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    Posted: 22 Nov 09 at 4:13pm
G.R.F

I'm not that smart so I'm gonna go simple.
The rig needs to be able to flex off upwind to exhaust the wind we cant
use.....right?
But surely it also needs to bend in a forwards motion with the kite (even
though it limits the efficiency of the main) because otherwise, if the Kite
loads up (without self depowering from the mast flexing forwards) then
the boat will spin up to wind (broaching)...... So where exactly is the
inefficiency?

It self depowers the main upwind and then downwind when the kite
becomes more important than the main, it self depowers the kite.

So what am I missing??

Doug H
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Posts: 915 		Post Options Post Options   Quote rodney Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 09 at 4:19pm

Originally posted by Doug.H

G.R.F

I'm not that smart so I'm gonna go simple.
The rig needs to be able to flex off upwind to exhaust the wind we cant
use.....right?
But surely it also needs to bend in a forwards motion with the kite (even
though it limits the efficiency of the main) because otherwise, if the Kite
loads up (without self depowering from the mast flexing forwards) then
the boat will spin up to wind (broaching)...... So where exactly is the
inefficiency?

It self depowers the main upwind and then downwind when the kite
becomes more important than the main, it self depowers the kite.

So what am I missing??

Doug H

You are missing nothing!  It works very well

Rodney
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Posts: 4028 		Post Options Post Options   Quote G.R.F. Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 09 at 4:31pm
Originally posted by Phil eltringham

Ok, I've avoided rushing into this reply, .. tongue in cheek, and perhaps a little facetious, ....however
it worries me that people will take it to be true when your scientific basis is wrong. ....moaning......



Why does it always have to be 'moaning' with me? It's not moaning it's a different perspective contary to the view
you are trying to 'sell/pimp' get over it, don't be so thin skinned...

Originally posted by Phil eltringham

For your first comments on the D-One rig we first need to consider two things, firstly the shot was
taken, in what looks like a decent breeze, some of your friends are out in the background so it must be north of 20 knots, i.e.:
the top end of the boats operating range, and secondly, it is a photo - a single moment in time, and is with limited context and
thus only viable for the most basic of analysis. 


I disagree, it was precisely because there appeared to be so little wind yet the rig was so distorted which prompted
the observation, the rest of this has blown up over the attempts of character assassination by the various parties with vested
interest in the sale of this and other craft, which in turn raises the level of the debate and the spectre of commercial pressure on
a rider/owner/customer forum. I believe the wind in the particular photo reprinted above to be no more than 15knots


Originally posted by Phil eltringham


You question the need for the upper roach on the mainsail leech when it is twisted off and the mast is bending forwards of its
upwind position and to leeward.  There are a number of reasons for this. Firstly being at the top end of the wind range it is
designed for it will be bending significantly, now that is not to say it cannot be engineered to deal with higher winds, but if that
is not the design brief then it cannot be said to be a failure if it does not do something it is not required to do.


I didn't question the need, I questioned the resulting application. The design brief I had always assumed is another
boat for lard boys, hence the need for the big sail. My feeling is, lard boys need a stiffer mast and so does that boat.


Originally posted by Phil eltringham


Secondly the kite will have a major impact on the onset flow around the mainsail.  If nothing else given that the kite is fractional
(not mast head) the apparent wind angle at the head will be significantly different than lower down the main where there is a
more significant interaction with the flow from the kite.  Thirdly, the extra sail area in the upper roach is used upwind far more
than downwind, the kite more than doubles the total sail area, and the total amount bladed off will be less than a square meter
by the looks of it, this will simply sit in line with the flow around it, not creating much if any driving force, but also having a
minimal drag effect.  Fourthly, the main, is as much about balancing the helm once the kite is up as it is about creating driving
force, the driving force from the kite will be significantly higher than the main, the point of having the extra sail (the kite), is
because its the one doing all the work.  However, going back to my earlier point about interaction between sails, the two sails
together are more than the sum of their parts.  They create a single composite lifting body. 

Don't think there's anything there I would actually disagree with you about.

Originally posted by Phil eltringham


Next you comment that the mast is "bent out of shape".  Out of which shape? It’s upwind shape, its static shape, its unloaded
shape? Of course it will be, it has a kite flying off it and it has less mainsheet induced leech tension as it has been eased
for a start. 

Well here you seem to be agreeing with me? It's bent out of shape - so now honest answer now, would you prefer it
as it is, or not so bendy - given you'd just spent close to ten grand for it?


[QUOTE=Phil eltringham]
(I am trying to work through your points in order, ) followed by lots of stuff about windsurf rigs largely irrelevant to the nub of
the matter which is an answer to the question above[/quote}

We can go round and round in circles, you ladies can try and compromise my credibility in order to defend your
boat, I will continue to point out the failings of all and every boat I come across in an effort to encourage a better product and I'd
certainly like better service. As I see it, I'm the one spending the twenty grand every couple of years or so.. And you all are
tolerating poor value for money..

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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 09 at 4:33pm
Rodney

I believe a while ago I was very hesitant about a not stayed rig with an
assymetric (I'm sure I posted something on the D-one thread) because if
you were to dosedive, thus suffering a MASS DEceleration, that mast
wouldn't be able to cope and would snap.

However I realize that a mast that flexes downwind can help the drive
forward by avoiding broaching (or avoid massive steering to avoid
broaching) and so makes sense.

But I'm intrigued to hear G.R.F's objections to this...... I may end up
agreeing with him.

Doug H
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Posts: 4028 		Post Options Post Options   Quote G.R.F. Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 09 at 4:40pm
Originally posted by Doug.H

G.R.F

I'm not that smart so I'm gonna go simple.
The rig needs to be able to flex off upwind to exhaust the wind we cant
use.....right?
But surely it also needs to bend in a forwards motion with the kite (even
though it limits the efficiency of the main) because otherwise, if the Kite
loads up (without self depowering from the mast flexing forwards) then
the boat will spin up to wind (broaching)...... So where exactly is the
inefficiency?

It self depowers the main upwind and then downwind when the kite
becomes more important than the main, it self depowers the kite.

So what am I missing??

Doug H


Basically doug there are other ways to 'flex off and depower the sail"
without having a flex top mast, it can be done with a stiff mast. Funnily
enough like one of the sails I have on the Alto.
And the boat has other levels of expensive sophistication, like the
traveller, why go to the extent of all that, then put a bendy rig on it?

Spoiled for a happorth of tar I guess is what I'm saying.
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 09 at 4:56pm
Stiff or floppy rig I'd still like a traveller on a singlehander.
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Posts: 915 		Post Options Post Options   Quote rodney Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 09 at 5:09pm
Originally posted by G.R.F.

Originally posted by Phil eltringham

Ok, I've avoided rushing into this reply, .. tongue in cheek, and perhaps a little facetious, ....however
it worries me that people will take it to be true when your scientific basis is wrong. ....moaning......



Why does it always have to be 'moaning' with me? It's not moaning it's a different perspective contary to the view
you are trying to 'sell/pimp' get over it, don't be so thin skinned...

Originally posted by Phil eltringham

For your first comments on the D-One rig we first need to consider two things, firstly the shot was
taken, in what looks like a decent breeze, some of your friends are out in the background so it must be north of 20 knots, i.e.:
the top end of the boats operating range, and secondly, it is a photo - a single moment in time, and is with limited context and
thus only viable for the most basic of analysis. 


I disagree, it was precisely because there appeared to be so little wind yet the rig was so distorted which prompted
the observation, the rest of this has blown up over the attempts of character assassination by the various parties with vested
interest in the sale of this and other craft, which in turn raises the level of the debate and the spectre of commercial pressure on
a rider/owner/customer forum. I believe the wind in the particular photo reprinted above to be no more than 15knots


Originally posted by Phil eltringham


You question the need for the upper roach on the mainsail leech when it is twisted off and the mast is bending forwards of its
upwind position and to leeward.  There are a number of reasons for this. Firstly being at the top end of the wind range it is
designed for it will be bending significantly, now that is not to say it cannot be engineered to deal with higher winds, but if that
is not the design brief then it cannot be said to be a failure if it does not do something it is not required to do.


I didn't question the need, I questioned the resulting application. The design brief I had always assumed is another
boat for lard boys, hence the need for the big sail. My feeling is, lard boys need a stiffer mast and so does that boat.


Originally posted by Phil eltringham


Secondly the kite will have a major impact on the onset flow around the mainsail.  If nothing else given that the kite is fractional
(not mast head) the apparent wind angle at the head will be significantly different than lower down the main where there is a
more significant interaction with the flow from the kite.  Thirdly, the extra sail area in the upper roach is used upwind far more
than downwind, the kite more than doubles the total sail area, and the total amount bladed off will be less than a square meter
by the looks of it, this will simply sit in line with the flow around it, not creating much if any driving force, but also having a
minimal drag effect.  Fourthly, the main, is as much about balancing the helm once the kite is up as it is about creating driving
force, the driving force from the kite will be significantly higher than the main, the point of having the extra sail (the kite), is
because its the one doing all the work.  However, going back to my earlier point about interaction between sails, the two sails
together are more than the sum of their parts.  They create a single composite lifting body. 

Don't think there's anything there I would actually disagree with you about.

Originally posted by Phil eltringham


Next you comment that the mast is "bent out of shape".  Out of which shape? It’s upwind shape, its static shape, its unloaded
shape? Of course it will be, it has a kite flying off it and it has less mainsheet induced leech tension as it has been eased
for a start. 

Well here you seem to be agreeing with me? It's bent out of shape - so now honest answer now, would you prefer it
as it is, or not so bendy - given you'd just spent close to ten grand for it?


[QUOTE=Phil eltringham]
(I am trying to work through your points in order, ) followed by lots of stuff about windsurf rigs largely irrelevant to the nub of
the matter which is an answer to the question above[/quote}

We can go round and round in circles, you ladies can try and compromise my credibility in order to defend your
boat, I will continue to point out the failings of all and every boat I come across in an effort to encourage a better product and I'd
certainly like better service. As I see it, I'm the one spending the twenty grand every couple of years or so.. And you all are
tolerating poor value for money..

What on Earth are you on about??  In my mind you have overstepped the mark!

We don't know Phil and have never met him so any implication to that effect is potentially defamatory!  Having said that I wish he were on our team as his obvious knowledge puts yours to shame!

Incidental I have a question.  When you use the term 'lards' is that meant to be derogatory or just a way of describing people  heavier than yourself?  I know most of the top Finn sailors in the World and I could never describe them as lards - in fact most of them, probably, have less lard than you.

Do us all a favour and come to Mengeham, on the 5th December, to try what you are determined to try and constantly knock - commercial interest maybe?  Declare it, I do!

Have a nice evening.

Rodney

PS Tim still has a few things to learn about sailing the D-One and the picture should help him to get a few more things right.  Tim will be with us for some coaching soon to help get the finer points of getting the best out of the D-One.  Bring your Blaze and we can coach you as well!
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Posts: 915 		Post Options Post Options   Quote rodney Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 09 at 5:14pm

Originally posted by G.R.F.

Originally posted by Doug.H

G.R.F

I'm not that smart so I'm gonna go simple.
The rig needs to be able to flex off upwind to exhaust the wind we cant
use.....right?
But surely it also needs to bend in a forwards motion with the kite (even
though it limits the efficiency of the main) because otherwise, if the Kite
loads up (without self depowering from the mast flexing forwards) then
the boat will spin up to wind (broaching)...... So where exactly is the
inefficiency?

It self depowers the main upwind and then downwind when the kite
becomes more important than the main, it self depowers the kite.

So what am I missing??

Doug H


Basically doug there are other ways to 'flex off and depower the sail"
without having a flex top mast, it can be done with a stiff mast. Funnily
enough like one of the sails I have on the Alto.
And the boat has other levels of expensive sophistication, like the
traveller, why go to the extent of all that, then put a bendy rig on it?

Spoiled for a happorth of tar I guess is what I'm saying.

ER!  You've missed something!  Bendy mast and traveller are the only way to go - silly question.  Come and meet us face to face and I will explain - 5th december - remember?

Rodney
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Posts: 4028 		Post Options Post Options   Quote G.R.F. Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 09 at 5:34pm
Originally posted by rodney


What on Earth are you on about??  In my mind you have overstepped
the mark!



Your mind Rodney is entirely compromised by your vested self interest.

This is a forum for sailors to discuss and express opinions (right or
wrong) form them, debate them, argue them.

Some of us can do that completely objectively because we enjoy no
commercial subjectivity - you can't.

Your job is to go back to the viral marketing manual under the heading

"Pimping products" for free.

and the sub heading.."Dangers of engaging in arguments on forums"

and take a deep breath.

Then ring up Luca and say "Oh Luca what are we going to do someones
spotted the problem with the rig how can we fix it?"



Edited by G.R.F.
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 22 Nov 09 at 5:41pm
To some level I agree with G.R.F on that Rodney.

If I've got questions about the D-One, you're the guy I'm going to come
to. However I'm always careful not to take anything on face value from
the guy selling the product.
Listing any faults with the boat would be a mistake on your part and
rightly so. However, I like others do want to know what the faults might
be and as much as in my eyes the rig seems to work quite well under the
conditions it has to perform, I'm intrigued to see it from the other side
that GR.F is presenting.

G.R.F.....the only issue is, at the moment I can't quite see the logic to the
side you're presenting.

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