Kite collapsing on itself during down loop !

[pākihiroa]

Behaviour: The outer thirds of the kite momentarily fold in on themselves during or after the lowest part of the loop, ie: when the kite is climbing back up. Happens quickly and just as quickly, the canopy 'snaps back' into shape. Moderate radius loop. Bar sheeted in moderately - certainly not fully sheeted. I likely sheet out to recover from the collapse but can't be sure as it is all happening quickly.

Kite: 2015 Cabrinha 8m Switchblade. I checked the inflation when I got back to shore. It seemed reasonably well inflated. Maybe not as much as usual but certainly not grossly underinflated. I could somewhat fold the leading edge albeit with a decent amount of effort.

What's up with that ? I could make this happen consistently but didn't want to experiment too much for fear of damaging the kite. I have never seen this happen on my 10m but may have on my 6m (all Switchblades). Are the smaller kites flying too fast during the loops ? Is it just an under inflation problem ? Do I need to pump them as tight as drums and beyond ?

[PullStrings]

Could have a slow LE leak....8-9 PSI needed i would think....check PSI before and after 2 hour session

[RedSky]

tight as drums but not beyond. I heard somewhere that cold water and warm air can lower the psi. not sure if i have that correct

[plummet]

Sounds like a slack line depowered flutter. Pump kite up more, more bar in, concentrate on maintaining line tension, try a tighter carve on the foil.

[iriejohn]

Behaviour: The outer thirds of the kite momentarily fold in on themselves ...

Been there, done that. Didn't tighten the inflation valve enough and LE slowly deflated with exactly that result.

[Matt_TYRCZ]

more PSI you need

[Peert]

Some kites don't allow riders with a little bit more mass to turn the kite quickly without folds...
I had that just on one particular kite (blade). Nice kite but quick turn with my 85 kgs and a fold (on the 7m)...
Hear bigger guys 100+ say that this is a common trait atv their weight as kites are designed for 75kgs riders.. pumps help...

[alexeyga]

Some kites don't allow riders with a little bit more mass to turn the kite quickly without folds...
I had that just on one particular kite (blade). Nice kite but quick turn with my 85 kgs and a fold (on the 7m)...
Hear bigger guys 100+ say that this is a common trait atv their weight as kites are designed for 75kgs riders.. pumps help...

Oddly enough - I've seen something similar happen with a couple of other kites also designed by MOMI (a hint: brand's name starts with an "E" and the owner is full of sh@t).

In first case - it was a 9m, purchased used by a buddy and although at first everything seemed normal and the kite has been flying great - after a few sessions it started to fold into itself under load - a jump for instance or when a gust hits. Just folds in halves often followed by an inversion.

In second case - it was my personal 13m kite purchased brand new. Never tomahawked or abused in any way, never even crashed. After about 12-15 sessions it started to fold one of the wingtips whenever turned aggressively (which includes downlooping) and sometimes during jumps.

In either of these cases - the original kite manufacturer was of no sound help.

I've personally measured and re-measured bridles of both kite to make sure that everything is even and found nothing outside of reasonable tolerances.

At the end we blamed the kite's canopy stretch and and overall unprofessional design. It was easier to unload these and other kites from that particular company in our possession, eat our losses and go shop elsewhere - than to deal with the "above and beyond" service provided by that spectacular kite brand.

[pākihiroa]

Thanks for the replies. I think that if (when) this happens again, I will head to shore and do a bit more pumping. Regarding the effects of kite size, some things I am still not sure about are:

(1) If it has to do with the lack of rigidity of smaller kites (it seems that the larger diameter leading edges of bigger kites are much more rigid when pumped to 'max' pressure compared with smaller kites).
(2) If it has to do with smaller kites generally flying/turning faster.
(3) The smaller kites are generally flown in higher winds.

And, why do I only see this happening when down looping, not general flying ? (I am not advanced/brave enough to loop the 'other way' when jumping).

I would like to get to the bottom of this because it is a bit disconcerting going full tilt, fully committed, into a carve only to have the kite collapse mid turn.

[pj sofine]

I live with this problem daily. I'm 225lbs and I can fold any kite in half if I try! Had problem with a new 9 mtr rpm. I could have sworn there was a defect. I thought I had it pumped up hard enough. It was so bad I was afraid to throw a powered loop, it would drop me like a rock! Ended up pumping it up much harder next time and its been fine since. Might want to check your line lengths,they can slowly stretch and youll get some strange symptons.