Greenturtle wrote: ↑Mon Oct 18, 2021 4:00 pm
...
Is added stiffness for kites definitely good? Or just in order to reduce le diameter and have similar flex as before?
There is another important aspect of the 'stiffness' (technically correct - modulus of elasticity or just elongation/stretch).
Every inflatable LE has the closing seam on the inner side of the arc, heavily reinforced multiple layer construction which is way 'stiffer' than the opposite side of the LE. In addition, the seam additionlly shrinks the material.
As a result, when inflated, the outer curve of the LE stretches more than the inner which causes closing of the arc.
Every kite designer struggles to overcome this issue by designing a more open arc which will close when the kite is inflated. So when they change the LE dacron, they need to do some testing to determine the correction in the design needed. The 'stiffer' the material the less testing and correction needed.
And different pressure has less impact on the arc shape.