How To Choose The Right Fins
The number of factors that affect how surfboard fins perform is abundant. As a result, tinkering with the fin setup on some of your go-to boards can open up new possibilities, and ultimately improve your surfing performance. The collection of fins we offer is the result of decades of experimentation and refinement, and the bottom line is that as your relationship with your fins expands and progresses so will your surfing ability. Here is a surf fin guide to help you choose the right fins.
There are lots of options when it comes to fin setups — single fins, twin fins, tri fins, quads... and the list goes on. A basic understanding of the performance characteristics of established fin setups will go a long way in choosing fins that are right for you.
The single fin is the original fin setup, and its characteristic tendency for smooth lines and free-flowing maneuvers permanently reserve its place in the lineup.
As an elaboration on a single fin, a 2 + 1 retains the smooth feel, but with added drive and hold.
With a searing blend of smooth speed and maneuverability, twin fins deliver a unique set of enviable performance characteristics.
The tri-fin, or thruster, has been the standard in high performance surfing for the past 25 years due to its ultimate blend of control and maneuverability.
Quads provide a desirable combination of speed, drive, and hold that leans towards lively maneuvers while maintaining “down the line” speed.
The bonzer is a lesser-known, but supremely viable option for high-performance power surfing.
True Ames specialty fins such as trailers, side bites, small box fins, and asymmetrical sets allow more eccentric fin configuration ideas to become a reality.
At True Ames we carefully select the most well-suited materials for producing the highest quality fins available.
In order to achieve the performance characteristics that have become the standard of solid fiberglass surf fins, we use E-glass. It is the most common type of fiberglass used in surfboard construction, and its qualities translate with great success into fin construction. Solid fiberglass has excellent flex characteristics and performance longevity, while featuring the bonus of outstanding color vibrancy that allows for the variety of colors we offer.
Handmade by the True Ames team in Santa Barbara, CA, the appeal of the fins we offer with volan fiberglass construction goes much deeper than their distinctive coke-bottle-green color and raw finish. Each of our volan fins is cut from the highest quality fiberglass and perfectly aligned for optimal flex characteristics. These limited supply fins flex from the body of the fin thereby producing increased speed and projection off the bottom and through turns.
The Resin Transfer Method (RTM) allows us to construct a composite fin, inside of which hexagonal pieces of lightweight coremat displace fiberglass and resin. The result: a fin that is 25% lighter than a normal solid fiberglass fin, without compromising performance. Our Hexcore fins have become the standard by which system fins are measured.
The evolutionary curve continues at True Ames with the construction of Marine Plywood and Bamboo fins. These ultra-light glass-on fins come in a variety of templates that is rapidly expanding, and they all feature wood’s characteristic positive buoyancy — they float! We make them in-house in Santa Barbara, CA, using cad/cam for precision foils before sealing with a layer of glass and sanding. We end up with the highest quality wood fins that are ready for top-level board construction.
Fin Theory and Terminology
Being familiar with basic surfboard fin theory and terminology is the foundation for deciding which fin(s) might best facilitate your style of surfing. More specifically, understanding the following concepts will help you sort through the True Ames collection of fins.
The template of a fin is the outline of the fin. Each True Ames fin model is based on a template that has been designed using decades of experience and knowledge, and has proven itself where it most counts: in the water.
The area of a fin can be described as the amount of area inside the outline – or template – of a fin. And you might apply your geometry skills to note that the length of the fin’s base, and its height (i.e. depth) are closely related to the the area. In general, more area equates to more hold and drive, and less area equates to a faster, looser ride.
An easy way to the think about rake is how “swept back” as opposed to “upright” the stature of a fin is. The more “swept back” a fin is, the more rake it has. A more technical definition is the angle between a line that runs parallel to the base of the fin, and a line that runs through the front corner of the fin and the tip of the fin. More rake will deliver more stability and a tendency for long drawn out turns, while less rake will deliver a more sensitive ride with a tighter turning radius.
In the most basic terms, the flex of a fin is how much it will bend side-to-side. More precisely, the flex of a fin is a description of how the fin flexes perpendicular to the direction of flow. Important qualities are how much force it takes to flex the fin (i.e. how stiff the flex is), and how quickly and reliably the fin returns to center. At True Ames, our craftsmanship and materials produce fins with consistent flex that quickly and reliably return to center, and with this as our starting point, we make each fin design with the optimal amount of stiffness. A stiffer fin will have a more sensitive and quick response, while a less stiff fin (i.e. lots of flex) will often provide subtly delayed, yet increased projection.
The foil of a fin can be described as the contours of the fin when viewed from an “edge-on” perspective. Similar to how the foil of an airplane wing affects the flow of air as it passes the wing, the foil of a fin affects the flow of water. A 50/50 foil has symmetrical contours on either side, and this will be the case for all of our single fins. Within our system fin collection, you may find anything from 50/50 foils to 70/30 foils to flat inside foils. Whatever the foil ratio is, all True Ames fins feature continuous foils with the thickest section of the foil towards the center of the fin, and thinner sections at leading and trailing edges.
Relevant to all types of side fins, toe is basically how much the side fins are pointed in towards the stringer. In other words, it is the measurement of the angle between the line that runs parallel to the stringer and the line that runs parallel to the base of the fin. If these two lines are parallel, the fin has no toe, or in other words they are pointed straight forward. Often fins will be “toed-in” by a few degrees, which results in enhanced control and maneuverability, while fins with no toe maximize speed by causing the least amount of resistance to water flow.
Cant is a measurement of how much a fin leans out towards the rail of the board. Or more precisely, how many degrees away from perpendicular to the bottom of the board the fin is. As a rule of thumb, center fins have no cant, and side fins have a few degrees of cant. However, there are some side fins that feature no cant. No cant on your side fins maximizes speed by causing the least amount of resistance to water flow, while some cant on your side fins will give you more control, especially during turns.
Fin Base Compatibility
A general familiarity with each type of base and the corresponding fin box will equip you to confidently choose fins that are compatible with your board.