Kite Trimming For Maximum Performance
Changing the knot positions at the kite or the bar is not magic for whatever kite brand you have or mysterious. Whether you are changing knot positions at the kite pigtails (front or rear) or you change knot positions at the bar, bottom-line is all you are doing is making the front or rear lines longer or shorter. You are changing the ability to power up and depower the kite within the movement of the bar up and down the chicken loop line. You are changing your ability to move the angle of attack (AOA) of the kite, which simply means tilting the kite forward (Leading Edge down), or tilting it back (LE up). Most people are aware of this but somehow they don’t always make the connection in how to determine what the optimal AOA is for the particular kite they are flying and the wind conditions present. Some just go by the knot position given to them by the manufacturer not realizing that you can find out what the optimal performance is from any kite you fly, and what the correct trim should be when flying it. There is also the variable of bar position; meaning how far away from your body do you like to have the bar when you are riding? Some like it close and some like it far away, so from the factory the setting may not be correct for your style or preference. Below is an explanation of how to rig and find the limits of performance for your particular kite.
First off if the wind is strong and you are rigging a new kite to fly for the first time it is better to error on the side of allowing yourself to have too much depowering ability and not enough powering up ability. It is actually better to tune your kite correctly, but it can take a couple of runs on the water to determine what corrections you need to make to rig your kite correctly, so if the wind is strong you do want the ability to depower the kite to its full potential.
OK so how do you error on making sure you will have enough depowering? Basically to depower the kite it has to tilt forward a little, nose down. How would you increase ability for it to depower? You would either make your front lines shorter, or make your back lines longer. Either one will accomplish the task of tilting the kite forward more. In case you don't know the front lines are the lines attached to the chicken loop and are also attached to the front leading edge pigtails on the kite, and the rear lines are attached to the ends of the bar and attach to the rear trailing edge pigtails on the kite.
How do you depower the kite more when rigging your kite? So the idea is to tilt the kite forward right? OK so how would you do that only using the front lines? You would either attach your front flying lines using a knot closer to the kite on the front pigtails, (if your particular kite has that option), or you will need to shorten your front lines where they attach at the bar (if your particular brand has that option), or do both if you really need to make that much adjustment. If you do not have the option to shorten the front lines enough by making these adjustments you will have to lengthen the rear lines. You can lengthen the rear lines at the kite by choosing to attach your rear lines to a knot on the rear pigtail further away from the kite, or by reattaching your rear lines where they attach to the rear leader lines. There are usually a few knots made in the leader lines where the rear lines attach for the purpose of adjustment. To depower the kite more by making the rear lines longer you would want to choose a knot on the leader lines further away from the bar, thus lengthening the rear lines.
To gain more ability to power up the kite you need to do just the opposite of what was discussed above. You need to either lengthen your front lines or shorten the rear lines, or do both if you need that much change. You can also tie a knot closer to the kite on the rear pigtails of the kite so you can attach your rear lines closer to the kite, thus shortening the rear lines.
So all that adjustment technique said, how do you know when a kite is trimmed correctly? Well you have to fly it and see how it reacts to both extremes of completely depowered and completely powered up for the wind conditions present. You need to find what the kite's ability or limits are to depower and power up. There are limits to both extremes for each kite, so you basically need to go past the extreme edge of its ability to power up, and past the extreme edge of depowering so you know where the limits are.
How do you find the limit of a kite’s ability to depower? Judging a kite’s limit to depower is often times easier than judging its limit to power up. It all depends on the kite. To find a kite’s limit to depower do this. First you do need to be able to achieve a state where the rear lines can go extremely slack when you let the bar out to depower the kite by an arms length with the adjusting strap pulled all the way in to full depowered. The rear lines need to be able to go very slack so that you see a big bow in the rear lines as the wind hits them, and you loose quite a bit of steering input. The rear lines should be so slack that it will take a great deal of bar movement in order for you to even initiate a slight turn with the kite. If you can’t achieve this level of rear line slack then put the kite down and re-rig the kite with shorter front lines and/or longer rear lines.
Before launching the kite don’t fully depower it or you will have trouble steering the kite. Now put your kite in the air and fly it statically at about a 45-degree angle to the ground. Pull in on your depowering strap to depower the kite once in the air. Pull it in enough so that when you let out the bar all the way the rear lines will go so slack that you can almost not steer the kite anymore. To keep control of your kite pull in on the bar when trying to steer it so that you still have some steering input. Now get a feel for where the maximum useable depowered state of your kite is by slowly letting the bar out further and further, and steering the kite up and down a bit. The maximum useable depowered state of your kite is when your kite is almost fully depowered, but you still retain enough steering input to control the kite and ride comfortably in control. Even though the kite can depower past this point, it isn’t very useful unless you decide to ride in a straight line fully depowered (sheeted out) with the bar all the way out, and then pull the bar all the way in to turn the kite. This approach can be used if you want the ability to let go of the bar in an emergency and not have the kite pull you very hard, even if it flies through the wind window. If you decide you want that ability then a very long chicken loop line throw is recommended, so that you can still steer the kite OK once the bar is pulled in towards your body. Keep in mind you always want to allow yourself some level of depower-ability. If you understand where the depower limit is of your particular kite and size, then you will need to change to a smaller kite size if you have no more room to depower the kite for the conditions present.
Ok how do you find the limit of how powered up your kite can be? This is done on the water while riding the board. The first step though is to rig your kite correctly so you can achieve maximum power.
Keep in mind that most all kites are designed to achieve maximum power when the front and rear lines are even, or when the front lines are about 1-3 inches longer than the rear lines. You want to be able to achieve full power when the bar is in the position away from your body that you normally like to ride in. So if you normally like the to ride with the bar 6 inches away from your body, look at what distance the chicken loop is away from the bar when you hold the bar away from your body while hooked in. You may like the bar 6 inches away from your body, but that can equate to the chicken loop only being 3 inches away from touching the bar. So hook into the chicken loop, put the bar where you like to normally ride with it away from your body, and you look down and see what distance the chicken loop is away from touching the bar while there is tension on the lines. For this example lets say that the chicken loop is 3 inches away from the bar. You need to make whatever changes necessary for your lines to be even when the chicken loop is 3 inches away from the bar, with the adjusting strap all the way out fully powered up. If you find your kite achieves full power with the front lines 1-3 inches longer than the rear lines, then make the front lines longer by that much when the chicken loop is 3 inches away from touching the bar. This setup will get you in the ballpark.
So you now have the kite rigged in the ballpark of being able to fully power it up. Once you are out on the water you are going to play with powering your kite up too much by pulling the bar all the way in towards your body, and then letting it out a bit to depower it. You will be trying to get a feel for where maximum power is for the wind conditions at hand. The wind conditions are important because it will be a little different in light wind as opposed to medium – high wind. You are going to want to let the adjusting strap all the way out, fully powered up for this exercise, but make sure you are within your limits. Don’t attempt this in high winds especially if you are inexperienced.
You will be able to tell when a kite it too powered up by a couple of indicators. Once is that some kites are sensitive to stalling. If you give them too much power for the wind present they will actually slow way down and almost stall out. These types of kites are pretty easy to find where their limit is because they stall if powered up too much, so you depower the kite until it doesn’t stall or lose too much speed. That will be your maximum powered up state for those kites. A lot of newer kites are designed not to stall even with a lot of rear line tension, or being over powered up (sheeted in). With these kites there will be a balance point between kite speed, and wind speed. A kite usually develops more power as it goes faster through the wind window (apparent wind). If the kite slows down through the wind window it looses power. Depending on wind speed there is a balance between how much you can power up the kite (sheet in) and how much that powering up slows down the kite. At a given kite speed or wind speed there will be a point where you can pull in and power up the kite more, but it makes no change in the power of the kite. At this point you are right at the limit of how much you can usably power up the kite. If you continue to power the kite up even further you will experience the kite actually slowing and loosing power. So play with this powering up the kite past the point of usability and then depowering it slowly until you gain a sense of where the limit is for the conditions present.
If you follow these suggestions for rigging your kite and finding the limits of how much you can power your kite up (sheet it in) and how much you can depower it (sheet it out) you will be a better kiter for it, and you will no longer need to depend on manufacturer’s suggested knot settings to determine whether your kite is trimmed for maximum performance or not. You will not wonder if you are getting all the performance out of the kite, you will know it.