Learn How Template, Bottom Contour, Tail Shape, Rails and Rocker Make Your Board Work the Way it Does
Surfersvillage Global Surf News, 21 June, 2017 - To make the right decision when choosing your next board, consider what makes a surfboard surf the way it does. When a board comes into contact with the water, template, tail shape, rocker, volume and bottom contour all contribute to make a board surf the way it does. But how?
Read on below for some very basic lessons on design. Should you want more in-depth discussions on design stay tuned as future articles will explore this subject further.
To over-simplify design theory: The more of the surfboard that comes in contact with the water, like a longboard, the faster the board will plane - especially through slow parts of the wave. The less of the board that comes in contact with the water (slim banana-shaped designs) the slower a board will go BUT the more manoeuvrable it will be. What most of us are looking for is the perfect balance for our level of surfing, the waves we ride and how we want to surf (realistically of course.)
Template: A curvy outline will help a board turn quicker and fit in tighter parts of the wave but can sacrifice down-the-line speed since not as much of the board is in contact with the wave as a parallel-railed board. A straight outline will help a board go faster since the water comes in contact with more of the board, thus more planing surface - think of a virtually parallel railed mini-simmons design or longboard - and you'll see that straight railed template equals fast.
Tail shape: Big, blocky squash tails will float through flat sections but can be harder to release from the water when turning. Thin, pin-tailed shapes provide control at high-speeds (think guns and tube-shooters) but tend to bog in the mush. In between pins and squash tails there are swallows, round tails, diamons, bat tails and more but they all have the same principle: more tail surface area in contact with the water means it is less responsive, but more float and better planing.
Bottom contour: How water is pushed over the bottom of a board and under your feet is very critical to a board’s characteristics. Roll, vee or flat bottoms release water quicker making it easier to turn a board, but these features can also slow it down. Concaves are complicated, but the most commonly utilized design feature on modern board bottoms. Concave provides lift and speed as water is forced through a central area along the bottom of the board. In many designs it is popular to place under the front foot and can act as a front-foot accelerator on a board, however too much concave can ‘lock up’ a board, especially at high speeds, making it difficult for the board to release during turns.
How the water exits out the tail of the board is usually done with vee or double concave depending on how much release one wants in the board. For example, a concave or flat bottom contour leading out of the tail would not be as responsive as a vee design, but would generate more speed. The best designs take into consideration rocker and tail shape when doing this. For an in-depth look at bottom contours check this previous article here.
Rocker: The more tail and nose rocker a board has, the better it fits into hollow, steep waves. Conversely, its speed - in both paddling and while up and riding - will be sacrificed if it has more curve. Most shapers combine various rocker formulas for different functions, i.e. flat under the chest for paddling with, say, extra curve exiting the tail for turns in critical parts of the wave.
Rails: Thick, boxy rails work in slow waves while thin, knifey rails tend to be more responsive and precise at higher speeds. That said, we are seeing more thick-railed boards fall into the high-performance category as shapers are blending other design elements to make boxy rails responsive.
Flex: The more a board flexes, the more responsive it will be, but the slower it will go. The stiffer a board's flex is, the faster it will go but harder it will be to turn. However, when taking into consideration different conditions: choppy surf, glassy surf, etc, this general flex rule can be turned on its head. This means a board with stiff flex properties might go slower in choppy surf.
Standard polyurethane boards have certain flex characteristics we’ve all come to love. But PU boards lose their magic flex over time, break easily and can vary from one blank to the next in flex properties. One option to PU is Firewire Surfboards whose boards are built with measured, consistent, life-long flex characteristics.
Volume: Generally, the more volume a board has, the faster it will go. Why? Because all that foam makes it sit higher out of the water so it can plane across the surface. The forward trajectory and speed is not interrupted by parts of the board being submerged. Thankfully for consumers there are many volume calculators out there to help you choose the right volume for your needs. More explanation of volume here.