“Rocker” is the dimensional curve along the bottom, top, and rail of the surfboard, usually referenced from nose to tail. Not one rocker is universally better than another. Rocker is just one instrument in an orchestra of design elements that contribute to a successful surfboard shape. There are, however, some basic rules of hydrodynamics that one must consider in order to understand the function of rocker.
|Ace Buchan uses every bit of his rocker to make this steep drop!|
Conversely, flatter rocker brings more speed but also a decrease in maneuverability. The flatter rocker allows more of the board’s surface to be in contact with the water and therefore generate more planing speed. Generally, flatter bottomed designs are applied to boards that will be surfed in small or gutless waves, i.e, fish boards. And, of course, with the flatter, straighter rocker the board will feel more stiff and will be more difficult to turn.
|Cut and ready to glue up|
While the blank is molded with a Natural Rocker, there are two additional opportunities to adjust the rocker before finishing the surfboard design. Once, when the blank is ordered and secondly, when the shaper is shaping the board.
Each blank can be ordered with any desired rocker adjustment. The blank is cut down the center lengthwise, stringer is chosen and the blank is glued with the rocker adjustment in place. The adjustments are written in a formula beginning with the nose (noted with an “N”) adjustment and followed by the tail adjustment (noted with a “T”). Us Blanks use the deck line to adjust the rocker which is referenced from the Natural Rocker, i.e., an adjustment of +1/4”N -1/4”T would indicate bending the foam upward to add one quarter inch of rocker to the nose and then bending the tail downward one quarter inch to decrease the rocker in the tail.
US Blanks has a large selection of Public Rockers available to choose from, specific to each blank, but we (Foam E-Z) can also accommodate "Custom Rockers" at no additional charge.
|A few of US Blanks Public Rocker Templates!|
It is important to remember that the resulting affect of any rocker adjustment is influenced by other design elements like rail contours, fin set up, and concaves. Finding the exact right rocker for a surfer, a given board and specific type of wave is the result of thorough communication between the surfer and the shaper.
Thanks to US Blanks for this thorough explanation!