Help re-tuning a Sonic 2, am I on the correct path? Bridle/mixer

[airsail]

I did the long mixer test on my 15mtr Sonic2 as per video above as it would only fly when fully depowered on a tuned bar, this reset the bar as B,C and Z bridles had shrunk. But when flown I had tip tuck and the kite wouldn’t inflate properly. I then checked each row down to the tip and found each A bridle had shrunk out towards the tips. Couldn’t see any point of stretching as the bridles would just shrink back again in time so added a 20-30 mm pigtail to a6-a12.
It now flies perfectly, no tip tuck at all and seems to be back to as new condition. So if your willing to put in a bit of time you can get a older foil kite back to as it was when new.

[Mossy 757]

Just watching the video I'd diagnose what I'm seeing as shrinkage in the A row of your bridle. Collapse like that usually means that the leading edge of the canopy is 'smashing into' the airflow instead of cutting through it and creating lift. When a soft cloth smashes into air, it collapses. This also happened to a local with his 15m Sonic2, adding some extensions to the A row also solved his problem. The same thing can be accomplished by shortening B and C to account for the shrink in A.

Several people have described their process for troubleshooting and diagnosis, and it sounds like you're on the road to recovery. My idea is to always start where you have fewer lines and solve problems from there, working your way towards many more lines. So if you think of your kite like a tree, start at the trunk and work your way to the individual branches.

So that means:
1) Tune your trimming system - if your depower rope knot is in the wrong place, move the knot.
2) If that doesn't fix the problem, tune your flying lines so that they're perfectly even with the bar fully powered against the chicken loop.
3) If evening your lines doesn't solve the problem, look at your spare-part lines running on the C pulley and replace those if they're old/worn/flattened.
4) If the spare-part lines are fine, tune the mixer (speed system).
4a) In most kites, the tendency is for B and C to shrink, with Flysurfers you can address both B and C by only extending B first.
4b) If extending B doesn't correct unpleasant behavior, try extending C a slight amount. This is where you now need to extend B, check C, adjust C, check B, etc. because moving 2 knots starts changing a lot of variables.
4c) If B and C don't seem to improve performance, try extending Z.
4d) If no amount of changes in the mixer improve performance or correct problem, begin measuring individual bridle lines under the specified tension needed to assess if individual components in the un-tunable portion of the bridle need to be replaced or modified. Since ALL of this work now becomes incredibly precise and usually requires splicing or full bridle disassembly, I really hope to never get here...
4e) Get super lucky and find that your bridle is out of whack in a completely symmetrical way that you can tune out at the mixer!
4f) Get unlucky and find out that your bridle is out of what in an asymmetrical way that requires individual line corrections.
4g) Order or make new bridle segments or a whole new bridle based on your level of splicing ability.

5) Sell the kite used and advertise, "Brand new bridle replaced, dozens of hours of on-the-water enjoyment await!"
6) Sweat uncomfortably for about 2 weeks after selling kite to make sure the new owner doesn't bug you with a bunch of questions about why the kite you sold them keeps collapsing.
7) Decide to only buy new kites from now on and then claim that all your experiences with foil kites are really easy and stress-free.
7a) Comment anonymously on their thread on Kiteforum offering advice about how to tune used foil kites.


For me, that seems to work every time.

[airsail]

With the large uptake of foil kites I predict there will be some demand for people who know how to tune the bridle system. And probably some bargains to be had when those who can’t be bothered learning sell their problem kites.
Flysurfer say their silicone cloth is good for over 1000 hours, that’s one very old bridle.

[mgs]

With the large uptake of foil kites I predict there will be some demand for people who know how to tune the bridle system. And probably some bargains to be had when those who can’t be bothered learning sell their problem kites.
Flysurfer say their silicone cloth is good for over 1000 hours, that’s one very old bridle.

I found this thread really useful in understanding speed systems and how to realign the Ozone speed system that isn’t actually adjustable!
viewtopic.php?f=197&t=2390593
There is a lot to read and many good contributions and highlights that bridle pulley lines should only be replaced when worn and adjusted as needed.
To have to replace pulley bridle lines that are out of tolerance in my view is wasteful.

[Mossy 757]

To have to replace pulley bridle lines that are out of tolerance in my view is wasteful.

Spoken like someone who has never maxed out their mixer trying to tune around shortened pulley lines...

I can't imagine having the mindset of not replacing consumable parts of a foil kite mixer when they are out of tolerance and degraded to the point of impacting performance. Do you drive around town in your car with bald tires because replacing them when they're out of tolerance is wasteful?

[davesails7]

Just watching the video I'd diagnose what I'm seeing as shrinkage in the A row of your bridle. Collapse like that usually means that the leading edge of the canopy is 'smashing into' the airflow instead of cutting through it and creating lift. When a soft cloth smashes into air, it collapses. This also happened to a local with his 15m Sonic2, adding some extensions to the A row also solved his problem.

Yeah that was me! This is the problem, A is too short relative to B, so the leading edge tucks under. I should have shortened B though instead of lengthening A. Lengthening A worked, but people had a conniption when they heard I lengthened A

I then had this same issue on an R1 V2 recently after doing the long mixer test, the leading edge would collapse and tuck under when I was pushing hard upwind with the bar out. Shortened B 1 cm, and worked perfectly.

IMO don't waste your time measuring all the lines vs the lines plan. In my experience, none of them match. Evening the mixer on the Sonic 2s always made them fly worse for me because things had stretched/shrunk above the mixer. On the Ozones, you can do the long mixer test and they are all the same length, but on the Sonic 2 I never got that to work out.

Just shorten B until the problem goes away. Probably only need 1 or 2 cm.

[Mossy 757]

people had a conniption when they heard I lengthened A

Guilty as charged

[downunder]

BTW,

this is exactly how my Soul 10m behaved, after last sesh ended up in the water and taking 500L...

Hopefully it's fixed now, need to test it.

[mgs]

To have to replace pulley bridle lines that are out of tolerance in my view is wasteful.

Spoken like someone who has never maxed out their mixer trying to tune around shortened pulley lines...

I can't imagine having the mindset of not replacing consumable parts of a foil kite mixer when they are out of tolerance and degraded to the point of impacting performance. Do you drive around town in your car with bald tires because replacing them when they're out of tolerance is wasteful?

I’ll give you the benefit of doubt that you’re not a patronising “individual” who attempts to form an opinion of me which is false and defamatory by making comparisons with reference to how I maintain my car!

I’m well aware that speed system pulleys including the lines that pass through them are a consumable part and should be periodically checked and replaced, in particular when showing signs of wear.
The point I was making was with reference to a thread where someone was seeking advice as to what to do having discovered their Ozone speed system was out of alignment having performed the “Speed system Zero Check” (The difference between connections point “A”, “B” & C” being greater than 15mm.
Ozone advises to replace the “Speed system” yet the pulley lines (PB1 & PB2) are in good order to terms of “lack of wear” but have shrunk!

The thread continued for some time with many contributions on how to address the misalignment issue, bearing in the mind the Ozone Speed System is not adjustable.
Adding pigtails to extend pulley line PB1, replace pulley lines PB1 &PB2, covert the speed system to be adjustable, make an adjustable speed system or purchase Ozone’s Pro-tune speed system being some of the suggestions.

I've been making sewn bridle lines loops for years and replacing pulley lines and pulleys takes very little time.
However, being able to make adjustments to a speed system where the pulley line is in good condition, albeit shrunk is a handy feature but except there comes a time where the replacement of a pulley bridle line takes precedence over making an adjustment to a speed system.

[Mossy 757]

the pulley line is in good condition, albeit shrunk

That's my only disagreement, I would just swap them out when they shrink badly enough to max out the tuning of the kite. Flattened = done, in my book at least because the headaches otherwise aren't justified.