Tribal Knowledge: Is anyone looking for SUP board design and or shaping tips?

[Pierre]

Hi all,
I'm stoked to see how this topic is interesting, and by the level of skill and experience you share, so thanks to all.
about waveriding SUBs, kingdavid's one looks great! i'ms thinking about something similar formy next. once again it depends what kin of wave we  ride and how we like to ride waves. so everithing is interesting.
About race SUBs I don't have much experience but during summer time i'm regularly using an old windsurfing board french made as a SUP ( in fact I use it as a tender for my sail boat )..since last summer I stand up paddled it- before it was knee-paddling.
This board is about 12'5" long 26" wide and 6" thick with a boat hull , a rounded nose and wide flat tail, flat deck on middle, concave fwd and aft-  for french readers it's "dufour wing" sailboard, one of the most popular in late 70's-early 80's in France.
 and I'm stoked about speed on flat water/ little chop ( lake condition)
there is very little drag. stability is enough in flat/little chop conditions (I use it fully clothed except shoes)
I should like to compare with my 12 footer NFA ( Gong model) but it looks much faster.

that means we must look why a board is fast, but stable enough.I have experience in boat and board design but not much in racing SUP.
-width: the narrower the faster
-wetted surface: thin nose and tails shapes...like a kayak or rowing skiff!
-length- the longer the faster in flat water but about choppy conditions?
-pitching in the chop- : rocker design...
 rolling. ( stability control): you cannot make too narrow, deck height as low as possible, etc...
-fin design: avoid yawing but minimum wetted surface!!
-weight: is the weight a problem for speed? a little heavy gives some inertia...
-hull surface condition: sanding or not? etc...
and try to design the "5-legs sheep" as we say!

the problem is to compare: race together with a friend of about same weight and skill, and exchange boards! I plan to work on it next summer!

I just realize I still need to learn a lot from this forum, so again thanks for sharing experience!

[Pierre]

I'm back after a small GPS test on my home river water, weather was so fine high tide and swell so little so it was good conditions:
flat water, chop less than5 cm, ( fortunately during that season no damn' f*9K## motor boat or jetskis!!!)  wind max 5 knots. current very little.
distance run abt.1 nautical mile on my 12' NFA and then same trip on an old 12'5" windsurf board ( dufour wing).
Average speed 3.58 knots with old windsurf board" dufour", 3.57 knots on NFA: about same!
Max speed 5.15 knots with 12'5"windsurf board, 4.85 knots with 12" NFA.
Lessons taken:

the sail board is longer, flatter rocker with rounded hull under nose: speed potential is more:
but it's less stable ( width 26") and has a smaller fin: less confortable paddling, more yawing and a little rolling. and daggerboard hole was left opened, increasing drag.
the NFA with increased nose rocker and concave nose is "pushing water" but it's 30.5" wide and paddling is very comfortable. V shape from middle to aft gives not too much drag and 10" fin is ok.
Sure that in choppy conditions a wide board will be winner!
my goal now is to design a easy but fast paddler board...

-here my 2 trips

[kingdavid]

Hi Gary,

I use a long straight bar to measure the rocker. I have a mark at the center of the bar and I place a mark on the blank at the center of it's length. Then it is simply a matter of balancing the bar and measuring the rocker at the tip and tail. Here is a link to a typical White Hot Foam blank showing the rocker and foil dimensions: http://whitehotfoam.com/95S.htm

Some guys use a rocker template as shown at the bottom of this page: http://www.shapers.com.au/category2_1.htm


Some blanks have the deepest point in the rocker either forward or behind center. It is important to know where this point is for every blank.

Great question,

Dave Daum

[srfnff]

Thanks Dave,
gary

[Jesper B]

Some guys use a rocker template as shown at the bottom of this page: http://www.shapers.com.au/category2_1.htm

Anybody knows were to buy one of these in the US, or even better for me, in Europe?

/Jesper

[kingdavid]

Hi Jesper,

The rocker measurement device is fairly easy to make. Attached you will find views of a rocker gauge you can make from the following list of materials:

A.  1 piece, 2" x 4" x 12' wood or metal bar.
B.  13 each, 12" long round head bolts with a continuous thread.
C.  26 each, hex head nuts.
D.  26 each, flat washers (not shown in diagrams).

Have a look and let me know how you come out and if you have some better ideas.

Best regards,

Dave Daum

P.S. sorry everything is in inches.
 

[kingdavid]

Here are the other views:

[srfnff]

Here's a couple more ideas.
DW at NC Paddle Surfer built one in his garage. http://ncpaddlesurfer.blogspot.com/2007/12/rocker-jig.html

He got the idea from looking at this one. http://surfsource.net/Manufacturing/Surfboard%20blank/Rockerstick.htm

Dwight's a pretty sharp guy. He's currently building a 14' Racing SUP in his garage.
http://ncpaddlesurfer.blogspot.com/2009/03/day-3-garage-built-14-race-sup.html

[Dwight (DW)]

http://ncpaddlesurfer.blogspot.com/2009/03/new-rocker-jig-design.html

Just updated to my NEW rocker jig.

[Dwight (DW)]

I water tested my garage built 14 footer tonight. It came out 29 lbs. It's way faster than I ever dreamed it would be.

[srfnff]

Looks really nice! More pics please!!!

[kingdavid]

Nice photo. Please send more.

[Sam Pa'e]

Dwight,
Is this the board you were inquiring about the EPS 1lb-1.5lb?

Can I see more pics please......

Aloha.......Sam

[Dwight (DW)]

Dwight,
Is this the board you were inquiring about the EPS 1lb-1.5lb?

Can I see more pics please......

Aloha.......Sam

Sam, yes that's the board. I'm withholding better photos until it's finished. The water test was done after a quickie rough sand. I just had to find out if the board worked 

I'll have it finished and painted by the end of the weekend.

By the way, I didn't have the courage to vacuum bag. It turned out 29 lbs without pad.

[Dwight (DW)]

Here it is. Almost done.