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A new class of dinghy?

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    Posted: 21 Sep 18 at 7:00pm
29er and the original 49er rigs had GRP top sections (the last metre or so I think).  The idea being to have something cheap and flexible at the top, so that the head of the sail blades off automatically in gusts.  "The Automatic Rig" according to the Bethwaite clan.  Carbon I guess does the same if carefully constructed with the right taper; but probably still costs more.
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Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 21 Sep 18 at 7:38pm
Originally posted by Old Timer

Advertising daft high prices then discounting heavily every sale isn’t a very smart marketing practice. 

Just think of all those potential customers put off by the high price who never even started the negotiations. 

^ this...
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Post Options Post Options   Quote maxibuddah Quote  Post ReplyReply Direct Link To This Post Posted: 21 Sep 18 at 7:56pm
Originally posted by Sam.Spoons

Originally posted by Old Timer

Advertising daft high prices then discounting heavily every sale isn’t a very smart marketing practice. 

Just think of all those potential customers put off by the high price who never even started the negotiations. 

^ this...

Works for DFS 

Admittedly I do know someone who actually bought a sofa when the DFS sale wasn't on
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Post Options Post Options   Quote RS400atC Quote  Post ReplyReply Direct Link To This Post Posted: 21 Sep 18 at 7:59pm
Originally posted by NickA

29er and the original 49er rigs had GRP top sections (the last metre or so I think).  The idea being to have something cheap and flexible at the top, so that the head of the sail blades off automatically in gusts.  "The Automatic Rig" according to the Bethwaite clan.  Carbon I guess does the same if carefully constructed with the right taper; but probably still costs more.

Likewise the old B14 rig.
The mast is supposed to stay in the same, fixed curve below the forestay, above that it responds to gusts.
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Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 21 Sep 18 at 8:02pm
Originally posted by JimC

Originally posted by 423zero

The technical specification of the 'Spectrum' states top section of mast is GRP, never come across this in dinghies, does it work ? And is it heavy at top of mast ?

Not unknown, but not much advantage, except in high tension overhead wire areas. Carbon is so much better.


Plenty of topmasts with a mix of glass and carbon, to get the right mast bend, not to be cheap. Windsurfer masts, too.
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Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 21 Sep 18 at 8:07pm
Windsurfing masts were all glass back in the day with just a few, expensive, aluminium race masts (I had a couple in my Div 1 days) available but gradually carbon content increased with even budget masts having 30% carbon and race masts being 100% carbon (and I still have a few of those) and cost was almost proportional to the carbon content.......
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Post Options Post Options   Quote Chris 249 Quote  Post ReplyReply Direct Link To This Post Posted: 21 Sep 18 at 9:09pm
Originally posted by mozzy

LOL You mean read loads of marketing crap in boards, then buy the one with most garish design and pull the down-haul on as tight as they can? 

Yep, and then run around saying "you've got to rig it just like Bjorn" while ignoring the fact that in the same conditions they were using a 5m and having to accelerate from almost stopped every gybe, he was using a 7m, planing at full tilt all the time, and sailing with twice the apparent windspeed.

I'm always rather depressed by the attitude of windsurfers towards boat sails. The windsurfers have no idea that boat sails can be about one third of the weight for their size, and commonly have a vastly greater range. Oddly enough it appears that the original dacron Windsurfer sail is about 50% of the weight, or less, of the modern sails, and it has greater lift, as well as much higher drag and handling issues. For all its advances in some ways, in other ways windsurfing has gone backwards.


Edited by Chris 249 - 21 Sep 18 at 9:34pm
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Post Options Post Options   Quote Chris 249 Quote  Post ReplyReply Direct Link To This Post Posted: 21 Sep 18 at 9:33pm
Originally posted by Old Timer

 
I know Frank was highly educated pilot & meteorologist; is Julian similarly educated?

I had great respect for Frank as a person, but I'm 99.9999% sure he didn't go to higher education, or if he started he certainly didn't finish it because of WW2. Sadly, I understand from someone who knew him better than I did that all his life, he felt that he had missed out badly because of his lack of higher formal education. Perhaps that's why although he had many great insights, he also had a tendency to bend evidence to fit the conclusion he desired.

Julian did a couple of years at uni. As Jim mentioned, his older brother Mark is a (very successful) engineer who actually designed the Tasar's underwater sections and is a major influence on Julian's approach. All very pleasant, well mannered and interesting people.
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Post Options Post Options   Quote Chris 249 Quote  Post ReplyReply Direct Link To This Post Posted: 21 Sep 18 at 9:58pm
Originally posted by A2Z

On the other hand, you’ll be hard pressed to find a cat without one.

Yep, but for what it's worth, as a cat and dinghy sailor it seems that cats have very different dynamics because of their different drag, stability and handling. Their long and low-drag hulls, for example, mean that sails can be tall and flat and therefore you only need a tiny bit of mast bend to flatten them out. Getting a wingmast to bend enough to depower the fuller sails you need to drive a mono is a major issue, as many people have found out. 

As Jim says, modern research has shown that pole masts are much more effective than we thought. It's interesting to see that the influential early Marchaj wind tunnel tests used ludicrously over-sized round masts, of 10% of foot length or more. Such tests seem to have given a spuriously scientific aura to the idea that wingmasts were much more efficient, despite the fact that they were proven time and time again to be of little, if any, real value.

It's interesting that there's a really deep-seated belief in our sport that there are some conservative forces that hold back true development. At the moment I've got Higher Performance Sailing open in the history section, where we see time and time again such claims. Almost none of them are actually backed up by the true historical record, and that sort of thing is reflected all through our sport. There are lots of silly claims about how wingmasts were banned from racing, for example. That sort of myth makes it hard to assess where sailing technology can take new classes. 






Edited by Chris 249 - 21 Sep 18 at 10:09pm
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Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 21 Sep 18 at 10:10pm
Originally posted by Chris 249

Originally posted by mozzy

LOL You mean read loads of marketing crap in boards, then buy the one with most garish design and pull the down-haul on as tight as they can? 

Yep, and then run around saying "you've got to rig it just like Bjorn" while ignoring the fact that in the same conditions they were using a 5m and having to accelerate from almost stopped every gybe, he was using a 7m, planing at full tilt all the time, and sailing with twice the apparent windspeed.

I'm always rather depressed by the attitude of windsurfers towards boat sails. The windsurfers have no idea that boat sails can be about one third of the weight for their size, and commonly have a vastly greater range. Oddly enough it appears that the original dacron Windsurfer sail is about 50% of the weight, or less, of the modern sails, and it has greater lift, as well as much higher drag and handling issues. For all its advances in some ways, in other ways windsurfing has gone backwards.

Windsurfing sails and boards were at the "cutting edge" and usually took design concepts to extremes with (often) marketing led concepts like cutaways and dedicated slalom boards. They often had their merits in less extreme forms but there always had to be a "new big thing' every year to give the marketing guys something to get there teeth into. Luckily not all modern windsurfing sail designers have followed the trend http://www.demonsails.co.uk I used these for nearly all my Raceboard sailing years, I still have my last VG5 7.5. Absolutely brilliant sails, fast and super light. It's interesting that the sailcloth they use is more commonly used in dinghy and small keelboat sails.


Edited by Sam.Spoons - 21 Sep 18 at 10:17pm
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