Once in a while, I used to break kneeboards in half on heavy drops, and eventually my orthopedic surgeon noted that although the medical problem in my knees was directly related to kneeboarding, the basic concept behind my designs had little to do with why they ended up in two pieces. I had to think about that one for a while. The decades old ideal of tuned, flexible surfcraft still waits to be discovered and appreciated by the majority of surfers, and is completely valid, but runs directly against the general trend of factory production, lowered labor/material costs and increasingly crowded beachbreaks. Unfortunately, it seems that much of what we create has more to do with accomodating the limitations around us… than the possibilites. Dale
Once in a while, I used to break kneeboards in half on heavy drops, and > eventually my orthopedic surgeon noted that although the medical problem > in my knees was directly related to kneeboarding, the basic concept behind > my designs had little to do with why they ended up in two pieces. I had to > think about that one for a while.>>> The decades old ideal of tuned, flexible surfcraft still waits to be > discovered and appreciated by the majority of surfers, and is completely > valid, but runs directly against the general trend of factory production, > lowered labor/material costs and increasingly crowded beachbreaks.>>> Unfortunately, it seems that much of what we create has more to do with > accomodating the limitations around us… than the possibilites.>>> Dale The problem is that you cannot apply kneeboard design criteria directly to a standup surf board; the board is 30-40 percent shorter, the whole dynamics of the kneeboard turn is different from the standing turn, and most importantly, the relation between the rider and the platform is entirely different (two feet aligned at right angles to the stringer vs. two shins aligned parallel to the stringer). The stand-up manufacturers are somewhat hamstrung by development costs (heavy expenditures in materials experimentation with a low potential of success) and the fact that the buying public is still enamored with 6’2" X 18" X 2" thrusters or 9’6" low perfomance longboards. It’s still up to the garage shaper to come up with the next step. In the next 5 years, I believe that the contibutions of flex to surfboards will be pioneered by the tow board, where flotation is not so much an issue (this will reduce the need for exotic construction materials). What about body boards? The most ridden surfcraft is the second-most flexible (after a mat). The wonderful part about surfcraft design is that it is still done by the riders’ themselves.
The problem is that you cannot apply kneeboard design criteria directly to a standup surf board; the board is 30-40 percent shorter, the whole dynamics of the kneeboard turn is different from the standing turn, and most importantly, the relation between the rider and the platform is entirely different (two feet aligned at right angles to the stringer vs. two shins aligned parallel to the stringer).
i don’t know “whack” this is going to sound but…a few weeks ago the boating section of our local paper ran a feature on a highly regarded boat manufacturer, whose name i can’t remember (but i think it starts with an ‘F’). this company is coming out with a line of hulls manufactured out of ropolyne (sp?), the same exact stuff that plastic milk jugs are made out of. they claim a real tough, shatter resistant hull that is lighter than fiberglass layup, but flexible to the point that they’ve have had to ‘rethink’ stringer configurations. maybe this material will find its way into our world somehow.>>> Once in a while, I used to break kneeboards in half on heavy drops, and > eventually my orthopedic surgeon noted that although the medical problem > in my knees was directly related to kneeboarding, the basic concept behind > my designs had little to do with why they ended up in two pieces. I had to > think about that one for a while.>>> The decades old ideal of tuned, flexible surfcraft still waits to be > discovered and appreciated by the majority of surfers, and is completely > valid, but runs directly against the general trend of factory production, > lowered labor/material costs and increasingly crowded beachbreaks.>>> Unfortunately, it seems that much of what we create has more to do with > accomodating the limitations around us… than the possibilites.>>> Dale
What don’t you know? When you turn a kneeboard you are rolling it up on an edge and are using the combination of rail rocker, bottom rocker and fin(s) to turn. The forces are based on the momentum gathered from the drop and the forward motion of the wave itself. On a stand up board you use these same things but, and this is the important part, you use your legs to add momentum to the turn. By extending your legs, you add forces you can’t when you are locked in a kneeling position. This additional force is what screws up the typical “Greenough” design transfer to standup boards. They over-flex. Its the same problem with the stand-up boogie (Doyle) approach. Too much force applied over a narrow area. Further, a kneeboarder turns from the same place on the platform regardless of circumstance. A standup surfer, even on a short board, will turn from different places on the platform even if it is only a fore-aft shift of the hips. Probably the biggest difference is one I failed to mention in the first post; flotation. A kneeboarder needs almost none while the standup surfer needs a lot. A lot of the failure in flex design for standup boards is the result of designers completely missing Greenough’s design basic; the Velos flexed the rail rocker only. The tip to tail rocker was extremely stiff what with the tip to tail rail pontoons and the rider’s shins and feet. The Doyles and others of that ilk were stiff from rail to rail but soft from tip to tail. That results in over flexing and turns the rocker into a banana or puts the curve in the wrong place. The partial answer has been to only allow the tail to flex but this is still only a variation on the tip to tail rocker flex. While it is fun to play with these designs for different “feels” the real problem with flexi-flyers is they need smooth, long walls to work. You’ve got to get a couple of turns in to get them up to speed. In the day to day slop most of us ride you can get more acceleration and ultimate velocity by pushing against a fixed hull or tri fin cluster. That’s just the physics of it.
i don’t know “whack” this is going to sound but…a few weeks > ago the boating section of our local paper ran a feature on a highly > regarded boat manufacturer, whose name i can’t remember (but i think it > starts with an ‘F’).>>> this company is coming out with a line of hulls manufactured out of > ropolyne (sp?), the same exact stuff that plastic milk jugs are made out > of. they claim a real tough, shatter resistant hull that is lighter than > fiberglass layup, but flexible to the point that they’ve have had to > ‘rethink’ stringer configurations.>>> maybe this material will find its way into our world somehow. Ramon, Was it “Fountain”, if so, he is a well known high performance (go fast) boat builder. Alway’s pushing the limits, for speed, bottom configurations and lighter hull’s.
sorry, R.I. i must have been having a report card flashback. the company is Triumph Boats, and i’m attaching a link to their roplene info. regards>>> Was it “Fountain”, if so, he is a well known high performance > (go fast) boat builder. Alway’s pushing the limits, for speed, bottom > configurations and lighter hull’s. http://www.triumphboats.com/roplene.asp
When you were talking about knee boards I was thinking more along the lines of what is depicted on the link below. Check the bottom of the page, Nice Afro no? The whole spoon thing did not come to mind. You’re ahead of the pack when you can figure out what does’nt work and most importantly Why it does’nt work. Although I have had a blast on a 9’ doyle, but I think it had more to do with the fact that I did not feel guilty running right over top of my buddies with it, demolition derby style. Thanks for the flex info. http://www.blasthawaii.com/designs.html
The problem is that you cannot apply kneeboard design criteria directly to > a standup surf board; the board is 30-40 percent shorter, the whole > dynamics of the kneeboard turn is different from the standing turn, and > most importantly, the relation between the rider and the platform is > entirely different (two feet aligned at right angles to the stringer vs. > two shins aligned parallel to the stringer).>>> The stand-up manufacturers are somewhat hamstrung by development costs > (heavy expenditures in materials experimentation with a low potential of > success) and the fact that the buying public is still enamored with > 6’2" X 18" X 2" thrusters or 9’6" low perfomance > longboards. It’s still up to the garage shaper to come up with the next > step.>>> In the next 5 years, I believe that the contibutions of flex to surfboards > will be pioneered by the tow board, where flotation is not so much an > issue (this will reduce the need for exotic construction materials).>>> What about body boards? The most ridden surfcraft is the second-most > flexible (after a mat). The wonderful part about surfcraft design is that > it is still done by the riders’ themselves.>>> What about body boards? The most ridden surfcraft is the second-most > flexible (after a mat). The wonderful part about surfcraft design is that > it is still done by the riders’ themselves. Newbalonie, (Welcome to Swaylocks!) With all their good qualities, no matter what design or means of constructing it, flexible closed cell foam bodyboards seem to have the unfortunate, self-limiting characteristic of deadening sensation, flex/torque and handling response. In contrast to high performance surfmats, bodyboards simply can
t adapt and quickly respond with a high degree of sensitivity and memory, or mimic the surface and curves of a wave to develop speed and control. Interestingly, in recent years most bodyboards appear to be moving closer to becoming fairly solid, but cushioned, prone boards, and away from the suppleness of Morey
s original “Boogie” in the early 1970s. Compounding these issues, the prone rider
s weight on the deck transfers directly to the bottom, suppressing any possibility of the running surface being active. By way of comparison, surfmats operate through means of their top and bottom surfaces, which are contantly moving independently of each other, resonating and closely conforming to both the riders body and the water
s surface, above and below a cushion of pressurized air that feels and behaves more like some sort of automatically reactive “muscular gel”, rather than a firm inflatable or flexible foam. With regular use, flex foam bodyboards increasingly suffer from rocker fatigue, caused by the riders weight, i.e. pressure point hinges on the deck. While various combinations of flexible internal stringers/skeletons and stiff outer laminations can help to remedy that particular problem, they only worsen others. As you noted, true weighting and unweighting, as accomplished by standing surfers, is impossible on kneeboards and bodyboards, whose rider
s dead weight is transferred directly to the bottom surface. The obvious exceptions to this fact are George Greenoughs previous flexible kneeboards, as well as modern high performance surfmats, which are both able to forcefully accelerate and drive themselves out of turns. The problem of adequate flotation and engineered flex has been a crucial one, with George
s kneeboards employing next to none, while the best surfmats offer not only plenty of flotation, but also the ability to easily adjust between waves, or intuitively tune (while riding) the volume for a wide range of changes in performance and speed. This is one of the primary reasons why, for a number of latter years, George has exclusively used his mats for surfing. For some smaller surfcraft, one way to approach the ideal of increased handling and speed in a wide variety of waves and surface conditions is to minimize the constant design compromise/limitations inherent in fixed, solid forms through the use of variable rocker and torque that responds with active memory. While this has as yet been largely unattainable to standing surfers, the fact that both nose to tail flex and calculated degrees of twist will ultimately benefit conventional surfboard design is undeniable. Look at all the other motion sports that are already based around controlled flex principles to attain their proper handling at velocity. Finally, while there is a general correlation between flatter (and concave) running surfaces requiring smoother and longer surfaces to function at optimum levels, the surprising enigma of the modern surfmat, is that it often travels much faster and with more control on bumpy, gnarly long walls. This singular example points the way to the future use of tuned flexibility in surfboard design, and graphically demonstrates that with properly balanced flex/torque, combined with supple conformability and responsive memory, significantly increased velocities can actually be a compliment to greater degrees of control on less than ideal surfaces… and eventually, a benefit to everyone who rides a wave. Dale
sorry, R.I. i must have been having a report card flashback. the company > is Triumph Boats, and i’m attaching a link to their roplene info. regards Ramon, Thank you for the link. Very interesting. Few years back we visited the “Cigarette” Factory. Can’t be to far from you. Don’t remember St., but they call that area “High Performance Alley” Best Regard’s PS: Some nice boards your building.
hey, R.I., yes, performance alley is up in north miami beach, and still pumping out cigarretees, donzis, and even magnums still (i think). the mucle boats that dreams are made of. sadly, the ‘grandaddy’ of muscle boat building, the guy whose name is synonymous with cigarrette and donzi, don aronow, was murdered gangland style a few years back…right on the premises. he was a real character! my dad built him some custom woodwork for his house many years ago, and he couldn’t have been nicer to us. i’m glad you enjoyed the link, and i wonder if we’ll be fixing dings with blow-torches anytime soon…>>> Ramon,>>> Thank you for the link. Very interesting. Few years back we visited the > “Cigarette” Factory. Can’t be to far from you. Don’t remember > St., but they call that area “High Performance Alley”>>> Best Regard’s PS: Some nice boards your building. http://www.triumphboats.com/roplene.asp
What a pleasure to read a well-reasoned, well written discourse on something I usually get blank stares or “Whatever, Duuuuude.” as responses. I agree completely that the key to using flex on a standup board is control; control of the amount, shape and location. The problem that I have not been able to overcome is that flex tends to take a lot of versatility out of the board’s performance. Follow the ski/snowboard analogy for a second and you’ll see the problem (hopefully you’ve skiied or boarded before). To turn a ski, there are two design fundementals; flex and sidecut (the concave shape of the ski outline). The more you bend the ski while on edge, the shorter the radius of the turn. The limit of the turn radius, however, is controlled by the sidecut of the ski. You can lengthen the radius of the turn by getting off the edge quickly or decreasing pressure and reducing the amount of flex on the ski. You cannot tighten the arc beyond the design limits without skidding. That’s been my experience with flex on standup boards; the arc of the turn is dominated by the design (no neutral handling). Great forehand bottom turns and staggered roundhouse cutties, but they are impossibly slow comming off the top. All efforts to use multiple fin clusters also failed. Its a single or nothing at all (an intriguing idea in itself). I guess I’m still searching for the Holy Grail - the perfect board: paddles like a 9’ 6" bottom turns like Velo and comes off the top like a 6’ 8" no-nose thruster, and pumps down the line like a little Liddle hull… Later…(Theres a nice head-high lined-up southwest filling in down here. First surf in about 3 months!) Newbs
hey, R.I., yes, performance alley is up in north miami beach, and still > pumping out cigarretees, donzis, and even magnums still (i think). the > mucle boats that dreams are made of. sadly, the ‘grandaddy’ of muscle boat > building, the guy whose name is synonymous with cigarrette and donzi, don > aronow, was murdered gangland style a few years back…right on the > premises. he was a real character! my dad built him some custom woodwork > for his house many years ago, and he couldn’t have been nicer to us. i’m > glad you enjoyed the link, and i wonder if we’ll be fixing dings with > blow-torches anytime soon… Ramon, We were in Fla., when Don Aronow was killed. It’s still unsolved ? When our daughters were younger, we would stay in Hyland Beach, Christmas,February and their spring breaks. We would do a long weekend, just the 2 of us, for the Ft. Lauderdale boat show, end of Oct.-Nov. I’m dangerous with the gas grill, God only knows what damage I could do with a blow torch.
What a pleasure to read a well-reasoned, well written discourse on > something I usually get blank stares or “Whatever, Duuuuude.” as > responses. I agree completely that the key to using flex on a standup > board is control; control of the amount, shape and location. The problem > that I have not been able to overcome is that flex tends to take a lot of > versatility out of the board’s performance. Follow the ski/snowboard > analogy for a second and you’ll see the problem (hopefully you’ve skiied > or boarded before).>>> To turn a ski, there are two design fundementals; flex and sidecut (the > concave shape of the ski outline). The more you bend the ski while on > edge, the shorter the radius of the turn. The limit of the turn radius, > however, is controlled by the sidecut of the ski. You can lengthen the > radius of the turn by getting off the edge quickly or decreasing pressure > and reducing the amount of flex on the ski. You cannot tighten the arc > beyond the design limits without skidding.>>> That’s been my experience with flex on standup boards; the arc of the turn > is dominated by the design (no neutral handling). Great forehand bottom > turns and staggered roundhouse cutties, but they are impossibly slow > comming off the top. All efforts to use multiple fin clusters also failed. > Its a single or nothing at all (an intriguing idea in itself).>>> I guess I’m still searching for the Holy Grail - the perfect board: > paddles like a 9’ 6" bottom turns like Velo and comes off the top > like a 6’ 8" no-nose thruster, and pumps down the line like a little > Liddle hull…>>> Later…(Theres a nice head-high lined-up southwest filling in down here. > First surf in about 3 months!)>>> Newbs Newbs, That
s exactly what I meant earlier, when I said much of surfcraft design simply accomodates limitations, rather than possibilities. It
s quite possible that a simple change of paradigm is more important to design progression than the discovery of new materials and methods of construction. By the way, you might take that snowboard/ski analogy and soften up the flex (but not torque) a bit in the ends. Fortunately for us, water bends! Dale
yeah, still unsolved after more than 15 years…due to who and how he was, there were enough suspects to fill a stadium; the mob, the cocaine cowboys who couldn’t buy his boats fast enough in the 80’s, ex-partners, ex-wife, girlfriends and mistresses, their jealous husbands and boyfriends, his competitors…you get the picture. this was a type A, life in the fast lane guy on steroids! you be careful with that gas grill, my friend!>>> Ramon,>>> We were in Fla., when Don Aronow was killed. It’s still unsolved ? When > our daughters were younger, we would stay in Hyland Beach, > Christmas,February and their spring breaks. We would do a long weekend, > just the 2 of us, for the Ft. Lauderdale boat show, end of Oct.-Nov.>>> I’m dangerous with the gas grill, God only knows what damage I could do > with a blow torch.
To turn a ski, there are two design fundementals; flex and sidecut (the > concave shape of the ski outline). Three: Add torque.>>> The more you bend the ski while on > edge, the shorter the radius of the turn. The limit of the turn radius, > however, is controlled by the sidecut of the ski. You can lengthen the > radius of the turn by getting off the edge quickly or decreasing pressure > and reducing the amount of flex on the ski. You cannot tighten the arc > beyond the design limits without skidding. On a snowboard you have more freedom in tuning the turn by moving your weight. Also, on both snowboards and modern carving skies, the limit of a thight turn is guide them three design factors + the sharpness of the edges, hold in the snow and the strength of your legs. At mid speeds you can tighten the turn to atleast 3 meters radius while keeping a carving track. Do the same at mach speed and one of the 3 last factors will fail. Thus I suggest that the board design is not the limiting factor(not entierly true, but there is some thruth in it). There are quite a few reasons I don’t think that snowboard flex knowledge can be used on a surfboard. First of all, sidecut, torque and flex are not independant designfactors, they all work together. In particular sidecut and flex, the sidecut give the board two pressure point to bend from and the flex stop as the whole edge is on the snow(providing the flex is right). I can hardly see how a surfboard with traditional shape can provide simmilar pressure(one reason I would like to try a swizzle). Another is how different the performance characteristics are on a snowboard vs. surfboard. Snowboards are going faster and have much more space to turn on. The 50 meters radius turn will never be of much use on a surfboard, nor will you use the snowboard to carve or cutback on a pipewall. Still snowboards turn in fresh powder without effort. Freshish is more like water then hardpack, possibly even less dense. What design elements govern these turns are still a mystery to me, but I know the board does not flex much. I have theories and I’m going to test some of them next winter on a no sidecut, no flex piece of plywood.>>> That’s been my experience with flex on standup boards; the arc of the turn > is dominated by the design (no neutral handling). Great forehand bottom > turns and staggered roundhouse cutties, but they are impossibly slow > comming off the top. All efforts to use multiple fin clusters also failed. > Its a single or nothing at all (an intriguing idea in itself). What is natural anyway? To me snowboards are natural, surfboards are not. I’m used to let the edges do their work, just lean on the edge and let the board do the work. Add pressure on the front foot and the turn tightens, lean back and streighten out. Maybe I should ride a singlefin? regards, Håvard
By the way, you might take that snowboard/ski analogy and soften up the > flex (but not torque) a bit in the ends. Fortunately for us, water bends! I’m not sure that water bends fast enough. Actually a little less torque rigidity could make a board fit better on the curved surface of wave, just like the surfmat. It’s the edge inside the wave that create the majority of drag and not the bottom of the board, right? In surfvids I often see surfers riding where the board, be it during a turn or riding straight, bobs up and down or vibrates and the surfer have to dampen this with their feet. It happens in extremly clean surf. It looks like the board wants to turn more all the time. This tells me there is something fundamentally wrong with the design. If the same happend with a snowboard it is because the flex and sidecut radius aren’t well tuned. On a surfboard it might be that the entry rocker and tail rocker are not well tuned to each other or the rocker and fins are not well tuned. Or maybe the board is not tuned for the conditions? I guess that flex(or lack thereof) is one of the reasons surfers have a quiver of boards while most snowboarders have one or two. regards, Håvard
Håvard, Youre right, it does appear that most of a solid board
s bottom while riding isnt always active, and a good measure of the drag while running at speed relates to the inside rear third of the design, its fin(s), traction pads and trailing leash. Ironically, a really good surfmat will operate with excellent handling and still go extremely fast by having a LARGER water contact surface! Some of the primary differences being hard, rigid, unyielding contours that penetrate vs. a supple, automatically adaptable, non-penetrating form that functions by means of 100% flexible memory. Improved efficiency will allow a single shape to achieve a much wider range, and is especially notable as surfcraft become smaller. Carrying this idea to its logical end, the designer will arrive at a place where the dimension and volume of a board
s accelerator and brake are operated from the same location on the deck, rather than having to continually adjust the handling fore and aft. In addition to all that, the importance of balanced handling characterisitics become even more critical as the size, length, texture and power of waves increase. “I guess that flex (or lack thereof) is one of the reasons surfers have a quiver of boards while most snowboarders have one or two.” Well said, Håvard! Dale
Håvard,>>> You
re right, it does appear that most of a solid board
s bottom while > riding isnt always active, and a good measure of the drag while running > at speed relates to the inside rear third of the design, its fin(s), > traction pads and trailing leash. Ironically, a really good surfmat will > operate with excellent handling and still go extremely fast by having a > LARGER water contact surface! Some of the primary differences being hard, > rigid, unyielding contours that penetrate vs. a supple, automatically > adaptable, non-penetrating form that functions by means of 100% flexible > memory. It's a bit funny that the fastest surfcraft is the one furthers away from the 'normal' or most used designs.>>> Improved efficiency will allow a single shape to achieve a much wider > range, and is especially notable as surfcraft become smaller. Carrying > this idea to its logical end, the designer will arrive at a place where > the dimension and volume of a board
s accelerator and brake are operated > from the same location on the deck, rather than having to continually > adjust the handling fore and aft. In addition to all that, the importance > of balanced handling characterisitics become even more critical as the > size, length, texture and power of waves increase. There are so many design issues with a surfcraft and I would be the first one to admit I know very little about it. Still, with the unpredictable and changing medium we ride on and all the functions a surfboard has to fullfil, it seems like an impossible mission. That said, there are still alot to be done.>>> “I guess that flex (or lack thereof) is one of the reasons surfers > have a quiver of boards while most snowboarders have one or two.”>>> Well said, Håvard! Thanks you. I admire your designs, your desire to build a better surfcraft and “to boldly surf what no surfer have surfed before”. Keep it up. regards, Håvard