What is variable-flex? How does it work? What are the benefits?
Variable flex is the direct result of the CODA Tail-Cable and the Deep-V swallow tail working in concert.
In the light pressure condition of a shallow incline, easy traverse, or the flat between turns, an overly stiff edge feels springy with a tendency to slide downhill. The camber (bottom side arch) of a board disperses downward edge-pressure away from the bindings, toward the front and rear of the board. An overly flexible board, however, fails in the converse fashion during the hard turn: The weight of the rider fails to spread out along the length of the board's edge as it too easily flattens out and settles all the weight centrally near the boots.
Traditionally, board manufacturers engineered the tension of their boards for an average between the extremes of the deep turn and a shallow traverse, reducing performance on both ends of that spectrum. The only variation in flex stemmed from core material, not from design. A wood core offered, and still does offer, the natural resistance of wood to bending pressure. A foam core, while offering cheaper, streamlined production to manufacturers, offers fewer advantages in material performance. The primary advantage of a foam core stems from weight reduction, not from behavior. Neither core material offers very much flex variation without an advanced shape and design.
Enter: the tail cable.
The introduction of the tail cable addresses riders' need to adapt to different riding conditions, to exert even edge pressure in both a flat traverse and a steep turn; to flex differently in the deepest carve of a turn and the flat transition between turns.
The CODA tail cable works in concert with, and because of, our Deep-V swallow tail. In layman's terms, when one edge flexes enough, its Deep-V tail branch pulls via the cable upon the opposite branch, drawing structural support. When this occurs, the board feels stiffer,and the bite of the edge on the slope feels more secure. And it is. Yet, conversely, when riding in less stressful conditions, neither Deep-V branch flexes enough to draw the slack out of the tail-cable, and the active edge feels softer. Only one Deep-V branch is in play, and that branch has far less wood core material to resist bending. The edge is more flexible, and feels so.
Again, in a deep, stressful turn, as the edge in play flexes, the distance between Deep V branches increases, drawing the tail cable taught. Stress from the active edge distributes and disperses into the opposite side of the board that was not previously contributing to resistance against bending. The opposite side of the board begins to offer greater resistance to the force the rider exerts to bend the edge. The flex, the ability of the board to bend vertically and torsionally, changes to meet the rider's needs. CODA tail cable boards adapt depending upon the amount of force attempting to bend an edge, changing behavior according to structural stress, varying the flex:
What's more, in addition to its critical contribution to the variable-flex function of the tail cable, the CODA Deep-V swallow tail offers the traditional advantages of a swallow tail board. Decreasing surface area in the back end of the board reduces drag during transitions and flat riding. Removal of the central-rear half of the board allows the tail end to sink in deep powder conditions for a more controlled, level, and enjoyable ride. Coda boards are excellent powder boards.
Combined with variable-flex performance, the added thickness and length of the CODA Deep-V takes the traditional advantages of a swallow tail all-mountain carving board to new extremes of performance.