Hello people of the internet, I've got a question regarding the depower strap on my naish torch.

What would be the best position to launch the kite in, do I want the strap pulled so that the bar can go a lot further up, or pulled so that the bar is close, also am I right in thinking that the purpose of the strap is essentially to "make the bar go further up" so it's not as much in the power?

Thanks

It's a trim strap. There's no such thing as depower...

You should be launching at the edge of the window.
Once launched, keep the kite and the edge of the window.
Assuming you have the kite bar and lines tuned properly, you should be launching with the kite trimmed for full control authority.

If you trim the kite, you shorten the front lines (or lengthen the rear - take your pick, you've changed the front to rear line relationship however you describe it) and in doing so, have given up control of the kite due to the slack in the rear lines. You also risk front stalls. Don't do it.

Take it slow and steady, be ready to punch out at any time... keep the kite at the edge of the window.

Kamikuza
Assuming you have the kite bar and lines tuned properly, you should be launching with the kite trimmed for full control authority.

What is meant by tuned properly for full control authority? I have been told to launch with the "kite depowered" or the rope pulled in.

Ed of the internet. Welcome. You should be able to download the manual from their website. Everyone is an expert, but my advice would be to always launch with the trim strap at it's least powerful setting, then you can dial in the power, rather than getting caught out.

It's personal preference, but this seems like the safest approach to me. Ensure you launch in a safe area and that your launch site is plenty big enough for at least a couple of kite lengths in all directions.

Ed517 said..

Struggled quite a bit with it this weekend, it's rather confusing as I couldnt really figure out which way is more/less power, so first launch was accidentally on full power, later once with the kite at 12 I tried to adjust the strap but it's so tight so I tried to yank it which resulted in the kite flopping inside out and crashing, eventually came to a nice setup with it where I could comfortably use it. Taking the whole setup to my instructor this weekend so he can give me the low down.

You're still thinking of it as power/depower.

All the bar does is alter the Angle of Attack (AoA) of the kite... the AoA is the angle the kite is to the flow of the wind. We use the bar and trim system to balance the AoA and control the lift the kite produces, which we turn into speed.

I bet you've put your hand out the window of a car while you've been driving along and enjoyed having it zoom up and down as you've angled it up or down? You're doing the same thing with a kite...

At an AoA of zero degree, your hand sits in the wind, parallel to the ground, and doesn't move up or down - like a kite sitting at 12 (or any other place at the edge of the wind window).
Increase the AoA - angle your hand to the wind - and it shoots up or down... this is like pulling in the bar.

An example.
Assuming good constant wind, a kite will naturally float at 12 without any bar input - it's AoA is zero.
Let's say the bar throw (full range of movement) is 40cm. Trim strap has a range of 20cm...

As you sheet in, the AoA increases and so does the lift - you feel the kite pull.
If you only pull the bar on one side, you increase the AoA (and so the lift) asymmetrically; only one side of the kite makes lift, so the kite turns.

Put the kite back at 12. Think about it side on, where the center lines and steering lines are, and how long they are relative to each other.
Now, mentally pull the "depower" strap - the center lines get shorter by 20cm relative to the steering lines. (Or the steering lines got longer by 20cm - it's the same thing.)
You've added slack to the steering lines...

The kite will still fly at AoA zero, at 12 o'clock, but now when the bar is moved, first the 20cm of slack is taken out of the lines before the control input affects the kite... and you only have 20cm of bar throw remaining to actually control the kite!

When the kite has enough wind speed to fly easily, this isn't really important at all, as you can still control the kite with small movements of the bar.
But should the wind drop, or air flow over the kite is disturbed (aka a stall) you may need to catch more wind to regain control... with a kite trimmed (short center lines) you may not be able to move the kite enough - give it sufficient AoA - to keep control.

So, what is the bar and trim strap for? Balance of trim. We want to balance the forces of lift and drag (which is caused by the increasing AoA) to do stuff - just the right angle to make kite speed, or lots of AoA to make lift and jump.

Use the trim strap NOT to "depower" the kite, but to trim the kite so that you can have a good stance on the board while tacking, with the bar held in a comfortable position at arm's length. Trimmed correctly, the kite will be balanced between lift and drag and you will zoom upwind.

Also, don't confuse the pull through the bar as "more power" - you can over-sheet the kite, semi-stall it and feel like it's pulling hard, but be unable to go upwind, for example...

Yep, get the whole angle of attack

BUT

im still going to call it the depower

No, you should be able to adjust it by small increments...

Naish bar of some description - assuming it's the above the bar depower (gah!) trim straps of the Shift system?

Great pic Jim!

nice work jim and kamikuza

iggypop to put it simply is a little tricky to do hahaha but basicly all the trim/depower strap is doing is either shortening or lengthening the front lines. this then changes the angle of attack as explained by kamikuza. this aoa is allso changed by pulling the bar in and out (shortening or lengthening the steering lines)

the kites are manufactured to be flown in a certain shape. trimming them doesnt decrease there power it just decreases the effectiveness that they fly. (see wind blowing over aerofoils etc to understand)

hope that is easy enough to grasp.

Your 1st ? Where to trim for launching.
RULE No. 1 - the most dangerous place to fly your kite is on the beach. So this is where you dont want to stuff up.
IMO (yes there are conflicting views) beginners should ALWAYS attempt to launch with the trim strap set fully in (depowered? if you like).
If you cant launch the kite at this setting (ie rear lines are too slack to even be able to steer up safely) its probably the wrong kite for the day.
But hey if thats the case try again 1/2 trimmed. If its unsteerable fully trimmed it shouldnt be too over-powered on 1/2 trim.

2nd issue?
The way I look at this issue - and the way we teach it in the school - makes it simple to understand (I hope).
Launch trimmed in for safety as above.
Walk into or at least to the shoreline. With your kite at 12 and bar extended trim in till the rear steering lines are almost as taut as the front lines.
This gives you maximum power with an arms length sheeting in of the bar. AND it ensures that if you throw the bar then the extra length beyond your arm reach to the stopper ball will definitely leave back lines slack = little or no power = end of emergency.
This process sets the trim just as whole system is built to work - in the safest possible mode - on that particular day.
Make this standard procedure every session till you have learnt for yourself how & why it can be done differently. But dont ever compromise safety over skill & experience.

I should probably add that you can do a rough check of rear to front line tension while your launcher is still holding the kite & you have the canopy set for launch. Ie. not flapping & not pulling your launcher around the beach.
At this point, with your bar out front lines not sagging, the rear lines shouldnt be too much slacker than the front lines. If they are very slack/sagging then it may pay to trim in at this stage before indicating you are ready for a launch. But check again, as above, when in position for your water start.