Figuring out why a board has later take offs.

General Discussion
1

Okay I have a 6’0" board(board #1) that does most things well.

Made another of these 6’0"'s (board #2) but with 2 changes.

Presently the new board hangs up a little bit on take offs.

I have to paddle more to get into the waves, or I get a little stuck at the top and really have to work to overcome that or take a later more precarious takeoff.

Here are the changes I incorporated into Board #2:

Board#2 is 1/4" thicker throughout than its predecessor

and with very much fuller boxy rails, much more than the predecessor board had. Very much hard edge from tail up

through near midpt of board…

In addition, I threw in an extra 1/4" tail rocker that it seemed to need. Currently its 2 1/4" on a 6’ board…for beach break.

Previous board had 2" but was more for point break waves.

Specifically I concentrated the last 1/4" from the fin area

back toward the tail.

Initially my thinking was that the fullness of the board/rails

was causing it to hang a bit on takeoffs. However,on second thought I thought it rash to consider only thickess and rail fullness, maybe concentrated tail rocker is to be considered also.

To be sure, the board doesnt really lose the wave or bleed off speed when I hit the lip…which is a sign of too much tail rocker.

So what may be the reason for the hangups on take offs?

Any thoughts?

2

I dont know.

3

My bet is…

Extra tail rocker…

Made a board that was basically a copy of an old favourite but with extra tail rocker a while ago and ir exhibited the exact same symptoms you describe.

Jesus…nice avatar…crap comment.

4

me neither… :slight_smile:

but, I do feel the same thing on fuller boards.

I feel it only on shortboards!

thicker shortboards ( say 2.5" and above) need quite a paddling to catch a wave.

thinner boards sink and feel like they are already in the wave’s energy and not above it.

in longboards and fishes ( I had to write it like that :slight_smile: ) it seems to be the other way around- the thicker the better.

5

Hard to pin down the reason for a performance change to just one thing unless both boards came off identically machined blanks–old problem! My guess is that the extra tail rocker is not the culprit, but subtle changes to the rocker under the chest area due to the additional 1/4" of thickness. Even a little too much right there is magnified because of the loading that occurs when your weight concentrates there as you make those last hard paddling strokes to catch the wave.

6

I’ve had a couple of boards like that in the past. The nose rocker on those boards had a "bump"or bulge in it. So instead of it having a smooth transitional flow in the rocker their is this protruding bump or bulge, which I think causes the board to stall on the take offs or slow you down when paddling for waves.

Hope this helps you.

7

Hello. Is there any chance of a couple of rocker shots. Maybe we’ll have a better chance of spotting why?

8

Hi everybody,

I’d like to know the type of fins are you using in both boards. Thicknes of fins can make a big differences on timing to catch waves. I suppose the boards have the same fin setup, don’t they? If not, this can be another path.

9

Thicker board, and you pushed the tail rocker. that means that the overall rocker is more pronounced. You picked up more than 1/4 i bet. One of the hardest things in shaping is keeping the foil proper for a thicker board, while maintaining a thin nose and tail. I’d look at the tail rocker up about an arms length…right at that spot where you were scrubbing the 20in sanding block. Chances are you have a flat spot.

Did you use a planer, or was this a surform jobby? Did you add concaves, or a flat bottom, fin placement change 1/16? So many variables, especially if this is board #2. I hate to say it, but with only 2 boards under your belt what did you expect? I’d say batting .500 your doing pretty well. Throw that one on Craigs list and have a do over.

I think Jesus’s comment was perfect…what would you expect from Jesus?

10

All good input, thanks guys.

Figure I’ll have to do some thinking and create another hypothesis , then apply the scientific method…making another board.

Well, the boards are CNC milled.

Everything else not previously alluded to is the same.

I’m tending towards it being the thickness w/full boxy rails

and that hard edge which will should keep the thing riding

at a higher waterline I suppose.

Additonally the foil(nose/tail thickness) is a little thicker toward the nose,tail is fine.

The board thickness is in excess of 2.5" but well under 2.75.

2 1/4" tail rocker is well within normal.

Actually the board tail rocker came out at closer to 2"

despite the program specs. Actually I was/am quite happy

with that because it allowed me to put in the extra

1/4" and concentrate it the way I wanted.

Which was essentially in the last 20" or less of the tail.

761×268 18.1 KB

11

I think what you have is called “corking”

as where the wave wants to pass you by cause of more float in the board

12

Hey KenSurf I would tend to agree.

Does this problem ‘corkiness’ exhibit itself with just an

overall greater thickness??

or can it be associated with a disproportionate amount

towards the nose?? You know nose and midsection floating

high and inhibiting entry on takeoff?

13

Otis

I dont know about all that

but

Epoxy boards when made too thick will do the corky thing

theres a happy spot to be achieved between weight and volume

14

Ive noticed the corky thing as well but that was with near 3" thick X 21" wide full foil boards. They seem to float you so much that they kinda plow at takeoff where a thinner board is already deeper and has more planning speed in the wave because of it’s deeper draft. It doesn’t seem like you added that much volume-enough to make it corky. I don’ t know that you’re 1/4" of additional rocker would give you that much drag at takeoff either- especially since you said you put it far back. I would think that you would be more likely to feel sluggish when up and planning if your rocker was to extreme. But, again this is board #2 so you’re probably doing better than you’re give yourself credit for.

I would place the most emphasis on the following factor however. Are your memories of board #1 from the winter, even spring nw swells, and your experimentation with board #2 during from this summer? I would suggest that south swells are a bit of ass draggers at ocean beach compared to winter nw swells. Not sure what it is. One theory I have is that the souths have to travel diagonal, and thus a longer distance across the shallow sapping shelf, and they hit ocean beach at a steeper angle, as opposed to the nw swells. From the nw the swell source is closer and ocean beach faces nw. If you look at the bathy diagrams of the mouth of the bay the nw swells travel over a much shorter distance of shallow water compared to a south. There is just something about souths in northern CA…and they just don’t dish out with the same juice at many spots. Its kinda like surfing in Hawaii or Indo, or some place without a continental shelf, and then coming home to CA. In comparison the CA waves feel like dogs. This is an extreme example however I think there is a similar, although more subtle difference, between NW and SW swells in Northern Ca.

You could also be succumbing to a common Northern CA phenomenon often referred to as 'Septemberitis". Winter was a long, long time ago in a galaxy far, far away. You have been surfing the bread crumbs of souths and windswell for months now. Everything feels slower and later. Are you sure you’re board #1 memories aren’t from winter? I dunno…its all just my 2cents and bullshit philosophy.

15

One thing nobody yet mentioned is the rider! If the bad board is having you position yourself differently when paddeling, it would make a huge difference.

A narrow nose or thin nose will sink when you push up. That sink will cause the board to radically slow down on the take-off.

Another thought is exactly where did the concave start and finish on the two boards. If the deepest part of the concave shifts even a little, it will change how the board planes.

Just remember that the proof is in the pudding! If the two boards ride differently, something must have changed.

16

One thing you did not mention is when you “added” tailrocker was it just in the bottom or did the deck curve up as well. I have found that boards with “deck kicked tails” do not get into waves as easy as non kicked.

17

Thanks to all,

some of these replies are starting to ‘jump the shark’.

For the record I’ve been surfing since the early 70’s.

Got taught and did a relatively short stint at shaping in the early 80’s and have now resumed via CNC.

I’m from California and quite mobile, surfing both North and South.

My feelings about the possibility of more tail rocker implicated for late takeoffs is simple. More tail rocker means less resistance and therefore less to push you down the wave at that critical time.

But my feelings are that 2 1/4" is not substantial in this

area or may have been exacerbated ‘somehow’ by having a more corky board…and a corky board it is!

However, it rides very well and has the best acceleration

rate of any of single concaves I’ve ever ridden.

Thank you all for helping me explore this matter.

18

Let me add this just to confuse things. I made a 6’-6" x 19-1/4" x 2-1/4" bonzer that has the problems you describe. Hard to catch waves, hangng up on the take off. Now I’m riding a 6’-0" x 19-1/4" x 2-1/2" that catches waves just fine. My conclusion was the lack of thickness and the very knifey thin rails made the bonzer hang up.

So I have the exact same problem and came to the opposite conclusions about the cause.

Oh, the bonzer had 2-1/4" tail rocker. The 6’-0" (Griffin style five fin) has only 1-1/2" tail rocker, but I didn’t think the rocker was the issue.

19

i agree with everysurfer

weve had this one before and ive asked the same question

imo

its width and volume at the front and rocker entry

but it depends on the waves

steep and sucky with a defined peak requires a diferent board then larger full waves that crumble

in shortboards in steep sucky waves, any nose width increase will improve wave catching more than anything

it stabilises the board so your paddling is more efective

you dont waste your energy rocking froim side to side

on bigger boards in large full waves then you want some length and overall width and volume

tail rocker seems to do sweet fck all ( it seems to me the more tail rocker the easier the board is to turn at high speed)

thick tails are no good as they pop out

rocker entry is real important

lots of nose rocker is good in steep waves for late drops but they slow your entry

but a good surfer in steeps waves generally has better positioning to compensate

shoulder hoppers and unfit are fcked with lots of nose rocker they need low entry

fat and crumbly waves need low entry

unfortunately low entry rockers are sketchy in ledgey waves

taking off behind the rocks at snappers needs more nose rocker cuz the steep wave throw and has steps and lumps in it

trying to get in on the shoulder there is waste of time

you gotta be under the lip and its bury the tail, spin and one stroke

on big fat point breaks ( head and half to 2 1/2 overhead) you want overall lots of width and volume

and more tail rocker for control

concaves have no qauntifiable advantage or disadvantage wrt to wave catching

but imo they add control at high speed

paddling leverage point position on the board relative to rocker is very important i think

so this is a subtle equation between volume under chest and nose rocker

a lot of aussie boards have more rocker then kiwi boards

queensland have short and sharp hollow short period

NZ has big longperiod but mostly fat waves

i seen a few and surfed a few hawaiian boards and they were hopeless in our waves

one i saw was a cambell brothers bonzer and it was really straight and narrow ugly thing (looked like it would be hard to turn in small waves)

i surfed a signed brewer xtr shorty and it was also overrockerd and hopeless(no drive)

i surf this wave like this at least 20 to 30 times a year and ive tried heaps of different foils and outlines on the the exact same rocker (molded rocker)

i like

thin tail and medium to low boxy rails

about 2 1/4 thick and around 15 wide in the tail and over 12 in the nose

overall width over twenty

fat based fins ( fcs thin foils are no good )

im 6 3 and 85 kg and fit

i can ride these dimension from 62 to 68 on this wave depending on size and crowd

i prefer more rocker in the nose but still no more than 5 1/4

if its crowded or im tired i get the 6 8

im not a flashy surfer can do reos and floaters and cutties

20

Otis,

I’d be inclined to blame the fatter boxierr rails up front. Just more drag around the rails as water wraps around them making it a bit harder to get the board planning as you get to your feet.