Reviewer: Mike Kazimer
Carbon fiber. Ceramic bearings. Compact double chainrings. The checklist of features for FSA’s K-Force Light crankset reads like a “What’s Hot in Mountain Biking” compilation. This is FSA’s top end mountain crankset, coming in at a flyweight 739 grams. These cranks even look fast – the black carbon weave stands out, accented by the red and white FSA logo. The BB cups are anodized red as well, adding to the overall bling factor of this crankset.
The K-Force Light crankset is constructed of hollow carbon fiber. According to FSA, “a unique air bladder molding technology is used, yielding a hollow crank arm and spider with an I-beam down the length of the arm.” Given the crankset’s light weight, stiffness was excellent. There was no noticeable flex, whether standing out of the saddle and cranking uphill, or pushing through berms on the downhill.
Many XC riders have made the switch to a double chainring setup. The available gear combinations allow for nearly the same ratios as a triple, but without the weight penalty. The K-Force light crankset is available in three chainring combinations: 39/27, 40/27, and 42/27. The test cranks had a 42/27 combination. I ran a 11/34 cassette with this crankset, and found the 27/34 easy gear low enough to get up the steepest climbs. Out of the saddle climbing is more common with these cranks, but they’re designed for XC racing, not leisurely meanders through the woods.
Shifting performance was quicker than expected - 27 to 42 is a big jump, but the ramped and pinned 42t chainring handled it without complaint. Both chainrings are CNC 7075 aluminum. FSA uses a unique 86mm BCD 3 bolt pattern to attach the rings to the crank arm. This is worth remembering when travelling away from home - 3 bolt proprietary chaingrings could prove hard to find.
The K-Force Light crankset comes with an external bottom bracket featuring ceramic bearings. The bearings can be serviced by removing the dust cover and injecting a specially formulated mineral oil based grease, which is included with the cranks. Conditions during testing were full on – torrential downpours, thick mud, and more mud. The bearings still felt smooth even after these harsh condition, a testament to the bottom bracket’s quality.
One issue I ran into was the durability of the clearcoat covering the carbon weave. Coming out of a harsh compression, I managed to drop my chain off the outer ring. It was back on within a pedal stroke, but the chain had chipped away the crank’s clearcoat in several places. Once chipped, the clearcoat was prone to come off more easily, exposing the carbon underneath. FSA’s technicians recommend using clear nail polish to prevent chips from spreading, or using a sticker of some sort to protect high wear areas.
For the XC racer looking to earn a podium spot this season, FSA’s K-Force Light crankset could be the carbon ticket to victory. MSRP $800.00
