You are mistaken, I’m clean.
.
Hi Roy, your individual manner/ idea of measuring rocker should be heralded by Sway-folk as a beacon of individual thought. The kind of thought that brought new innovation to surf design and progress in general. And for that, you should be respected as a maverick of design.
I started this thread with the idea of excluding other design elements (( Post 1, Line 1,)> “Without going into the murky depths of any complete design”…) but I looked at another thread where a guy ( BENNY 1 ) had a neutral board and only changed----->>… the fin.
The Spitfire Fin thread I think…
Thats probably where the ‘magical’ board ( or any new addition) can be de-constructed into simple components much like a car or any multi-component item.
Take a neutral base
and vary a single, individual input.
And then consider the variation,
for better or worse.
The ‘neutral base’ would be an agreed standard, tested in a standard set of circumstances, with a measureable scientific variation.
Like the standard yard, kilo or decibel. We need a solid scientific standard from which to start.
And from there,
it could be determined the fastest rocker,
least drag rail shape,
fastest flex rebound,
most effecient concave angles.
As well as a wealth of proven variables that would separate the knowledgeable craftsmen from the hokey shamen…
And then the truth,
within the parameters of the testing variables,
would be revealed.
And from there worked into
new,
proven,
advancements.
Belief, proof, advance.
And isnt that the real ‘holy grail’ of surfboard design??
SF.
Quote:
Top idea actually, I usually measure rocker in millimetres per foot, that is, get a one foot ruler, lay it on the bottom, and measure how much the rocker diverges from it at each end ( both measurements must be equal.)
plus a free bar of heavenly wax.
.
Roy, I am your friend, and I was when I adjudged the point, but Kendall makes several good touches.
I also agree with Brett (Hello Brett) on his overall point,
and I find the method of measurement reasonable, as mms are easier to use than the Imperial equivalents, and feet easier to recall than the metric equivalents. It is eclectic and un-doctrinaire, and very useful. As he says, perfect Swaylock’s.
Car tires are measured using millimeters, percentages, and inches… along with a speed rating. For example for a 205/50ZR17:
205 = mm wide contact area
50 = percent of rubber height (from rim) in relation to the width
ZR = speed rated over 130mph
17 = size of rim in inches
Seems a bit quirky, but it’s the industry standard. And they make a lot more tires than surfboards.
Yea…they might be easier to make than elaborate concaves, hulls, channels, etc…you’re right about that.
But to say they don’t work well in the barrel…man…you’re just dead wrong. They might not work well for YOU in the barrel. For me, and for many other fish lovers, short, flat rockered, deep crack, modern keel finned fishes work great in fast, hollow waves up to just overhead. After that, I’m going to a thruster with a single concave (to make it flatter down the stringer) to tighten up the turning radius for added snap.
But to answer the question, what kind of rocker is fastest, you have to entertain the idea of flatter is faster along the planing surface. To me, that means relaxed entry rocker, flattened (but not dead flat) between the feet, and a bit of kick in the tail for release and tight pocket turns.
In single to double concave bottoms, the single flattens the stringer rocker, maintains rail rocker in the middle, and directs water into the double concaves. Properly placed double concaves, working in concert with fins, tail kick, and rail edges increase drag, but provide a feature that can generate bursts of speed when you need them. So, my theory is, it’s a good design for what people call “performance” surfing that lends itself to acceleration-turn-acceleration-turn type surfing, staying close to the curl and using all the power that can be tapped. But they’re not the fastest shortboard rockers for flat out down the line speed. IMHO, natural, relaxed rockers with flattened planing surfaces are faster.
Quote:
Hi Roy, your individual manner/ idea of measuring rocker should be heralded by Sway-folk as a beacon of individual thought.
Thanks, but really it’s just common sense, it doesn’t have to be done as I suggested, but unless the amount of rocker is measured over a standard distance then it is meaningless as a way of comparing the rate of curvature.
What is really weird is that everyone keeps on trying to compare rocker curves without any idea of what the curves are
Add to that the fact that apart from you and I no one seems to be measuring speed, and we have a speed vs rocker thread is about as vague as it can get.
Anyone want to take a plunge and attach some meaningful figures to their comments ?
.
Quote:
Anyone want to take a plunge and attach some meaningful figures to their comments ?
.
not me… I’m just a dumb surfer.
Q.E.D.
.
Quote:
Quote:What is really weird is that everyone keeps on trying to compare rocker curves without any idea of what the curves are
I drop in late and steep… rail grabbed… crank a bottom turn… then up to the lip… I hook a tight gash… sending a big fan spray. If each portion feels sweet and buttery, its the right curve. That, my friend, is the ultimate measure.
Roy, Sorry I dont have any figures either but I will keep records from now on. My hulls are multiple-foils and I dont think the numbers translate. But I agree that design is a science and personally believe that Figures will replace Phrenology, if only because it makes financial sense now that design is high volume and low profit.
As Im now ‘forcing’ myself ( joke) to do a monohull, I thought Id ask about rocker first and then bottom contours, and then rails and then…
So I would like to comment on faster rocker using this comment of yours.
Quote:
The theory behind those boards with low tail curve and loads of nose lift is the same as why that sort of curve is used for shortboards: a high lift high drag nose curve to lift the board onto the plane early, and a flat tail which is used when going faster, the nose is then clear of the water. . . much like a planing powerboat.
Roy.
(The emphasis is mine - SF.)
Can a board have 2 rockers, 1 for high lift/no-pearl and the 2nd one for speed ?
This is a crude version of a rocker for a ‘fastest indian’ style board.
The top one has a very flat rocker, but pearls/digs/grabs.
The 2nd one has an even flatter rocker but has the most forward area set at a higher angle for lift and it would be clear of the water once planing.
This is just a theory and a stick drawing so all variations are possible.
Not overly pretty at first glance either, but it does give 2 effective and independent rockers.
Isn’t this pretty much what some guys are doing by carrying a flat rocker up to about 8" off the nose and then have the nose flip to well over 5"? You get a flat rocker even on entry, but enough nose rocker to not pearl.
Quote:
I drop in late and steep… rail grabbed… crank a bottom turn… then up to the lip… I hook a tight gash… sending a big fan spray. If each portion feels sweet and buttery, its the right curve. That, my friend, is the ultimate measure.
You always do that, no matter what the wave is doing ?. . . . . Rofl that’s what grommets who have beeen watching too many movies try to do . . . apply pre determined moves to waves regardless of the wave shape !
You on the wrong thread Craftee, this one is about flat rocker and speed, not about making fans. . . . . . . same mistake as above, applying predetermined answer to thread regardless of subject… . . it doesn’t fit
.
Quote:
Can a board have 2 rockers, 1 for high lift/no-pearl and the 2nd one for speed ?
This is a crude version of a rocker for a ‘fastest indian’ style board.
Yes that’s the idea we have been basing our rockers on, and as Haavard says, it’s really the standard for most shortboards already
It doesn’t have to be markedly 2 stage though, it could be a continuously flattening rocker from nose to tail. . . a hyperbolic or parabolic rocker would do it, I’m keen to do one soon, the step looks interesting though.
.
Hi Haarvard, I think shaping has some very strict aesthetic rules that constrict the evolution of the craft.
So all thoughts are allowed… but no variation is permitted.
As for the nose flip guys, yes its a similar idea, also a compromise within the permitted limits, but where their rocker has the most curve near the nose it has the most drag as well, and forms a weak point/area. Im thinking the stringer grain ( 0 and 90 deg) loses continuity and strength with sharp rocker.
I see, and maybe you do also, a lot of boards snapped ~ 12in down, and that might be because of that extra curve.
My highly original, and ingenious plan ( another joke) was to Not compromise, Not follow tradition and take from all areas of fluid or hydro dynamics as it suited the final design.
Im planning to put 2 windsurfer fins on this beast as well, just for a bit of bite…
SF.
Quote:
I was looking at widening the possible number of makeable waves by designing something for very fast straight tubes that are just too fast with standard equipment.
Design a purpose built board for really fast left or right tubes, no turning required. Like they already have speed skis, downhill snowboards, drag cars.
The Fastest Indian, but on water.
SF.
SF,
In my opinion: Waves that pitch out i.e., tubes, they tend to be way more vertical and critical…like a lot more. Therefore the board that you surf needs to be able to fit into that shape. Nose & tail rocker are extremely critical in “fitting into” the wave. Flat boards tend to catch rails and get “sucked up and over”. In short tubes your not trying to generate speed, a lot of times your trying to shed speed or stall. You know “jamb your hand into the wave face to create a speed break”…then let it go and fly out from all the presure created from the angle of attack and the steepness. Fast down the line tubes need to be pumped at best, and at least roller coastered to generate speed. The only wave I can think of right now that would let you just stand there and get hiddiously shacked would be the inside section of Sunset, but by the time you get to that point your completely hauling ass fast, and all you can do is just “pull in”.
So If I had to make a barrel board that was flat? I’d give it a go by making a flat entry rocker, but i’d kick the tail pretty good. The reason for the tail kick is that you can stand on the tail during the drop in and lift the nose out of the water. Also the tail kick will help on the bottom turn, and then the little snap you need to stall for cover up. But…making a super flat board for a tube board would be let’s say interesting.
Now you didn’t say how big of tubes. I mean if you looking for knee size tubes then you can surf any size or rockered board. But something where you pretty much pull in and stand tall…well that would be a bit different, and I’d recommend staying away from totally flat boards.
My 10 cents.
And yes flat is fast, but what good is Corvette speed, without a steering wheel? It would come down to how fast do you want to slam into the wall?
Flat nose rocker and pronounced tail rocker is a recipe for going slow.
A flat board is good in hollow waves if the planshape is suitable ( e.g Lopez at pipeline in the 70’s)
This board has only an inch and three quarters of rocker over 9 feet and handles steep drops and tubes easily:
Quote:
My 10 cents.
Make it a dollar.
I like this one best… understated but serious as a heart attack:
Quote:
Waves that pitch out i.e., tubes, they tend to be way more vertical and critical...like a lot more.
The critical big-wave spots I’ve surfed all require specific boards. The wrong thing… even a little wrong… can get you a nice date with god. The boards they use there aren’t designed the way they are on accident. They’ve been refined for generations. They have rocker to fit the wave. Find me a flat spot on a wave.
I believe that length is the shortest distance between two points, so if a rocker is more curved then water has less distance to travel before it exits the board. The downside is there is less board touching the water so poorer weight distribution would probably result. And vice versa I think. So no idea is my answer.
Boards don’t have to be fast to make tubes - just fast enough.
You’ll do better using a decent rocker (whether you prefer 1,2,3 stage is up to you) combined with a tailored outline.
Push the wide point forward in a short board and you’ll achieve a board that “pulls” itself out of tubes.
Overdo the narrow tail/ wide nose formula and you’ll get a board that catches up front
Flat rockers may be fast, but they’ll hang you up in the tube and you’ll go over the falls. Here’s what happens: The water “sees” the bottom of the board as it sucks up the face. Release up front and fins in back means that the back of the board is 'seen" more. Result is the board rear pulls up the face and nose points down. The board slides down the face under gravity. Insufficient rocker - too much of the bottom of the board is “seen” - board doesn’t point downhill enough to slide - gets pulled too high - over she goes. Sure good surfers can overcome it, but I prefer boards that get me OUT of trouble, not into it.
some thoughts about bottom curve. I hear a lot of talk around this subject about pressure differentials, as on an airplane wing, however, with the incompressible nature of water, this explaination is weak. sure theres pressure differentials holding the rider up and propelling him, but these pressure are caused by acclerating (or turning) the water, not stretching it, as on a wing. When you have too much rocker to fit the shape of the wave, you are turning the water around a concave relative to the rider. this acceleration sinks the board and rider which increases the amount of water your moving. too little and you are turning the water through concaves at the nose and tail. seems with rocker if you can find a curve that will fit the wave you want to ride its the best. these are all new thought in my head, so dont anyone take them too seriously.
i side note about bottom concaves. concaves seem to turn the water flowing perpendicular to the board convex to rider without creating too much drag. this produces more lifting force, your are higher out of the water and have less drag, ie go faster. so a question, what are the limitations, why dont all boards have them. is it because it increases manufacturing time?
shoot back harvard, u seem to be a fellow M.E.