Contact   Imprint   Advertising   Guidelines

Aluula\SLS alternatives ?

Forum for kitesurfers
User avatar
iriejohn
Very Frequent Poster
Posts: 2592
Joined: Fri Dec 18, 2015 11:04 pm
Weight: 80kg, 1.78m
Local Beach: West & East Wittering (UK South Coast)
Style: Make it up as I go along
Gear: Bars, Kites
Twintips, Directional
Brand Affiliation: None
Location: Noviomagus Reginorum
Has thanked: 540 times
Been thanked: 271 times

Re: Aluula\SLS alternatives ?

Postby iriejohn » Sun Oct 17, 2021 7:22 pm

Regular Ozone kites are pretty much the same weight as Duotone SLS equivalents. Duotone are taking the piss.

Just like the BMW mantra "The Ultimate Driving Machine" or the Audi mantra "Vorspung Durch Technik", both of which are intended to persuade the consumer that they are somehow superior to other marques.
Last edited by iriejohn on Sun Oct 17, 2021 8:25 pm, edited 2 times in total.

madworld
Very Frequent Poster
Posts: 511
Joined: Mon Apr 29, 2013 8:52 pm
Local Beach: Never never land
Style: Cruising
Gear: Rich peoples throw aways.
Has thanked: 18 times
Been thanked: 26 times

Re: Aluula\SLS alternatives ?

Postby madworld » Sun Oct 17, 2021 8:24 pm

iriejohn wrote:
Sun Oct 17, 2021 7:22 pm
Regular Ozone kites are pretty much the same weight as Duotone SLS equivalents. Duotone are taking the piss.
Duotone SLS besides weight discussion has a stiffer leading edge than Ozone.

User avatar
Havre
Very Frequent Poster
Posts: 1642
Joined: Tue Jul 18, 2017 11:38 am
Kiting since: 2015
Local Beach: Oslo
Favorite Beaches: Jericoacoara (area) & Cabarete
Gear: Ozone Zephyr 17m, Ozone Enduro v1 12m, Ozone Enduro v1 9m, HQ Topaz 7m, Shinn Ronson Player, Mystic Majestic X Harness, Mystic Stealth Bar
Brand Affiliation: None
Has thanked: 231 times
Been thanked: 263 times

Re: Aluula\SLS alternatives ?

Postby Havre » Sun Oct 17, 2021 8:52 pm

Yeah. Who knows what kind of compromises Ozone have made to get the weight down.

That said it is far from a given that a Duotone SLS kite will be better than the comparable Ozone kite just because it is now SLS. Even if Duotone want you to believe that.

A friend of mine got an Evo SLS, but he still prefers the regular Dice (obviously he might have liked a Dice SLS even better - point being SLS isn't a revolution- more like incremental change it seems).

User avatar
Greenturtle
Frequent Poster
Posts: 463
Joined: Fri May 12, 2017 6:51 pm
Local Beach: Presque Isle, Erie PA
Favorite Beaches: Bahamian Cays
Gear: Flite 17, 14.5, 12, 10, 8, Cloud 13.4, 10.4
Tons of boards for water, land, and snow
Brand Affiliation: None
Has thanked: 56 times
Been thanked: 83 times

Re: Aluula\SLS alternatives ?

Postby Greenturtle » Sun Oct 17, 2021 10:57 pm

Havre wrote:
Sun Oct 17, 2021 8:52 pm
Yeah. Who knows what kind of compromises Ozone have made to get the weight down.

Lighter bladder material is the main thing.
Lightest dacron that does the job of course too.
I personally, have no problem with this. I have an ozone kite from 2009 that holds air like a champ, its the lightest lei I own per meter and I only own light leis. I use it exclusively for snowkiting. Im not exactly sure what making the bladder thicker would accomplish other than adding weight to the kite. Thorn/shell/etc piercing in through the dacron for example is going through the bladder too, whether its “thick” or “thin”. Perhaps sand or salt crystals inside the le would wear through it faster? I think some has been written on the forum about that somewhere. Never been a problem for me. The flites I own also have lightweight bladder material compared to others. Also no problems with those ever, but I do my best to take care of them and dont generally drown them in salt water and sand etc.
The valve delamination problems so many people with all brands experience from high heat exposure would happen no matter the thickness of the bladders so no advantage there that I can think of.
Lighter bladders - enjoy a lighter kite every second it is in the sky. If there is a durability issue with them Ive never experienced it.
These users thanked the author Greenturtle for the post:
iriejohn (Mon Oct 18, 2021 10:07 pm)
Rating: 6.67%

Ice101
Frequent Poster
Posts: 351
Joined: Wed Sep 06, 2017 10:06 am
Gear: Free ride want to branch into strapless riding and more freestyle
Brand Affiliation: None
Has thanked: 1 time
Been thanked: 24 times

Re: Aluula\SLS alternatives ?

Postby Ice101 » Sun Oct 17, 2021 11:13 pm

They would have to be to keep up. All this stronger business just seems that they are adding a new Light strong material across the leading edges to stiffen them up. (Didn’t they lose those before to make them lighter???, seems like going around in circles a little, oerhaps they flew better before?) Fione have also done this this year and using lighter bladders and reinforced leading edge. Likely they all buying from the same factory so the advances duotone making likely the same in the other kite brands made in the same factories. A lot of the top kites like core etc and north, eleveight and others seem to be made in Sri Lanka mysteriously they all have new materials this year. Likely all the same but named differently if I was a betting man and just an excuse for them all to raise prices.

User avatar
Greenturtle
Frequent Poster
Posts: 463
Joined: Fri May 12, 2017 6:51 pm
Local Beach: Presque Isle, Erie PA
Favorite Beaches: Bahamian Cays
Gear: Flite 17, 14.5, 12, 10, 8, Cloud 13.4, 10.4
Tons of boards for water, land, and snow
Brand Affiliation: None
Has thanked: 56 times
Been thanked: 83 times

Re: Aluula\SLS alternatives ?

Postby Greenturtle » Mon Oct 18, 2021 2:32 am

I don’t think the le material makes a kite stiffer or softer. How hard you choose to pump it does. Last time I checked, any kite in good condition can be pumped rock hard. Maybe the new stronger material can be pumped even harder with less fear of bursting on a bad tomahawk, but more stiffness isn’t really something I personally have a problem achieving (haaaaa) or have a need for, even with the lightest of dacron le’s
These users thanked the author Greenturtle for the post:
iriejohn (Mon Oct 18, 2021 10:09 pm)
Rating: 6.67%

User avatar
GregK
Very Frequent Poster
Posts: 558
Joined: Sat Jul 24, 2010 6:22 am
Kiting since: 1996
Local Beach: Comox, BC
CANADA
Style: Hydrofoil mostly
Gear: Lift 170 Fish & 110 wingsets, 32" strut
Ocean Rodeo & BRM kites
Brand Affiliation: Comox Kite Repair
Location: Comox, BC CANADA
Has thanked: 18 times
Been thanked: 87 times

Re: Aluula\SLS alternatives ?

Postby GregK » Mon Oct 18, 2021 4:19 am

Greenturtle wrote:
Mon Oct 18, 2021 2:32 am
I don’t think the le material makes a kite stiffer or softer. How hard you choose to pump it does.
Probably because "stiffness" to you means how far the LE can be deflected/bent before it buckles ( inner edge wrinkles or folds over ).

To an engineer, stiffness is the load/force required to deflect a solid object a unit distance, and it's a function of the object's :
- cross-sectional ( perpendicular to the bending direction ) geometry
- object's material's modulus of elasticity , which is a measures of the material's resistance to being deformed elastically ( and the material property that's improved with Aluula, SLS, or now Airush's Hookipa fabric ).

So where does the kite's inflation pressure enter into it you ask ? If the object is an internally pressurized woven fabric tube, then it's made up of this network of pretty finely woven filaments or threads. Think of them as tiny ropes, and bear in mind that a rope can only support tension - you can pull on it, but you can't push or compress it. When you bend an object, let's say downward at the ends, about the top half of the object is in tension, and the lower half is in compression. And it's the internal pressure that is keeping the lower half in tension.

When a kite's LE buckles or folds, the compression from bending exceeds the tension from the inflation pressure, and like trying to push a rope, it folds up.

Clear as mud now, right ? Don't be discouraged, kite LE stiffness is complex. There's also an additional stiffening effect of the internal pressure I've omitted. Or if you are liking the above, just ask for more, and we'll go another round.
These users thanked the author GregK for the post:
SENDIT! (Mon Oct 18, 2021 8:00 pm)
Rating: 6.67%

knotwindy
Very Frequent Poster
Posts: 2032
Joined: Mon Sep 26, 2011 4:49 am
Local Beach: baja, gorge
Style: erratic to none
Gear: yes, I use gear
Brand Affiliation: None
Has thanked: 202 times
Been thanked: 198 times

Re: Aluula\SLS alternatives ?

Postby knotwindy » Mon Oct 18, 2021 4:59 am

Do you know how much the modulus elasticity differs in the older Dacron relative to the newer ‘stiffer’ materials?
Is it enough to actually feel a difference compared to an increase in the internal pressure increasing? And by how much?
Not sure anyone has measured any of this yet?

User avatar
purdyd
Very Frequent Poster
Posts: 1785
Joined: Mon Jan 06, 2003 1:00 am
Has thanked: 205 times
Been thanked: 191 times

Re: Aluula\SLS alternatives ?

Postby purdyd » Mon Oct 18, 2021 6:46 am

Penta Tx is twice as stiff and aluula over 2,5.

I know on the duotone sls kites you can feel that the pentatx middle strut is notably stiffer than the regular struts.

I know there was the paper floating around examining deflection in inflated structures that showed an increase in stiffness with pressure but I don’t recall it being linear.

The aluula 10m roam that I tried had amazing drift but I never really got the bar position dialed in.

My 10m evo sls has a better feel at the bar.

So kite design parameters still are important I think.

I really like my evo sls 7m and has a surprisingly good low end. It goes upwind in less wind than the regular evo.

I think with the pentatx the weight difference is noticeable when you carry the kite and on the upstroke but really it is the difference in stiffness you notice on the water.

It will be interesting to see how hookipa cloth fits into this mix which is from challenge sail cloth like pentatx I believe.

And in the duotone magazine I think from last year, it sounds like there are other suppliers coming to the table with new fancy products.

It might be bad time for saving money.

User avatar
Greenturtle
Frequent Poster
Posts: 463
Joined: Fri May 12, 2017 6:51 pm
Local Beach: Presque Isle, Erie PA
Favorite Beaches: Bahamian Cays
Gear: Flite 17, 14.5, 12, 10, 8, Cloud 13.4, 10.4
Tons of boards for water, land, and snow
Brand Affiliation: None
Has thanked: 56 times
Been thanked: 83 times

Re: Aluula\SLS alternatives ?

Postby Greenturtle » Mon Oct 18, 2021 4:00 pm

GregK wrote:
Mon Oct 18, 2021 4:19 am
Greenturtle wrote:
Mon Oct 18, 2021 2:32 am
I don’t think the le material makes a kite stiffer or softer. How hard you choose to pump it does.
Probably because "stiffness" to you means how far the LE can be deflected/bent before it buckles ( inner edge wrinkles or folds over ).

To an engineer, stiffness is the load/force required to deflect a solid object a unit distance, and it's a function of the object's :
- cross-sectional ( perpendicular to the bending direction ) geometry
- object's material's modulus of elasticity , which is a measures of the material's resistance to being deformed elastically ( and the material property that's improved with Aluula, SLS, or now Airush's Hookipa fabric ).

So where does the kite's inflation pressure enter into it you ask ? If the object is an internally pressurized woven fabric tube, then it's made up of this network of pretty finely woven filaments or threads. Think of them as tiny ropes, and bear in mind that a rope can only support tension - you can pull on it, but you can't push or compress it. When you bend an object, let's say downward at the ends, about the top half of the object is in tension, and the lower half is in compression. And it's the internal pressure that is keeping the lower half in tension.

When a kite's LE buckles or folds, the compression from bending exceeds the tension from the inflation pressure, and like trying to push a rope, it folds up.

Clear as mud now, right ? Don't be discouraged, kite LE stiffness is complex. There's also an additional stiffening effect of the internal pressure I've omitted. Or if you are liking the above, just ask for more, and we'll go another round.
Right, I can definitely see how the amount of elasticity of the material especially on the back side of the bend would allow more or less bending especially considering the whole length of an le.
Im just not sure how much more stiffness is needed or is more beneficial on a kite vs dacron when the bridle points are supporting it, vs a wing for example where I totally see the advantage to making it stiffer with all the pull coming from the center with no other support on any of it other than the stiffness of the tube.
I think maybe added stiffness in the le of kites could allow thinner le if that was a desire, keeping similar flex as before.
But like I say Im not sure if a lot of additional stiffness (in and of itself) in general is a guarantee of increases in performance for bridled kites, where some flex and twist and movement is something that can be built in as part of the magic of what makes it tick and feel good and smooth through turns and sheeting angles etc.

Im really stoked on the weight savings of the new materials, as that to me IS a guarantee of certain performance increases. Rigidity for wings is also obviously better.
Added rigidity in bridled kites I just think might have pros and cons and will have to be dialed in, as compared to simply making a kite lighter, with the flex being basically equal to before.

I don’t know, obviously for me this is speculation, from your much more experienced perspective what do you think? Is added stiffness for kites definitely good? Or just in order to reduce le diameter and have similar flex as before?


Return to “Kitesurfing”

Who is online

Users browsing this forum: Google [Bot] and 33 guests