**Hey! I just ran into these calculations that I put together a year ago, but never got around to do anything with it. It is based on a theory that all surfers should have the same change in rocker when they do a bottom turn (given same wave conditions and same board shape). Therefore the stiffness of the board, k, needs to be adjusted depending on the rider. The key phrase is "based on a theory"...I'm not claiming this is true...though I think there is some truth in it. _______________________________________________________________________ We have all come to realize that the average surfer should not be riding the same shape as a pro. By the same token, THEY SHOULD NOT BE RIDING BOARDS WITH THE SAME FLEX. Here’s how you customize flex: (THE ATTACHED SPREADSHEET DOES ALL THE CALCULATIONS DESCRIBED BELOW!) 1. Calculate how many Gs a rider experiences when they do a bottom turn. 2. Multiply Gs by their weight. This is the weight that the board experiences. 3. Calculate how much more (or less) flexible the board should be than the pro model 4. If a surfer requires less flex (more stiffness) then you probably already have the technology to meet their needs. These will typically be heavier surfers. In most cases, your technology is too stiff for the average surfer (who also wants a durable board), so you would need to develop a new technology that is more flexible(while still being durable). To get an idea of how flexible different boards are, I put together a spreadsheet that compares 7 different constructions to the pro model (PU with wood stringer, with 4oz top and bottom, Polyester Resin). All constructions use PU foam and Polyester Resin. There are 3 classic PU constructions that are compared to the pro model and then there are 4 sandwich constructions (yes, these are with PU, Polyester, divinycell sandwich). If you wanted to use Epoxy, the numbers would change very little (for a stiff epoxy), because these are k values for a board. However, natural freq. would change a tiny bit more because of slight increase in damping. Remember though that this theory is not based on finding an ideal nat freq. The spreadsheet compares each construction based on the following criteria: breaking resistance, dent resistance, flexibility, weight, and cost. For example, the spreadsheet demonstrates that the classic 8oz top / 4 oz bottom PU board: 1. Will break as easily as the pro model 2. Is 81% more resistant to denting on the deck than the pro model 3. Has the same resistance to denting on the bottom 4. Is 23% less flexible (or more stiff) 5. Weighs about ½ lb more 6. Costs about $8 more in materials The spreadsheet does not account for weight or cost of fins, and the cost of labor (depends on your methods and equipment). All these numbers are theoretical and vary based on the skill/methods of the craftsman!! -Buckling calcs were based on the Rayleigh-Ritz buckling model--beam with an elastic foundation. -Stiffness calcs were based on bernoulli plate bending model. -Dent calcs (if I remember correctly) were also based off the ******Rayleigh-Ritz buckling model. --this is pretty lame, but seems to reflect reality pretty well. Any criticism of this dent calc is warranted, and I will not defend myself. -The weight was calculated by some common sense method. -I don't remember where I go the numbers for cost. (if they were bulk prices or individual consumer prices???)****
Apparently, it didn’t want to attach the spreadsheet. Here it is.
https://swaylocks7stage.s3.us-east-2.amazonaws.com/s3fs-public/SurfboardTechComparisons2.xls
thats a nice comparison of builds, I’ve always wondered what the various standard builds produced.
They all look very light to me and I think would take expert building to achieve them. The ultra-light pro-model looks feasible at 2.35 kg - single 4oz all over. I’m using Mick Fannings boards as a benchmark for that statement -they are never > 2.3 kg according to DHD and that is achieved through blank weighing and extreme sanding.
To achieve the super-light retail board you specified looks a challenge to me at just 2.58 kg with 8oz on deck and 4oz on underneath but I’m no expert - perhaps some of the PU/PE industry pro experts on swaylocks can comment with their weights.
If your sandwich builds used PU (you do say they are polyester sandwiches which is incompatible with EPS) then thats not really a meaningful build and I think very hard to achieve the weights you specified. Also sandwich build with stringer is not the usual - although you do give the sandwich without stringer as well.
The ultra-light pro-model looks feasible at 2.35 kg - single 4oz all over. I'm using Mick Fannings boards as a benchmark for that statement -they are never > 2.3 kg according to DHD and that is achieved through blank weighing and extreme sanding.
5.180575 pounds or 2.35 Kgs is achivable with a 4oz bottom 4oz deck with a 3/4 deck patch sand finish. Resin needs to be warm as well as the room. Also use the lightest PU Blank. I use a US Blank Red formula with a 1/8" Ply stringer. The board will be less than 5.25 pounds or 30 grams heavier than your model.
Sandwich Build with a special core and secrete sauce is: 4.5 pounds or 2.041279201 Kgs
These are all the same shape just different materials.
6'1" x 18 3/8" x 2 3/16" 11 1/4" Nose 14 1/8" tail
To achieve the super-light retail board you specified looks a challenge to me at just 2.58 kg with 8oz on deck and 4oz on underneath
5.68761 pounds or 2.58 kgs is obtainable for retail by 4+6 deck 4 bottom sand finish again warm room and well sanded with no weave showing... Lighthest density PU.
Benjamins pretty close!
By the way DHD's boards for Fanning are extremely well made (Shaped) from a Professional level of Performance regardless of the material used. The foil on Mick's boards are spot on! Very impressive boards! However Mick is a impressive surfer and needs equipment that good.
Surfding
The core for all of the boards was 3lb PU foam. You don’t have to use EPS for a sandwich core, even though everyone does. The point of the spreadsheet was to isolate the core variable and board geometry, so that I could see how different layups affect the properties of the board. If I didn’t isolate this variable it would be difficult for me and others to see where the enhancements come from.
You see that a 12oz/8oz board is the strongest board, but the board weighs a bit more (some people may like) and there is a huge stiffness disadvantage (at least for me…which is why I put in the equivalent surfer weight calc). If you plug in a 220 lb surfer and look at the desired flex for a 220 lb Pro level surfer, you’ll see that he needs a board that is 47% stiffer than the average pro(which I set at 150lbs). The 12oz/8oz board is 47% stiffer than the standard pro-model board, so that would be a candidate. The caveat is that all these calcs are for a board that is 6’x12"x18.5"x14"x2.125", and I doubt there is a 220lb pro that rides this shape. Larger surfers ride larger boards which will be stiffer without changing the layup.
Again, the point of the spreadsheet was to isolate the core variable and board
geometry, so that I could see how different layups affect the
properties of the board.
Be careful, Benjamin. You're going to mess up the party line that says the ''stock'' pu/pe boards ride just like ''what the pros ride''.
cheers Surfding, I was hoping you would come up with some weights.
Benjamin, I was focussing on what are sensible sandwich builds and weights, however I get one of the main points of the spreadsheet now - a point made by your resonance test - board flex needs to take rider weight into the equation to make a meaningful comparison.
Mike, yes yourself and Surfding have pointed out that ultra-light pro build is not the same as retail super-light and nothing like retail robust build. However I think board weight is a preference, my mate (same age as me 48) is a very competent surfer and likes a little extra weight than say what the tufflite comes in at (he has been thinking about swapping his tufflite McCoy for a PU one). He has nothing to say on the subject of flex. His brother visited here from NZ and brought with him a Placebo brand flex-lite and was raving about it - super-light and flexy - Placebo is M. Biolos design epoxy made in Vietnam - not available in Aus - at least I’ve not seen it.
Then there is me - I’m on super-light sandwich and if you put my bodyweight (55 kg) into the equation I’m on ultra-stiff and I love it. I have specific needs - need to throw around oversize chips and get max response from the high-frequency pump - if I could get ultra light and ultra-stiff I would, but its not available so I settle for super-light and ultra-stiff.
Another thing that can be seen from the spreadsheet is that weight is not synonomous with flex or durability. I went on a rave in another thread that durabilty and board stiffness are not the same thing, but I should have also mentioned weight. Personally, if I wasn’t trying to do airs I would rather have a heavier board…an 8lb performance board. It seems so strange to me that people who want more weight, do it by adding more glass.
Here’s my dream:
-All boards should be made at least as durable as the tuflites
Then for any board, a shaper has
-3 variations of flex: stiff, standard, flexy (where standard would be pro model and flexy would be more flexible)
-3 variations of weight: ultra light, standard, heavy
That’s 9 permutations of the same board shape. It could be done economically today, if somebody really wanted to. However today, a surfer can customize a shape how he likes or find a stock board that meets his customization (to me, both routes are equally good). But in both routes, you’re usual stuck with a technology with some mystical flex pattern and some mystical buoyancy (“Dude, this eps is super buoyant!”…you’re kidding right?)
I want to be able to go to a shaper or shop and tell them that I want a board that’s good in xyz conditions; they size me up; they fit me with a shape; they say that I can have that board in 5lb, 6.5lb or 8lb weight; I say 8lb because it is for strong off/cross-shore wind, no-aerial surfing in hawaii; they say okay, do you want it standard flex, or 15% stiffer or 15% more flexible; I ask which one is more durable; they say that all boards are rated to last X number of sessions; I say "really?! in that case I’ll get 15% more flexible. They look at me, “no big deal, it’s not in stock, but we’ll order/make it to your specs”…Today, they would look at me like I am crazy and say “you’re dreaming.” --you’re right, I am. But, it’s just a matter of time before it will happen, and someone is going to have a lot of happy customers. -I’ve noticed some people on this forum are headed in this direction.
Nah man, that 'dream' scenario is available to you TODAY if:
1. you have a good surf budget and work closely with more advanced builders - ex. Mike D @ Coil and others like him
2. you have lots of time and DO IT YOURSELF, iteratively
3. you just enjoy your ride and be thankful your surfing and not somewhere else far less desirable, like fighting in iraq or afghanistan
Its here NOW.
The only restrictions is time, money and proper attitude, if you dont have lots of that, there is a tendency to feel unsatisfied.
Slater has all three of those so he's not complaining.
If a pro surfer was my weight of 70kg what would be their board dimensions for say a 6 ’ 3" length be? Width, thickness, volume?
Mark
looking at http://www.aspworldtour.com/2009/profiles_men.asp then their regular ride would be < 6’ 3".
eg.
Taj Burrows, 72 kg
lots of 5’ 11"
Mick Fanning 72 kg
five 6’ 1"
so although they have quivers my guess is that their 6’ 3" boards would be for quite challenging waves.
Mick Fannings board dimensions are 6’ 1" x 18 1/4 x 2 3/16. Single to double concave.
I picked 6’3 " as its my go to winter board. I can and have surfed it in chest high slop though. Its 18 1/4 and 2 1/8 with deep 5mm concave and 6" nose and 3" tail rocker. Probably way more rocker than is fashionable these days. On average small days its not out classed in speed or manouverability by other allegedly more user friendly designs but really shines in critical waves. Same model and size ( well thinner really) is surfed by a way better surfer than me and he is 14stone/89kg. As you may guess I completely disagree that boards designed for pro surfers are unsuitable for average surfers. Unless average is way lower than competent.
I don’t want a dumbed down board. So give me Fannings board and some decent waves and especially if it is only with 2 people in the water (heats with a priority system) then I reckon I have a fair chance of being able to catch and ride those waves. Obviousely not to that standard but I wouldn’t expect to look silly either.
I have noticed that shapers tend to ere on the side of flatter and more volume. Is this because they don’t want the customer coming back not being able to catch waves and labelling the board a dog?
Mark
Mark, your go to board has comparable dimensions to my 6’ 3"
Pancho
Sullivan TL2 - which has a whopping 2 7/8" of tail rocker although
the concave is just 3-4mm max. Pancho Sullivan is a power surfer
renowned for surfing pipeline - Its supposed to be taken from his
contest board and it goes great for me in all sorts of waves - I’ve
used it down to 2’. It really excells in bowly type waves and point
surf. For the first time in decades I’ve been able to go into the front
foot pressured cutback where a long length of the rail is engaged
through the turn which feels fantastic - I think I used to be able to
do these on my squirrely MR style twinnies 2 decades plus ago. So no I
don’t see why a board should be de-tuned either provided it is big
enough. There is nothing difficult about riding this board, however the
high tail rocker does require me to dance around on it in flat sections.
There
does seem to be a case for having boards with different rockers though
- my latest aquisition is the Byrne Phil Macca 6’ 1" and although I
haven’t put the rocker stick on it I’m convinced it has lower rocker
from the way it behaves - I’ve put 10 sessions on it so far. It is
better at maintaining speed in variable beachbreak.
Phil Macca is
also renowned as a power surfer, so its rather funny that both these
boards are great for me (little skate type surfer). So my way of
dumbing down the boards to allow my ordinariness to cope is to go
bigger than what the pros would ride. However in my more youthful days
5’ 10" twinnies were my standard shape, so if I was younger I’m sure I
would choose shorter than my current quiver.
I think Mick
Fanning has boards the same length with different rockers and I assume thats usual for the pros, so I’m wondering if I got one of Macca’s
flatter boards. I’m happy anyway, through happy accident its a perfect
complement to the Pancho Sullivan, I had no idea of the rocker when I
ordered it.
Some more examples of WCT pros and their board sizes. These two have shapers from Swaylocks.
Kieren Perrow 68 kg - quiver from 5’ 11" - shapers DHD and Yorky
And now for someone closer to my size:
Aimee Donohue 57 kg - quiver includes two 5’ 10" shortboards, shapers include Dave Verrall aka feraldave
after checking some other profiles my 6’ 1" Byrne Phil Macca board is at least 3" oversize for me.
Got the rocker stick on it this weekend in
my mate’s garage. I was correct, but its not as low as I thought, I
guessed it would be closer to 2" of tail rocker due to the very
different feel it gives me from the Pancho Sullivan which has 2 7/8" of
tail rocker. However rocker specs are:
Nose 5 3/16" Tail 2 1/2"
After
my Pancho Sullivan experience I was expecting another rockered out
board due to Macca also being a power surfer, but I didn’t. However its
best it worked out this way - now I have a quiver with rocker to suit
different wave types. Board has now clocked up 15 sessions
That also seems to be
correct, I emailed Byrne and they
replied telling me that Macca gets the same template made in polyester
with different rockers and fin angles. So its quite possible the public
gets the Macca board in one of the more detuned/general purpose configurations, however my
Pancho Sullivan isn’t looking detuned due to its fairly extreme rocker.
[img_assist|nid=1047601|title=Measuring Rocker of Byrne Phil Macca 6 1|desc=|link=none|align=left|width=640|height=480]
Thats a question I’ve been asking myself for some time and as a result of riding my two recent “pro” models, I think I might have some of the answers.
Although I did say that my two recent aquisitions are not particularly difficult to ride, the name potato chip doesn’t exactly inspire a image of user friendliness and I think there is a certain amount of difficulty built into these boards, all for good reason.
So why so thin? Jumping on my Pancho Sullivan after stepping down from the chunky Flyer 2, one of the first things I noticed was the ability to bury rails. So although I can never be a power surfer I can get to experience gouging a wave more on a pinched rail board. So thats the thin rails, but I was wondering why so thin in the middle? In Mark Occhilupo’s book there are several pictures of him burying half his board in a full rail turn all the way up to the stringer - including when he was going through a chunky railed phase in his career. Not even all the pros are as powerful as him so if they want to bury half their board I can see why they would resort to thinner boards. I’m never going to do that so getting pinched rails is enough for me.
Mick Fanning in his book says that he matches rocker selection to the wave and as you and I have both discovered we can get our high tail rockered boards to work, but there are disadvantages in flatter waves. For the dumb user like me high tail rocker makes front foot surfing easier - the board will hold its arc through a full railed cutback with plenty of front-foot pressure without accidentally catching a rail.
Why so narrow? I get the impression that all the pros are really good at front foot surfing - I haven’t figured out whether they are generally front foot surfers or not, but heavy loading of the front foot is the only way of getting the full rail bury power at which they are all so good at. As I discovered on my Pancho Sullivan a heavy front foot heelside turn can cause my toes on front foot to lift off the board and that effect would have been much worse on a wider board. So I think to front foot bank and bury, the narrow board is necessary.
Fins are also packed close together. The thing I have noticed with my two pro models is a feeling of having the rear foot behind the front fins and having to use front foot pressure to keep it all under control without overturning - this creates finer control but doesn’t suit the “just stamp on the tail” type of surfing. These are my experiences anyway.
Could we move this “pro design vs. average surfer design” to it’s own thread? I have some thing to say about it. In short: no, they shouldn’t be the same. And it’s not because of paddling or dropping in.
Yes, I’d be happy to move over to a new thread. A lot of threads do end up like this and get sidetracked on swaylocks. How shall we do it? we could start a new one and link to this one. Copying and pasting is a bit tedious.
Easiest is to rename this one?
PS. I’ve already given my personal pro-design versus boards for the masses preference. I want to pick out a few pro-designs, shape absolutely unmodified, but choose various rockers from their considerable selections. Get them built ultra light (down to 2.3 kg), but much stiffer.