Dialed In: Fin Selection

Words by John Streit.

Few surfing accessories are more important — or more misunderstood — than the fins.

Flex. Cant. Foil. Base. Rake… and so on: It seems that there are as many technical terms as there are fin options. In this edition of “Dialed In,” we’ll break down the buzz words to help guide you to the ideal fin setup. By no means is fin selection an exact science; but several principles of design — both of the board and the fin itself — the rider’s weight, individual style and local conditions are all important variables to understand when searching for that perfect setup.

The Board. First and foremost, the type of board you’re riding will dictate the type of fin setup you’ll select. For example, thruster (three-fin) and quad (four-fin) setups are featured in most high performance boards. For alternative/retro board types — hybrids, fishes, pods, etc. — there are fin designs (twin keels, etc.) that can enhance performance or alter the feel of the ride. We could go on and on, but in the interest of keeping things simple, we’ll focus on the performance side of surfing and the fin characteristics that transcend thruster and quad setups.

The System. Currently, Futures and FCS dominate the removable fin market. Be sure to match your fin purchase with your board’s specific system. As a general rule of thumb, FCS are two-tabbed plugs and Futures are long, rectangular boxes with a single slot. FCS is introducing two new systems — FCS II and Origins — as we speak, but look for those to begin to take hold in the market with more force in 2014.

Surface Area. There is no more important aspect of fin design than surface area, as there’s a direct connection between the rider’s weight, the size of the fin and how the fin will perform. Overall, riders that weigh less will want a fin that is smaller in surface area; while larger riders will want larger fins. Both FCS and Futures make this easy for the consumer as they assign sizes to their various templates.

Here’s a good guide to finding the right size fin before fine-tuning the ride with the other design variants: Extra-small to small riders (weighing between 75-155 pounds) will want fins ranging in surface area from 12.56 to 14.25 square inches. Medium-sized riders (between 145-195 pounds) will want fins ranging from 14.25 to 15.25 square inches. The big boys (more than 180 pounds) will want to start their fins sizes at around 15 square inches and increase from there depending on weight, ability and desired feel. For reference, Futures’ Pancho Sullivan pro model fins are 17.51 square inches intended for a rider over 225 pounds in powerful surf.

Within these ranges, the larger sizes will offer the rider more hold and the smaller sizes will offer more release. You’d also want to run larger-sized fins for larger-sized surf, and smaller fins in smaller surf to create more release in those weaker conditions. If a fin setup that’s within your size range feel just a little “sticky” through turns, try riding a smaller-sized trailer fin. For example, I often ride two side fins that are 15.73 square inches and a trailer that’s 14.22 square inches (Future MB1 sides, F4 trailer).

Dallas Tolson. Photo: Shaun Devine.

Height. Height is one of the elements that comprise surface area. Like smaller to larger fins, taller fins have more hold and stability than shorter fins. This means that a taller fin of the same surface area as a shorter would offer the rider more hold. Generally, taller/heavier surfers would ride taller fins (starting at about 4.54 inches and up).

Base. Of the three elements of surface area (we’ll cover rake next), the length of the base is key in the generation of drive — or forward acceleration — off of applying pressure to the back foot. Wider-based fins provide more drive, especially in set-up maneuvers like bottom turns and check turns. Should the amount of drive exceed the weight of the rider, the ride will feel “sticky,” meaning the board will feel difficult to turn. If this is the case, a fin with a shorter base is required. The challenge of the advanced rider in finding the perfect fin setup for their style is finding the balance between height, base, and rake to create the best feel and highest performance potential for the individual.

Rake. Rake refers to how much the tip of the fin extends past the base. Fins with more rake are more stable and hold true in heavy conditions. They’re also great on open-faced waves for big, sweeping turns. The inverse: fins with shorter rake provide a more pivotal feel and can be turned on a dime in the pocket. The amount of release created makes this possible, but the rider must sacrifice that “safe” feeling fins with a lot of rake provide through turns. In other words, fins with shorter rakes are the highest performance fins since they call on the rider to exercise more control over their release.

Forrest Roberts. Photo: Elliot McCallister.

Flex. The fin’s flex can vastly affect the quality of the ride, even between fins of identical dimensions. Should the fins be too flexible, they will kill the board’s drive. A fin that is too stiff produce namesake results: a stiff, difficult-to-turn ride. Different flex patterns are achieved through different construction materials. Usually, a fin with “good” flex is found by matching the fin’s materials to the type of wave you’ll be surfing. Stiffer fins, like those made from solid fiberglass, go well in heavy, powerful surf. For everyday conditions, carbon-honeycomb core fins are engineered to flex in the “performance” range for spring and liveliness felt through turns.

Foil. Foil refers to the concave on the inside of the side fins. Fins that feature a scoop from front to back provide more acceleration and fluid transition from rail to rail. Flat-foiled fins break free sooner and thus provide more control, making them a great option for more powerful surf. Quad trailers are vastly affected by foil, coming as either double-foiled (like a trailer fin) or single-foiled (like a side fin). Double-foiled quad trailers provide more hold and allow for more vertical turning ability while single-foiled trailers break free sooner and provide a loose, skatey feel.

Cant. Cant is the angle of the fin toward the rail. Fins with more cant create more lift and are easier to transition from rail-to-rail. More upright fins provide more hold and are the weapons of choice in pumping surf.

The Balancing Act. Sure, that’s a lot to digest, but here’s the good news: the fin companies have done most of the work for you! As previously stated, the most important aspect of fins to consider is the surface area. Be sure that you aren’t riding fins that are too small or too large. A great fin construction to try first is honeycomb core. These feature a great performance flex pattern, are lightweight and excel in a variety of conditions. From there, be introspective about how the fin differs in performance from the stock fins you rode previously. If they feel too loose or lack drive, try a wider based fin. If you feel like there’s too much hold, try a fin with less rake… and so on.

At the end of the day, every surfer will experience the same set of fins differently, so nothing’s better than experimenting with different templates and constructions to find the set that feels best. Swap sets with your friends and feel out the differences. Dialing in your perfect set of fins can open new doors for your surfing.