This whole concept is new to me and I am having trouble grasping it ?

The description I get for Sled is semi supported ? Is SLED an acronym for something.

Sled boosting makes you go higher and float better by changing C.O.P. and A.O.A. automatically ? Works on 2 line and 4 line kites? I don't get that ?

Can anybody explain this concept and how it is different from a typical jump by sending the kite and pulling in the bar ( with depower ).

Somehow I had it in my head that those big open cell foils like used for toy drops etc. were SLED kites ? Are they ?

I think I am looking for a dumbed down version. Best description I found so far is on www.kitesurfingschool.com

Good question Blade. A "Sled" is what Lei used to be called. When 4-line c-kites came out, the term Lei came and replaced the term Sled. Sled essentially means c-kite. I don't think it is an acronym for anything, but I may be wrong. That being said, sled boosting is how sleds create more lift than foils.

The kite surfing school link describes the primary effect well, but it doesn't tell you how it happens. When the AoA changes in flight, the kite will increase the AoA to try to get to a high lift state. When the AoA gets too high the kite will decrease it to stay at a high lift state as long as possible.

The main factor is anhedral, or the downward curve of the kite. The deeper the curve, the more sled boosting. The deeper profile causes the CoP to move more with a AoA change, which causes a larger tow point movement, which increases the AoA
more and the cycle continues. When the profile stalls and a AoA increase causes less lift, the CoP moves backwards, which causes the tow point to move back, which decreases the AoA. This continues until the kite is at it's max lift state.

There are secondary effects that offer more advantage over bridled foils, which are still considered sled boosting. The lift in the shoulders of the kite is less affected by AoA changes which causes less lift loss in low AoA state, such as the accent of a jump.

Depower allows the user of the kite to change the AoA. The user is "creating" the boosting effect by sheeting in. Sle, bow, and 4 line c-kites still create the sled boosting effect, but it is dampened by the user's pressure on the bar. With the correct jumping technique, the user imitates the sled boosting effect to achieve the most lift.

Sled boosting will give you the most lift and hang time out of the kite. Depower adds the ability to kill the lift when you don't want it, but you can still create the same lift when you do.

a little background on sled kites - you've probably seen hundreds built at kite festivals from plastic bags: http://www.thekitesociety.org.uk/PDF/Sled%20Kites.PDF

Thanks I think I'm starting to get it.

So ... 2 line C kites were SLEDs and that is referring to the shape . Particularly the swept shoulders of the C / arc shape.

I think I finally understand why 2 line Mandibules boost so huge !:duh:

I am still a little stuck on why when jumping with a 2 line foil you aren't " sled boosting " ? I see how the " sled effect " is less due to the shape but the boosting principle ( aoa and cop moving automatically ) seems the same to me ?

Sled sounds so odd , I expected it to be short for something.

Thanks !

I guess I am calling the single line foils by the wrong name ? I knew I had heard it at kite festivals. The style they use for candy drops. What is that style of kite called ?

I wish we could get our hands on a mandibule kite. I would like to experiment around and see how the work compared to depower kites. I can't imagine jumping with a 2 line foil kite and going as huge as the do with the mandibules. Definatly towards the edge of the kite industry with not a lot known about them

Quote: Originally posted by Bladerunner

Somehow I had it in my head that those big open cell foils like used for toy drops etc. were SLED kites ? Are they ?

If you are talking the kites like Art Ross used to make with the long tails, Art used to call them flow-throughs.
S

The big foils that Art made (Wind Dreams etc) are flowforms, the small plastic kites with sticks taped on for simple workshop kites are sleds and then going to the lifters based on the simple sled you have what is sometimes called a fluted sled but when purchasing these kites from Premier, HQ, Gomberg they are usually just called sleds (and power sleds and mega sleds as they get bigger) and yes often used for line laundry, as a pilot or for candy and parabear drops (or do parabears jump not drop?)

Thanks again,

Just to be sure I have this straight in my head.

The kites that Art made were " flow forms " or Flow through because he didn't have wingtips that point down on the sides. ( I think he counted on his tails for stability ? )
A SLED as in Marks examples is a sled because of those down swept wingtips are there ?

I miss Art ! R.I.P. ! :saint:

based on a parafoil with a variation in shape, keels, venting and aspect ratio you have flowforms and airforms and skyforms etc with name variants based on designer or retailer. Art was know for his large flowforms with long integrated tails. Dean's Airform uses very long twin tails suspended off the corners and the Sutton flowform has what many describe as a molar shaped foil with sides that extend longer.

Sled kites are single line kites used to lift things into the air. They used to be used as a cheap option for aerial photo's until RC helicopters and UAV's became available.

type "Sled kite" into Google images. They all look pretty much the same.

This is also the type of kite used to pull boats along... They use a fixed angle of attack that creates lift from airflow over the kite (like a wing)

Here's an article about them from "The kite Flyer" http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s...

I have never heard an LEI refered to as a sled kite and I have never heard the term "Sled boosting"

Quote: Originally posted by lives2fly

Sled kites are single line kites used to lift things into the air. I have never heard an LEI refered to as a sled kite and I have never heard the term "Sled boosting"

Sounds like exactly what I was thinking until this topic came up.

I think I get the concept of " sled boosting" now but am stuck on one thing.

I understand how a 2 line foil kite is not a SLED kite because it lacks the down swept wing tips. What I don't understand is why you wouldn't be " sled boosting " when jumping with one ? The principle of AOA and COP changing naturally giving max boost and float is the same ????? :duh:

Agreed!. Any jump you do by creating lift via airflow over the kite is "sled boosting" Its the same effect that makes planes take off! I'm not sure what reaction you would get if you asked an airline pilot about the "sled boosting" effect on his 747 though :evil:

You can pop by creating tension between you and the kite and then releasing it which will work on its own in the water to get you airborne. Some land boards have enough flex that you can get a small jump by just edging and pushing off hard with your legs and the flex of the deck give you an extra lift.

Neither of those use the airflow over the kite for lift. Most jumps will be a combination of pop and boost.