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Can I sew new backline attachment point for faster turning?

Posted: Sun Sep 08, 2013 4:44 pm
by omg
Hi,

due to shoulder problem and also for waves, I would like to have my big kite turn faster and with less bar pressure. Could I just sew a new backline attachment point on the kite nearer the trailing edge than the current attachment point? I remember someone did these for 2013 Rally kites because in big sizes they were too slow and reported very good results.

Is there any problem for doing this?

Thanks!

Re: Can I sew new backline attachment point for faster turni

Posted: Sun Sep 08, 2013 6:00 pm
by flybykite
I think it might be easier just to use a longer bar. Not sure about sewing new attachment points on "X?" kite but the turning pressure will significantly decrease and your kite will react faster with the longer bar. Maybe try a 65cm bar. I doubt bar pressure will drop anything significant with only the rear lines moved an inch or so. Try both and let us know the results.

Re: Can I sew new backline attachment point for faster turni

Posted: Sun Sep 08, 2013 8:55 pm
by omg
Thanks, but the longer bar would be a solution but when steering with one hand only (centre of the bar) the longer bar adds leverage in a way that the force needed to turn the kite is greater ie. just the opposite I am searching.

Other views appreciated.

Re: Can I sew new backline attachment point for faster turni

Posted: Sun Sep 08, 2013 9:36 pm
by edt
good idea go for it. there is a good chance the wingtips will deform because there they make the bladder so thin there, if this happens you'll see it happen in the kite and it might backstall. It's possible if you don't fly the kite aggressively you won't notice anything other than lower bar pressure which is what you want. At worst now you have the option of two different rear line attachment points. Can't really hurt the kite by doing this.

Re: Can I sew new backline attachment point for faster turni

Posted: Mon Sep 09, 2013 2:38 am
by Bille
omg wrote:Hi,

due to shoulder problem and also for waves, I would like to have my big kite turn faster and with less bar pressure.
...

Thanks!
I "Think" you can have either One or the Other, but not Both ?

If the Top-line attachment to the kite is the fulcrum point where the
kite changes it's Angle Of Attack, (AOA) ; the further Behind that
point you go the More leverage you get, (Less bar pressure)
BUT
the further behind the fulcrum point you go the Less AOA change
you get for a given amount of travel , or (Less turning).

Billle

Re: Can I sew new backline attachment point for faster turni

Posted: Mon Sep 09, 2013 2:47 am
by pj sofine
I would think if there was an advantage to an extra attachment point it would have been on the kite to begin with.I'm sure the designer would have had multiple attachment points on the protos.Or I might be totally wrong!

Re: Can I sew new backline attachment point for faster turni

Posted: Mon Sep 09, 2013 3:41 am
by knotwindy
i did it on the 2013 Rally 12m and it worked very well if underpowered to powered up. If overpowered the original point worked better. Yes, it loweres the bar pressure and the kite does turn with less effort but not really faster. With other shape kites i have no idea what would happen but i would try it.

Re: Can I sew new backline attachment point for faster turni

Posted: Mon Sep 09, 2013 9:22 am
by tautologies
pj sofine wrote:I would think if there was an advantage to an extra attachment point it would have been on the kite to begin with.I'm sure the designer would have had multiple attachment points on the protos.Or I might be totally wrong!
well protos I have seen have a ton of attachment points, but you never know what they have tested.

I would pay attention to exactly what is mentioned above. Moving the point can buckle the wingtip..you can counter act it with pumping the kite super tight, and maybe even adding a spar.

I also agree with Billie..you get lower bar pressure, but the turning should be slightly slower...might not be super different.

Re: Can I sew new backline attachment point for faster turni

Posted: Mon Sep 09, 2013 2:09 pm
by bay surfer
You could always put a small V bridle between your new backline attachment and the old attachment if the backline is long enough, that would help support edge and help stop the edge from deforming.

Re: Can I sew new backline attachment point for faster turni

Posted: Mon Sep 09, 2013 2:55 pm
by KristianE86
No, it takes a certain amount of work to change the shape up of the kite. Work = <distance> x <force>, it is thus impossible to reduce bar pressure, while getting the kite to turn faster with less input. The only way to achieve that is with a more (directionally) unstable kite.

For the sake of your shoulder it might be a good idea to sew in an attachment point at the rear of the strut to reduce the bar pressure, but this will make the kite less responsive. If you are just mowing the lawn, this should not be a problem, since you can just yank the steering line directly, when you happen to need a tight turn.