3rd generation carbon hollow crankarms.
Monocoque construction for maximum stiffness.
Al7075 Torx T-30 alloy chainring bolts.
Oversize Ceramic Cartridge Bearings.
Length 170, 172.5 or 175.
Q-Factor: 147 mm.
110mm Bolt Circle Diameter.
Chainrings: 34/50 or 38/52.
630 grams (incl. BB).
Currently offered only in English Bottom Bracket Cups. Ceramic Bearings:
K-Force Light is the first FSA crankset to come with a ceramic bearing bottom bracket. FSA ceramic ball bearings are up to 10 times harder, 50 grams lighter (per bb), and maintain a surface perfection that is much higher than steel bearings, allowing for a 3-4% reduction in mechanical friction.
Tests by the Danish magazine Cykel-Motion (Mar 2005) and subsequently supported by calculation, show how using ceramic bearings can reduce rolling resistance by 50%, saving 22m in just 55 seconds at 32kph. In short, astounding speed improvement of 4%.
Ceramic bearings last longer, perhaps 5-10 times more. From a strictly economic perspective, they're less expensive to run even without considering the labor savings.

Stiffness to Weight Ration:
FSA's K-Force Light crankset has the highest stiffness to weight ratio when compared to other options - the proof is in the numbers. Consider the following test conducted by the independent laboratory EFBe in Germany:
EFBe used a load frame to calculate the deflection of each crankset for a specified force. EFBe then used this information to calculate the elastic modulus (stiffness) for each crankset.
From this information, it is possible to determine the stiffness to weight ratio of each crankset. The stiffness to weight ratio consists of the elastic modulus divided by the weight of the crank arms, spindle, and chainring.

Strength to Weight Ration:
If you think FSA has sacrificed strength for weight, think again. The Center for European Normalization (CEN), the International Organization for Standardization (ISO), the German Institute for Normalization (DIN), and the Japanese Industrial Standard (JIS) are just a sampling of the cycling specific test standards FSA has met and exceeded.
Not only does FSA continuously benchmark their own products and those of their competitors, FSA also evaluates the test parameters themselves. For the K-Force Light crankset, FSA engineers went above and beyond any published test methods, developing proprietary fatigue, yield, and impact test equipment and procedures.
Continuous testing and refinement throughout the development process have allowed FSA engineers to optimize the bonding interface between carbon and alloy components of the crankset, to develop an entirely new bomb-proof spindle interface, and to optimize the stiffness of the carbon structure. The end result is a crankset which is not only exceptionally light, but also possesses excellent stiffness, fatigue and ultimate strength characteristics.

Hollow Carbon:
FSA has developed an exclusive bladder molding process for the K-Force Light crankset, enabling a true high modulus carbon fiber monocoque structure. The resulting shape is hollow inside. Not only are the arms hollow, but the hollow cavity also extends completely around the spider. Only a slender I-beam shape remains inside the outer skin to carry shear stresses through the body.
All excess internal weight has been removed from the structure, yielding an unbelievable weight of 633 grams for the crankset, bottom bracket, spindle, and chainrings.
No comparable crankset is lighter.