by alexaben » Tue Mar 30, 2021 9:52 am
Surfboard fins are a crucial part of your surfboard setup. Choosing fins that will work best for you and your surfboard depends on your size, riding style, and your surfboard's fin box. Before talking about fin size or different fin configurations, it is important to distinguish between glassed-in and swappable fins.
Glassed-In vs Swappable (Removable) Fins
Glassed-in fins are laminated into the surfboard. As you might imagine, a glassed-in fin might be smoother and sounder than a removable fin. However, glassed-in fins are difficult to repair and do not offer you the versatility of removable fins.
Surfboards with removable fins have “boxes” that fins are screwed into. Removable fins can be added or removed using a fin key and adjusting the small (typically stainless steel) inset screws. Don’t force your fins into the box as that may damage your board or the fin; instead, make sure the screws are loose enough and that your fin is facing in the right direction. Center and outside fins have different shapes, so make sure you are using the right fin for the right box. Once your fins are in place, tighten your screws with the key, making sure the fins are secure but not TOO tight.
Box Types & Compatibility
Although longboard fin boxes are generally cross-compatible across all boards, the rest of the fin boxes out there are almost certainly equipped with one of these three box types:
Dual Tab (FCS & FCS II) Fin Boxes
FCS stands for Fin Control System. Originally designed in the early 1990s, FCS is the most successful, widely used surfboard fin system in the world. The fins have two tabs or plugs that are secured to the board using set screws. FCS recently launched the FCS II keyless Fin Standard, meaning fins can be installed or removed without a key or grub screws. FCS II is also backwards compatible, meaning you can use your old dual tab FCS fins with the new FCS II system. A compatibility kit is required.
reference
https://www.evo.com/guides/how-to-choose-surf-fins