Thanks for all in the insight and ideas… Now that we have covered many ways of creating flex now we need to regroup. Remember i want to keep this project within a cost effective manner. I have been giving it a lot of thought on the most cost effective way to build it using standard materials. I still think using the flat deck staying thin 2 to 2 1/8 thick with a flatter rocker using a 6’0R fish blank superlite. That should give me good overall flex thru out the board. Building flex into the tail from about 16" up from the tail but keeping the tail thick to compensate for the removel of foam along the rail in the tail… I believe i can get the flex i’m looking for with less flex then what we all wanted back in the 70’s. Boards are smaller and materials better then 30 years ago. With tris we gained more drive now i’m looking to gain a little more snap from a fish. I believe i can build a flextail that will be light 7 pounds. I do think Rusty has the right idea bit he isn’t getting the flex he could if he added flex in that last 16" of the tail. I think he has covered flex thruout the board but i’m looking to create more off the tail. I want the perfect small wave board for 2 to 4 foot surf… Questions?? A light Carbon fiber cloth in the tail section will it add more flex with less cloth then a standard e-cloth??? it should i would think. Leaving a small amount of foam along the rail ( but removing foam between the pin tail and the flex tail outline) thru the tail to the tip of the SW wouldn’t it stiffen the flex but allow for less cloth and less weight??? Plus no death edge to deal with thru the tail?? Shaping in about -3/16 rocker in the last 4" of the tail should help with load to add more snap… I just want to keep this design easy to build within reason… I plan to build to boards same but one being a flex and the other standard to get a feel for the flex… Thanks to all of you…
Thanks for all in the insight and ideas…>>> Now that we have covered many ways of creating flex now we need to > regroup.>>> Remember i want to keep this project within a cost effective manner. I > have been giving it a lot of thought on the most cost effective way to > build it using standard materials.>>> I still think using the flat deck staying thin 2 to 2 1/8 thick with a > flatter rocker using a 6’0R fish blank superlite. That should give me good > overall flex thru out the board.>>> Building flex into the tail from about 16" up from the tail but > keeping the tail thick to compensate for the removel of foam along the > rail in the tail…>>> I believe i can get the flex i’m looking for with less flex then what we > all wanted back in the 70’s. Boards are smaller and materials better then > 30 years ago. With tris we gained more drive now i’m looking to gain a > little more snap from a fish.>>> I believe i can build a flextail that will be light 7 pounds. I do think > Rusty has the right idea bit he isn’t getting the flex he could if he > added flex in that last 16" of the tail. I think he has covered flex > thruout the board but i’m looking to create more off the tail. I want the > perfect small wave board for 2 to 4 foot surf…>>> Questions??>>> A light Carbon fiber cloth in the tail section will it add more flex with > less cloth then a standard e-cloth??? it should i would think.>>> Leaving a small amount of foam along the rail ( but removing foam between > the pin tail and the flex tail outline) thru the tail to the tip of the SW > wouldn’t it stiffen the flex but allow for less cloth and less weight??? > Plus no death edge to deal with thru the tail??>>> Shaping in about -3/16 rocker in the last 4" of the tail should help > with load to add more snap…>>> I just want to keep this design easy to build within reason…>>> I plan to build to boards same but one being a flex and the other standard > to get a feel for the flex…>>> Thanks to all of you… Carbonfiber will add rigidity to the tail. The reason many boats are using carbon fiber is to maximize the stiffness of the hull. They need really rigid platform to tune the rig and sails from. If you want shear strength without adding too much rigidity use a very light schedule of kevlar.
Sorry if this bursts anyone`s bubble, but these are the ground rules for exploring flex in a relevant manner: 1) Unending perseverance, time/labor & financial resources. 2) Ready access to a wide variety of uncrowded quality waves. 3) The intelligence, experience & skill to interpret & fully exploit (both in the water & the shop) all of the above. P.S. When you think “flex”, think “years.” Attempting to sort out the complex variables of this subject, with any less commitment, is nothing more than a crap shoot in the dark.
This is true that’s why i’m willing to try… #1 I’m still building boards after 30 some years?? Thats Perseverance!!! money is a small part of it as i have found out… #2 Washington coast gets waves year round and most uncrowded surf you will find, Westport being the best testing waters i’ve lived and i have lived all over… A true shortboard builders nirvana… #3 With about 40 years of wave riding and at 48 still riding shortboards still. Plus as much back ground in board building as just about anyone I feel i understand design. Plus i know how to interpert what i feel when i ride what i build. Intelligence??? I’m still trying to make a living building boards so i guess i’m not so intelligent??? PS>>>>>>> You have to start someplace and Swaylocks is the place to start… Anyplace else is a BIG CRAP SHOOT!!! It’s all about surfing and being happy with what you do!! Not what others think. Thanks for the insight…>>> Sorry if this bursts anyone`s bubble, but these are the ground rules for > exploring flex in a relevant manner:>>> 1) Unending perseverance, time/labor & financial resources.>>> 2) Ready access to a wide variety of uncrowded quality waves.>>> 3) The intelligence, experience & skill to interpret & fully > exploit (both in the water & the shop) all of the above.>>> P.S. When you think “flex”, think “years.” Attempting > to sort out the complex variables of this subject, with any less > commitment, is nothing more than a crap shoot in the dark. http://surfnwsc.com
Rob, Somebody correct me if I’m wrong but I believe that Greenough discovered that he could get more flex in his fins by having the cloth weave laid up on the diagonal. Keep this in mind as the foam dissappears and you begin to lay up the tail. I wonder what kind of a fin set up your going to glass on to this baby? Mahalo, Rich
Rob,>>> Somebody correct me if I’m wrong but I believe that Greenough discovered > that he could get more flex in his fins by having the cloth weave laid up > on the diagonal. Keep this in mind as the foam dissappears and you begin > to lay up the tail.>>> I wonder what kind of a fin set up your going to glass on to this baby?>>> Mahalo, Rich Rich i hope to use FCS the only place i see it being a problem is the trailing fin… Because of the the way i plan to remove foam from the tail i hope to have the room… If not Glass ons but then again i wonder how much the fin lay up will play in flex in the back fin??? I know if i lay up with a good tear drop patches it shouldn’t screw with flex in the last part of the tail. Because the trailing fin is set only about 3 1/2" from the tail i feel that i may have a problem with stress on my back fin… Stress on plugs or glassons on my side shouldn’t be a problem… I’m glad you brought up the cloth weave and running it diagonal that would make a difference… Good point. http://surfnwsc.com
One of the best flextail surfboards that I had ever seen was made by Michell Rae in Australia. That guy is one of the best.>>> Sorry if this bursts anyone`s bubble, but these are the ground rules for > exploring flex in a relevant manner:>>> 1) Unending perseverance, time/labor & financial resources.>>> 2) Ready access to a wide variety of uncrowded quality waves.>>> 3) The intelligence, experience & skill to interpret & fully > exploit (both in the water & the shop) all of the above.>>> P.S. When you think “flex”, think “years.” Attempting > to sort out the complex variables of this subject, with any less > commitment, is nothing more than a crap shoot in the dark.
Because the trailing fin is set only about 3 1/2" from the tail i feel that i may have a problem with stress on my back fin… Stress on plugs or glassons on my side shouldn’t be a problem… Rob, The last generation of Greenough spoons has NO flex running down the center line. In fact, the thickest part of the center spine was at the trailing edge of the fin. What he discovered was that getting the corners to bend up in a turn are what’s paramount. By corners bending up, I mean inches of flex, not 1/4" or 1/2" like most glass spoons. The corners have to get out of the way in a turn with virtually no effort. The rest of the tail is so stiff, that it compensates for the soft flex. Believe me, it works. The bend in the corners should lead the board into a turn, not merely respond to the rider pushing on it. The rest of the board provides the drive. Your task is somewhat different than that of a spoon kneeboard, but the general lesson should be the same, I think. If it were my board, I would build up around the fin area with lots of thickness for stiffness and flotation (like the McTavish flex tail), then taper out the corners to either very thin foam or solid glass. I would also use a combination of a slightly wider square tail and slightly less rocker, then compensate for both with flex in the corners. The benefits are numerous, with no drawbacks in the water, assuming you can keep your flotation. George’s 5’ x 18.75" wide edge boards had 15" tails a foot up and 11" wide tails at the very back. Very, very straight in the rear two feet…virtually identical to a Lis Fish in curve and proportions.
Thanks for all in the insight and ideas…>>> Now that we have covered many ways of creating flex now we need to > regroup.>>> Remember i want to keep this project within a cost effective manner. I > have been giving it a lot of thought on the most cost effective way to > build it using standard materials.>>> I still think using the flat deck staying thin 2 to 2 1/8 thick with a > flatter rocker using a 6’0R fish blank superlite. That should give me good > overall flex thru out the board.>>> Building flex into the tail from about 16" up from the tail but > keeping the tail thick to compensate for the removel of foam along the > rail in the tail…>>> I believe i can get the flex i’m looking for with less flex then what we > all wanted back in the 70’s. Boards are smaller and materials better then > 30 years ago. With tris we gained more drive now i’m looking to gain a > little more snap from a fish.>>> I believe i can build a flextail that will be light 7 pounds. I do think > Rusty has the right idea bit he isn’t getting the flex he could if he > added flex in that last 16" of the tail. I think he has covered flex > thruout the board but i’m looking to create more off the tail. I want the > perfect small wave board for 2 to 4 foot surf…>>> Questions??>>> A light Carbon fiber cloth in the tail section will it add more flex with > less cloth then a standard e-cloth??? it should i would think.>>> Leaving a small amount of foam along the rail ( but removing foam between > the pin tail and the flex tail outline) thru the tail to the tip of the SW > wouldn’t it stiffen the flex but allow for less cloth and less weight??? > Plus no death edge to deal with thru the tail??>>> Shaping in about -3/16 rocker in the last 4" of the tail should help > with load to add more snap…>>> I just want to keep this design easy to build within reason…>>> I plan to build to boards same but one being a flex and the other standard > to get a feel for the flex…>>> Thanks to all of you… Somewhere around 1979 I met a guy in a coffee shop in Santa Monica who was sitting in the waiting area with a surfboard. He told me he was waiting for somebody from the surfing industry that he was to show this new mechanical flex tail surfboard he had designed. My memory is vague, but I recall it looked pretty sophisticated and he was really passionite about it, yet frustrated in his attempts to get the industry to buy into it. Could there be a mechanical solution to tail flex laying in the rafters of some dog town garage?
Somewhere around 1979 I met a guy in a coffee shop in Santa Monica who was > sitting in the waiting area with a surfboard. He told me he was waiting > for somebody from the surfing industry that he was to show this new > mechanical flex tail surfboard he had designed. My memory is vague, but I > recall it looked pretty sophisticated and he was really passionite about > it, yet frustrated in his attempts to get the industry to buy into it.>>> Could there be a mechanical solution to tail flex laying in the rafters of > some dog town garage? That was the Tinker Tail weight was it’s down side. You could dial rocker into the tail. I remember him coming into the Robert August shop when i was a salesmen. It was way to heavy at the time but i bet it could be built better now with the tech we have to work with. http://surfnwsc.com
One of the best flextail surfboards that I had ever seen was made by > Michell Rae in Australia. That>>> guy is one of the best. I check into Mitchell Rae and sent him a e-mail i hope to get him to post with some insight on flex… Check out his site below. www.outerislandsurf.com This guy would have the answers for so many questions… http://surfnwsc.com
I see what your saying but something i know a Kneeboard can run a wider tail and be stable because of the low center of gravity.??? I find it hard to compare boards when building a different style of craft. Flex in a spoon would need to be more because of the lack of leg movement to weight on and off when surfing rail to rail… and a high center of gravity?? Please tell me if i’m wrong but can we really compare spoons with standard surfboards… I was checking out Mitchells site and boards and his flex is only in the last 16" or so… The big Question is how much flex is really needed???>>> Because the trailing fin is set only about 3 1/2" from the tail i > feel that i may have a problem with stress on my back fin… Stress on > plugs or glassons on my side shouldn’t be a problem…>>> Rob,>>> The last generation of Greenough spoons has NO flex running down the > center line. In fact, the thickest part of the center spine was at the > trailing edge of the fin. What he discovered was that getting the corners > to bend up in a turn are what’s paramount. By corners bending up, I mean > inches of flex, not 1/4" or 1/2" like most glass spoons. The > corners have to get out of the way in a turn with virtually no effort. The > rest of the tail is so stiff, that it compensates for the soft flex. > Believe me, it works. The bend in the corners should lead the board into a > turn, not merely respond to the rider pushing on it. The rest of the board > provides the drive.>>> Your task is somewhat different than that of a spoon kneeboard, but the > general lesson should be the same, I think.>>> If it were my board, I would build up around the fin area with lots of > thickness for stiffness and flotation (like the McTavish flex tail), then > taper out the corners to either very thin foam or solid glass. I would > also use a combination of a slightly wider square tail and slightly less > rocker, then compensate for both with flex in the corners. The benefits > are numerous, with no drawbacks in the water, assuming you can keep your > flotation.>>> George’s 5’ x 18.75" wide edge boards had 15" tails a foot up > and 11" wide tails at the very back. Very, very straight in the rear > two feet…virtually identical to a Lis Fish in curve and proportions. http://surfnwsc.com
I see what your saying but something i know a Kneeboard can run a wider > tail and be stable because of the low center of gravity.??? I find it hard > to compare boards when building a different style of craft. Flex in a > spoon would need to be more because of the lack of leg movement to weight > on and off when surfing rail to rail… and a high center of gravity?? > Please tell me if i’m wrong but can we really compare spoons with standard > surfboards… I would agree we are dealing with a different dynamic between kneeboarding and stand-up surfing, not to mention single fin surfing as opposed to thruster surfing. The flex tail surfboards I’ve made and ridden over the years seemed to be more suited to single-fin, rail carving type of surfing…with the rider weight more forward. Standing over the tail and driving off the fins presents a new and different challenge. In some ways, the toe-in of a thruster provides the springy quality of a flextail single fin, in that the fins are loaded up against each other. Maybe the two concepts combined would need to compromise both design ideas to work together??? Les toe in, and less flex?
Maybe the two concepts combined would need to compromise both design ideas to work together??? Les toe in, and less flex? >>>> My point. So we should be able to get the flex i need without as much tail area flex??? I should be able to get enough flex with a smaller flex panel on each rail. Allowing me to keep more foam under my back foot???>>> I would agree we are dealing with a different dynamic between kneeboarding > and stand-up surfing, not to mention single fin surfing as opposed to > thruster surfing.>>> The flex tail surfboards I’ve made and ridden over the years seemed to be > more suited to single-fin, rail carving type of surfing…with the rider > weight more forward. Standing over the tail and driving off the fins > presents a new and different challenge.>>> In some ways, the toe-in of a thruster provides the springy quality of a > flextail single fin, in that the fins are loaded up against each other. > Maybe the two concepts combined would need to compromise both design ideas > to work together??? Les toe in, and less flex? http://surfnwsc.com
Maybe the two concepts combined would need to compromise both design ideas > to work together??? Les toe in, and less flex? >>>> My point. > So we should be able to get the flex i need without as much tail area > flex??? I should be able to get enough flex with a smaller flex panel on > each rail. Allowing me to keep more foam under my back foot??? Probably. One thing that Greenough harps on all the time is that while the amount of flex is important, it also has to carry up into the rail a fair bit. Just the last 2 or 3 inches bending is the worst. So, you might not need much flex with your concept, but it should run up the rail something like 6" to 8" before it gets completely stiff.
Probably. One thing that Greenough harps on all the time is that while the > amount of flex is important, it also has to carry up into the rail a fair > bit. Just the last 2 or 3 inches bending is the worst. So, you might not > need much flex with your concept, but it should run up the rail something > like 6" to 8" before it gets completely stiff. I’m looking at running it up as far as 15" just about the front of the side fins. Shaping the tail the way the Mc Tavish flex i have but not as much flex area. The flex won’t be that much by the fins but i know i need to start high on the rail to get the bend i’m looking for. http://surfnwsc.com
I’m looking at running it up as far as 15" just about the front of > the side fins. Shaping the tail the way the Mc Tavish flex i have but not > as much flex area. The flex won’t be that much by the fins but i know i > need to start high on the rail to get the bend i’m looking for. I have the last graphite spoon kneeboard George made, in the early 90’s. It was the most carefully tuned in board he said he ever had. I just measured the flex, and it goes to stiff 9" up the rail from the square tail. I don’t see much need to go further than that, especialy with the side fins coming into play around that point.
I have the last graphite spoon kneeboard George made, in the early 90’s. > It was the most carefully tuned in board he said he ever had. I just > measured the flex, and it goes to stiff 9" up the rail from the > square tail. I don’t see much need to go further than that, especialy with > the side fins coming into play around that point. So your say i should think about starting my flex behind the side fins?? What about flex over all does the board flex any in thru the middle. Even a little??? I would think it does a bit… http://surfnwsc.com
So your say i should think about starting my flex behind the side fins??>>> What about flex over all does the board flex any in thru the middle. Even > a little???>>> I would think it does a bit… No, there’s no linear flex, due to the structure of the foam rails and the thick spine running from the mid point through the back of the fin, which is only 3.5" up from the tail. The two areas that bend are the twist, which is very soft, and the corners, which are also very soft. The twist and the corners bending allow the board to assume the shape of the wave, and give way even further in a turn. Once you get the hang of letting the forward third of the rail drive the board, it all maes perfect sense. To answer your first question, yes, I would run the flex up to the back of the side fins, but no further. How far up are they intended to be?
No, there’s no linear flex, due to the structure of the foam rails and the > thick spine running from the mid point through the back of the fin, which > is only 3.5" up from the tail. The two areas that bend are the twist, > which is very soft, and the corners, which are also very soft.>>> The twist and the corners bending allow the board to assume the shape of > the wave, and give way even further in a turn. Once you get the hang of > letting the forward third of the rail drive the board, it all maes perfect > sense.>>> To answer your first question, yes, I would run the flex up to the back of > the side fins, but no further. How far up are they intended to be? Can you guys run that by me again??