I am trying to get a duplicate of a surfboard made by Will Allison, the original shaper, for my wife for her birthday I can get the basics but how do I determine the existing rocker for a longboard?

2. Originally Posted by Blackfish
I am trying to get a duplicate of a surfboard made by Will Allison, the original shaper, for my wife for her birthday I can get the basics but how do I determine the existing rocker for a longboard?
There is a simple way to measuring rocker that involves finding the midpoint of the board on the bottom, holding a straight edge tangent to the board at the midpoint, and measuring the nose rocker and tail rocker by measuring the distance from the straight edge to the board. The diagram below only flipped upside down for ease.

But here's the thing, "duplicate" is a lot more complicated than a rocker measurement. Foil, bottom contours, rail contours, and countless other factors. The person making the duplicate , assuming they are a fairly experienced shaper that you would use for this project, should have a "rocker stick" which can measure the rocker continuously along the length. At least that's my take on it.

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Is the old Will worn out? Will is still shaping if I'm not mistaken, just give him a shout and let him make the clone.
If you are shaping it then the only way is to get a perfectly straight edge balanced perfectly at the center set at the stringer (or center) and measure increments. That will only be the center rocker because the rail rocker will be different depending on vees, rolls, concaves, chines or combinations thereof. Another fun way is to put modeling clay at increments and lay the board bottom down on a perfectly flat, hard surface and measure the clay. Seen plenty of those handmade rocker jigs but from my noodling around with them it seems the adjustable slide square and square metal stock works better to pinpoint entry, entrance, the apex and exit rocker at the stringer. Have fun!

4. Originally Posted by garbanzobean
Is the old Will worn out? Will is still shaping if I'm not mistaken, just give him a shout and let him make the clone.
If you are shaping it then the only way is to get a perfectly straight edge balanced perfectly at the center set at the stringer (or center) and measure increments. That will only be the center rocker because the rail rocker will be different depending on vees, rolls, concaves, chines or combinations thereof. Another fun way is to put modeling clay at increments and lay the board bottom down on a perfectly flat, hard surface and measure the clay. Seen plenty of those handmade rocker jigs but from my noodling around with them it seems the adjustable slide square and square metal stock works better to pinpoint entry, entrance, the apex and exit rocker at the stringer. Have fun!
No Will is just fine, I have spoken with him already and Im just trying to figure out a method to remake his board without having to take my wifes board to him, as she would definitely notice her favorite board missing. Thanks