Depower or Trim strap ?

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Addikt
Addikt
WA
553 posts
WA, 553 posts
9 Oct 2009 10:44pm
I was reading an article in one of the kite mags the other day and they were talking about the depower strap and how the guy was saying that it was not a depower strap but a trim strap.........!!!!!

This got me thinking and I was out the other day in about 15 knots and was having to work the kite as I only have a one kite quiver, and had it on the end centre knot and had the "strap" fully out for supposed max power..........

I fell or hit some chop but anyway dropped the kite and was having trouble relauching..........was getting dragged down wind and normally the kite rolls to the edge of the wind and ready for relauch I had to pull it round and get it right to the edge of the window and even then it was harder then normal to launch. Now the point I am getting to is thinking back I have had this problem before and I think most of the time it seems to be when I am flying with the kite MAX powered and "strap" at the end......

So are "we" lead to believe the strap is for power and actullay incorrectly adjusting the kite making things like relauch difficult and causing the kite to fly back in the wind because the trim is all wrong.

Where should the "strap" be will haivng it set all the way in or all the way out make it hard to relauch........ I am going to have a play next time I am out and see if this actually makes that big a difference for relaunch................

Any body have any wise words in this...........
Kitehard
Kitehard
WA
2782 posts
WA, 2782 posts
9 Oct 2009 11:12pm
Hi Addikt,

It is a trim strap. Yes it depowers the kite but it is supposed to be used to trim the kite for most efficient angle of attack. Most bars on kites these days have more than enough "depower" of movement of the bar up the center depower line, so that you don't really even need the trim strap but to make small semi permanent changes to your power.

You need to start from the point of correct trim to begin with. Correct trim on most kites is with the bar sheeted in to full power and the trim strap set to full power, then the kites should be set so that all lines are even in length.

What almost no one does, is "tune" their bar and lines and adjust for stretch. I have flown some peoples kites that are so far out of tune, the kite will barely fly and yet they notice nothing as the kite slowly stretches out of standard design trim.

Will this effect relaunch, stalling and luffing? Definately, especially in lighter winds.

Re-rig your bars to the lines are all even as dscribed above, then use the trim strap to trim the bar closer to you when you are more powered than you are comfortable holding Ie your leaning forward to reach max depower whilst you push your arse out for leverage and counter balance.

I hope this makes sense to you. Come and see me at Pinnaroo and I'll trim your lines for you and set he kite up properly. We don't charge for this sort of service.

Cheers,

KH
NSW, 4382 posts
10 Oct 2009 12:25pm
Like the magazine, I don't like to call the AOA adjustment system a "depower system".
The use of the term "depower" leads to confusion and to people assuming they can take their 12M kite out in 35 knots if they depower it enough. As an Industry I think we should drop the use of the term.

The AOA adjustment system on your kite, is there so that you can TRIM the bar to be at a comfortable distance from your body when you are riding, to unhook, and actually nothing else.
Pulling the trimmer in does not change the size of the kite, letting it out does not make the kite bigger.

Pulling the trimmer in, shortens the front lines, allowing the bar to be pulled in close to your body when riding. This means that when the wind is stronger, we can shorten or trim our front lines, to adjust the bar.

Overall the system is more like a speed system, letting the front lines all the way out, actually slows the kite down to its slowest forward flying speed, pulling or trimming the front lines in makes the kite fly faster through the window (ands more speed=more power, so thats the opposite of what a lot of people believe).

Relaunching your kite will be easier if you pull the trimmer in a bit and don't pull on the bar until the kite is sitting upright on one tip ready to lift off. If the kite flies or slides backwards into the water from this position then your front lines are likely too long (stretched), and trimming in (depowering) will help with relaunch.

What make and model of kite is it, some require quite different techniques, what works on some does not work on others?

Cya and

Goodwinds

Steve
richswing
richswing
WA
724 posts
WA, 724 posts
11 Oct 2009 1:02am
Well I checked my lines today and found the front lines 4 inch's longer than the back, I always wondered why I always pulled in so much trim - thought I was an efficient kiter!

The last time I checked was the start of last season, so there we go.

Cheers
Rich
NSW, 4382 posts
11 Oct 2009 9:26am
richswing said...

Well I checked my lines today and found the front lines 4 inch's longer than the back, I always wondered why I always pulled in so much trim - thought I was an efficient kiter!

The last time I checked was the start of last season, so there we go.

Cheers
Rich


Nice! That discovery will help you a great deal in getting the original wind range and performance from your kite.

One of the properties of the spectra/dyneema lines we use for kite sports, is that they have a property called "creep". When under load, the fibres and molecules that make the lines have such great tensile strength and low stretch, elongate.
Over time and loaded use, the more loaded front lines of all kites will get longer, especially if you are a bigger lump of humanity!

Moral to the story, like KH said, check your lines regularly, adding pigtails to your rear lines will even them up again, it should be a once ot twice a season regular maintenance thing for every rider.

Cya and

Goodwinds

Steve

Addikt
Addikt
WA
553 posts
WA, 553 posts
11 Oct 2009 7:24am
Hi, thanks for the great advice, the kite in question is a Bandit Dos, so not sure
on how you go about messuring the front lines with the back lines as you would with
kites that have the front and back the same length?

So basically the kite is still newish so I doubt it has much line strech, I did do a left and right length check a few months ago! I guess if I try and get the power to come on with the bar as close to the chicken loop as comfortable this will be the correct setting so if I eventually get to riding unhocked
the extra travel when the chicken loop is against the bar it does not stall the kite?

Thanks again for the help.
roder
roder
27 posts
27 posts
11 Oct 2009 8:19am
When I dicovered my front lines had stretched, I figured that they are all equally rated, so swapped front and rear. Any reason why this should not be done?
NSW, 4382 posts
11 Oct 2009 1:47pm
roder said...

When I dicovered my front lines had stretched, I figured that they are all equally rated, so swapped front and rear. Any reason why this should not be done?


No, BUT, now your front lines will be too short and your rears will be too long. At least the other way around you can use the trimmer to shorten the front lines, your way the kite will be "depowered", the bar will be sitting on the c-loop and steering will be crappy. Much better to make some pigtails and equalise the lines so that you get back to original wind range and performance.

If you do it, remember if lines are colour coded then you need to be careful that you don't forget one day and connect a front to a rear.
Kook proof connectors can stop that mistake easily though, so make sure you fit them or swap them over as well.

Cya and

Goodwinds

Steve

NSW, 4382 posts
11 Oct 2009 1:54pm
Addikt said...

Hi, thanks for the great advice, the kite in question is a Bandit Dos, so not sure
on how you go about messuring the front lines with the back lines as you would with
kites that have the front and back the same length?

So basically the kite is still newish so I doubt it has much line strech, I did do a left and right length check a few months ago! I guess if I try and get the power to come on with the bar as close to the chicken loop as comfortable this will be the correct setting so if I eventually get to riding unhocked
the extra travel when the chicken loop is against the bar it does not stall the kite?

Thanks again for the help.


The Bandit One is a bit harder to relaunch (in lighter winds) than a lot of other kites of the same year. Maybe some others here have more experience and tips with that particualr kite. I've based my observations on the people I have seen struggling with relaunch on that kite.

Cya and

Goodwinds

Steve

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