In fact MrJ, for me, light is not necessary more responsive. I made surfboards with balsa deck around 2,2kg that’s feel less responsive than my last wich is around 2,5kg, Xglass,Warpglass and UD carbon mix. I experiment projection feeling for the first time with this technology, after good double pump bottom the board jump to the top of wave like a missile, i have same feeling when i pump hard down the line and i do section i would never hope to do. I made a small gun with this tech to a friend who experiment same feeling.
hi Lemat, sorry if I didn't make myself clear, but we are both saying the same thing. ie we agree with each other on that point - If the material has extra special flex properties then it can overcome weight penalties.
however increased weights on identical laminate builds does reduce responsiveness - eg I knew very quickly when a shoddy homebuilt sandwich of mine was leaking - the weight of the water it sucked in killed its responsiveness.
Dave has told me that he has made Dynocore down to 2.2 kg, it would be interesting to see what responsiveness that would gain us.
hi Guys, i never set out to make a really light board… weight was not my first goal. what i really wanted to achieve is the flex and feel of a lightweight 4x4 PU with Durability… yes i can make them really light, probably 2kg even… but i hate throwaway boards. i want them still usable and enjoyable in a few years… im happy with 2.4 to 2.8 kg for the average HPSB.
Structural response is determined precisely from mass, stiffness and damping.
Almost all structural models consist exclusively of masses, springs and dampers.
For a given surfer in a given wave, with a given shape, there’s an optimal combination of mass, stiffness and damping
…a combination of mass, stiffness and damping that will make the board as responsive as physically possible.
I keep saying mass, stiffness and damping, because when we think of response, we should think of how mass, stiffness and damping interact. Not just one of them.
With that said, if MrJ’s board was .5kg less massive, I guarantee that it would be more responsive in a vast majority of conditions…of course then it may not be economically viable, as Dave said.
hi Wouter, I have 3 more builds left and can guess what your thinking: try a very thin tail with extra reinforcement on say build 2 and if I didn’t like it go back to where I was on the next build or two. However 3 months is still a long time to spend on a board and at all stages I am aiming to be on something I’m very happy with. One of the things which plagued my young and early years of surfing is that I rode exclusively self builds, but for economic reasons I had to ride some of my failed experiments for up to a year! So I don’t want to go there again and will be aiming for improvements with every dynocore build. Also Dave’s Premium membership relies on having something with commercial value for every build/resale.
Regarding Bert Burger favouring thin boards, he was very willing to share his ideas on design here and as an example he is to my memory the first person on Swaylocks to push the idea that low nose rocker and high tail rocker can suit front footers – something which seems to be much more generally accepted in recent times. So I do have much respect for his knowledge, however he also liked to relate his ideas to how he liked to surf eg. I think his magic carpet design was based on his own favourite mush instrument. His magic carpet was exceptionally wide - but I know from experience that I like narrow for rail to rail response reasons amongst other things, even for little waves. So that’s why the MJE II is just 18.5 wide (like Benjamin’s butterball whose specs I liked the look of). So just coz Bert personally liked thin boards doesn’t mean its good for everyone – I’ve been there and don’t want to go back.
Also we all surf different ways, so you are saying that on your spring loaded board you can 1) go into a turn and feel the board bend 2) then feel the board spring out and accelerate you forward faster than a conventional board?
I’m just not looking for this effect - of all the boards I have tried in the past its the ones with immediate response which keep me happy. Sounds like you look for a two phase turn - I look for a one stage turn - I push into the turn and immediately want to respond/go forward! I want an immediate surge for both small rail to rail moves and for big pumps.
OK if tell me that you are experiencing this two phase loading and spring back into turns then I believe you.
Paul Cannon and myself discovered on Makakilo’s big bloke thread we both share similar design ideas, but ride quite different designs - to quote Paul “different requirements mate!”. That’s something I need to keep reminding myself when discussing other peoples boards and thats why I like the big bloke threads - makes me think outside of my little box.
No need for more pics of your PF board thanks, but if you can get its flex frequency and some boards of comparable shape - maybe your coils, then that would be more interesting. Won’t be able to usefully compare it to my readings coz I am a lightweight, but can see how your PF board compares with your other ones.
g’day Benjamin, I posted the MJE II boardCAD spec sheets towards the end of page 1 if thats what you are interested in. It should have at least a passing resemblance to your Butterball. Tail is fairly thick, but overall different thickness distribution to yours. As you know I’m on a slightly different path to you with my design - you have been producing Butterballs to study the effects of different material builds and incidentally getting yourself a great daily driver, whereas my aim is to get myself a good board rather than experiment.
Dave’s main objective was to produce a more durable HPSB with similar weight and flex to a lightweight PU/PE build and according to the flex tests and weighing I did he has in simple terms achieved that. However the main reason why I am so excited about the Dynocore is because my senses are telling me that the build Dave has done for me has achieved a very responsive feel which rides nice in a variety of conditions.
Although I’ve still got a couple of months of fun on this one we already have plans for its next iteration. Neither Dave nor I see any reason to change the reinforcement levels/pattern - he tells me that the density and distance it travels up the rail can be altered.
[img_assist|nid=1059132|title=Flex rig|desc=|link=none|align=left|width=640|height=480]
As I said earlier different people can get different things out of the same board, so it stands to reason that different people can get different things out of the same tech and I’m told that some Dynacore riders choose to go thinner than their regular boards, but as I was saying to Wouter I don’t want to do that.
I will discuss the planned tweaks for iteration 2 this weekend.
I did something similar a few years ago with one of my last Clark blanks and 1# up front, d-cell rails. Board went killer, but broke. Always wanted to revisit for the theories you’re chomping at. These dynocore look tits. Got me thinking…
whats been interesting to me is that the flex distribution theory that I am chomping at wasn’t discussed with Dave before delivery, but emerged after I performed the weight and flex measurements on the Dynocore and my shortboard quiver - if the Dynocore had come out lighter and stiffer than my Byrne TL2 (a very nice board) then I would have just put down the extra Dynocore response to that, but neither measurement registered the usual correlation.
I’ve actually supplied very little input to this board so far, having a total of 4 builds up my sleeve has to a large extent allowed me to sit back, leverage off the Butterball design and Dave’s design experience and avoid micro-managing it before I even know how it works. I will of course be very involved with the tweaks in the future iterations. My lack of input extended to the reinforcement - I did not state any preference or ideas on how I liked stiffness - thats the build I was given.
I can see where the stringer ends on your pic and where the low density EPS must start. What were your motivations for producing that density distribution? Was it to reduce swing weight up front or to produce a similar flex distribution that I’ve illustrated in my last pic?
If your dual density board went great and its only the snappage that stopped you from pursuing it further then I think you should have another go! I’ve followed some of your posts and am sure that you have the resourcefulness to find the right construction to overcome the weak point between the two densities. I don’t know much about the Dynocore construction although I will say that one of the materials used surprised me.
yes Claude I reckon you are on the money with the suitability of this rocker for me and I’ve now got the diagrams together to help explain this.
Here is a comparison chart of my HPSBs and whether they allow me to effectively use my front foot or not. What is considered high and what is consider low is my personal idea of the HPSB rocker scale, others may ride different sorts of boards and have different ideas.
Looking at the comparison chart, the rocker does easily explain why I get little front foot experience out of the Macca compared to the Pancho - both are towards opposite ends of the rocker distribution scale.
However the Sprint and MJE II are in the same rocker class, but ride with a different emphasis. There is a bit of a question mark on the Sprint coz I tended to ride this board only occassionally, but I don’t have any front foot memories of its performance.
So I have to look elswhere for the answer - and I believe it is the widish nose of the MJE II that makes it readily ride front footed (in certain situations only). So my belief is that it is a combination of these two things that determine foot emphasis on a HPSB.
[img_assist|nid=1059387|title=rocker to front foot emphasis comparison|desc=|link=none|align=left|width=640|height=464]
One of the benefits of dropping 2 inches in length from my Byrne Macca goto board is that its shifted my back foot more towards a standard HP position. I do need oversize boards and one of the symptoms of this is that it places my feet more forward than an elite HP surfer would have them on a size matched board. Elite surfers seem to have their foot well back. It also places my back foot off centre with toes more towards the rail than my heel.
I’ve shown a comparison between my 5’ 11" MJE II and the much longer 6’ 3" Bushman Pancho Sullivan board as it illustrates the difference well. The difference between the MJE II and the 6’ 1" Macca board is less marked, but I’ve still got an improvement. Having the foot further back into the fin cluster is a definate advantage for increasing board control.
These boards both allow me to use the front foot well so for me at least distance of my rear foot from the tail is not an indication of front Vs rear foot emphasis.
[img_assist|nid=1059389|title=Effect of board length on foot position|desc=|link=none|align=left|width=480|height=640]
So rather than look at what I’ve gained with this board, I’m going to focus on what I’ve lost from my previous goto board.
The plan is to only tackle point number 1 above. Point number 2 is barely an inconvenience and although increased tail rocker is a possible consideration for future builds we don’t want to put in too many changes or we won’t know what change is doing what.
The board is thick and EPS so its possible that is the cause of the more limited ability to bury a rail. Although the rails are normal thickness with a domed deck they do feel thicker than my Macca board and a tad thicker than the Pancho board and given that my Pancho board is also light and 2 1/2" thick I think I can get increased burying power with a slight reduction in thickness in the rails up front. So I don’t want to reduce its thickness.
[img_assist|nid=1059386|title=MJE II, thick board domed deck, normal thickness rails|desc=|link=none|align=left|width=640|height=319]
Although this should tackle the loss I don’t want to mess up the gains I’ve had with this board either - I don’t know for sure, but I suspect some of the zippyness of this board comes not just from the response, but from the sit on the surface effect of the chunkier rails. So I want a slight rather than drastic reduction in rail thickness and only in the front section.
One thought which has occurred to me is that I might be able to get the best of both worlds by increasing the height of the rear boxy section at the same time as a thickness reduction in the rail up front. This thought is more from experience rather than theory. The rear boxy rail section of my Pancho Sullivan board is exceptionally tall, normally I would look at a tail rail section like that and think too tall for me or might even cause spin out problems, but absolutely the Pancho board is an exceptionally well behaved board and I can’t ever remember spinning it out, and considering how much tail rocker it has I can get it to go remarkably well in small waves provided I front foot drive it.
So one thought is to perform a slight height increase in the boxy section at the same time as reducing the up front rail in build 2. If that goes well then go for a more aggressive height increase in build 3 more in line with my Pancho board. This will then still allow me to either reverse that change or play with something else in build 4. I haven’t actually mentioned this to Dave yet, but I think he is reading this thread! Dave we can sort this out further down the track, I’ve still got plenty of time left on this first one.
[img_assist|nid=1046359|title=Very tall boxy rails on the Bushman Pancho Sullivan|desc=|link=none|align=left|width=640|height=480]
Two other things that Dave suggested and I want to go ahead with in build 2 are:
Make the rear boxy section more square on the deck surface.
Footwells in the front - when I was up in Queensland he showed me how he does these on a Dynocore - quite subtle
Shape3D has a function where you can increase or decrease the whole rail foil as a percentage.
If you dropped the whole rail foil say 5% then that might be easier to dial in your optimum short board rail thickness than changing the foil distribution (or foil algorithms) at this stage.
Pancho has the heaviest hack, so I guess his back rail is thick so he doesn’t disappear into the wave!
I’m guessing your optimum rail thickness is around 1.38" give or take 1/16". That is if you measured the centre slice from the bottom of the tuck straight up to the deck.
I am 171 cm and 55 kg. My size is not a genetic anomaly and entirely consistent with that of my south east asian mother!
I have noted that you followed some non-intuitive advice from Mike Daniel to downsize volume to increase your wave-catching ability and the Coil board he did you achieved that!
I am interested, could you post up a pic and some measurements of that board? and maybe give your personal litres per kg?
Hello cuttlefish, I think I am on a different fin trip from most others so not sure if my choices will be of use to you, but it is an interesting subject.
my former goto Macca board and the MJE II both have FCS glassflex (economy material) M7 - these are meant for medium to heavy surfers. The are big fins. The Pancho board are fitted with fins almost as big EA 450.
M7 area is 15.71 sq in and EA 450 are 15.16 sq in. respectively.
The PU Diverse Sprint got tried with a variety and in the original box position worked better with M7 up front in combination with the cheap small fin solutions rear fin rather than the complete fin solutions set that it was supplied with. I later had the rear box moved up by local ding repairer to bring it more in line with my Macca and Pancho boards and I tried all M7 Vs all M5 set (also cambered but smaller at 14.76 sq in). Coz the Sprint was the board I used least there is some question mark on my preference but I felt the smaller M5 worked best and thats what it ended up with.
I am completely happy with the economy glassflex and once tried fibreglass fins by Rainbow whose template was a very close match to the plastic Futures I had at the time - the fibreglas didn’t gain me anything. whereas I’ve seen a number of swaylockians say the plastic fins don’t do it for them - I think its a body weight/power thing
The Pancho board I haven’t experimented with, but it feels good. Due to the much larger amount of time I spent on the Macca board I was able to get a far more definate idea on what was best - it was without a doubt the large M7 which beats the M5 in both larger and small waves. If the board works well with large fins then I think large fins is a big speed/glide advantage in small waves - my theory is that its like sailboarding sail situation - lower windspeed => move up the sail size.
I have a theory that lightweight epoxy boards sometimes do better with bigger fins even for small people and would be interested to hear if others agree/disagree. I first observed this personal preference when I was living in Cali and surfing Santa Cruz - I never used to pay much attention to fins and then read some fin marketing stuff about matching them to body weight, so I took a look at the big G-AMs in my tufflite flyer and I thought too big for me, downsized and immediately got the ability to flick the board around more tightly, but it had lost a lot of speed - notably in big arced cutties and I think down the line glide (as opposed to driving) in small waves too. So I put the big fins back in. For me the test of a fin is how does it feel in a big arced cutty - if it seems to hold a high speed throughout the arc well then. I suspect people who surf at a more advanced level than me may have different ideas.
the MJE II, Macca and Pancho boards all have fins at 11 1/8" and 3 1/2".
I am reliably told that Jordy Smith likes his fins exactly 1/8" back on all these measurements, so asked Dave to set up the FCS fusion boxes to allow for this, but I just don’t want to move them. Everything feels so good when I go into a cutty on a big wave face on the MJE II that I don’t want to waste time trying smaller M5s either!
^^ I do ramble on a bit sometimes
[img_assist|nid=1059428|title=M7 fins|desc=|link=none|align=left|width=640|height=480]
Cuttlefish, you say you are planning a volume downsize into a more conventional HPSB shape than what you have been on, would I be right in guessing that you are planning an overall size decrease both for demo and a potential personal build? I may be off the mark so if I am please tell me, but my take on trying out smaller boards - say 3" or so shorter than normal is that it can take up to 4 sessions to get it wired and get rid of squirrely feelings and until then objective assessments are hard to make. So if say the only available Dynocore WD models are substantially smaller than what you are used to then maybe trying to borrow a bigger size WD in PU might be an idea - I think you would like the feel of Dynocore anyway. I’m just thinking out aloud here.
I’ve been trying some of a mates boards recently - he has been experimenting with downsizing, but even so they are slightly oversized for me, but trying an oversized board is easier than trying a downsized board.
One option which could be done when downsizing on Premium membership is to drop say 1" on each build - as Mike Daniel noted some time ago I’ve been slowly, but steadily downsizing over a period of years which I think is an easier way than taking a big bite off length.
There will be no length changes on the next iteration of the 5’ 11" MJE II, nor any changes to the outline shape whatsover. This size was designed to be a complement to my 6’ 1" Macca board - the thinking being that the lower nose rocker of the MJE II in combination with a wider nose would effectively place a greater percentage of its front surface area planing, so the board wouldn’t feel too small or squirrely. This strategy has worked - I was immediately able to jump on the MJE II and feel at home, its a little looser, but not drastically so. It did of course feel different, what I noticed was when I was into about my 4 th surf on it (by this time in the Gold Coast beachbreak) I was no longer noticing the differences and surfing without thinking about them - I think this was the indication that I had completely become accustomed to it.
because there is very little difference in stability in the upper wave size range between the Macca board and the MJE II, the MJE II has effectively obsoleted the Macca board from my quiver, but the Pancho board is still there for me.
cheers claude!
that was very helpful. I am a computer shape newbie and I see what you mean, I’ve just opened up boardCAD and started to see how I can communicate with the designer and assess rail mods to the computer shape.
because I personally haven’t designed using Shape3D or other software and then looked at the physical results, I’m not in a position to sensibly suggest % drops or supply rail height measurements - instead what I will do is ask Dave to move the rail thickness forward of the boxy section down a “tad”. Dave is very experienced with computer shaping, he was telling me how he had sliced up a shape and analysed each slice to see how it compared with what the software was telling him and that he also takes it to a level which some of his industry comrades considered unecessarily detailed. So I will let him use his judgement of exactly how big a unit of one “tad” is.
Then when I get iteration 2 built, I can feel it up with my hands, ride it and then use boardCAD to see exactly what sort of reduction has been made and this will give me a feel for communicating/assessing any further rail mods. I’m now going to take a look at the boxy tail section - standardise some distance from the rail (or use your suggestion of using the tuck) and see what sort of measurements are there and visually look at the physical MJE II tail rails.
[img_assist|nid=1059427|title=using boardCAD to assess rail thickness|desc=|link=none|align=left|width=640|height=464]
that Jordy Smith likes his fins exactly 1/8" back on all these measurements, so asked Dave to set up the FCS fusion boxes to allow for this, but I just don’t want to move them. Everything feels so good when I go into a cutty on a big wave face on the MJE II that I don’t want to waste time trying smaller M5s either!