Any Ideas on how??? I have a few of my own… I just think we all need to have some say and come up with a new design from old designs… I’m know about Rustys i’m looking for something better. Give me some good ideas and i will build it and lets see how it works?? Pulling the Swaylocks think tank all together for something new a online design! It has to be 6’0 to 6’4 that’s what i ride. i’m open to width differences. i like 18 1/2 but if you think it should be wider why then??? I’m looking at doing glass ons to keep it(Foam filled, carbon or flex??) light as i can. So bottom and flex can be design anyway we want. Single to dub if we want?? Concaves with flex??? There are characteristics of Flex i think could be designed into todays Thrusters. More snap out of turns maybe?? Maybe i could go even shorter and add more width in the flextail yet still get release when driving thru a turn with a lot of controled snap?? Has anyone built a true Flextail Thruster shortboard??? I will call this design “The Swaylockflex” I feel a need to look outside the design box… Let me know and i will build it… http://surfnwsc.com
Any Ideas on how??? Rob, This is a tall order, because of your need for at least some bouyancy and having to work around 3 fins, flex-wise. My experience has been that the primary benefit of flex is that it allows you to use less rocker, because the tail bends away during a turn, compensating for the low rocker in turns. When the board straightens out, the flat rocker kicks in again, and you take off. Unless the flex is pretty liberal, not much is gained. Greenough’s boards flex INCHES when you put a small amount of pressure on the tails with your finger. Of course, they have NO rocker in the back 60% of the board, so a lot of flex is necessary. The benefit is that he gets the best of both worlds…an extremely easy to turn board that also flies in trim because it has no rocker. I doubt you could replicate that extreme, or would even want to. I think you would ned to glass on the fins with a minimum amount of glass-on width. Like an inch on a 4 inch base, or something like that. The tail would have to be free to bend almost unimpeded. If you used a solid glass tial, the only way you could regain the bouyance would be to build up the glass area with closed cell soft foam (like Boogie skin). That would end up wighing a bit more, due to the added glas in the tail. Personally, I wouldn’t get too bent out of shape about the weight in the beginning. It would all be in the back end, which isn’t as harmful as up front. Geroge’s sailboards used a false deck where he stands, and the rest of the board is a big glass spoon. They are very complex to build, even by his standards.
Rob - I have seen some boards from Sunset Cliffs, San Diego area that utilize a “soft top” type of deck in the tail of an otherwise all fiberglass board. The deck curves of a glassed board have a lot to do with flex - a dome deck will flex very little while a scooped deck will flex more. The shape of the glass shell after it cures has more to do with it than the shape of the foam. Anyway, this guy in San Diego removes that rigid shell component of the board and the tails flex quite a bit even with a tri fin set up. Paul’s take on rocker and fin base rigidity sound exactly right.
Rob - I have seen some boards from Sunset Cliffs, San Diego area that > utilize a “soft top” type of deck in the tail of an otherwise > all fiberglass board. The deck curves of a glassed board have a lot to do > with flex - a dome deck will flex very little while a scooped deck will > flex more. The shape of the glass shell after it cures has more to do with > it than the shape of the foam. Anyway, this guy in San Diego removes that > rigid shell component of the board and the tails flex quite a bit even > with a tri fin set up. Paul’s take on rocker and fin base rigidity sound > exactly right. One of several advantages of a flat-to-domed-to-flat tri-plane deck is that the nose and tail are lighter and more flexible, while the center section is completely rigid.
might be able to shed more light on the flexie subject… Pendaflex???
Rob - I have seen some boards from Sunset Cliffs, San Diego area that > utilize a “soft top” type of deck in the tail of an otherwise > all fiberglass board. The deck curves of a glassed board have a lot to do > with flex - a dome deck will flex very little while a scooped deck will > flex more. The shape of the glass shell after it cures has more to do with > it than the shape of the foam. Anyway, this guy in San Diego removes that > rigid shell component of the board and the tails flex quite a bit even > with a tri fin set up. Paul’s take on rocker and fin base rigidity sound > exactly right. John, What does the rail look like where the soft top is incorporated? Does the soft top cut into the rail line at all? I tried a soft BZ type 8’ board the other day (keeping to the mantra of trying as many different types of sticks that I can get my hands on to compare design elements etc…). The board had a great deal of flex – to the point that it hindered the utilization of the board if pushed aggressively. So, that being said: (thinking while I’m typing here…) What about joining both types of boards with some fiberglass reinforcing to the soft section to control the flex? You can flatten the bottom rocker knowing that the soft section will flex significantly. You could have a 2 stage board which would be a conventional board married up to a reinforced soft section; a three stage board which could be a conventional married to soft married to conventional at the very end to greater control flex. Or what about a conventional board that blends into a pneumatic surf mat type of bottom? You would have to have button hole type(for lack of a better visualization) openings that would allow the fins to engage with the water… Just some thoughts to stimulate the conversation. Magoo
Rob, I’d want a bit more flex under the front foot ie near the middle of the board rather than in the tail. You need the snap and extra speed when you are unwieghting out of a turn on the flatter part of the wave - bottom turn or carving cutback. When you are using the backfoot to turn off the top or slashing on the face - you’ve got gravity and the energy of the wave near the curl to give you speed. If you could get a board to flex (and snap back quickly)in the middle, you could have a flatter rocker through the middle for speed but when you loaded it in a turn it would flex, giving you slightly more rocker under the front foot and therfore a tighter turning radius. You have to have a real top to bottom stlye because low speed turns might not generate have enough G-forces to flex the board although with the flatter rocker you’d be moving a bit quicker across the flats anyway. How to get more flex out of the centre of the board? - maybe you could cut the stringer out and drill a horizontal row of holes - say 1/2 an inch in diameter in the middle, where you want the flex happening. This would change the dynamics of the way your stringer flexs. Alternatively you could use a flexy stringer material and stiffen the ends with laminations of carbon fibre. A good thing about playing with the stringer is you could test your variations against a normal stringer in the workshop and when you arrive at more elasticity - build the board. You could then use a planshape and foil that you’d normally use for a board with more rocker through the middle ie longer and narrower or more bullet shaped with a wider tail. Good luck, Stephen
Sorry that I’m a bit vague on details… I just remember a soft closed cell neoprene-like deck pad, flex and three fins. I’ll try and get hold of the guy and see what’s up if we don’t hear from Newbalonie.
Rob - I have seen some boards from Sunset Cliffs, San Diego area that > utilize a “soft top” type of deck in the tail of an otherwise > all fiberglass board. The deck curves of a glassed board have a lot to do > with flex - a dome deck will flex very little while a scooped deck will > flex more. The shape of the glass shell after it cures has more to do with > it than the shape of the foam. Anyway, this guy in San Diego removes that > rigid shell component of the board and the tails flex quite a bit even > with a tri fin set up. Paul’s take on rocker and fin base rigidity sound > exactly right. Well thanks Paul, John and Magoo for the ideas and thoughts. I was thinking about it all day today while i sanded boards… I’m thinking flat deck 2" thick to gain the flex thru out the board. It will be more fish then rip stick design 5’9 to 6’0 high wing around 15 inches. With a 5 1/2" SW tail so the tips would flex even more? The tail will be on the wider side 14 1/2. Wide point in the 18 3/4 range. Moving more width forward (front foot surfing) nose say 12 plus as much as 13. Keeping the width under 19 should allow for a strighter rail line more drive on rail. Because of the width in the tail i think i can leave enough foam in the tail area to allow for the flex to be shaped out?? I’m thinking i can start the flex edge at the wings and still leave enough foam in the tail for my foot. I would think because of the size of the board and dub concave running thru the fin area i would build a slight concave in the flex tail. This should build in more load when in a turn and snap even more out of a turn?? Because i’m shaping in more load up spring i should beable to use less glass and resin?? Less weight?? and because flex would start at the wings any glass around fin lay ups shouldn’t hender flex??? I should be able to use a fin system for my side fins. The wing is more for a point where the wing blends into the foam part of the tail. It’s like looking at my retro Pin Wing and adding a SW tail to it. The tip of the pin tail would end about 4" from the inside of the SW tail making it 5" from the tips… I could even draw the pin out to a tip allowing for a FCS pulgs in the tail??? I’m hoping to gain more squirt from rail to rail surfing in small mushy waves. Questions? How many layers of 4oz. should i use s glass??? it could help in building up more load without weight of more cloth?? SW or square?? Would shaping the board with standard bottom Single to Dub concave to light vee under the back fin to flat off the tail to get even flex at the tips work?? Now what could be different or what do you think?? A True Rocket Fish maybe??? http://surfnwsc.com
Rob, I’d want a bit more flex under the front foot ie near the middle of > the board rather than in the tail.>>> You need the snap and extra speed when you are unwieghting out of a turn > on the flatter part of the wave - bottom turn or carving cutback. When you > are using the backfoot to turn off the top or slashing on the face - > you’ve got gravity and the energy of the wave near the curl to give you > speed.>>> If you could get a board to flex (and snap back quickly)in the middle, you > could have a flatter rocker through the middle for speed but when you > loaded it in a turn it would flex, giving you slightly more rocker under > the front foot and therfore a tighter turning radius. You have to have a > real top to bottom stlye because low speed turns might not generate have > enough G-forces to flex the board although with the flatter rocker you’d > be moving a bit quicker across the flats anyway.>>> How to get more flex out of the centre of the board? - maybe you could cut > the stringer out and drill a horizontal row of holes - say 1/2 an inch in > diameter in the middle, where you want the flex happening. This would > change the dynamics of the way your stringer flexs. Alternatively you > could use a flexy stringer material and stiffen the ends with laminations > of carbon fibre.>>> A good thing about playing with the stringer is you could test your > variations against a normal stringer in the workshop and when you arrive > at more elasticity - build the board.>>> You could then use a planshape and foil that you’d normally use for a > board with more rocker through the middle ie longer and narrower or more > bullet shaped with a wider tail.>>> Good luck,>>> Stephen Stephen I like the idea about flex in the middle?? I think you may have something there… I think by shaping a flat deck i will get the flex i’m looking for plus i will shap a flter rocker. Has anyone ever used flex resin??? We used it in blank glue ups back in the 70’s. http://surfnwsc.com
This is such a fascinating subject, and Im pleased that its surfaced again… While the benefits of flex in surfcraft are significant, and to some of us, all-important, the problems frequently associated with developing their optimum function are also significant. Over the years, Ive built various types of flexible surfcraft (with and without fins) and can truthfully say that Ive learned a lot more about wrong “solutions”, than what shouldve been right. Unless a chosen design calls for minimal flotation, two of the primary issues Ive faced in the creation of flexible surfcraft are how best to provide the means of uninhibited flex and adequate buoyancy, but with the least amount of compromise. This seems to apply to most all forms of surfcraft, whether for prone, kneeling or standing. In surfboards, specifically those that are ridden from the tail, the problem of flex is soon obvious as the riders weight/feet interfere with any functional bending that would occur in the back of the board. The most common attempt at resolving this dilemma has been to scoop out the rear deck, leaving only fiberglass, which provides the potential for flex and a dramatic increase in sensitivity. Yet this eliminates a significant amount of foam and buoyancy, and the riders standing weight/foot position still inhibits the boards flex and handling. The usual means of replacing the tails lost buoyancy and (hopefully) retain some of the flex, has been to shape and apply a replacement deck of flexible bodyboard foam, the most common being closed cell polyethylene. Its been my experience that attaching such foam to the top of a flexible tail only serves to further deaden the very qualities for which flex tails are designed in the first place. Whether by contact cement or mechanical means, the foam absorbs and mutes sensation, and feedback to the riders feet is completely different than traditional polyurethane foam and fiberglass. Plus, foam thats firmly attached to flex panels makes repeated removal, sanding/fine-tuning and re-gluing to the fiberglass tail section a major hassle. An additional surprise sometimes occurs during temperature changes, when the rear fiberglass and polyethylene foam expand and contract at different rates… making the flat tail rocker morph into something entirely unplanned. IMHO, the bonding of flexible foam to flexible fiberglass is literally comparable to "poisoning" that design. One of the answers to these nagging problems has been to employ "false" decks, which prevent the riders weight from interfering with the bending of the tail, while offering the potential for improved flotation. As Paul mentioned, George Greenough has successfully used a very complex false deck on his carbon fiber sailboards (but with minimal flotation), describing them as “flexible spoons to stand on.” For those of you who are familiar with the performance of Georges flexible kneeboards (and wondered what it would be like to ride one while standing), his statement is worthy of thoughtful consideration. Another promising direction may be a hollow carbon fiber board, in contemporary form, having a thinned and partially separated rear 1/3, i.e. deck and running surface, surrounding an inflatable, pressure adjustable bladder. In fact, a project of this nature is in the initial stages and will likely incorporate three small, Greenough- inspired "paddle" fins with extremely narrow bases. A board like this could offer responsive, adjustable flex, light weight, and be buoyantly thin. The riders weight would not inhibit the tail section nearly as much as with flexible polyethylene foam because the air bladders top and bottom surfaces tend to react independently of each other. The air bladder would absorb a measure of shock, yet remain resonant and responsive. This boards overall function begins to sound like a high end radial tire: pneumatic and aggressively responsive. A clear downside is expense, while a less obvious problem might simply be just how satisfying such a board would feel. Ironically, the most user-friendly and uniquely functional place to foster an intimate personal understanding of the complexities of flex that occur while riding a wave, is the deceptively sophisticated, modern high performance… surfmat. –
SW or square?? Conisder making it a thin swallow tail, add a bit more thickness in the center to force the tail to flex more, and then cover the open area of the swallow with tape or fabric. You get the independant bend of the swallow, with the more fluid (in my opinion) performance of a square tail
Rob, I’d want a bit more flex under the front foot ie near the middle of > the board rather than in the tail. I think that flex anywhere in the back 2/3 of the board is valid (on a shortboard) so long as the area that is most flexible is also the flatest rocker-wise, as you point out. What about lateral grooves along the deck of a shaped blank, in the areas meant to flex? Maybe only 3/8" deep, just enough to relieve the pressure and allow some bend? It would probably break at some point in the early stages of testing, but it might be a relatively cheap method (time-wise) to get a feel for what is going to work down the road. Or, maybe take some old beaters (thrusters) and rig up tooling to cut some lateral groves in the deck, then glass over the slots. Heavy and crude, of course, but at least it would start the practical aspect of your design lineage going.
Stephen I like the idea about flex in the middle?? I think you may have > something there… I think by shaping a flat deck i will get the flex i’m > looking for plus i will shap a flter rocker.>>> Has anyone ever used flex resin??? We used it in blank glue ups back in > the 70’s. When I look at videos of pro’s surfing, I’m always blown away by how much speed those guys get coming off the bottom. Your post has got me thinking now that the way their boards are made, might have something to do with it (increadible natural talent, reflexes, and fitness aside) superlight foam - less dense, more bouyant means they can go thinner, which means less depth in the stringer therefore more flex plus super light glass job, which also means more flex. Using a flatter deck to give you a shallower stringer with the same bouyancy would work - but aren’t flatter decks harder to lay over for skinny guys like me? I thought they were just for shorter guys with powerful, stumpy little legs?
Conisder making it a thin swallow tail, add a bit more thickness in the > center to force the tail to flex more, and then cover the open area of the > swallow with tape or fabric. You get the independant bend of the swallow, > with the more fluid (in my opinion) performance of a square tail Do you mean more glass in the center to create more flex?? and thining out the releasing edge with less glass??? Foiling out the flex? Like a fin How deep would you make the SW??? the deeper the more independent flex you would feel?? Would you want to stiffen the tail to the SW inside cut making each tip work independant. I would think the tail would get a washed out mushy feel if there is to much flex thru out the tail?? http://surfnwsc.com
When I look at videos of pro’s surfing, I’m always blown away by how much > speed those guys get coming off the bottom. Your post has got me thinking > now that the way their boards are made, might have something to do with it > (increadible natural talent, reflexes, and fitness aside) superlight foam > - less dense, more bouyant means they can go thinner, which means less > depth in the stringer therefore more flex plus super light glass job, > which also means more flex.>>> Using a flatter deck to give you a shallower stringer with the same > bouyancy would work - but aren’t flatter decks harder to lay over for > skinny guys like me? I thought they were just for shorter guys with > powerful, stumpy little legs? I’m thinking super light blanks would add to flex over my standard Blues that i use… I’m really wanting a full twist flex to gain snap out of every turn… I surf and shape dome decks on my boards just cause there stronger. I just think because this board will only be for small surf i can give up a little to gain a lot??? http://surfnwsc.com
I think that flex anywhere in the back 2/3 of the board is valid (on a > shortboard) so long as the area that is most flexible is also the flatest > rocker-wise, as you point out.>>> What about lateral grooves along the deck of a shaped blank, in the areas > meant to flex? Maybe only 3/8" deep, just enough to relieve the > pressure and allow some bend? It would probably break at some point in the > early stages of testing, but it might be a relatively cheap method > (time-wise) to get a feel for what is going to work down the road.>>> Or, maybe take some old beaters (thrusters) and rig up tooling to cut some > lateral groves in the deck, then glass over the slots. Heavy and crude, of > course, but at least it would start the practical aspect of your design > lineage going. Wouldn’t groves stiffen once glassed??? Because of the extra cruve added to the tail area. Just as a dome deck would be stiffer then a flat?? http://surfnwsc.com
Adequate buoyancy is the one thing i hope to over come by keeping it shorter… I would think the smaller the craft the less flex would be needed?? Adding foam to the tail (closed cell polyethylene) i agree with you it would not be the way to go. Hollow is one way but as you said a tone of work and COST??? Thanks Dale for such a great post you gave me a few things to think about today. I did a Goggle search last night and found a few good things to think about to. Just search Flextail surfboard design.>>> This is such a fascinating subject, and Im pleased that its surfaced > again…>>> While the benefits of flex in surfcraft are significant, and to some of > us, all-important, the problems frequently associated with developing > their optimum function are also significant. Over the years, Ive built > various types of flexible surfcraft (with and without fins) and can > truthfully say that Ive learned a lot more about wrong > “solutions”, than what shouldve been right.>>> Unless a chosen design calls for minimal flotation, two of the primary > issues Ive faced in the creation of flexible surfcraft are how best to > provide the means of uninhibited flex and adequate buoyancy, but with the > least amount of compromise. This seems to apply to most all forms of > surfcraft, whether for prone, kneeling or standing.>>> In surfboards, specifically those that are ridden from the tail, the > problem of flex is soon obvious as the riders weight/feet interfere with > any functional bending that would occur in the back of the board. The most > common attempt at resolving this dilemma has been to scoop out the rear > deck, leaving only fiberglass, which provides the potential for flex and a > dramatic increase in sensitivity. Yet this eliminates a significant amount > of foam and buoyancy, and the riders standing weight/foot position still > inhibits the boards flex and handling.>>> The usual means of replacing the tails lost buoyancy and (hopefully) > retain some of the flex, has been to shape and apply a replacement deck of > flexible bodyboard foam, the most common being closed cell polyethylene. > Its been my experience that attaching such foam to the top of a flexible > tail only serves to further deaden the very qualities for which flex tails > are designed in the first place. Whether by contact cement or mechanical > means, the foam absorbs and mutes sensation, and feedback to the riders > feet is completely different than traditional polyurethane foam and > fiberglass. Plus, foam thats firmly attached to flex panels makes > repeated removal, sanding/fine-tuning and re-gluing to the fiberglass tail > section a major hassle. An additional surprise sometimes occurs during > temperature changes, when the rear fiberglass and polyethylene foam expand > and contract at different rates& making the flat tail rocker morph into > something entirely unplanned. IMHO, the bonding of flexible foam to > flexible fiberglass is literally comparable to "poisoning" that > design.>>> One of the answers to these nagging problems has been to employ > "false" decks, which prevent the riders weight from interfering > with the bending of the tail, while offering the potential for improved > flotation. As Paul mentioned, George Greenough has successfully used a > very complex false deck on his carbon fiber sailboards (but with minimal > flotation), describing them as “flexible spoons to stand on.” > For those of you who are familiar with the performance of Georges > flexible kneeboards (and wondered what it would be like to ride one while > standing), his statement is worthy of thoughtful consideration.>>> Another promising direction may be a hollow carbon fiber board, in > contemporary form, having a thinned and partially separated rear 1/3, i.e. > deck and running surface, surrounding an inflatable, pressure adjustable > bladder. In fact, a project of this nature is in the initial stages and > will likely incorporate three small, Greenough- inspired > "paddle" fins with extremely narrow bases. A board like this > could offer responsive, adjustable flex, light weight, and be buoyantly > thin. The riders weight would not inhibit the tail section nearly as much > as with flexible polyethylene foam because the air bladders top and > bottom surfaces tend to react independently of each other. The air bladder > would absorb a measure of shock, yet remain resonant and responsive. This > boards overall function begins to sound like a high end radial tire: > pneumatic and aggressively responsive. A clear downside is expense, while > a less obvious problem might simply be just how satisfying such a board > would feel.>>> Ironically, the most user-friendly and uniquely functional place to foster > an intimate personal understanding of the complexities of flex that occur > while riding a wave, is the deceptively sophisticated, modern high > performance… surfmat.>>> – http://surfnwsc.com
Hollow is one way but as you said a tone of work and COST??? The cost is not the issue… It’s gonna be a one of a kind…And what, are you afraid of a little work??? Oh yeah, I forgot…Westport…
Hollow would give that independant deck and bottom…And with hollow you get more floatation than with foam, inch for inch…So possibly to overcome the reduced floataion of a flex-tail it could be hollow… With an independant bottom / deck you might be able to have the under foot feel comparable to conventional… Dale give us some hints how you might go about it??? Paul http://www.hollowsurfboards.com/Index.htm
The cost is not the issue… It’s gonna be a one of a kind…And what, are > you afraid of a little work??? Oh yeah, I forgot…Westport… :-)>>> Hollow would give that independant deck and bottom…And with hollow you > get more floatation than with foam, inch for inch…So possibly to > overcome the reduced floataion of a flex-tail it could be hollow…>>> With an independant bottom / deck you might be able to have the under foot > feel comparable to conventional…>>> Dale give us some hints how you might go about it???>>> Paul Rob, It may be that hollow construction in the tail of the craft may well facilitate the kind of flex you are looking for but that method may completely defeat the flexing capability of the tail. If you build it with some structural integrity that can only be provides through some kind of internal supporting members I would propose some variation of the following construction methods. Considering that in boat construction bulk head and ribs are use to prevent twist and flex these type of members (Bulk heads) won’t serve to facilitate twisting but I think that some sort of solid bulkhead forward of the tail seems a good place to embark on the flextail construction. If bottom and deck are of solid laminated construction it will allow one to afix as serious of stringers of greater thickness in the center and less toward the rails to allow the tail to flex. The number, thickness, and spacing of the stringers will determine how much flex one gets. The fins could be put into fin boxes or plugs that are contained on foam encapsulated between stringers. No small project this! I think the swallow tail ideas is the right one. Glass on fins are an easy way out but don’t allow for easier experimentation with fin changes. One could consider working parallel stringers the width of the center box as a good place to start. This would give a good strong central place to build from. However if you want the whole thing to flex fore and aft the multiple stringer idea may defeat this completely because as soon as you contect the two shear surfaces with either stringers or bulk heads, or with any internal support at all you tend to make the whole thing more ridgid. So the stringer thing may not work at all. Another approach would be to run bands fore and aft the strengthen the hollow tail in decreasing thinkness as the approach to rail and would be the best way to approach it in retrospect. Maybe building the bottom and deck of the tail separately with interal bands and then attaching them to the body of the craft and putting a shell over the whole thing would work. It’ll be tricky bussiness to be sure and certainly making the thing flex a putting floation in it too is a major task in engineering. A single laminated construction will flex almost any way you want to and carbon fiber has a wonder weight to strength ratio. Unfortunately the negative bouyancy of this method it’s a main draw back but if you put an air bladder on top of it that’s made out of Dale’s surfmate material your problem is solved. How much of the tail you want to flex will have much to do with how you approach things I’m sure. It seems to me that you’ll have to combine Surf Mat technology with surfboard technology to get where your going. But what do I know? Keep us posted on how you plan to approach the project. This all may just be rambling but sharing these thoughts may trigger some valuable ideas so I feel I should share them. Better Surfing, Rich