Switch Labs

[Tiago1973]

hi Bill,
fabrics were pretty much steady for some time, but in the last couple of years we have seen the introduction of new stuff - Teijin D2, Airush aramid frame or Best Cuben Fiber (this being a old story)

Can you comment, as possible, this new stuff?

What do you see as the future and how that will impact kite perfomance and durability?

[ShaveTheWhales]

Switch kites should just pay full retail for some top brand bars - and then break them with the same tests .... If the said bars are not up to scratch - id really like to from a safety point of view and then why we get ripped off 500$ + for a 'Nike' style bar !!!

[naishdude]

Hi Steve: Good question!
I cannot comment on what other brands do, have or haven't done. I either no longer work for them or never did so I simply do not know. Surely Switch are not the first to do some level of failure analysis. Some products like paragliders require certification and the factories who make them have dedicated testing facilities. Some also make kites for most popular brands. I have personally been involved in this regard and can honestly say the extent and expertise of the testing varied greatly from extremely competent to rudimentary. What I can say is the technical level and extent of testing at Switch Labs is refreshing. It shows the sort of independent planning, resource dedication and engineering to be the market leader.

What are we or have we tested?
1) Components - Switch bar components are designed in-house in NZ and manufactured exclusively for Switch. They are stress tested to failure and repetitively under higher working loads for wear and degradation. We want to know exactly when and where failures might occur. Simply actuating a quick release on the beach is an irrelevant test when the forces might far exceed your weight.
2) Fabric - Switch works with several fabric suppliers and is constantly searching for new ones. They are happy to charge us for new test fabrics and even provide numbers for weight, tear, puncture, elongation, elasticity, UV resistance, etc. However, we have found that our own sophisticated in-house testing with consistent procedures, allows us to directly compare them with confidence. With our test numbers, when we make a kite out of new fabric that performs differently, we then know exactly why by checking our test data. Example: if reduced or increased stretch is changing the dynamic shape, we can adjust our patterns to compensate (or reject or change the fabric accordingly.)
3) Construction - In sail and kite production, proven construction is mostly from experience as to what does or doesn't work. Most modern-day kites adhere to these tried and true ways. We can and do build test kites and send them out for abusive testing by team riders. But, our lab testing shows conclusively what is strong and what is not. We have found profound differences in seam strength related to stitch type and width, substrate gluing procedures, reinforcements and thread type which would be unobvious to the casual observer and unlikely to show quickly (or even after a year) in a test kite. Sometimes removing a bar tack or switching from 3-step to two rows of 1-step zig-zag makes a huge difference in failure and the forces required to cause it. Some constructions may prove to be OK but a slight change may make them 'bombproof.' Our lab testing actually shows the difference so we can make it so.

Future Switch Labs projects - real world numbers for bar pressure, sheeting/steering loads, real and apparent wind velocity, total force, lift vs drag, VMG, turning speed, etc.
Exciting isn't it?

[Hansen Design]

@ Tiago1973 - There are some interesting new canopy fabrics from several suppliers with added threads, differing weights, finishing and printing capabilities. The goals are improved durability, improved performance, lower cost. Our lab testing has shown (in some cases) higher tear strength associated with higher weight or higher stretch. When used in test kites, the performance and handling for either was significantly different. We have also seen compromises for some lower-cost materials. Obviously, there are trade-offs to consider and the various brands independently make those decisions and market them accordingly.

What we have found is reduced weight is the biggest factor in improved performance. In this regard, we view construction/fabric changes to the inflatable structure along with bladders the area of biggest promise. Exotic materials could definitely play a role but the the trick is to save weight without sacrificing durability or structure while keeping the price within reason.

Here is another small Switch Lab test: http://vimeo.com/78884205

[experienced1]

txs Bill for your response.
Having some awareness of previous testing, one thing in particular has been a disappointment. Seems that a lot of tests are very linear in nature; slowly and continuously adding force until failure. Seems to me with kiting, quite offen the force is exponential, not linear. Like when a kite falls back into the window and then suddenly powers up...but haven't seen this kind of testing.

As you can probably tell, I'm no engineer, but think you can understand what I am trying to describe. Hope I didn't mutilate terminology.
steve

[Tiago1973]

coincidently this guy here also identified weight as the biggest factor
http://kitesc0op.com/2013/11/12/a-peak- ... trut-kite/

but he then followed a different approach than Switch and instead of playing with different construction/ fabrics configurations just removed all the struts.. ahha

not wanting to go off-topic -> just found funny reading weight as a concern from 2 different sources


thanks for your view on fabrics!

[barrybarryr]

Whilst it's good Switch have put the videos up, all these tests are done in perfect lab conditions. Kites aren't used in lab conditions.

It's all very well saying we did a motion with a weight 10 thousand times when there is no imperfection and the test is a straight up and down exercise.

Would be good to see the tests with sea water and sand added to the mix - i.e. the depower line wear test in real life conditions.

Also tests done in different temperatures, not everybody kites in hot weather or hot water.

[Hansen Design]

@ experienced1 - Impact testing requires mass, speed and dissipation distance to arrive at a force. We could drop known weights a fixed distance from a suspended chickenloop assembly as a test. But the real life situation has a spreader bar, harness, soft tissue, kite lines, inflatable structure, canopy distortion, etc. all collecting the energy as they move and distort. When things go wrong, the forces are sufficient to accelerate a 100kg kiter to world-class sprinting speed in about a meter (which we occasionally see at the beach.) Ultimate failure and fatigue data are good to know. Once they exceed what can be expected in real life, perhaps the most important data is the force required to activate a highly loaded quick release.

@ Tiago1973 - Eliminating structure is certainly one way to save weight. Our goal is to reduce weight and preserve structure.

@ barrybarryr - Absolutely! Benchmark data is needed first so please allow some time.

[ShaveTheWhales]

HP - so why throw a harness on a MythBusters dummy and drop him - attached to a suspension spring with the guestimated sprung force - works well in superbike racing

[ShaveTheWhales]

So why 'not' throw a harness on ...