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I pump my Edge kites up to around 9psi. ( I think) hard enough that you wouldn't want to crash them onto anything remotely sharp as the bang would attract police!

They fly best when rock hard.

not quite as hard for my Fuel.

I catch kites at the beach on a weekly basis that are not even CLOSE to being pumped up hard enough.

The harder the kite the better it will hold shape meaning it will turn faster, jump better etc.

i used to pump really hard until i detroyed the leading edge stitches of my olds Ions in a couple of months.. I´ve also saw a canacopy of a friends kite being tear appart from leading to trailing edge on a single tomahawk. that guy used to pump it super hard (and still does it..)

nowadays I pump it hard but not too much & just clip the middle strut except if conditions are raw

i tend to pump it slightly harder in the summer - the air is hot but the water is not - than in the winter

for years i miss to have pumps with gages and to be honest, if usefulll, i don´t think we really need them. the "feeling" method works fine

Perennial debate.

cglazier wrote:The 2013 Naish pump gauge shows the proper pressure ranges for various kite sizes. Small kites like 7m can be over 8 psi but large ones should have somewhat less pressure. This is because bigger leading edges result in more force on the leading edge fabric and seams...

I don't think that's the reason.
The reason is that a wider diameter tube needs less pressure to be the same rigidity as a smaller diameter tube. There's a fancier way of saying it, but that's what it comes down to.

On average I pump my kites to 10-12 psi in normal conditions. 8-10 psi if it's a particularly hot day. I only use the gauge as a reference, though. I'll give it a ping test and you can also see when the LE fabric JUST starts to swell wider than the seams, it's hard enough. (the stitched seams that wrap around the LE will not expand with pressure, but the areas with no stitching will expand a bit)

It varies from one kite design to another, of course.

I ping and then fold...

CaptainArgh wrote:
There's a fancier way of saying it, but that's what it comes down to.

Yup. the fancy way is to say "Hoop Stress"

Here is the 2013 Naish gauge which shows appropriate pressure which is probably applicable to other kites.

There are two reasons why smaller kites can take higher pressure. There is less strain on the leading edge fabric and seams with a smaller diameter leading edge. Less square inches of fabric results in less lbs of force for a given psi (pounds per square foot). The other reason is that a larger leading edge on a bigger kite has more rigidity due to the more square inches of fabric under pressure (thanks to CaptainArgh for pointing this out).

CG