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Ralf Groesel and Bullshit Light Wind Claims

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Ralf Groesel and Bullshit Light Wind Claims

Postby Pump me up » Mon Oct 11, 2021 12:09 am

There are a LOT of bullshit claims by kite companies regarding light wind capabilities. NO kite will perform in < 7-8 knots.

Ralf Grösel’s bullshit claims (attached) are incredibly disappointing. Ralf is highly respected among kite designers, which makes his bullshit claims all the more upsetting. Ralf’s previous comments about RAM AIR INFERIORITY were spot-on and widely applauded viewtopic.php?f=1&t=2400039 But for Ralf to claim the Juice D/LAB can perform in "4 knots" is ridiculous and a blatant lie and leaves Duotone wide open to claims from disgruntled users.

LIGHT WIND KITE DESIGN
It is simply not possible for the Duotone Juice D/LAB to surpass significantly the performance of every other light wind kite in existence. There is NOT enough energy for ANY kite to perform in "4 knots of wind".

DISPROVING THE BULLSHIT
It would be EASY to test Ralf’s "4 knot" claim by putting up the Juice D/LAB in stadium, a school hall, or similar enclosed space and walking briskly backwards at 4 knots (7.41 km/h). It simply WON'T FLY, let alone provide enough power for traction.

STOP THE BULLSHIT: RETURN THEIR KITES
There IS a simple way to put to rest ridiculous claims by Duotone or any other kite company: BUY THE Juice D/LAB! If it doesn’t perform in 4 knots (and it won't), then return the kite. A "class action" against Duotone, perhaps using this forum as a meeting point, will force kite companies to be more truthful.

Ignore the lies. Ignore the propaganda.
No kite can perform under 7-8 knots, let alone 4 knots.


Pumpy ……………………… :pump:
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Re: Ralf Grösel and Bullshit Light Wind Claims

Postby Pump me up » Mon Oct 11, 2021 12:15 am

Sorry - should've said - Ralf's comments were in the latest edition of iksurfmag: https://www.iksurfmag.com/issue89/?page=147

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Re: Ralf Grösel and Bullshit Light Wind Claims

Postby matth » Mon Oct 11, 2021 12:30 am

Even if it was possible, I would rather do something else. If my kite won't relaunch with minimal effort I have zero desire to kite.

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Re: Ralf Grösel and Bullshit Light Wind Claims

Postby RedSky » Mon Oct 11, 2021 12:40 am

It’s possible but theres more going on which these manufactures will omit. There should be a disclaimer, it takes skill. Something like 4kts + apparent wind + line tension + working the kite. It can be done but why would anyone want to. Unless your name is Robby Naish and have a 50m kite to pull you and your friends along in a boat in just 1 knot of wind. :D

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Re: Ralf Grösel and Bullshit Light Wind Claims

Postby Pump me up » Mon Oct 11, 2021 12:48 am

RedSky - what you're saying about skill levels etc is true but flying a kite in 4 knots, let alone getting traction, is simply IMPOSSIBLE. America's Cup yachts, widely regarded as the most efficient water crafts in existence, don't start until the wind speed hits 6.5 knots.

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Re: Ralf Grösel and Bullshit Light Wind Claims

Postby OzBungy » Mon Oct 11, 2021 1:07 am

In the article Ralf makes it clear that skill is required.

I'm a bit more concerned about the physics. When I kite foil my minimum water speed is around 10-12 knots. Arguably with a wind wing and a big foil I can be almost stationary during a clumsy gybe or tack,

For me to foil in 4 knots I would have to do at least 2-3 times wind speed. Even then I would be barely moving. For it to be fun I would need to be doing 4 times wind speed. That would be interesting to see.

Every claim of ultra-light wind riding (both kite and wing foil) shows dodgy evidence; hand held wind meters, videos of smooth looking water. Hand held meters are far too vulnerable to user error and terrain effects. Smooth water is usually on a lake or lagoon with a lee shore with low ground. You can often see trees waving around in the background.

I want to see some proof of light wind riding with an array of fixed wind meters and flags/streamers, clear of turbulence and wind shadows and gradient effects. Perhaps a group of pro riders of matching skills and weights doing back to
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Re: Ralf Groesel and Bullshit Light Wind Claims

Postby Toby » Mon Oct 11, 2021 1:35 am

The question is: where were 4 knots measured?
2m height? 10, 25m?

Because wind at surface can be 0, while up in 20m 15 knots…
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Re: Ralf Groesel and Bullshit Light Wind Claims

Postby OzBungy » Mon Oct 11, 2021 1:45 am

Toby wrote:
Mon Oct 11, 2021 1:35 am
The question is: where were 4 knots measured?
2m height? 10, 25m?

Because wind at surface can be 0, while up in 20m 15 knots…
That's wind gradient. For kiting you'd need an array of wind meters mounted at 2m, 10, and 20m heights.

You'd also need to take into account turbulence on the beach. My local has an extra 5-10 knots 100m from the beach. It can be hard to get off the beach but easy to ride once out.

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Re: Ralf Groesel and Bullshit Light Wind Claims

Postby SMJ » Mon Oct 11, 2021 2:12 am

Pump me up wrote:
Mon Oct 11, 2021 12:09 am
There are a LOT of bullshit claims by kite companies regarding light wind capabilities. NO kite will perform in < 7-8 knots.


Here's a YouTube video of a 4.4 knot (at 20m height) foil ride water start - riding comfortably at 6.3 knots (at 20m height). So it's possible, but would you want to make this a regular thing? Probably not.

I would be careful when saying these are false claims by the kite companies. There are PLENTY of YouTube videos out there documenting sub 7 knot foil rides.
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Re: Ralf Groesel and Bullshit Light Wind Claims

Postby PullStrings » Mon Oct 11, 2021 2:38 am

Agree
LW numbers too low
Only comes in a 13 or 15m sizes......those are small sizes !!

LW freeride 7 to 18kn.... 70kg> 15m...........true ideal wind to go perform is 7 plus 18 divided by 2 equals : 12.5 knots
Foiling 5 to 15kn.... >85kg 15m.............true ideal wind to go perform is 5 plus 15 divided by 2 equals : 10.0 knots

Ha ha.... performs in 4kn
Funny stuff..... epic claim
Somebody spiked the Juice punch in D lab !!!
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