S - curve in tail - why Bert?

Bert - just been looking at your 6 9 small wave board. The tail is really unusual - it curves in and then out again at the 12" (?) point. Never seen any other tails like this - what’s your thinking.

(my idea - prob bollocks - to rapidly pull the tail in from a wide rear end but still end up with enough drive for the shape to be fun)

If anyone else does tails like this - I’d like to hear from you too

yep thats exactly what the curve does …

i flip my template and reverse the curve between the 14 and 6" mark …

if you want to do a deep pocket turn , it happens quicker and easier on a narrower tail … only problem is when your tail is narrow and it carries narrowness from the centre , its not exactly going to carry you real well in small waves …

so the concept is keeping some width between the centre and front fins , so you can work some speed on that area , then pulling in the tail so you can get a quick rail to rail transition off the tail , also taking advantage of the extra outline curve at the fins , which tightens the arc of the turn …the hip and the fins focus at the back foot for tight snaps under the lip…

that particular board is designed for small but very sucky waves …

that outline is very rocker sensitive …

most shapers will do a tail fliped rocker to achieve the same thing , only problem with that approach is your board is kept back in the pocket even when you dont want it to …

using the outline to get it to turn tight under the lip and deep in the pocket means you can still run flatter tails so you have the ability to drive out on to open water when the board is flat , you get more coverage on the fave of a wave than you would if you used the tail flip approach …

plus you still get a whole range of manouvers your board will perform better …

long floaters , boosts and way more down the line speed when working it all because of the flatter tail…

regards

BERT

Interesting…how flat is your tail rocker on this board?

Interesting?

Is this board in the Resources area?

Drew

We’ve done the same type shapes that we called warp tails. Anytime you straighten a curve behind the front fins, you add a lot of drive to the board plus as Bert says it allows you to carry more width in the tail .Straightening lines in the tail gives more drive whether it’s used in outline or rocker. You can have a fairly sizable break in your rocker and still have it straight behind the break and have good drive. IMHO that area, on high performance boards, behind the front fins is the best place to change to get different riding characteristics, the most sensitive area of the board. Many times the angle of the curve leading into that area of the board is more important than the curve itself because you are using that angle to build the tail section from. Actually one of the beat warp tails I ever built was one for Bill Hartley. He rode it for a time and then loaned it to David Speir, who wouldn’t give it back. Speir ended up winning a ton of money on that board and I always kid him about the percentage he owes me.

I’ve been thinking about trying this type of design- makes sense. Where is the picture please? (I tried searching the resources with no luck).

this board is still my all time favourite all round shorty, for waist to double head waves…

this pic below was my second surf on this board ,i think ive ruined this board , about 18 months back i put futures boxes in it , even tho i made fins identical in size , i think where it stuffed up was the elimination of shear movement and the general flex it had in the tail before i put the boxes in …

i tied the boxes to the deck and it stiffened the whole tail , it doesnt spring out of turns like it did before , for the last year ive only ridden it once , in super clean head high solid beachies (normally where it went best ), and it just wasnt the same …

so even tho i said it was my all time favourite , its not like it used to be …

i got 6 good years out of it , i will just retire it and make a copy of how it used to be …

like greg said about the straight section , when your laying into a turn and focusing your weight on that part of the board between the front and back fins , it just wants to drive forward …the board has 2 distinct drive zones …

one between the feet for when you lean evenly on both feet and need to drive around a section then a pivot zone right on the front fin and hip , then the next drive zone under the back foot after youve initiated your direction change …

this board surfs very square …i can keep good speed when the board is flat , then as soon as i put it on a rail slightly biased on the back foot , it goes square into a turn , so i get all the time in the world to approach the lip straight on …

if you check out my path in the middle photo you can see the board has done 180 degree direction change , then still driven hard out of the turn , thats the hip allowing direction change without the need for a slide to complete the turn …

this outline allows more for small wave power surfing , it will still slide when you keep the board flatter and bust the fins , but any time youve got it on the rail , its all bite and drive …

fast rocker , loose outline …

regards

BERT


what type of fins did it have before you changed them? it seems glass ons would have the same effect…

Looks really solid with the pintail Bert. Terry Fitz had the first ones I saw with the s curve in the tail but his were squaretails and didn’t look as intuitively clean to me as yours ( I just prefer rounded pintails). Too bad about the board- I can share, in that I’ve ruined some magic ones too by sanding off fins or taking down some vee or edge and never getting the same performance again. Amazing how much difference 1/16"- 1/8" here or there, or flex, makes.

hey jip …

yep it had glass ons before …i make all my own fins as im very particular about foils …when i made fins to fit the futures boxes the foils and templates were the same , there was some small differences at the base , but the fact the board was different was more to do with flex than anything else …

if you have glass ons or shallow boxes that dont tie to the deck your board can flex way more…

for your board to flex it needs maximum shear movement … when you tie the deck to the bottom you eliminate shear , so now you cant use flex as part of the equation …

stopping the flex in just the last 18" of the tail still meant it affected the overall flex even at the centre …

coz even if just the centre of your board flexes , itll still transfer load right to the tail …bend a book sometime and youll see what i mean …

speaking of flex …

check out the boxes im making now …

im doing a rockered version , for obvious reasons …thinned it down so the box is lighter , but best of all ive got the boxes to flex , to reduce the load where the box contacts the board , and also to flex and move freely with the skin of the board …

ive pretty much had to make these if i want my boards to work well and be able to offer a fin system …

not taking anything away from all the other systems , its just that none of them are designed specifically for high performance sandwich boards …

also tubedog , your dead right about subtle changes …

move a fin 1/8th or tweak your tail rocker 1/8th in the wrong spot ,maybe pull your tail in 1/4 and youve ruined your board …

my boards havent really changed in over a decade , once you work out exactly what works for you ,after that it comes down to real small changes , most of which dont make it go any better , just different in different conditions

that pin on the board you were talking about does make for a tighter tail hook in the pocket , once your weight transfers right to the tail of the board on the transition you start using the last 4" of outline curve , only when your hard up in the lip can you feel it working … it allows you to tighten the turn super tight without feeling like you cant push it hard enough into a tight spot , so no need for a drift to complete the direction change …that means you get to the bottom before the lip does , so your ready for another one straight away …

if you keep it running straighter all the way to the tail , like a swallow or square … you end up having to complete the final stage of a tight hook with a slide , once you get drift , it becomes lost recovery time, which quite often leaves you floundering in your next bottom turn , so your not powered up for another reo straight away …

not that i know what a wave feels like lately …

ive had 3 times as many sandboarding sessions as i have had surfs …

its been about 8 or 9 days without a decent swell , a few more days till we get one …

thatll be 2 weeks …

before sandboarding i woulda just surfed the knee to waist high days … but now the rush of a decent dune drop and long carves into a bowl or a bust off a vert section carved out by the wind ,means the not so good surf days become dune surfing sessions …i think in the last few weeks sandboard production has over taken surfboard production …im all amped to try out new designs every few days …

im so glad im not locked into running a production anymore …hm looks like i got sidetracked from the thread … um my sandboards have s curve tails as well ??

regards

BERT

Great looking outline Bert. What dimentions would I use if I currently ride 6-6 x 19 3/4 Weight 165 height 5-11

6’-3" x 18 3/4 x 2 1/4 would do your size small to medium waves …

you could go 5’-11" x 19 3/4 x 2 1/4 and lean towards smaller stuff or 5’-11" x 20 3/4 x 2 for the ultimate groveler …

6’-7" x 18 1/4 x 2 1/4 for some solid stuff …

those dimensions are just guide lines , as the curves you combine those dimensions with will determine how well they work …

but for any board to work well at all , first it needs to be matched to your size …

those measurements mentioned would be for a competant advanced surfer …

your board sounds a little big for a guy your size … i would normally recomend that size board for 195 lb surfer …

but if you surf total grovel or are still developing then it could be ok …(another consideration is age …30 seems to be the age where crew start feeling like there board is shrinking …even tho i know guys in there 50s at 150 lb still surfing 6’-3" x 18 5/8 , there not sitting around watching superbowl swilling beers and eating pizza …)

if not i suspect youd have trouble throwing a board that size around , especially if youve got some rail volume as well …

regards

BERT

Hey D,

yeah b4 I went to EPS/Epoxy I rode the same dims…6’6 x 19.75 but thicker for better float. Similar to a CI Flyer. Then I started making ESoxy’s…I’m using a 6’4 x 19.3 x 2.4…rides so much better/faster than anything I’ve ridden in years (I had a Loehr epoxy in the 90’s)…fast rocker with single concave. In sucky waves its a bit harder to top turn on the lip but I simply adjust…I’d rather have the ease of speed…some light fluid pumping and Im just blazin’…IMO most shorties turn better when your going fast. Florida waves tend to be on the weak side so a little extra width helps.

Btw, I just turned 41, weigh 175lb and surfing advanced…most of the 20 something’s can’t keep up…as Bert said, keeping fit doesnt hurt.

Thanks guys for the input. Yes I have been surfing since I was 12 . Ripped in high school, surfed B level in my 20’s. The reason I know this is my roommate was a world class surfer who got second in the Katins contest in Huntington beach. He surfed for Ken Bradshaw in Hawaii. He could surf on anything, twenty something years ago I made him a 4 fin with some help from the shapers at mcCoy and he ripped on that thing ??? Talented. I knew were I stood, but around regular guys I was the hot guy. Anyway laid off for the last 10 years only surfing a dozen times a year on a fun board. But now I’m sufing alot, and I’m were I left off but I’m 46, so I went to 6-6 till I felt I can ride smaller. I feel I’m there now. Fit. So back to the board. I think you gave me some good dimentions to mess with. My blanks I use has 2" natural tail rocker and board #1 doesn’t go vertical as fast as I want ?? Should I kick it up to 2.5" ?? thanks DR

Greg when you designed your warp tail was it a tear drop outline with wide point behind center ? narrow nose

Also regarding rocker for a board like this what type of bottom did you put on it. Example what was the dimentions of the board you made for your friend ? Love that shape ,looks like Bert said will surf real square turns. thanks DR

DR !!

personally , i would leave the natural rocker of the tail …

the fact youve already thinned the rails reduced nose and tail area and have a finer foiled board will be enough …

you still want some drive …

for some reason 99% of shapers i know try to loosen up a board by increasing tail rocker …thats fine if you want to lose drive off the back foot as well .

its hard to get more vert on a board if it doesnt have the legs to drive up to the lip …

you can keep your rocker flatter through the tail , then decrease tail rail volume , decrease tippy tail area, pull in nose area , carry wide point back, get your nose entry starting nice and early near the front foot , reduce the size of your tail fin , move your tail fin forward 1/8th ,run a real light single between the feet …

all those things will contribute to getting your board more sensitive and going vert earlier without comprimising speed and drive off the back foot …

unless you have super powerful waves and speed to burn off and need a measure of control to slow your board down in the pocket , and like the feeling of your board hanging in the lip every time you hit the pocket to hard …

then the tail rocker may not be a good option …

hawaii definatly …florida definatly not …

regards

BERT

Thanks alot Bert… I cant wait to get started making a template tonight !! One thing my friend who shapes for Stewart told me was to lower the entry curve, move the apex back near the front fins, so I channeled that area which lowered it. He said it’s better for paddle and smaller surf. Is this contradictory to what you said by nice early entry curve near front foot ? I believe you, because he shapes now and doesn’t even surf much anymore, but he was JC hawaii’s top shaper. Also move the wide point 2" behind center. Here what I’ll draw up 6-3 x 18 3/4 x 2.25 11 or 11.5 nose x maybe 16 tail at hip area before the wings 16" up , Then 12" up around 14.5 what do you think ? round pin too. Much thanks DR (Also like those snaps you are doing on that board looks crisp)

one statement ive always used is paddle power versus performance …

you can flaten the nose entry so you have a longer flat before a later nose flip . yes that helps with paddle , but its notorious for rail grabbing and making you draw your bottom turns and not allowing you to get vert square off the bottom …plus has a tendancy to not allow your board to swing around underneath you on the way back down , lowering your entry causes it to get in the way and cause problems …

bringing your entry as far back as possible so you have a drawn out nose rocker that comes all the way to your front foot , will keep the nose feeling free and give you the ability to place the nose where ever you want , it will also be reliable every time you snap in the pocket allowing the nose to swing freely so its always back underneath you on the way back down …

plus youll get way more squirt out of your first pump , because the nose is higher and free-er , youll be able to swing it and get fin drive instantly …

what your friend said did contradict my statement about the rocker , it depends on what is more important to you ,paddle power or tight hacks in the pocket without catching the rail…

your dimensions sound pretty good , depending on how far your hip is placed you could come down to 14 1/4 at the 12" mark …

rounded pin is always gonna give better control in the tightest part of the pocket …

it just fits in there so much better …allows you to feed more power into a turn before it pops and drift starts to happen …i dont mind slide at all , but i hate it when i dont want it …

11 " nose as well …

hey dorian heres a few more pics from one of those sessions above …same board as the pic above …

doh , i really need to build this board again …had so many magic sessions on it , even tho ive got the flexing boxes now , i think ill just do set fins, keep everything the same and just build a copy with boxes , have two identicals and compare …

this was the only board ive ever owned that i couldnt fault …

you know how you always want more out of a board somewhere for some little reason …i think thats why i rode it as my main board for 5 years … mostly i just on sell a board if its not magic within a few months or even after a few days in some cases …

the whole time i rode this shortboard i had no idea what i would do in another board coz this one did everything i wanted …so i had no need to try something different …

ive based all my team guys boards on the same formula as this board and had the same response from all of them …

cant fault it …

crispy hard edges to … maximum release …

have fun i hope it works for you …

regards

BERT



Much thanks Bert, Love picture #3 the fan your throwing is nice. Board #2 is only shaped and on the racks I flatned the entry curve, But after I read what you said it’s the opposite of what i’m looking for , more vert !! May not glass it. I did move the bump back on it though to about the front foot. But I dug out the concaves and made what you described above. DR

HAPPY NEW YEAR EVERYONE!!!

Hi Bert,

I’ve enjoyed this post…tons of useful micro info!! I was hoping you could clarify…there are couple of unturned stones in my mind.

I’m interested in your concepts and improving upon my current board for my next project cuz the conditions you describe are very similar to what I surf 70% of the time…and you mentioned power surfing in small waves…yeah thats what I like but with smooth style. The dimensions will be very close…6’3 x 19.2 x 2.4.

I’ve got this 6’4 x 19.3 x 2.4 EPS (see attached pic) Im riding now that I’ve reworked a couple of times and I’ve got some magic out of it particularly in the ease of speed category…its got boxy/edgy rails lower half with somewhat soft/rounded rails forward half…medium rail volume….2.25 tail rocker with 3/16 single concave, 4.7 nose rocker no flip. The entry rocker is very low/fast so the board doesn’t go vert as much as you describe but again the board flies and I like that. Its also got a soft hip around the front fins and semi-rounded squash.

The one thing that I feel missing is the free underlip snaps quickness you describe….in vert walls it kind of hangs just a bit so I have to make physical adjustments…I use my legs and a very low stance to power thru it but I feel I don’t have the control at the finish…like the board drops to the bottom late and wants to pearl….the width is helping or hurting me here…I think. What Im riding now is close, but based on your detailed concepts, I think the way to improve upon my current ride is to implement the Scurve/roundpin tail with a little more entry rocker and slightly more pulled forward half.

But here are my concerns….

  1. How the planshape affects a fluid rider’s style….how would Parko ride it?
  2. loss of projection on rail (too much curve in the outline? My thought is to flatten the outline curve in the center a bit)
  3. pro/con effect of using off-the-shelf fins templates (currently using big Rusty fronts and medium center)
  4. using correct rail profile/edge/volume along the entire length of board so that it maximizes both release and neutrality (sounds almost too good to be true)
Thanks in advance!