Hi all. I posted this on racekites but got no response, hope someone can help.

Well.. I brought my first power kite a few weeks ago, a 7m concept air traction wave from Ebay. I intend to use it for kite surfing in the future (making a ply board at the moment) but am just playing with it at the minute to get used to the power (bit of body surfing and skudding down fields). The kite is air ram design with a skirt/valve internally to stop it deflating on impact with the water, it is on a 3 line dakine bar. I have a couple of questions;

The strings at the minute are about 40m, can I just shorten them? Or will that cause problems? I was thinking of about 30m.

The kite has an adjustable centre line (angle of attack?), on a strap loop thing that you have to pull (not chicken loop) I don't understand what this does to the speed, power, upwind ability, or how it affects the kite luffing at the edge of the wind window?

Anyone flown one of these? Are they any good?

I feel about 9 again when I'm biking down the road with my kite, bloody brilliant isn't it! Hope someone can help me

Thanks

Benjamin.