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Gybe tip: let the sail pull you into the turn
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PeconicPuffin



Joined: 07 Jun 2004
Posts: 1138

PostPosted: Sun Sep 08, 2013 3:33 pm    Post subject: Reply with quote

isobars wrote:
I just don't see how plantarflexing (pointing) that ankle does anything but stretch the footstrap fabric


It allows the hips to come further forward and over the carving rail. Try it...it will help you plane through your jibes.

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isobars



Joined: 12 Dec 1999
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PostPosted: Sun Sep 08, 2013 3:36 pm    Post subject: Reply with quote

You're confirming my point, snd you're right. Its purpose is to get us forward, not to lift the rail as everyone claims.
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PeconicPuffin



Joined: 07 Jun 2004
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PostPosted: Sun Sep 08, 2013 5:29 pm    Post subject: Reply with quote

isobars wrote:
You're confirming my point, snd you're right. Its purpose is to get us forward, not to lift the rail as everyone claims.


No. Your point was that its a trick to get people to bend their knees. It is specifically not that. It is a technique that allows people to move their weight forward and over the rail. Knee bending goes along with this, but is not caused by it. It is quite possible to bend one's knees and not have body weight in the right place at all (Peter Hart goes on about wrong ways to bend the knees). ABK emphasizes the ankle bend so that carve initiation is smooth and firm, driven by the move in body weight.

As I've recommended to you many times: Take an ABK clinic. You'll learn a lot.

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whitevan01



Joined: 29 Jun 2007
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PostPosted: Sun Sep 08, 2013 5:51 pm    Post subject: Reply with quote

ascott72 wrote:
It seems to me it's really your forward momentum before you started the turn, wanting to keep going in the original direction even after you have started turning.
.


You are absolutely right. Like I said, there is no "outward from the center" force (which is what centrifugal means.). In order to turn, there needs to be a net force towards the center of the turn. this force is provided by other forces, it is not an applied force. for cars, friction provides the force. for a ball on a string, the tension in the string provides the force. for a windsurf board, it would be sail force and the force of the water on the board. for the sailor, it is actually normal forces from the boom and the normal force from the board. Gravitational force is always straight down (actually, centripetally - towards the center- to the center of the Earth).

ok, this thread is about to diverge into 3 threads, one about jibing, one about basic high school physics, and one about isobars.

so, here is a video. the first guy doesn't do it correctly, but the second guy (the "Terminator" on Josh Angulo's old gear) does do it correctly.

here's the link (thanks to the Dimanator for the video):

http://www.youtube.com/watch?v=5dD7IU9-YfY&feature=youtu.be

I'm now out, have fun!!
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isobars



Joined: 12 Dec 1999
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PostPosted: Sun Sep 08, 2013 6:35 pm    Post subject: Reply with quote

God, PP ... it both bends the knees AND gets us forward (or ... sheesh ... allows both)... the "curtsey, not bow" principle of my jibe discussions for 20 years. What I do NOT believe it does is lift the rail, as people have argued here for many years; THAT'S the issue. We can bend our ankles, bend our knee(s), thrust our hips into the turn, pick our noses, and/or put our weight where it belongs ... or not ... relatively independently, and we can jibe just fine without lifting that front heel off the deck, but through all that the basic fallacy is that flexing that front ankle, all by itself, lifts that rail. It's much like the published claim that blipping a dirt bike's throttle in mid-air "raises the front whee [don't go there]l" by accelerating the rear wheel to make it spin faster, thus increasing its centrifugal force, making it heavier, so it falls faster.

I refuse to type every little damned thing about jibing (and FFF vs BFF, and hip thrust, and MFP, and trads vs stubbies, etc) every damned time the topic comes up. You're taking advantage of that to play games again, and astute readers know it. Most of them wish I'd type less, not more, as you seem to want. They have the intelligence to fill in the gaps themselves rather than expecting me to type every nuance so guys like you can't find anything but typos to nitpick.

Please ... give it a rest. Let people use their brains.
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whitevan01



Joined: 29 Jun 2007
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PostPosted: Sun Sep 08, 2013 7:13 pm    Post subject: Reply with quote

isobars wrote:
It's much like the published claim that blipping a dirt bike's throttle in mid-air "raises the front whee [don't go there]l" by accelerating the rear wheel to make it spin faster, thus increasing its centrifugal force, making it heavier, so it falls faster.

.


sorry, can't resist. where is that published? gosh, most Americans really don't know much about physics do they? maybe it's because only around 30% of American high school graduates take any physics, and maybe that's because of the term "nerd" or " geek".

in any event, it's not about centrifugal force, it's about conservation of angular momentum. maybe you already knew that.
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watermonkey



Joined: 16 May 2003
Posts: 62

PostPosted: Sun Sep 08, 2013 11:12 pm    Post subject: Reply with quote

whitevan01 wrote:

ok, this thread is about to diverge into 3 threads, one about jibing, one about basic high school physics, and one about isobars.


whitevan01 wrote:

sorry, can't resist. where is that published? gosh, most Americans really don't know much about physics do they? maybe it's because only around 30% of American high school graduates take any physics, and maybe that's because of the term "nerd" or " geek".



Four! Another about declining interest in HS science...different than the actual science concepts themselves.

Somebody get another tangent in here...."tangent" - geometry! d'oh! Five!

Wink
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isobars



Joined: 12 Dec 1999
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PostPosted: Mon Sep 09, 2013 8:28 am    Post subject: Reply with quote

TANGENT ALERT. DO NOT READ THIS UNLESS YOU WANT TO LEARN MORE ABOUT THE APPLICATION OF PHYSICS TO OUR EVERYDAY LIVES.

whitevan01 wrote:
isobars wrote:
It's much like the published claim that blipping a dirt bike's throttle in mid-air "raises the front wheel [don't go there]l" by accelerating the rear wheel to make it spin faster, thus increasing its centrifugal force, making it heavier, so it falls faster.


sorry, can't resist. where is that published? gosh, most Americans really don't know much about physics do they? maybe it's because only around 30% of American high school graduates take any physics, and maybe that's because of the term "nerd" or " geek".

in any event, it's not about centrifugal force, it's about conservation of angular momentum. maybe you already knew that.

Yup. But that explanation was published in earnest by the most technically erudite dirt bike magazine in print during their heyday decades ago. They never corrected it despite its triple layer of violations of high school physics and letters informing them of that. Ditto for an equally erroneous explanation in Weatherwise Magazine of why the outflow winds generated by a squall so often switch off within seconds of the first raindrops we feel while sailing those winds. Tip: you'd better hope you're heading in, not out, when those first drops hit your face, if you don't like long swims (hours, in some predicted cases, even in the little old Columbia River, for those who ignored the obvious signs and warnings.)

Here's one you'll love. Local newspaper diagrams and explains the lunar eclipse observed that day. Advance-degreed reader writes very profound letter explaining that "that's just the White Man's version" of eclipses, that in fact they're caused by some offended gods, or crystals, or karma, or some such forehead-slapping blather.

Or the windsurfing student who could not even begin to fathom ANY association between wind direction and the motions of clouds, leaves, flags, etc. We advised her to try a different sport.

Of all the topics I've studied in 20 years in school, none has proved more useful in and relevant to my daily and professional lives than basic physics (and the simple math and reading skills required to study it.) Why, without physics I'd never have intuited the advantages and correct execution of BFF, without which I'd be missing an important alternative to the hidebound FFF-only mode 90% of us are stuck in. Wink

NOT going there; don't bother.
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PeconicPuffin



Joined: 07 Jun 2004
Posts: 1138

PostPosted: Mon Sep 09, 2013 8:35 am    Post subject: Reply with quote

isobars wrote:
God, PP ... it both bends the knees AND gets us forward (or ... sheesh ... allows both).


No, it doesn't. You are missing the point. Emphasizing ankle bending is entirely and only about repositioning body weight. I suspect that because it was not listed in Cort Larned's jibe tips 20 years ago you don't get the difference. It's crucial.

isobars wrote:
What I do NOT believe it does is lift the rail, as people have argued here for many years; THAT'S the issue.


If you read the thread, you'll see you're arguing with nobody. Nobody said that.

1. Try emphasizing ankle bend at the initiation of your jibes the next time you're out. Just think "ankles" and see what that does for your carve. If you try it sincerely I suspect you'll be surprised at how much speed you can carry into the carve, particularly in moderate conditions.

2. Try reading threads before taking issue with them. You are arguing a point that nobody has made.

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whitevan01



Joined: 29 Jun 2007
Posts: 423

PostPosted: Mon Sep 09, 2013 9:05 am    Post subject: Reply with quote

[quote="watermonkey
Four! Another about declining interest in HS science...different than the actual science concepts themselves.

Somebody get another tangent in here...."tangent" - geometry! d'oh! Five!

Wink[/quote]

Actually, 15 years ago or so only about 20% of high school graduates in the US took a physics course, so interest in physics is going up.

anyway, back to jibing.
so, any comments on the jibe video I posted? notice how the guy with CV1 on the sail, lifts the heel on his windward leg and bends his ankles, and comes out planing.

can't tell you how many people tell me they plane out of jibes, but acutally don't. however, Pete does - out of most of them anyway. (CV1 in video).
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