop and change depending. For instance just tonight it was really light, so I used the high Y north bar on the dyno to tighten it up and create a stiffer canopy. When the wind rises I get out the low Y..but funny enough when it's really really lit, on goes the high Y fifth.
Experimented a lot as you can see.