I need convincing too:) Bar back lines!

[Regis-de-giens]

Matteo V got all my points.

My lines have nothing special and the main reason why I never have to change is that I uses them at far below loadings that others : less weight, mainly hydrofoil in light winds, low or medium jumps , no freestyle, loops many on hydrofoil i.e at low loading, only few dozens of hours ride per bar each year.

Fatigue increases a lot with load reduction (^3 as far as I remember : I always ask for rder's weight when I buy a second hand kite).

It is not representative of all riders but it my case I think I do not take more risks reducing back lines vs a heavy freestyler on standard lines. Hence in summary there is room for line reduction for some people like me, specially for light winds having less dynamic loadings.

Just to clarify my use of the "Optimum " term. It deals with AoA stability ( in gust ) only , not on wear or other parameter that will be rider depedant.

[Matteo V]

Just to clarify my use of the "Optimum " term. It deals with AoA stability ( in gust ) only , not on wear or other parameter that will be rider depedant.

Could you say more on AoA (angle of attack of the kite to gust/shear?) stability? Is that improved by thinner lines to a degree that you can describe the feeling, or explain performance improvements you notice on the water, when going from thicker lines to thinner lines?

This is something that I have no understanding of as my style is primarily highly loading front and back lines (relatively), regardless of my weight. My hydrofoil time is best described as occasional at less than 40 hours per year.

[Regis-de-giens]

My remark on elasticity optimization was initially a note to temper below message :

I think people need to factor in your lightweight Regis with such weak lines, while the lines are still new that strength is quite practical.

I do think elasticity is an issue as you go weaker, but then maybe a benefit for the more relaxed riding as it would smooth out gusts! I do think kite designers looking for the more instant response and feel ,which would originate from there international pros, well then high strength lines would be more desired and would explain why brands like Slingshot have such strong lines.

100grams saved, most inflatable riders would probably laugh but in the crazy lightwind some foil kites can fly this really makes quite some difference.

But to be franck since I use my thin lines on hydrofoil light kite only, with my smooth ride style and light weight, I have not noticed any impact of elasticity ...and few chance to test back-to-back with same kite , same gust , same wind , ect ...

My point was just that if someone is affraid (not me... ) of any significant increased elasticity due to thin rear line, he should consider that in fact in some cases , having rear line thinner than front line could help because it should led to a more constant AoA during gusts . Said differently : rear line of same diameter would extend less than front line in a gust (Because main effort transit to front lines specially on foilkites) => increase of AoA => more power as if sheeting in during the gust... not "optimum "

[downunder]

To recap:

- no one knows how much we are pulling since the answer is: it's complicated (*).
- one answer was presented, it's 5%. No one disputed this number for a TT, see *.
- 160kg was presented as a lowest with no jumping. 200kg with jumping. No one is disputing this, since it comes from the manufacturers, even tho we do not know anything how was this number created, see *.
- even with jumping, the notation is that "no jumping" actually means "no boosting", again and again, see *.

- it was also presented that 70kg lines are fine, for that particular rider and his conditions. Let me repeat that: his conditions.

From the reading above posts, looks like 'pushing' the boundaries with equipment, using the super thin lines, no matter of rider conditions, as a general rule is a .
Some riders, only some, will not listen and will create theirs own rules, however, this is discouraged in general as a threat to the kiting community. Not so much a threat for our own safety tho, from reading the posts.

In reality, the answer to my question is really 'how long is a piece of string'? Long enough...
And I'll continue to jump, 10m or so with my super thin lines. I guess, because I can. And that is the real answer. Regis too can do whatever he does.

Because he can.

[Regis-de-giens]

Sorry but your post is a bit reducing the conclusion; let me summarize your though as I understand it: if a rider wants to cover all disciplines and rider weights with one bar only, and/or if you are among the rider that solliciate a lot you lines (heavy, TT, freestyle, old school, snowkite, ect ...), then you can trust manufacturer choice and calculations (that is exactly why they are developped their bar for) and be in love with your standard bar.

Now let me summerazise my view (and from other riders, I see) : if you have some specificities like light/medium weight, or hydrofoil use, or light wind use without BIG jumps, you can benefit from reducing line diameter (and in particular rear lines), for below REAL benefits:

- better control when trimmed in medium winds, specially with line extensions ; this feature is amplified for a light bar pressure kite like race foilkites which will have high curvature when sheeted-out. Rear line tension (= Bar pressure / 2 ) is somewhere between 5kg (or less in hydrofoil light wind) and 30 kg in above condition ( easy to prove if you really need evidences, just use a lugage weighter, but try to maintain 30 kg per arms during one hour : it is far higher than average bar pressure), i.e. far below the rating of front lines; hence safety is preserved if you ride the adapted style. Years ago , I had calculated that the curvature of rear line could lead up to a loss equivalent to 10/15 cm trim and bar width when turning the kite)

- better upwind/speed angle in light wind: racers will confirm

- better hang in the air of the kite for light weight foilkites: I can confirm

- lower price by the way.

But below cons :

- less all-round bar (which is already the case if you have extensions)

- more risk to wear due to beach drag, ect ... hence more frequent change-out

- more risk of cutting your finger ( I always uses gloves)

At first, my intention of 70 kg lines made laugh of some of my friends, but it worked ! I am not recommending that everybody should reduce up to such small diameter, but just mentionned my specific case to show that there is (plenty of) room in between 70 kg and 300kg lines, like the 160 kg of Flysurfer but even lower for medium foiler in light wind on a dedicated foil light wind bar.


Trust you can understand this point of view.

[downunder]

^
That's covered with: conditions.

See, this is a problem. We can go on and on about the conditions (many variables already, now you introduced a new one, which is a price, or extensions Earnestly, I could add probably a few as well. I mean, really, cutting fingers on thin lines is surely not the main reason not to use them. That is a least worry.

Here is a thought, would you take a 150kg lines on a 40-50kn wind? They say no jumps, do they say it's ok for a 50kn? Are 200kg good for 40-50kn? This are all conditions the lines are not tested and proven. So how would one know which one to take will leave to a rider discretion to decide.

Completely wrong about the BIG jumps if we agree that a 10m jump is big. Once for all, racers DO jump occasionally even higher than that. On race lines. Would you like a pic or two? Did you guys ever witnessed that? An 15yo jumped more than many ever will on Sonic v1 in a huge gust with FS race bar. He was about 45-50kg back than. 10kg less then me. C'mon guys, he does not need 200-400kg lines with 45kg weight. Horsers for courses.

As you've said, there is enough room for reducing, but when I've said it, I was accused as an liability, danger for local community So, you should be proud of yourself because you are too pushing the boundaries, you will be the one who industry will ask for advice on how low can we go. For your weight, obviously. Conditions, right? Remember, we do not know from where 200 or 150kg come from, just like we can't tell for 100% that no one ever 'jumps' with 150kg lines. I have a proof that this is simply not true, and it works for others but also it is obvious that might not work for the rest. So don't use it if scared, simple.



Hence, I agree with you, but just surprised about the general response from others that this is not pushing the boundaries but going actually backwards?

Backwards to where? I would never ever go back to stock lines after 3 years on the race lines. Again, because I can.



PS
Be careful with the statement: that is why they developed xyz. There is no Standard to compare with or even to start from. And that is a 'can of worms' if ever introduced in kiting. Think about it for a sec, no Certified equipment, no insurance claim possible. Certification means Standard, and that means a 'blanket rules'...