Tuning the Flysurfer Boost v1 9m? Flutter issue.

[downunder]

Heya,

here is a problem: something is not quite right with Boost v1 9m on 25-30kn wind. The tips are fluttering, very annoying. Also has a tendency to 'jelly fish' - if that is a proper term, basically behaving like an under pumped kite even tho it's not. That happens when riding, not jumping.

Than depowered by, let's say 20cm, and I recon fluttering was not that bad.

To put this into perspective I see other kites around me, none of the kites look like 'jelly fishing' or flutter that bad. Looking from the water, both tip sides canopy are clearly visible when in the wind window, like the kite is 'breathing' much more, that's not a flutter, that's folding I think. When kite on zenith, I can't see none of the sides tip canopy. So the shape is ok. But not so on a side wind window.

So I'm thinking the bridles are not right. The bar is the same on all my kites (bigger Edges), the lines checked. Can I do any bridles tuning? Can I get the proper dimensions to compare with a factory design?

What else can it be?

Thx

D.

[Adventure Logs]

Not sure how to fix your problem but Flysurfer usually has all of it's line plans on their website.

=Jason-

[downunder]

Ok, thanks!

No one else noticed this?

[Skywalker7]

Hi,
I had the Boost 1 11. Boost 1 has a pretty slim tube so it means that it will work well to be pumped on relatively high PSI. My advice to look at the table of pressures for the Boost 2. Per this you should pump your kite to 9 or 9.5 PSI (as far as I remember) especially if you are a heavier rider. Some turning flutters do happen on very narrow or pivotal turning but it is normal and it less than on the F-One Bandits. Just try to pull in the bar in the case of kiteloops and this and the higher pressure will handle your problems. There are Open C shapes which has very little flapping but those are pulling way more at the kiteloops and unless you want to pull megaloops you will not necesarilly like them if you are not an advanced rider.

[Nem0]

Did you checked the PSI after riding?
I had a similar problem after 1h riding.
I had a micro whole in the bladder.

[downunder]

Ah,

ok, thanks guys. I pump my kites by the 'ping test' No gauge:) ~60kg only. Got the bridle measurements from the FS site, will check them.

I'm not concerned about flutter when turning, that's expected.

It flutters in normal flight at the window edge. That's annoying. It just does not like 25-30kn coz up to 25 it's ok. And I would think a 9m kite would handle 25-30kn with a 'breeze'. It is more like I'm fighting a kite with all that flutter and jelly fishing. Very annoying, and if Boost 9m v2 is the same, well, that's not great.

I can't imagine an Edge v8 9m behaving like this in 25-30kn, it would be a disaster.

I don't think it is loosing air tho, but good point, will double check as well and report back.

D.

[downunder]

So here it is guys,

a proof that all attachments are waaay off from the design OR the lines shrunk so badly (which I do not believe).

This is particularly important for lines a1, a2 and a3 since we talking 4cm shorter a3 line:

If the kite is powered well and the line a3 is shorter than designed that would fold the kite at the connection point. Assuming everything else is as per design. That can distort any kite to be fair, but we do not know the measurements for other products.

Correct?



I did not measure A1, A2, A -main tho. Will do that and the left kite side as well. The question is how to measure ? We can't take the bridles off, so just measuring from the line start will do as ALL lines should be smaller just by the end loop size (to whatever we looped the line).

Still, the Back line 3cm difference? How to explain that...

Thoughts?

PS
Now I see a1 4cm shorter as well?! Whow. Meaning if a1,2,3 are all 4cm shorter than A1 should be longer to accommodate. Same with a4,5 and A2....

[jyka]

Did you find out what was wrong with your boost? I have also 9m boost v1 and it flutters in higher winds.. Did I just reach its high end or is there something wrong with the kite.

[downunder]

No,
the bladder exploded and ripped a kite.

Bladder is also poorly designed, with two seams on each side. It blown on seam, obviously.

I hope they fixed the issues in newer versions.

[joriws]

Thoughts?

PS Now I see a1 4cm shorter as well?! Whow. Meaning if a1,2,3 are all 4cm shorter than A1 should be longer to accommodate. Same with a4,5 and A2....

For Flysurfer foil kites line plans are to be checked against 5kg load on measured bridle. Your pics shows that you have no load(?) so maybe that's additional 1cm of measured wrong bridle length?

Disclaimer: As LEI bridles are thicker and kite pull is distributed between fewer bridles, I don't know if test load should be higher like 10-20kg.