Boarding School: Flex
By Cory Russell
In the last episode of Boarding School we looked at volume, a relatively new and contentious way of quanitifying surfboards. For this entry we’re gonna stay on a modern tip and discuss a new, but also kinda old, surfboard characteristic - flex.
It was George Greenough who initially got me thinking about flex in surfboards through his spoon design as well as his love for riding inflatable surf mats. George’s motivation was always about fitting the wave and harnessing its energy.
The flex properties of a surfboard are often discussed amongst surfers and shapers with various experiences and opinions established yet little in the way of objective analysis.
The truth is there's been very little research done about how our surfboards flex during use. We're able to document the specifics of each material used in surfboard construction but the assessment of the final product is difficult to calculate. It's even harder when varying ocean conditions are added to the equation; a surfboard may require different amounts of flex owing to a person’s weight and the waves they surf.
I don't have all the answers to understanding flex in a surfboard but I'm determined to know more. In an effort to explain the flex properties of a surfboard I've provided a list of the defining factors.
Foam Core
The foam used in the majority of surfboards is either polyurethane (PU) or expanded polystyrene (EPS). For PU, a mixture is created and poured into a mould by hand. Attention to detail can't be underestimated as the goal is to produce a consistent density of foam throughout the blank. Failure to achieve this will result in a blank with varying densities which creates unpredictable flex and unwanted soft spots. PU blanks are available in various densities from heavy to ultra-light and they all have different flex properties. In Australia, we're blessed with a number of PU blank manufacturers that consistently produce great blanks for shapers.
Expanded polystyrene is created from small pellets injected into a mould and expanded using steam. In the past, shapers have manufactured their own blanks from blocks of EPS but I find the producers are unable to maintain a consistent density. The best EPS for surfboards is created in specific moulds under pressure. Unfortunately, there are no local manufacturers for these types of blanks - they must be imported from the United States. I've used many types of EPS blanks and Marko foam is definitely the leader in this area. They're constantly improving their products for manufacturers.
Stringers
The stringer or lack of is the single most important factor in determining a surfboard’s flex capabilities. The type of timber, number of laminations, and thickness all determine the amount of flex. Surfboard manufacturers have experimented with the stringer structures for decades and the two main stringer constructions are traditional and paraboilic.
The traditional use of a stringer down the centre of the board provides structural strength and resistance from nose to tail, yet it allows the board to flex in a twisting motion. The use of multiple stringers spread across the width of the board provides more strength and reduce a boards twisting flex.
There has been a variety of methods applied to the traditional stringer construction including the tapering of the stringer as it travels from nose to tail (see the work of Jed Done). Also, I recall Rusty Priesendorfer making boards for the Hobgood brothers many years ago with a ¾ length stringer to increase the flex in the tail.
Parabolic timber stringers have been explored a lot in recent years. The motivation for shapers to use this type of construction is to improve a surfboard’s ‘torque’ by increasing the stiffness around the perimeter of the board.
I refer to ‘torque’ as the efficient transfer of energy between the rotational force applied by a surfer compared to the response provided by the surfboard. A parabolic stringer limits the amount of twisting flex. The amount of flex in a surfboard can slow the board’s response time as it bends and twists. More flex means more lost energy.
I recently spoke to Elliott Bemrose from Core Surf Industries who explained the combination of the stringer to foam density is equally important as they should compliment one another. He told me there are some manufacturers that specifically request different tensile strength stringers but often it is more about aesthetics or what the pro’s are riding.
Fibreglass
The fibreglass cloth we use on surfboards has changed a lot since we first started using it over sixty years ago. At the time the fibreglass cloth available was not specific to surfboards and was particularly heavy. In the first issue of Surfer magazine (1962) an ad for Dave Sweet Surfboards advertised 20 ounce cloth. The standard these days is 4 or 6 ounce!
Aside from weight, surfboard manufacturers must consider the actual fibre strand, weave, clarity, and whiteness. The weave is the main factor when talking about flex. Standard fibreglass (E class) cloth is made with fibreglass strands running nose to tail as well as running at 90° from rail to rail. There is also ‘S’ class cloth available which has an increased number of fibreglass strands running from nose to tail which reduces longitudal flex. The tighter the weave the stiffer the board, while loose or open weave will provide more flex.
These days there are so many different fibreglass cloths available as well as the introduction of fibreglass cloths that have been knitted. The additional knitting of the weave in fibreglass cloth reduces flex while providing more strength. This type of cloth is popular on stringer-less boards.
The use of carbon fibre on surfboards has reached such high volumes that it can be hard to find a surfboard that doesn’t have any carbon fibre on it. Carbon fibre is extremely strong and was designed to provide structural strength, yet contrary to what people think or the marketing spin, when a piece of carbon fibre tape (as found on the tails or along the centre of most surfboards) is laid flat on a surfboard it provides very little strength if any to the structural integrity of a surfboard. It can alter the way a surfboard flexes the same way an additional equivalent piece of fibreglass would.
However, when carbon fibre is wrapped partially or completely around the rail of a surfboard it can provide structural strength. Stringer-less surfboards with carbon fibre rails rely on this structural strength and they create a reduced amount of ‘torque’ compared to the timber parabolic stringer construction. The stringer-less carbon fibre rail construction flexes a lot more and this increased flex makes these boards a great option for waves under 3-4 feet. The reason is due to Newton’s third law of physics that ‘for every action there is an equal and opposite reaction’. A board with greater flex will react and respond quicker compared to a stiffer board. This is ideal for short, quick turns not long, drawn out ones.
Resin
There are two types of resin used in the construction of surfboards: polyester and epoxy. Polyester resin has been the most widely used but things are definitely changing. As a general rule, the tensile strength of a polyester bond will be around 20 percent weaker than epoxy. Epoxy resin has greater resistance to wear and which is sometimes referred to as the ‘Barcol’ factor. Years ago epoxy resins were difficult to use, they weren't clear, and had inferior UV inhibitors so they would go brown quickly. Nowadays, manufacturers have created excellent epoxy resins for surfboards that are easy to use and comparable to polyester resins. Surfboards constructed with epoxy resin are usually post-cured in an oven at high temperature and ready to surf soon after they come out. For the first time ever the market place is demanding more and more boards be constructed using epoxy resin.
****
As you can see there are so many elements that go into making a surfboard that it's almost impossible to re-create a magic board. The amount of flex and where a board flexes is a key element. When flex is isolated to a specific area of a board it can be a great enhancement to the design. Mitchell Rae from Outer Island surfboards has been committed to understanding flex in a surfboard and using it to our advantage. Mitch’s flex tails are well known and revered around the world. His dedication to his craft is of the highest standard and the application of knowledge, design and materials makes him an expert in my opinion. Mitchell doesn’t follow market trends but creates what works from the feedback he receives from his customers.
A few years ago I started talking with Guy Walker from Geoblanks and was immediately impressed with his dedication to isolating flex patterns in a surfboard with his EPS blanks. Guy uses a series of hexagons with various densities arranged and fused together to determine the flex in a blank. He's taken a short hiatus to improve the technology but they'll be back on the market shortly.
Nick Miles is a passionate shaper on Sydney’s northern beaches and is dedicated to creating a better product. Approximately 18 months ago Nick created a blank design called X-Core that uses carbon fibre stringers placed on an angle and in a butterfly shape in an EPS blank. This design aims to provides strength and resistance where you need it but also increased flex through the tail. Nick is always thinking about how he can keep improving surfboard construction and an exciting guy to talk to.
As surfers we generally prefer a surfboard to be more rigid between our feet but an increase of flex in the tail of the board allows for tighter turns at high speeds as well as a level of forgiveness. If a board has too much forward flex the board will push water when it bends in front of your front foot.
At the beginning of the article I mentioned there's been little scientific reserach done on flex in surfboards, yet there is an area of science that covers it. Scientists refer to the ‘Modulus of Elasticity’ to measure an object's resistance to being deformed elastically. I have no doubt the rigours and demands of surfing will see the technology improve and, just as volume has become a measurement, so too will a modulus number.
That's all for now,
Cory Russell
Shaper
Cory Surfboards / Stretch Boards Australia
Outline
Rocker
Foil
Bottom Curves Part 1
Bottom Curves Part 2
Volume
Comments
Its not rocket science(only nature!)
GGs observations of how things worked for fish was a major factor to his spoon.He showed the surfing world what could be done on a wave.A fish moves its torso/tail to gain propulsion and the flex tails we have seen so far copy this.
Its just a matter of time and flex will make a significant contribution to waveriding around the world(wont be too long).
Ah yes the surfboard "bow and arrow" effect! Comes twice in your turn from you fins and your board!
I find a carbon strip down the center of the bottom stiffens up the stick a little creating a larger spring effect!
Speaking of flex evo! I will now flex my brain at you a little!
If you rember a couple of weeks ago I said I had a vision of 8-10ft jbay with a wilko win!
25ft at 15secs should do it . .
I think the carbon on just the bottom helps in the same way a arrow is shot from the bow!
The carbon on the bottom acting as the string and the board the bow!
You are in hindsight the arrow!
Hi Winkipop2017,
I like your analogy but a bow string is without structural integrity and therefore must be securely attached to the structure of the bow. Some surfboard manufacturers would be pleased to hear you 'believe' it provides more spring and strength etc but it is only minor if any. The main motivation of these manufacturers is purely aesthetics.
Hmmm I have found the boards I have with the bottom carbon strip draw a much harder line off the top!
Placebo?
Hey Winkipop,
Can you describe the way the carbon was used on the board you are referring to... where was the carbon? Where did it start and finish?
In the middle about 5inchs wide and from about the top of the side fins to about half a foot of the nose.
Be interesting to see if a surfboard with carbo had more "pound for pound" flex/harder spring back than one without must be hard to measure. .
I'm thinking in surfboards and water minor difference make huge differences.
As if a fin is a few millimeters forward or back it will either stiffen or loosen a board sometimes dramatically..
Also that sharp edge on a rail...
Its only a mil high if that! But if it runs more than two hand lengths from the top side fins you will find you board has no release and doing say a tail high air! Very friken hard just because of that fine edge!
So... if you believe carbon fiber laminated down the stronger provides structural strength and the carbon fiber stops before the fins... shouldn't the flex in the tail increase? Making it less rigid when you turn off the top of the wave?
I guess that depends on whether your a front foot surfer or back?
I think with most turns being tail high these days there is a shift from most of the weight on the back foot to the front!
If you can Imaging a woman's stiletto shoe travelling across a wave ( the same shape as most performance boards) these days you have most weight on the front while the rocker at the back is lifted with water pushing it along behind!
Now during a off the top tail high I would go into it with a bottom turn! Release my weight and go vert up! As i feel the thump of the lip in the middle of my board I would remove all weight to the front foot in the middle of the board! While rotation my body and dropping the left arm.
Most of that turn is done with me left foot I'm a natural footer!
Hey Winkipop,
The way I see it, It doesn't matter whether your a front or back foot surfer... a turn off the top of the wave is initiated with your weight on your back foot and it remains there depending on how sharp you want your turn to be. As you complete your turn your weight should shift to your front foot and try to get your chest over your knee to make to way down the face again. This is what I based my previous response to you on and wanted to clarify. Cheers
No offence! But that's ridiculous! A lot of Danes off the tops are very front foot driven!
I just had a look though the internet and found this in 30 seconds!
Pay attention to the third paragraph!
The a) answer will usually indicate a front-foot-oriented style, the b) a back foot.
Deck denting is another good indicator of consistent pressure, although it can't always be relied upon, since most boards are a lot thinner through the tail and show tail dents in a correspondingly exaggerated fashion.
Of course, the likely truth is that you're neither. Very few of the current cream of the crop pros can be said to be "front-footed" or "back-footed". Elite surfing technique has gone well beyond that level of analysis. A top surfer today might be back-footed at the start of a turn and front-footed at the finish, plus any combination of both all the way through.
Design-wise: what's more important than foot orientation is intention. A front-foot-weighted surfer might benefit from the concave run a little further up; a back-footer might prefer flatter rocker curves. But the bigger questions will still revolve around wave type, size, and character.
Here's another weird one to think about: If you're back-foot-heavy in your normal stance, what would you be if you switched feet?
I lot more turns these days begin under the lip! So as you're looking up its already pitching! you drive up and around with the curve! Not snapping with you back foot as to do a snap! But continued front foot drive and relaxed back foot pressure as to make the loop "tail high" off the top to the beach!
Or maybe that's the "new school" of the top!
Down carve and Jack freestone come to mind for a great front foot topturn/carve.
Most of this is front foot driven..
https://m.
Oh and Cory! I respect your shaping and wave knowledge! Nothing I say means more than asking your opinion! Seriously!!!
Now see that vid below and slaters last reverse? How front foot driven and pivoted is it? And guided by his frontfoot it is?
Right driven and guided by his front foot and powered by his front foot on that turn hey?
Again your the pro! I am just ?????? It's physics:+) a little more flicked by the back leg thanks to easing need off pressure off back foot.
These days due to flatter nose rocker and higher tail lift ! while you can see all the leg muscles flexing most turns in the front leg????
I think Cory the front 1/3 is the planning surface now while the tail is lifted!
Which will favor more front foot pressure?
My bizarre "Stilettos" effect!
Hey Winkipop,
It's all good... I thought we had just exchanged ideas and opinions. I am always up for talking about surfboards and surfing. My take on the questions you posed about front foot vs back foot can be found in my rocker article. Cheers
Cool.
It may "not be rocket science" but just you try and measure it, espeically when flex changes it through a material. Greenough's Velo had an increasing amount of flex through the tail. Hold one of the originals up the light and you'll see layers of glass behind the fin, so it may have had ten layers just behind the fin and was stiff, decreasing down to about four layers at the end of the board and was very flexy.
How do you measure something that has changing flex patterns?
If you thought volume measurement was a pain in the arse wait till this lands on your doorstep.
@kneepete, is there a need to measure it?
MAY? have had ten layers?...how did you count these?
ABOUT 4 layers?....have you ever laid a fin panel up?
Seems easily understood about the layers tapering off towards the tail .
Hi Kneepete,
It's true, it could be difficult but that is where a better scientific understanding of flex would assist that. The level of testing done on other sporting equipment is amazing. The small margins in surfboard manufacturing has prevented the introduction of this sort of analysis in my opinion.
Bring back 20oz glass, then we wont be troubled by flex.
Given the difficulty of assessing in the water performance, lab analysis of flex is essential. In particular the energy output from the materials needs to be measured to see if it is significant compared to the mass of the surfer and the board. The return time after the stress is removed also needs to be measured and compared to the rate of transition out of a turn. Personally I doubt if it comes into play for most surfers in most waves, there are so many other factors influencing performance.
Hi Blindboy,
The guys that created Solomon Surfboard technology many years ago were very interested in how a surfboard performed in the water under pressure. They created a board with sensors etc to compile the data. Unfortunately, their business is no longer around but it is possible.
The mass of the surfer, the way they surf, the conditions they surf are all factors on how a surfboard flexes. The truth is flex plays a major part in how our surfboards perform. I had the opportunity to make the same board for a person, one was in PU/poly and the other was PU/epoxy. The guy dialed the quad fins he used in the PU/poly but they didn't work in the PU/epoxy.
The comparison between the boards is anecdotal cory. I have been interested in flex for a long time, going back to the Tinkler tails in the 1970s and earlier. To date I have never seen a thorough analysis of it either experimentally or theoretically. It is all guess work and personal impression. There was a video posted earlier that seems to have been pulled that showed some lab work going on in Spain which seemed a promising start. The Tinklers used steel springs which gave an amazing burst of speed when you hit the turn just right but it was a primitive set up and the constant stress caused the tail to sag pretty quickly. Still if you look up the data you will find you can't beat steel for energy return! Have a think about that!
damn you are old BB, 1978 Bob Tinkler came to Australia with his Tinkler tail , and started making them , in the end the people who surfed them found out that it was not the flex that was apparent it was the twisting of the back of the board , called Torsion , that made boards faster (less rocker) and the drive off the bottom was second to none to the point in trying to spin out the board , they all broke during turns , but you are right about the steel springs in these boards , and it will be very interesting to see what Johnny Cabianca comes up with in measuring Flex and Torsion?
Carbon on Surfboards is the new Kale of the surfboard makers , to the point the new Sci-Phi's , from Slater surfboards actually have no carbon , but use a printed Lam,has anyone noticed??? Hahaha
I was surfing a long time before 78 sharkman, in fact I seem to remember spending the 77-78 season in the North Shore.
shit you might be nearly as old as me , my first winter in Hawaii was 73/74 , but 78 was a mazing year , so do you think carbon serves any purpose on a Surfboard , and is there an argument of Flex Vs Torsion ?
Hi blindboy,
Thanks for the homework... I will check it out.
Just went through the published literature using "surfboard" and "surf board" as search terms. Since 1966, I've only been able to find 221 articles published containing these terms and within these, only seven actually investigated some aspect of surfboard design (6) or instrumentation (1). In terms of empirical (objective) research, that is an enormous gap in knowledge given the size of the industry. Kudos to Professor Killen too by the way, you certainly do put the fμn into physics!
I would have thought any flex would need to be progressive and controllable like a spring on a motorbike or a two rate spring where the little bumps are taken up with the softer spring rate the big ones with the heavier part. Also the twang in fibreglass would go pretty quickly not sure on the new age blanks and what glassing would be appropriate.
Hi Memlasurf,
You raise a very good point. The feedback I receive from guys is the team boards constructed from ultra light blanks with one layer of 4oz cloth on the top and bottom using polyester resin definitely lose their 'pop' (positive flex) quicker. Higher tensile stringers can help but may start off feeling a little too rigid.
I'm just waiting for Gary G's comment on flex...
Gary G has nothing on Larry Lee .
He even tried to claim LL's for himself and rename it Gary's .
On another note I'm disappointed no one on this site payed condolences to the man Herc speaks of being " Dog " . !
RIP . Stephen " Dog " Hayden .
No doubt charging somewhere on another plain !
Cory what do you think of Paul Gravelles theory that 5 fin option with Future boxes takes a good percentage of flex out of the tail?
Hi Udo,
There is no doubt fin boxes are made from strong material to withstand the rigors of use. Of the fin systems available, Futures is definitely the longest and has been criticized for being too rigid. I heard Futures did some testing and found the boards flexed in a twisting motion more than a longitudal motion. Personally I think whatever system you use in a 5 fin option will add weight and make the board more rigid.
Udo , ive heard this repeatedly over the years & dont agree with its worth .
just recently saw a mates new gravelle board , with a ten inch fin box , plus futures quad fin option ,now thats going to stop the flex even further .
It doesnt stop manufacturers making them .
Glassed in fins with rovings they also will stop the flex just the same as a future box .
Thats why a good flex tail board is higher end price range because its very difficult to build all of the luxurious flexings into a boards tail .
The best fin system for allowing flexing of a tail is fcs 1 .
Just remembered how i could always hear creaking noises from fcs systems , the metal screws were grinding into the fins due to the tail flexing .
Thats why you needed to keep tightening the screws over weeks of use .
The creaky fin plugs and fin base contact in the plug wouldnt help the fcs overall performance because its poor for transferring energy . Metal screwed into plastic , into the side of fin is low technology.
i think its only lightweights & pros who should be concerned about performance as such .
4 or 6 ounce cloth and width of stringer etc , are bigger factors . even those little carbon wraps for foot dents will create similar weak stress points .
One thing ive noticed is the leash plugs are so small nowadays , its difficult to thread rope thru and being so small is looking rather weak when it comes to considering xxl surf . Using two of them plugs is bare minimum for safety by the looks .
They also, add stiffness to the tail .
Im sure theres a better way somehow ?
Mr Udo,
I have spent the past ten years riding futures. I think the future boxes add rigidity to the tail of the board. ( I actually prefer that.)
I think flex is also very much dictated by the thickness of the blank/ board and the glassing of the board.
I remember surfing some prototype surf techs , one was thin one was medium thickness both performed average in the flex department.
Yes FCS are a tougher fin to turn! My blue AMs are way harder to fine slice a wave"especially" if its tight and small! Where my "bumble" bee future AMS are easier to whip around...
Hi Winkipop2017,
This is due to the fact they are made in different factories and not a direct copy of one another. Often I have flexed the tips of a boards side fins to find they are completely different! It doesn't make it easy for the surfer.
Hi Lanky dean,
Very true... the amount of deck roll can effect the strength and flex of a board. In my opinion surfboards with flatter deck are more likely to snap.
Thanks cory , great article.
Quote : "spoke to Elliott Bemrose from Core Surf Industries who explained the combination of the stringer to foam density is equally important as they should compliment one another."
This part is interesting as it directly relates to the typical standard design i like using .
That is ; thinner than average stringer combined with hi density foam and multi layer glassing . Putting more strength in the shell and less in the stringer ( Egg shell )
Hi Clam,
Thanks for the support. What you describe is a great option especially for thicker boards as it helps keep it flex.
S-Glass is really the key to good performance in the flex of your board. S-Glass combined with epoxy resin is equal to carbon in strength but has much improved flexural properties. S-Glass with epoxy resin is used in helicopter blades which must flex millions of times without cracking or over flexing. E-Glass which is cheaper and the most widely used in combination with polyester resin is in comparison 30% weaker and exhibits poor flexural properties. If your surfboard maker doesn't use S-Glass and epoxy resin combinations for their hi-tech board models then they are nuts. While S-Glass is a little bit more expensive the benefits far outweigh the small additional cost. Carbon is great for adding stiffness to boards without conventional stringers and preventing tail warp from foot and toe pressure. Otherwise S-Glass outperforms carbon when you require a board that has great flex feeling.
http://cdn3.surfersvillage.com/sites/default/files/field/image/surfboard...
This experiment shows a reading of 2.23 of flex.
But it doesn't say whether it is mm or cm.
Anyone know which.
Hi Philosurphizing,
Thanks for posting the link! I had not seen this and was very excited. Let's hope the guys can gather some great data that we can learn from.
http://cdn3.surfersvillage.com/sites/default/files/field/image/surfboard...
This experiment shows a reading of 2.23 of flex.
But it doesn't say whether it is mm or cm.
Anyone know which.
I am guessing at centimetres. If it was millimetres then the energy return would be minimal for that load (Energy return = Work done = Force x Distance). The energy can then be equated to the kinetic energy equation 1/2mv2 to find the potential increase in speed.
Flex is something that Gary knows quite a bit about.
And believe me, it's quite the science.
The first thing to do, is make sure your flex is Systematic
Then, get it in water and make sure it's Hyyyyyyyyyyydromatic
The hit the gym like you're G G G G Gary Greased lightnin'
Keep talkin', oh keep talking!
I believe you mean to say "Tell me more, tell me more?" @Zen?
Tell me more, tell me more - Like was his name Ga-ry?
Tell me more, tell me more - King of all the fac-eys.
A whella whella whella Woooop!
Gold Gary G
Well worth the wait...
read http://surfersvillage.com/content/new-technology-quantifies-surfboard-fl...
here is a link to JC , he's working on flex but more important Tortion , the result of Torque !
should be able to narrow down the parameters of Flex and the resulting affects!
Great article thanks sharkman
"Torsion" the next advancement into the future
I only pass these ways when Blindboy needs someone to stand on his shoulders.
The Elliot I knew was a plumber. It's rare for good surfers to deeply understand physics and materials.
For Clam's comment about skins, think about hollow structural sections (e.g. steel pipe and tube). The key properties to a boffin are "modulus of elasticity" and "moment of inertia".
For a reasonably uniform material (e.g. stringerless foam) the flex (deflection) is inversely proportional to the thickness CUBED. So for the same forces, a 2" thick piece of foam will flex three times what a 3" one will.
Once we move into composites, multiple axes of rotation, point loads through the feet and fin tabs, and curves going everywhere, it gets even harder (;-) Gary G).
My visceral contribution, is the adaptability of surfers, especially good ones, to different characteristics. If you had put a 1960's longboard legend onto a wafer thruster in 1962, they would have kooked it, but would probably soon have got the hang. Similarly, I adjust my average surfing to each of my board's characteristics. Many characteristics of a board are not better or worse, just different.
Customising FLEX to each surfers requirements is the next advancement into the future.ITS NOT FAR AWAY.
Outers and Bushrats cost a lot and consequently not many take the step up...there will be an affordable alternative.
- "how much flex would you like with that? And how would you like it distributed?"
- "fucked if I know"
Can't wait for the spread of misinformation and bullshit marketing pitches.
What misinformation and BS?....fucked if you know!
Not referring to this article or that the technology can't be successful.
Referring to how big brands market their products to unassuming punters.
like , ah , Vertical Integrated Flex , or VIF?
God, it's the volume debacle all over again, but worse if VIF is anything to go on.
Remember when the most you had to think about was how many fins you wanted?
Future Flex , Carbon Flex , Flexi-tails ,Carbon Wrap , Asian Carbon creations, all just tech marketing for the masses that need to feel like they have the latest greatest innovation , carbon on surfboards , ah how many Pro's are using stringerless carbon surfboards, and please don't use the GOAT , as we know he rides normal boards painted to look like...?
We can all be sceptical of "new" or "different" things....
Remember when the earth was flat?...I don't
Remember when the Internet didn't exist...I DO
Change comes, and when it comes its good.Espescially if it enhances the sensation of riding waves.
Theres very few genuine design innovators who are making surfboards,be patient!
Ha Ha.
Bodyboard builders have been incorporating an amazing range of flex properties into boards for years and could probably teach stick surfers a few things about flexible crafts .
Most of it is to do with water temperatures and "breaking in" boards to flex just right .
Quote :"Flex is essential to high performance bodyboarding, but a board with too much flex can bog and push water. Too stiff and you’ll find it hard to turn. Consider the water temps you typically surf, combined with your personal flex preference, for the perfect ride."
https://www.surfertoday.com/bodyboarding/5762-the-bodyboard-stringer-rev...
https://bodyboard-depot.com/blogs/bodyboard-depot-blog/163998663-nmd-vs-...
http://spongercity.com/global/2010/06/12/board-test-nmd-ben-player-41-5-...
This is apparently 50 years ago, footage of George Greenough flying on a mat in 1967 Its remarkable ;
Maui
Great footage of Greenough:)
Sluggoe nailed it - a good surfer will hone a technique around a particular characteristic of their equipment. Often not better or worse, just different
Yeh sluggoes got it right. Now Elliot? Wasn't he the mayor of south curl curl for a while? Caught more waves than anyone else, shredded them more thoroughly and took no shit from anyone.
Congratulations sharkman , learning how to spell "torsion" ✔ after years of tortion !
better late - than never .
Sharkman : "it was the twisting of the back of the board , called Torsion , that made boards faster (less rocker) and the drive off the bottom was second to none"
" it will be very interesting to see what Johnny Cabianca comes up with in measuring Flex and Torsion?
Carbon on Surfboards is the new Kale of the surfboard makers , to the point the new Sci-Phi's , from Slater surfboards actually have no carbon , but use a printed Lam,has anyone noticed??? Hahaha" unquote .
A printed fake carbon Lam now that is funny sharkman !
Funny but true
Ha I would say sad but true , and wonder about how many of those boards are creasing and should the manufacturer actually replace a board that breaks or creases , as its fake carbon , alternative facts used for promotion , but will it make somebody great gain,haha
Mr Sharkman ,
It probably is carbon........they are ever decreasing the thickness of the weaves though, to make it pretty much pointless/ worthless. As it would probably would decrease the bond between the blank and the resin/glass bond adhesion . Much like fine sanding a blank, thus limiting the bond between blank and fiberglass bond adhesion . I think most 3d printers use carbon.
Try sanding one , the paint comes off!
Carbon.. i thought the fibers need to be laid down and held under tension till cured otherwise pointless.Ask the boat builders. And to the ridiculous theory aboot board design to fish form wat a load of crap. Fish move through the water , surfboards are planing hulls.how many fish plane on top of water.(quadzillas comment from the top, unless he's talking fin design )?
Why don't you read what I said?...
OK, i'll explain it again....fish gain propulsion by moving their torso and their tail..., just a flick and they move.George G observed this and made his boards to do the same thing,bend then reflex, which produces propulsion.Most fish are built vertically but some are built flat but both produce propulsion.....In the water or on the wave....reflex produces propulsion.
Ah ha fair enough but, they moving through a liquid creating pressuure difference, pretty hard to do that with air on one side and liquid on the other.The wave is providing the propulsion for a surfboard. Watch what happens when a fish is out of water,not much foward momentum despite all that flapping. I just don't think flex in a board produces propulsion. I really have no idea though!
Yes, a wave provides propulsion ....but only directly to the shoreline.A surfer moving their weight provides the propulsion ACROSS the wave.
You don't think flex in a board produces propulsion? SO, how many flextails have you ridden or owned?OR how many have you ridden?
Or as an experiment grab the most flexible board you can,and jump up and down on it in flat water , see how far you go....
You don't need to post nonsense.
Or when your out diving next, see what happens when you kick you flipper with the top surface completely out of water
YES, kick it down and it will produce some propulsion.
I'm willing to be convinced....can you explain how flex produces propulsion in a surfboard? Although i agree there is many aspects of flex that may alter the characteristics of a boards ride.and the idea is compelling .prove it in a way a backyard shaper like myself can understand,and i will give it a go.you seem to know.
And just to be clear, you'll need to explain it in the context of a planing hull not a fish traveling through the water
OK, no fish...BUT NO PLANING HULLS EITHER that's a boating term...propelled by oars/sail/motor....no relevance to a object used to ride waves.
Scroll up to the Vflex Outer....flex starts at the end of the V stingers but its mild, the white pad on top of the Carbon Fibre tail section has intense flex.When these style boards are banked off the bottom of a wave,the board bends,then the reflex of it returning to is static position provides the propulsion out of a turn.You really cant explain the feeling,the speed is multiple of what a rigid board provides.Very difficult to say if its 10/20/50/100% more acceleration....but its an immense sensation.
My observations are from direct experience.No theories,its just the way they work.
Lots of aspects of flex can increase surfing performance. The fake carbon application can also be applied, in fact has been applied to the surfer. This has been beautifully demonstrated by swillnut flexer extraordinaire, 'brokeback chicken soufle/gary... gee I flexed the truth and blax won'. For short, 'geeitschickensoufle... I flexed the truth and blax won', used extreme truth flexing, to surf, without even having to go in the water! Where he flexed the truth from all angles. First he told us twice, that the first time he 'surfed' blax wasn't the first time. That time he didn't, but the second time, when he was actually younger, he didn't surf because he would charge too hard? All this started with primary, but unsuccessful flex loading.
https://www.swellnet.com/news/swellnet-analysis/2016/03/29/rip-curl-pro-...
'The plot thickens . i was in WA for this swell . WA got the same swell in earlier in May .
( there's a photo floating round cyber space of Paul Morgan dropping down a mineshaft at Margie's ) . Anyway , if pig dog is the same dog I'm thinking of , then that is small for him . Although I thought this other dog was a goofy ? That Guy rode the biggest wave I've seen ridden in person . Would of been 5-6 Garry's . Was towed aswell so not sure it counts though.'
However, 'geeitschickensoufle... I flexed the truth and blax won', initial flex loading was quickly brought to a standstill.
'Pauls wave 1-7-07 , almost but no . I was in margs surfin some big lefts apr-may 09 & it did get huge'
He then re flexed his flex.
'okay sorry . it was second hand from a friend that it was 09 . i wasn't in the SW at the time . ;-) But yeah SOLID swell where i was too . Just presumed .
Things quickly turned into spiralling flex, for 'geeitschickensoufle... I flexed the truth and blax won'. From there he flexed from more angles, growing even younger, taking wrong turnoffs, miscalculating rewards, stitching up WL at his secret spots, before later when he was even younger stitching up Donda in the barrel in the NW. After which, when he was younger, he was too intimidated. Finally he spiral flexed out of control, when he and some old guys discovered that he could surf the wave without even going in the water. All he needed was a campfire to get extreme flex level performance.
In this case it shows that flex isn't always a good thing. The end result is that 'geeitschickensoufle... I flexed the truth and blax won', has never surfed blax, and merely shit his pants, when he over flexed his quivering clacker and butt cheeks into a useless, frenzied pile of stinking, steaming bullshit.
When measuring this type of 'geeitschickensoufle... I flexed the truth and blax won', extreme spiral flex, the term of flex unit is shortened to, 'gee, that sounds a bit far flexed'.
I know there are those thinking, as if, as if anyone would flex the truth that much! However, with a quick investigation, it can be seen, WTF, in a swillnut shelter, all this is actually true. Blax will do that to those like 'geeitschickensoufle... I flexed the truth and blax won', who's surfing is based solely on extreme campfire loading and flexing.
https://www.swellnet.com/news/swellnet-analysis/2016/03/29/rip-curl-pro-...
Ta.
Regarding the stringer/flex points, for a while shaping legend Glenn Minami was routing grooves along the bottom edge of his boards, following each rail line, about 1/2" or so inside the bottom edge of the rail. They ran a fair length of the board, stopping short of the nose and tail. We first saw them when a Hawaiian friend came and stayed at blax, and brought his quiver of Minami's. The rails were very similar to McCoy's, although not as thick. I don't know who was the first to do them, but it could have been Minami. Brickie/arnie/spud was similar size to my mate, and fell in love with them. He went to Hawaii specifically to order a quiver of 3 and bring them back. In the era before the airlines realised that freight was more profitable than passengers, and you could carry things on planes.
It was the best I've seen brickie surf, he was always a bit of a ledg, but it went to a different level. The rovings were supposed to stop breakage, the twist and cracking from the rails, but I always wondered about the flex, spring in them, they were about 3/8" fibreglass rod. His boards looked alive, twitchy, really springy, super powerfull off the bottom. He liked delaying his turns anyway, before stomping his back foot, and always hooked hard under the lip, but he was accelerating harder through all his turns, winding up the whole wave. Maybe it was just the buzz of him having such good boards, but they were the best boards he's had I reckon. They all broke in the end, so didn't do that job well. Although he surfed the things to death in a barrage of bombs. He could never quite duplicate them, despite numerous attempts. One thing, those rovings became deadly when the boards broke, they were like thick, splintered knitting needles sticking out of the board.
How can you post an interesting, relevant, completely sane post like this, but then post that absolutely schizophrenic insane nonsense that you posted above this one?
I don't get it...
Herc does stream of consciousness better than anyone since James Joyce. Go with the flow goofy!
Is he the guy who paddled out to maxed out Waimea and got arrested for it?
Get what foot? Why gary g/soufle' said/says all that 'schizophrenic insane nonsense' drivel? I'm just repeating it. Its all on here, his 'schizophrenic insane nonsense'. Surely you don't believe any of that bullshit? Surely? So, just having fun, keeping it real balanced.
Spidermonkey im with you there about propulsion .
I like knowing different peoples theories ?
I think flex will benefit the control qualities , but its not whats propelling anything .
With control comes the benefit of being able to go faster , of course .
Its a fine line to discern what's what
Yes Clam, ofcourse you are in the same place...both of you are NOwhere!....As far as understanding what Propulsion can be built into a surfboard.And that's easy to fix....buy or build a board with a flextail...then and only then, will you be saying HALLELULAH, ive finally found propulsion.....Theres NO fine line...theres facts and fake news.
Facts are, that V flex outer with the carbon tail that you scrolled past is "probably" the most advanced waveriding object yet discovered by humans( for standing on).After it flexes in a bottom turn and reflexes back to its original shape, the propulsion from the reflex provides speed and drive that a non flexy tail isn't capable of.
Once again, no theories just personal experience.
quadzilla , i agree about the "outer flextail" concept ive seen a guy at g-land making impossibly fast waves, next level untouchable speed down the line .
No doubts there, it was possibly the fastest thing ive seen .
Are the rockers on flextail boards the same as a normal rocker or is it flatter ?
I suppose the rocker on a flextail would be flatter than a regular boards ?
Then when you surf on it and it flexed then it has more rocker during the turn for example ?
After the turn/flex the rocker returns to its natural shape which has less rocker than a normal board .
so thats why it goes fast - its flatter but has flex during a turn , that gives control .
Clam, the outer rocker follows the normal line on Outers.As opposed to bushRats that have a flatter flextail(and no rubber pad attached)...they are same principle designs but very different.My experience is only with Outers(standing) and kneeling back in late 60s with Velo copy.(velo being what GG called his kneeboards)....Outers are popular with longtime Indo visitors due to Mitchells many trips....the flex makes a difference(but so does the price!)
The flex in a turn doesn't do anything, its the reflex of the tail returning to its static position that provides the propulsion, kind of like the effect of a turbo boost in a car.You have seen one in action,FEELing the sensation is WHERE its at.
And I should have made it clearer that Minami filled the routed grooves with long strands of glass, like rovings, making around 3/8" fibreglass rods, which filled each groove, when the board was glassed. It was the Blue Hawaii era.
There was this guy years ago, I think his nick name was Feather, lived in Queensland. 35 or so years ago, Tracks did an article on him. He made these fins, a little bit like McCoy's boomerang fins, but much more rake in the rear of the base, almost semi keel, then the top part of the' boomerang', for want of a better name, was about 1/1/2" wide, 1/4 - 3/8 thick (foiled though), went back parallel to the bottom of the board, 8" or so height above it, to about 10 inches behind the base. It had a foiled egg plan shape on the end, hanging out behind the board. I had some made, he gave all the measurements and detail in the article, they felt insane. You noticed a really smooth whip/drive in and out of turns. You could push them really hard. I cracked them all in the top part of the boomerang. I used them at solid Ulu's etc for a couple of months, and they felt great. Heaps of hold, drive. Once they cracked they were fucked. I would like to try them again in a single, but doubt anyone could make boxes/boards/glass jobs strong enough to cope these days.
On a side note, you should look at Midget Farrelly's glass fin range clam. Insane quality. Beautiful fins. Not many to pick from, futures though.
http://www.surfblanksaustralia.com/shop-online/shop/fins/shortboard-fins
http://www.surfblanksaustralia.com/shop-online/shop/fins/shortboard-fins...
They are great prices for glass fins .
Herc no thanks !
I have absolutely no reason to see more fins .
No, sounds like its all done and dusted on the clifftop these days. Fins have taken a back seat to flexing and the inevitable dollars. I knew it. And sounds like a job for the little Aussie bleeder, double decker blowie! Crawling out of one crack, straight into another! This should put the fear of God up em!
https://www.swellnet.com/forums/wax/12736
I'll just go round the little aussie bleeder double decker blowie up! See if mummy will let him out on his own!
Its called finless surfing herc !
You dont have to buy fins ;
Ryan lovelace insty clip of ari browne
Tom wegener flexy corky alaias .
Hopefully get a ride on one ;
Cory are you around to repair this thread that lost rating points over the weekend ?
Hi Clam,
I always keep an eye on the discussion... hoping to learn and share information. This thread certainly has been a wild ride at times :)
Quadzilla : "buy or build a board with a flextail...then and only then, will you be saying HALLELULAH, ive finally found propulsion.....Theres NO fine line."
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I have ridden this board and it does go fast down the line . So far thats about the best feature . Hollow with flexible spoon bottom & carbon flex tail .
Ok, that's good you have experience "some" flex.
Was a board like that featured ON swellnet a while ago?....@ a ridiculous price?
Building FLEXtails is labour intensive @ the moment.....as time goes by,it will get cheaper as the design evolves....that time is coming(I just don't know exactly when at this point in time)
Far out I love this series. I'm anticipating an article on the importance of fins (and all the good stuff that comes with them)!!
Britt Merrick /The Happy models Blue tail patch - Youtube
Explains why they stopped using Carbon patches on the Tail area
In regards to carbon patches.
Marketing giveth, marketing taketh away.