Rocker theory...

General Discussion
1

Folk’s - there’s probably no right or wrong in regards to rocker. But how and where do you like setting your rocker up on a short board?

A little history: I read boards had originally been almost dead flat - w just a little bevel under nose ( obviously to prevent pearling)… Then I read - Dick Brewer started to experiment with rocker pulling from the center… not sure if this is factual info? I just read about it. Anyway, how and where do you shape in your rockers? Note: this question is to help understand rocker and how it affects ride… have fun!

https://swaylocks7stage.s3.us-east-2.amazonaws.com/s3fs-public/20140919_204356.jpg

https://swaylocks7stage.s3.us-east-2.amazonaws.com/s3fs-public/20140722_211722.jpg

2

Shapa, Brewer worked off a three-stage rocker for years.

Flatter mid section, he called the sweet spot.

Lots of rocker combo’s out there now.

Excellerated, continuous, etc.

Lots to learn.

Do your homework.

**Rocker**

The rocker is the bottom curve of the board from the nose to the tail. It is the curvature of the surfboard from a profile or side angle.  The basic reason for this curve is to fit the surface area of the board to the curvature of a wave face.  If your surfboard had a straight rocker, you are more likely to pearl when dropping into the steep part of the wave.The amount of curve in the rocker will affect the turning or carving ability of the board.  Performance shortboards typically have more rocker to give a smaller turning radius.  It is also more suitable for getting into steep and hollow waves.

Surfboards with low rocker keep more surface area on top of the water, allowing the rider to generate more speed when paddling and surfing. This is in contrast to boards with more rocker, which have less surface area on the water and, thus, do not pick up speed as easily. Longboards are designed to catch waves with ease and typically have lower rocker than shortboards. The low rocker makes longboards more suitable for slow, mushy waves as opposed to steep hollow waves.

Nose Rocker

The nose rocker is curved near the front of the board.  Similar to the front of a boat’s hull, this is designed to keep you from digging into the bumps of the wave.  As a surfer drops into a wave, the curvature of the nose will help to keep the board on top of the wave’s surface.  Otherwise, the board’s nose may dig into the water and pearl.

Tail Rocker

The bottom curve at the back end of the board is designed for tail kick.  With more tail curve, the easier the board squats.  This loosens the board up to change directions and making more pivotal turns.  Tail kick also makes it easier to drop into waves without pearling because the upwards lift of the tail isn’t forcing the nose downwards as much as a straight tail rocker would.

While a board with more tail rocker will offer increased control, this design will slow the board down.  The less curve in the tail rocker, the easier the board will plane, making the board faster.

3

Barry - ty for sharing! Rocker is mind boggling… I mean, difficult to grasp - with many various combos that work… you know what I just discovered!? At center apex, or center, there appears to be a flat spot? Or is it bent slightly? But I think
get what - Brewer meant? Or with a flatter sweet spot at center…and nose/tail rockers flowing into the center. Nice write up! I geuss it’s kinda personal how and where one makes rocker break? Fyi - on my quad fish I discovered my blanks nat rocker break is roughly about a third the length of board. I’ll check nose tommoro. Whatever I did when I added tail kick, it does flow into the tail rocker break there FWIW.Peace

4

Mc Tavish, also has his 3 stage rocker.  It is still most likly true today as it was in the 1970s you had a diffrent rocker for surfing Pipe then you did for Sunset. the Designs that are out there now are more sophisticated but due to close tolerance blanks easier to get there. 
Yet finding that nuance that hidden line in the blank still takes time and effort dig out from the excess foam. Build a rocker stick get the numbers off as many boards as you can. The numbers are a small part of the story but the best place to start. I know what I like but I’ll be damed if after surfing and working in the board industry i have still got a lot to learn. Tomorrow I start on my catamaran flat-water SUP Barry don’t shoot me!

5

Stretch on rocker

McCoy on rocker

http://www.youtube.com/watch?v=EcfYH3EZzvw

http://www.surfline.com/video/premium-partner-video/proctor-surfboards-how-low-can-you-go_48130

6

Thanks for chiming in -Artz! Yup. I found the perfect rocker stick at ace. I just got to pick it up. But I’ll keep learning from existing rocker #'s - thanks for the tips.

Anyway, I read back in the sixties Folk’s didn’t rely on teacher’s, but rather learned Shaping from trial & error. Or they took shaping as a personal thing… they put a lot of imagination into how their boards rode. What they did was fine tune them to their own personal needs…I think they had personal feel for their boards - something that is lost today. Just a thought.

7

Anyone want to chime in with more on rocker apex in correlation, or not! with the wide point. Was always told/read? that the wide point had to be on the apex. I have found this not to necessarily be the case within my limited experience. Would like to learn more & still playing around with it in my own way. Slanj

Smile @ strangers & use the force…

8

Hi Harry - 

Hope you’re doing OK.

After watching those video links I couldn’t help but remember my girlfriend’s little brother over in Hawaii showing me his new board with flat nose rocker and boosted tail rocker.  His description was similar to Todd Proctor’s.  Granted, the board’s overall design was different - thicker, beak nose, and single fin but what the heck… it was 1972!

9
  • rocker is localy modify by bottom shape.
10

I think boards used to be built like that? But guy’s started to experiment back in the day - by testing theory in the water. What they did: they actually moved wp for or aft center (apex) to discover different feel… but maybe you might not want apex to stray too far away? I dunno, but apex of rocker, I think, is at center of the blank. Try it! Take a yard stick, or a tape measure and you’ll see what I’m referring to. It’s probably the MAIN " sweet spot " Brewer was referring to? But when you really ponder surfboard rocker - it all flows into the center. But as a single unit w out stops…or un- even transition. Why? You’d prob create excessive drag if rocker lines were broken in segments… Probably not the end of the world if they were slightly? Cheers!

11

I’m referring to the rocker apex, not the outline. Like i said i had always believed that the rocker point/apex, ie-lowest point of bottom curve had to be at the wide point on the board. I don’t believe this to be necessarily so! Was looking for some conformation on this or just a bit more info, different perspectives on this?! I have played around with this aspect, but nowhere near enough! Would have to try 3-4 identical templates with the exeption of altering rocker apex with regards to the wide point of that particular outline. Will go & have a search now. Prob should have done that to begin with… Slanj

Smile @ strangers & use the force…

12

After watching some of the vids, you come to realize that your rocker apex ( center ) seems to be at center… but wp can stray within reason? But I am not positive. Also, note how -Mr Procter says he puts a bit more tail rocker in REAR HALF. KEY WORDS; rear half. So he says he uses a flatter entry rocker, and puts more rocker curve in tail half…but that could suggest, also, an accelerated tail rocker. Not really tail kick? Maybe some can chime in about it.

13

Little rule of thumb: Don’t mess with a blank’s rocker too much when shaping. The rockers are designed to work well

~Brian

14

just IMHO but

seperating everything apart like dissecting a frog doesn’t really work when it comes to surfboards

you can’t just take on  rocker with out looking at outline,profile, bottom contours, rail profiles and fins

you can have staged (brewer), continous curve (parmenter), or complex (alexander/maurice cole) 

but its how the combination of these intricate parts of a design make or break it

the beak nose boards we rode in the early 70’s had little if no rocker but were shaped like little missles

the worlds most perfect rocker built into a terrible outline with lousy fin placement is still gonna suck

I think that’s why the great shapers shape with both their eyes and their hands and not just the numbers…

but then I’m an old fart who started before the magazines took over…

but i do listen when i talk to my shapers

15

Onuela - I agree totally that all of the components must somehow work together. But I think I know what you’re getting at? Rocker wasn’t really measured. It’s shaped in…

16

There’s always three stages…start, middle, end…one little thing I learned from studying some Brewer shapes (amongst others!) was that the three stages were blended beautifully…now there’s where the magic happens…

17

This, from the Harbour Surfboards website;

 

Rocker is the term for the curvature of the board from nose to tail, looking at the board’s edge.  This is measured on the bottom of the board.  A long straight edge is placed on it, with the straight edge’s center matching the center of the board.  The distance from the board to the straight edge a given point is considered a rocker measurement. Key numbers are zero (or the end of the board), 6”, 12”, 18”, 24”, and the board’s mid point.  A basic rule of surfboard design is that as the board’s nose rocker decreases, the nose width increases.

There are three primary areas of rocker: nose, middle and tail.  Using a long board as an example, increasing the nose rocker will cause less water to splash in the face while paddling, and decrease the chance of catching the nose while dropping into a wave or while turning.  However, increased nose rocker combined with increased nose width when paddling into a wave, will push water, making dropping into a wave more difficult.  Too much nose rocker can also cause the tail to release prematurely when nose riding.

Increased rocker in the middle of the board will lower the board’s drive, and slow the paddling. Too flat of a rocker curve in the middle will make the board stiff.

A key area of rocker is the area between 12 and 18 inches from the tail. There should be a bend in this area with a flatter curve forward of this bend. This joining of tail curve and flatter area of the mid section are one of the key elements of surfboard design and must be in concert with outline and rail shapes. It takes years of knowledge to know how much and where to put this bend.

Increased tail rocker will ease turning and increase tip time.  But it will slow paddling, down line speed and decrease drive out of the turn.  Decrease the tail rocker and the board becomes stiffer in maneuverability, but the forward drive increases.

18

About cutting in rocker, I watched one shaper mow it (rocker) in from tips in towards wp where I think he faded out w otf lever… but on shaping 101 on YouTube J c cuts open at tips, closed at center, open out tips…or he accelerates the planer in and out the tip sides…would this be a more traditional technique? That said, it looks doable! His board did look nice. That said, I cross cut my rocker in. I also tried what - Bill Thrailkill suggested of cutting from tips towards center in steps… Bill if I forgot to thank you - Thanks again! I thought your method helped carve out that un-wanted foam in the tail rocker. Upfront, I think my upper most fade out (shallower) cuts were about 16" up board… so roughly 3 zig zag cross cuts, and three of -Bill’s method to shape it… then sum serious surform/sandin…overall I’m extremely STOKED and can’t wait to try it out! Upfront, I haven’t glassed it yet as I’m testing for a career. Good news is, I just passed an OFFICIAL test and scored 30 out of 30 questions! I’m pretty pumped up! Pay is 3 times + more than I ever made in my entire life! I don’t mean to boast, but I had been down on my luck for yrs. I geuss when ya hit rock bottom - the way to go is UP!:slight_smile:

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19

what’s the numbers?

looks pretty flat

but that’s usually an illusion from what I’ve seen

unless there’s a stick for reference

20

Shapa,

First.

Congrats on the new gig.

Second.

Rocker is a curve.

Just as important as any other surfboard curve.

When you get deep into it,

You’ll need one of these.

The only way to replicate rocker curves and make rocker templates.

Just another tool in the shaping room.