FCS K-Flex Fins

FCS K Flex Fins

The FCS K-Flex fins were designed with 8-time World Title holder Kelly Slater.

Made from his signature template used on the K2.1 GF fins, the K-Flex fins are designed to provide you with the same high performance surfing you can expect from the other FCS fins in the line of K fins.

However the K-Flex fins give you added safety. This is because the FCS K-Flex Fins are constructed using FCS’s glass flex core material but have an added layer of polyurethane elastomere.  This layer provides a great shock absorbing coating without compromising the fins’ performance.

How Much Will This Fin Set Cost?

The K Flex fins retail for US $59.99. Below are the current prices of this fin set at a variety of online stores and surf shops.

FCS K Flex Fins  
US $60.00

Design and Feel

The K-Flex fins are a medium-sized tri fin thruster set and therefore come with two side fins and a single center fin.  Like the K2.1 fins the center fin of this FCS fin set is smaller than the side fins.  This provides a touch of looseness that Kelly likes while surfing in the pocket.

The larger side fins, which have a base of 4.33” (110mm) and a depth of 4.53”(115mm), have a total surface area of 15.23”2 (9824mm2).  Combined with their flat foil these side fins provide you with lots of drive. These side fins also feature more sweep than the center fin set at 32⁰.

With a base of 4.28” (109mm), a depth of only 4.41” (112 mm) and a total area of 14.22”2 (9172mm2) the smaller center fin then adds the right amount of release.  The sweep of the center fin is also slightly less at 31⁰ increasing pivot.

Something you will notice about the FCS K-Flex fins, as their name states, is how flexy they are due to their construction.  This makes them one of the flexiest fins FCS fins has manufactured.  This not only helps prevent against injury but also makes these some of the easiest and most forgiving removable surfboard fins to ride.

Wave Conditions

Based off of the K2.1 fin template these FCS fins are best for ridding hollow beach breaks and surfing tight in the pocket.  However these fins can be used in any surf conditions especially if you are concerned about safety or want added protection against injury.  If you are not that concerned with safety then the K2.1 Glass Flex fins are a great alternative choice.

The Look

K Flex Fins LookFCS K Flex Model StampThe K-Flex Fins are a clean looking fin set that shows off a simple, almost transparent looking blue color.

At the front of the base of the fins is a stamp that reads… K-Flex FCS.

Surfer Specifications

The FCS K-Flex fins are specifically made for surfers in the medium weight category and similar weight to Kelly Slater.  This makes them ideal if you are a surfer weighing between 140 to 175 lb (65kg-80kg).

What We Say

If you are learning to surf, or surf often in a crowded spot, then these elastomere coated fins will protect you and others from the many injuries that can result from surf fins.

While there is no guarantee that you WON’T get hurt if you use the K-Flex fins, you will enjoy some peace of mind knowing that you’re a little better off than using some of the sharper counterparts in the lineup of K fins.

These K fins are also extremely forgiving due to their flexiness.  This makes riding these fins very easy for those who are new to surfing and surfboard fin systems.

Fin Specifications
  Side Fin Center Fin
Material Glass Flex & Elastomere Glass Flex & Elastomere
Base 4.33"
(110.0 mm)
(109.0 mm)


(115.0 mm)
(112.0 mm)


(9824 mm2)
(9172 mm2)
Sweep 32° 31°
Foil Flat 50/50
Flex Very Flexy Very Flexy

Other FCS Surf Fins You May Like

FCS K2.1 Glass Flex Fins FCS K2.1 Performance Core Fins
FCS K2.1 Glass Flex Fins FCS K2.1 Performance Core Fins

What Do You Think Of This Fin???...We Want To Hear Your Opinion!

Leave Your Fin Review Below....

Return from FCS K-Flex Fins to Surfboard Fins at FinPlug.com

Receive Fin Updates

Share This Site

| More

Featured Fins

FCS H-3 Nexus Medium Fins

Most Popular Fins

FCS K3 Performance Glass Fins
  The FCS K3 Performance Glass fins are the fins ridden by 9 time world champion surfer Kelly Slater.  

FCS K2.1 Glass Flex Fins
  The FCS K2.1 Glass Flex fins are the world beating FCS surfboard fin set.  

FCS M5 Fins
  The FCS M5 Fins are the most popular FCS fins from the M-series.  

FCS DHD 2 Glass Flex Fins
  The FCS DHD-2 Glass Flex fins are Darren Handley's signature template with an adjustable center fin.