Sorry man but you are sadly mistaken and I will tell you why. Below I have added a picture of a half circle with radius r and arc length C where r = the length of the kite lines and C = the distance the kite has to travel to go from 9 o'clock to 3 o'clock.
First a little about speed:
There are two kinds of speeds that needs to be taken into account. One is the actual speed of the kite itself. This is what creates lift when you sine the kite. The other speed is called angular speed and it's a measure of how fast the kite is changing position on "the kite-clock".
Kite speed is how fast the kite travels along C and if it travels from far left to far right, the kite has changed its position in the window by 180° (a whole circle is 360° as we all know). Angular speed is how fast the kite changes position in window, typically measured as degrees or radians per second while the kite's speed when it travels along C is measured in meters per second.
Ok, now that we understand speeds, we can cut to the chase:
The length of the arc equals pi
x r where r is the length of the lines and pi
is a constant that some old greek duy came up with some thousand years ago. Let's say that we have two sets of lines, the first one being 15 and the other one being 24. That gives us two different values of C: With 15 meter lines we get C=47 meters and with 24 meter lines we get C=75 meters and C is how far distance the kite has to travel to reach the other side.
As C get larger with the longer lines, the kite gets a longer distance to generate lift and as the distance is longer, it has more time to accelerate and reach a higher speed. Thus you will get more lift over a longer period of time than you would get with the shorter lines. More force over longer period of time = more power. Therefore, you will get better low-end with longer lines (and sometimes you get better winds the higher the kite is which just adds to the effect). With shorter lines, C is shorter and the kite will have to travel a shorter distance to go from left to right and will therefore reach the other side faster. So the time it takes to cover the 180° is shorter, hence the angular speed is higher. This is why we experience a kite with shorter lines as faster. You can compare it with two cars competing on an oval race track. The car on the inner lane will go around the course faster while the car on the outer lane will have slower lap times but will experience higher centripetal forces
Crap, this became longer than I had planned. Did my point get through?
scklandl wrote:Yes, it will speed up- the kite. I have flown my 13SLE a lot on 20m lines. It makes larger kites quite a pleasure to fly.
YOU WILL NOT LOSE ANY BOTTOM END. This is a misnomer spread by people who spend too much time working on the theoretical physics of kiteboarding. ***For those naysayers: The kite moves faster so you can generate more apparent wind, AND the kite is more sensitive and reactive so you get better feedback and can make quicker corrections thereby keeping more power in the kite, easily offsetting longer lines if not beating out longer lines on the low end.
you might lose a little hang time, and by this I mean very little. After three years of riding on a 13m on 25m or 20m sets I can only say that I have the impression that on average I might be a losing a foot or two (off of 25+ jumps, thats not much!)