Why you have to trim your kite
So, first of all, what is “trimming” and where do you do it? You know the little rope above your bar that you can pull in or let out? Some people call this the de-power system, but we prefer to call it the trim system. Trimming means to fine tune, or to optimize. By using the trim system in the correct way, you don’t only influence the power of the kite, but you also optimize the way the kite flies. Basically this system works by adjusting the length of the two center lines compared to the length of the two control lines. When correctly trimmed you have:
- the right amount of tension in the control lines
- the right amount of power in the kite
- the best upwind efficiency
- the right amount of lift in the kite, which also means your kite will have the optimal speed
- most importantly, with the right trim you will avoid your kite from backstalling*, especially in light wind conditions. When your kite doesn’t backstall, you make the wind range of usability of your kite bigger and it will improve the water relaunch big time!
(* Don’t know what backstalling is? Keep on reading this article!)
To understand how to get the perfect trim, you need to understand these kitesurf terms:
- Leading edge
- Trailing edge
(If you are familiar with these terms, you can choose to skip to the last part of this article: “Steps to achieve the perfect trim”)
Leading edge & Trailing edge
Just like a car has a front and a back, so it can drive forwards and backwards, a kite also has a front and a back. The front of the kite its called the leading edge. The back of the kite its called the trailing edge. Unlike a car, the kite should always fly in a forward motion, it should not be ‘driving’ backwards. The kite flies in the direction of the leading edge. On inflatable kites the leading edge is the big inflatable tube:
Sheeting means the change of the angle of attack of your kite to catch more or less wind. Sheeting also happens in windsurfing and sailing. For more power/speed we need to “sheet in”. In kitesurfing, sheeting-in means changing the angle of the kite by pulling the bar in, with this you create a bigger angle of attack where there is a bigger surface of the kite catching the wind – and so creates more power. When sheeting out, you move the bar away from the body, where the angle of the kite will make that less surface is exposed to the wind – and so creates less power.
This happens when a kite is too much sheeted-in, which is also called oversheeting. The kite is flying in the direction of the trailing edge, which basically means it’s falling backwards into the powerzone, in the unwanted direction. Remember the kite should always fly in the direction of the leading edge, moving forward (just like with a sailingboat, which you also don’t see sail in the reverse, right!?). We never want the kite to backstall. If your kite is backstalling, you should definitely try to solve this by checking the trim system.
The perfect trim
Now comes the important part… How to achieve the perfect trim? The perfect trim is when there is a perfect balance between the tension on the center lines and the tension on the control lines – which is what can be adjusted with your trim system. Remember, the right trim might be different every day, depending on wind speed, so make sure you do this check regularly! You can use these steps to find the right trim for your kite:
- Launch the kite with your trim system set up between medium and fully de-powere
- ly your kite directly overhead, steady on 12 o’clock
- Pull the bar slowly all the way down towards the chicken loop (so, fully sheet in your kite)
- Watch the kite: does it stay perfectly in position without moving, or does it shift backwards (is it backstalling)? If the kite is backstalling, you can adjust the trim by de-powering a little bit
- After adjusting the trim system, repeat these steps again and again, until the kite stays in perfect position on 12 o’clock for about ten seconds, not shifting backwards at all.
Extra tip #1: Light wind & strong wind trim
On light wind days the biggest mistake is to fully power the kite. Most will be thinking, the wind is light, I will need more power today so let’s power up this kite. On light wind days the kite will backstall much easier as there is less wind to carry the weight of the kite. You can use the same ‘steps to the perfect trim’, but instead of keeping the kite at 12 o’clock, try to keep the kite 10 seconds in a steady position at 11 or 1 o’clock in your wind window. This will give you the perfect light wind trim. As long as it keeps backstalling at 11 or 1, you have to keep de-powering. If you have the kite at its maximum de-power and the kite is still backstalling, it probably means there is not enough wind to go out and have fun.
On days with lots of wind when you are flying your kite overpowered, make sure to de-power the kite enough. To check this, make sure you can easily hold your ground when doing step 3. So when you have the kite at 12 and pull the bar slowly down towards the chickenloop (sheeting in) you should be able to hold your ground. If you can’t, de-power a little more.
Extra tip #2: Line stretching
If you notice you almost always need to de-power your kite to make sure your kite is not backstalling, and for this reason you hardly ever fly your kite with the trim system on full power, it means it’s time to adjust your lines. Especially if you are flying second hand gear which is 2 years or older. What happens over time is that the center lines which hold most of the pressure of the kite, will get stretched out around 10/15 cm longer. Your control lines as they hold less constant pressure are only stretched out 2/4 cm. Now let’s do the math… if your control lines are that much shorter than the center lines, you can trim and de-power what you want – the kite will always be more sheeted in than it’s supposed to be, increasing the chance of you being overpowered on windy days or the kite backstalling on light wind days. No stress, it’s a very easy fix: just put some extensions on your control lines! You can easily find extensions at any kiteshop/repair centre. It will make your kite fly much better with a bigger range of trim adjustment, so take care of it!
Now, trim that kite and start flying with optimal efficiency for an easier and more fun session!