" When it comes to a board having a good or bad "feel", one of the primary components is the amount of foam contained in the rail. The overall thickness of the board down the center is important, but how that thickness is carried out to the rail is absolutly crucial to performance. Among top surfers various rail volumes suit each one's style a bit differantly. For example, Bobby Owens at 140 pounds prefers a very, very slender rail with as little volume as possible. On the other hand, Shaun Tomson at 175 pounds prefers a rail of substantial volume and fullness. While there is a signifcant differance in their body weights, the actual center thickness of their boards varies by less than would be expected. This indicates that a board's center thickness is less important to them than rail volume is, and rightly so. The way a board rides is much more dependent on rail volume than overall center thickness. The effects of this are felt primarily during the weighting(sinking) and unweighting(releasing) of the board throughout the turning process. The actual shape of the rail area can come in many differant forms, many of which have several differant volumes and will feel quite comprable to one another during weighting and unweighting. Among good surfers I find that we rarely talk about the actual shape of the rail, all our time is invested in getting the volume correct. I will be the first to acknowledge that rail shape is an important aesthetic feature in an attractively built board, but its worth in the area of function, though respectable, is often over-emphasized. The rail volume as it compares to an unchanged center thickness is affected by two main factors; one, the amount of vee in the bottom, and two, the amount of dome on the deck. If you have alot of vee and a very domed deck the rail will always be thinner than the center thickness. You can form that rail into various shapes, but its volume cannot be increased. To increase its volume you will need a flatter deck or bottom so that the available thickness can be carried out to the rail area. Once you have determined a starting thickness for your boards you can begin trying differan board shapes to arrive at the board volume most appropriate for your style. I suggest you make most of the changes to the rail volume from the deck since you need to secure a bottom shape that is workable for your needs and once you find it you won't want to be changing it too much. The extreme results of a very domed deck or a very flat deck are rails either so sloped and thin or so full and boxy that very little can be done with them to refine their shapes. Rail volume and shape are probably the most difficult areas of a boards shape to consistently arrive at, even for the expereinced shaper. While other areas of a board's shape can be measured in some simple manner, the rail area can only be felt and eyed until the proper shape is gained. This is a highly error ridden method for acheiving something so important. The differance between the size of your hands, or the fact that one of them has been holding the planer all day can grossly effect their ability to feel accurately. Anyone who has experience in the field of Industrial Design knows how easy the eye's perception of a form can be altered by numerous factors." Article by Bill Barnfield -------- Surfing Magazine May 1985, Volume 21, Number 5
Borrowed this from Surfing Mag. Would have posted it under the numerous threads that Bill has contributed to concerning rails, rail marking etc. But This kind of thought and insight into design theory is "Stand Alone" . Thought it would be of interest to all and most especially the author, as it may have been awhile since he has reveiwed this series of design articles that he did for "Surfing" in the "80's. All of these articles are a good read and though some things have changed as surfboard design has progressed, many things remain the same. Would have posted this a couple of nights ago, but I'll be darned if I dldn't get down to the last word, hit the wrong button and lost the whole draft. Using my laptop and don't have a scanner or I would have attemtped to do it the easy way. Now that you know the effort it took, please forgive the typos etc. For your reading and thought provoking pleasure Lowel
Thx, that was a gem.
Personally I'm always ready to learn, although I do not always like being taught. - Winston Churchill
Very Appreciated!
Amazing contrast between the depth of thought in this article, and the superficial treatment that the magazines print today.
http://markmillerconstruction.com
Aloha Everysurfer and others
This thread slipped past me earlier, sorry I am coming in so late on it now. Firstly, thanks McDing for digging that up and posting it.
Your comments above are so accurate. As we have all noticed there isn't any ongoing design discussions in the magazines anymore. It is all style and very little substance. When Surfing magazine asked me to contribute an ongoing series of monthly articles on surfboard design, I was pretty excited but also very wary as these things are never managed in ways that best benefit the consumers but rather the bottom line of the magazines.
The original agreement was that I would have a full page every issue that I could also use graphics and photos in to better define and clarify the subjects discussed. That would still allow for about 1,000 words and as such the articles could have strong presentation and depth of information. By the time it got going it was reduced to 500 words and no pictures or graphics. This made if very difficult to approach any design subject in any depth and forced me to be way too brief and often use language that wasn't as easy to understand.
I have joked about this before, but I used to get two kinds of letters. The first type were ones thanking me and complimenting the depth and breadth of the subjects discussed. The second type were ones saying the words used were too big and the subjects were too confusing. The magazines were most worried about the latter. Seemed to me they wanted something more like this. .......
Today we will discuss board thickness. Thicker boards tend to be thicker then thinner boards while thinner boards are generally thinner then thicker boards. Stay tuned because next issue we will discuss board lengths and how longer boards tend to be longer then shorter boards.
Exciting stuff! No? Luckily we have the Internet now so one's design knowledge isn't restricted by the Major Magazine's "FILTRATION" processes.
Those columns lasted a couple of years but the magazine never could get a grasp of the real value in them or the subjects discussed. The space was seen as wasted, since it couldn't be directly turned into revenue for the magazines. And yet, even decades later, well known shapers continually tell me how much they benefited from those articles and how it helped inspire and shape their early interest in surfboard design and construction.
The payoff for these kinds of subjects being in magazines is not immediate economic rewards but rather the long term nurturing of curious young minds into being the new leaders and master craftsmen of the next generation. But that kind of thinking is probably well beyond the concerns of modern mainstream media these days.
Now THAT'S thought provoking! :)
Yeah , thanks for that , a great read.
That's a nice case Bill puts forward for using rail templates , too.
Great writing, reflecting deep thinking... from a generation ago?! And today, we're still thinking about the same things! It's suprising how many sufers don't distinguish rail shape from volume, and their almost independent effects on performance. Here's something I wrote not too long ago, that might suggest a different way to see things...
".. Normal.dotm 0 0 1 39 225 Monmouth County Vocational School District 1 1 276 12.0 0 false 18 pt 18 pt 0 0 false false false even small changes in rail shape and volume can have dramatic effects on how a board performs, and something like a miscalculation in volume, or a misplaced edge, can ultimately become a “make or break” design element in what would otherwise be a finely tuned surf craft.
It is helpful to view rail shapes on a continuum, from hard – having a distinct, hard turn or corner at the bottom of the rail, either created by the shape of the rail, or a bead of resin that is carefully sanded to a sharp edge along the bottom of the rail (or both), to soft – completely rounded, having no edge or corner at all. These two extremes are at the ends of the spectrum for most modern rail shapes, and in the middle there is an infinite continuum of shapes and combinations of shapes that gives the designer/shaper a lot of ideas to play with. To clarify, a rail’s shape can be hard or soft, just as a rail’s edge can be hard or soft – confusing terminology. But it should be understood that a rail can either be hard or soft, depending on it’s shape, and may or may not have an edge… and that edge may be hard or soft itself. Normal.dotm 0 0 1 27 156 Monmouth County Vocational School District 1 1 191 12.0 0 false 18 pt 18 pt 0 0 false false false And in addition to hard or soft rail shapes, and hard or soft edges, there is also the matter of rail volume, which becomes another determining factor in a rail’s overall shape and performance.
Later...
"Rail shapes are not only modified by the location of the apex, but also by their volume. While changing the volume of the rail alone without changing the rail’s shape can be accomplished by simply scaling an existing shape down to the desired volume, a shaper can manipulate both volume and shape using a variety of basic, tried and true rail designs. “Egg” rails, “pinched” rails, and “knife” rails are three commonly used terms to describe a sequence of rail profiles that effectively reduce volume and manipulate release without the use of hard edges.
And later...
" For the most part, the foil of the rail – its change in volume as you go nose to tail – should be smooth to minimize turbulent drag and create the feeling of balance and predictability for the rider. Abrupt shape or volume changes along the rail greatly increase drag as the laminar flow along the rail is disrupted and deflected. Viewed from the side, the thickness of the rail should flow, gradually thicker, then gradually thinner, without noticeable transitions between changes in rail volume, apex location, edge, etc., except for the deliberate introduction of bumps, wings or the like, as discussed earlier.
The modern performance shortboard rail is a perfect example of how different rail profiles can be combined along different lengths of rail to achieve a very complex final result that allows the rider to use different sections of rail for different purposes at different times. Particular attention should be paid to the smooth, seamless, nearly unnoticeable transitions between rail profiles as the rail is dissected from tail to nose. This is perhaps one of the greatest tests of a master shaper – the ability to blend dynamic contours that are sometimes very different from one another into a graceful combination of design features that all fit seamlessly together.
Sorry for the messy formatting...
hi nj,
we're lucky in this respect only because the internet gives us the opportunity to consolidate and add to what's been documented previously.
if pioneering foam shapers & HWS builders had this technology in their day, consolidating and passing on to everyone here all their accumulated shaping expertise, we'd probably be thinking about... more and more of the same things! hehe " )
great thread btw
Very interesting... if you want to quantify that, what part of a cross section should arbitrary be considered as the rail ? 2 inches from the apex towards the center? Let's say I want to compare the volume of 2 different rails in the middle of a board, I have to compare the surface taken by the rails on each cross section, are there any proven method to put numbers on that variable? With such numbers, it would in theory be possible to test different rail shapes with same volumes to isolate variables. My understanding is that it would be best to know which rail volume suits you best before tweaking rail shape around that volume as the first factor has more impact then the latter.
You can compare rail volumes by either making a mold of the rail that's a specific length, and filling it with liquid, and measuring the liquid, or the opposite... make a mold of the rail, fill the mold with pour foam, cut a specific length of that foam, then measure the volume of liquid it displaces when submerged. A less accurate way is to measure the circumference of the rail to a specific distance in from the apex. Longer circumferences mean greater volume.
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