Arnaldo

There is nothing illogical about wanting to have control over the shape/foil of your sail under as wide a range of conditions as possible. Just because the sail material has less stretch does not say the sail doesn’t move…the whole point is to control the movement…to have it attain and retain the designed shape…not just randomly respond to the conditions.

A hypothesis is one thing…real world sailing is a different proposition. When a sailor’s career lives and dies on his/her race results, they are going to use the fastest equipment they can get their hands on. Windsurfing has never been shy about taking on the most radical ideas and putting them to the test. If your design ideas are all that you purport them to be we should be seeing a shift to more flexible sail material in the future. Good luck. It sounds an awful lot like 1985 technology to me.

Personally I have been hard core windsurfing for 26 years, I have used all the different type sails that I spoke of earlier. There is no way you can equate a top of the line soft sail design that was popular when I started with a top of the line sail of today...been there done that!

I designed and built high performance sailboards (till about 2000) that hung in there with just about anyone’s with an equivalent rider. All my attention was on performance increases… board, fin, sails, masts, booms and the interaction between them, getting the feedback first hand...Bottom line is …The only thing that counts, is performance on the water…all the rest is just batting the breeze…regardless of who it comes from. Show me measurable advantage in real world conditions (against the industry standards) and then I will consider adopting your position.

Bob

Gee, Sharky, look what you started. I went back to your original question and noticed it doesn't say what kind of boat you sail.
Remember, on some boats (like mine) you can change the shape of your sail with enough downhaul to bend the mast. If you are using dacron, you have to be careful not to rip the sail in half with a 16:1 downhaul. It doesn't seem to be an issue with the Pentex. (yet) I just got new square-top Pentex sails for my P19. They're great.
My opinion is: Pick your sailmaker, then follow their suggestions on fabric.

Edited translation of Arnaldo's reply:



Cheers,

<<”Basically, sails with variable geometry require a good eye and active trimming. Many of the resources that my sails use wouldn't make sense in a windsurfer. This is the exact reason why windsurfers evolved into a system that modifies the sail shape more or less automatically.”

What I am beginning to see here is, this is as much a philosophy of what sailing entails, as it is a discussion of sail design. I see setting a preshaped sail with stiffer sail material, one, which automatically adjusts in the gusts and maintains its designed airfoil as a major advance and advantage to sailors who want to concentrate on maximum performance. Call it the KIS principal (if you add the second S you are making it too complicated). If major portions of sail trim can be automatic, that frees the sailor/sailors up to concentrate on other aspects of performance. It is not as if there are not enough duties in sailing fast to fill your time. It is in no way an autopilot. It just takes some of the variables out of the equation to bring the whole performance level up a notch or two across the board, it might help to close the gap a bit for those who are not “Rock Stars” of sailing. Heaven forbid… it might make it a little more enjoyable…

I cannot understand why sailing is always binding itself with artificial restraints. Some where along the line... the goal of building the fastest boat/sail took the back seat to self-imposed rules, and the fascination of making things more complex for no other reason than to make it more complex…as if doing things the hard way is something to be admired and embraced as “better” “more noble” or a sign of greater skill.

<<”This system, however optimal for windsurfers, doesn't seem to have real possibilities to work reliably in a bigger boat. The closer matches to be found here (and with many restrictions) are in the Moth or in the old Finn. But the manual trimming is not abandoned, even in this cases.”

Why not? Bigger boats? Most of the Cat Sailors on this forum sail boats that are between 14'-22'long. What are you including when you say trimming?
The windsurfer still sheets in and out…When he/she rakes the sail back and closes off the foot…isn’t that some what comparable to playing the main sheet line and the traveler? What about some of the racers using adjustable outhaul? Down Haul? How much more do you want tweak?
Don’t get me wrong…I don’t want to take away your lines to adjust this and that endlessly…if that’s where you get your joy far be it from me to rain on your parade.
Just a different philosophy…there is plenty of room for both approaches.

<<”That's why you are correct only with regards to windsurfers and not to bigger boats.”

<<”One detail: the technology does look with that of a 1985 windsurfer, but while windsurfers basically stopped there, we have evolved for another 20 years.”

I think it is just the opposite…Windsurfing has always been very tech driven…the rebel…the cutting edge…no rules…absolutely rabid about performance increases. Because of this mentality and the ability to crank out so many proto types due to the smaller size and lower cost (when compared to sails for most boats). In its hay day, Windsurfing Sail design was evolving so fast that a sail over a year old was no longer competitive, all other things being equal. In some cases the new sail designs were so much faster and controllable that a decent average short boarder could hang with, and sometime out run a more experienced rider (in a straight line) for no other reason than a superior sail design just one generation newer. Can you say that about Cat Sails year after year?

I would have to respectfully disagree with your statement that soft sails for boats have evolved for anther twenty years, while windsurfing stopped there. I would be more inclined to say that soft sails were one of the first stepping stones to be used by the windsurfing industry but they quickly evolved to more and more advanced rigs in an effort to satisfy the hunger for faster sails that covered a wider wind range and were more controllable/less tempermental.

Unlike "most" of the boat building community … which seems to say, “this is what you’re going to get and your going to like it!”

… Windsurfing was/is very consumer driven…and extremely responsive. A company would come out with a sail or board, and before it even hit the market they were finishing up the testing of the next generation, addressing as many issues as possible that the market brought to light. The improvements were/are amazing. And while many in the windsurfing community have defected to Kite Sailing, or moved on to other sports, to ignore the lessons learned in the accelerated R&D within the Windsurfing community would truly be a crime.

One interesting spin off from this discussion has been to remind me of Dave Calvert’s expertise in designing both Windsurfing sails (He was building some world class smoking fast race sails) and the Catamaran community…It puts him in a unique position, and the logical choice to go to when new sails are needed. (By the way I have never met Dave…but I do know his work…it speaks for itself…on the water…where it counts.)

Bob Hall

<<”Basically, sails with variable geometry require a good eye and active trimming. Many of the resources that my sails use wouldn't make sense in a windsurfer. This is the exact reason why windsurfers evolved into a system that modifies the sail shape more or less automatically.” What I am beginning to see here is, this is as much a philosophy of what sailing entails, as it is a discussion of sail design. I see setting a preshaped sail with stiffer sail material, one, which automatically adjusts in the gusts and maintains its designed airfoil as a major advance and advantage to sailors who want to concentrate on maximum performance. Call it the KIS principal (if you add the second S you are making it too complicated). If major portions of sail trim can be automatic, that frees the sailor/sailors up to concentrate on other aspects of performance. It is not as if there are not enough duties in sailing fast to fill your time. It is in no way an autopilot. It just takes some of the variables out of the equation to bring the whole performance level up a notch or two across the board, it might help to close the gap a bit for those who are not “Rock Stars” of sailing. Heaven forbid… it might make it a little more enjoyable… I cannot understand why sailing is always binding itself with artificial restraints. Some where along the line... the goal of building the fastest boat/sail took the back seat to self-imposed rules, and the fascination of making things more complex for no other reason than to make it more complex…as if doing things the hard way is something to be admired and embraced as “better” “more noble” or a sign of greater skill. <<”This system, however optimal for windsurfers, doesn't seem to have real possibilities to work reliably in a bigger boat. The closer matches to be found here (and with many restrictions) are in the Moth or in the old Finn. But the manual trimming is not abandoned, even in this cases.” Why not? Bigger boats? Most of the Cat Sailors on this forum sail boats that are between 14'-22'long. What are you including when you say trimming? The windsurfer still sheets in and out…When he/she rakes the sail back and closes off the foot…isn’t that some what comparable to playing the main sheet line and the traveler? What about some of the racers using adjustable outhaul? Down Haul? How much more do you want tweak? Don’t get me wrong…I don’t want to take away your lines to adjust this and that endlessly…if that’s where you get your joy far be it from me to rain on your parade. Just a different philosophy…there is plenty of room for both approaches. <<”That's why you are correct only with regards to windsurfers and not to bigger boats.” <<”One detail: the technology does look with that of a 1985 windsurfer, but while windsurfers basically stopped there, we have evolved for another 20 years.” I think it is just the opposite…Windsurfing has always been very tech driven…the rebel…the cutting edge…no rules…absolutely rabid about performance increases. Because of this mentality and the ability to crank out so many proto types due to the smaller size and lower cost (when compared to sails for most boats). In its hay day, Windsurfing Sail design was evolving so fast that a sail over a year old was no longer competitive, all other things being equal. In some cases the new sail designs were so much faster and controllable that a decent average short boarder could hang with, and sometime out run a more experienced rider (in a straight line) for no other reason than a superior sail design just one generation newer. Can you say that about Cat Sails year after year? I would have to respectfully disagree with your statement that soft sails for boats have evolved for anther twenty years, while windsurfing stopped there. I would be more inclined to say that soft sails were one of the first stepping stones to be used by the windsurfing industry but they quickly evolved to more and more advanced rigs in an effort to satisfy the hunger for faster sails that covered a wider wind range and were more controllable/less tempermental. Unlike "most" of the boat building community … which seems to say, “this is what you’re going to get and your going to like it!” … Windsurfing was/is very consumer driven…and extremely responsive. A company would come out with a sail or board, and before it even hit the market they were finishing up the testing of the next generation, addressing as many issues as possible that the market brought to light. The improvements were/are amazing. And while many in the windsurfing community have defected to Kite Sailing, or moved on to other sports, to ignore the lessons learned in the accelerated R&D within the Windsurfing community would truly be a crime. One interesting spin off from this discussion has been to remind me of Dave Calvert’s expertise in designing both Windsurfing sails (He was building some world class smoking fast race sails) and the Catamaran community…It puts him in a unique position, and the logical choice to go to when new sails are needed. (By the way I have never met Dave…but I do know his work…it speaks for itself…on the water…where it counts.) Bob Hall