Trail Tested: FSA K-Force Disc Brakes

Designed primarily as a lightweight cross-country and trail-bike stopper, FSA’s K-Force brakes have plenty of key features. The levers are carbon fiber, and the ambidextrous, split-perch body is made from magnesium and uses reliable Torx stainless-steel hardware with a titanium upgrade option. Its minimalist caliper houses two 22 mm pistons. Since appearing in Dirt Rag #183 FSA has dropped the price by $70 per wheel to a new retail of $299 each.

FSA uses mineral oil and also utilizes a stiffer rear-brake hose. FSA explains that because the rear brake line is much longer than the front, using a stiffer hose will equalize the feel between the two, ideally giving the rear brake the same crisp feel as the front. The brake pads are top loading for easy changing, and while they come stock with FSA’s own semi-metallic pads, standard Shimano pads fit as well, ensuring you’ll never be high and dry if pressed for a last-minute pre-ride brake-pad search.

Two other main highlights are external, tool-free adjustable lever reach and stroke. This allows for a nice degree of customization not only in feel, but also in how your brakes perform on the trail. The stroke dial (how far the lever comes inward to the grip) is located on the body near the lever pivot and the reach dial is nestled behind the lever. Total weight hovers a bit over 300 grams per wheel, depending on hose length, which is very light. Our brakes came with FSA’s cool, lightweight two-piece rotor with a forged aluminum carrier and narrower profile compared to the standard one-piece rotor.

Setup and installation were a snap and I was immediately impressed with how quickly the caliper moved into place around the rotor with zero pad rubbing on the first try for both the front and rear—a testament to some very true rotors. After a summer and winter of riding they have remained drag free and silent with zero maintenance or adjustment— simply amazing. Setting up the lever reach and throw was also hassle free. With the wide range of adjustment available, most every rider will be able to find their sweet spot for both. The reach tended to remain constant, yet as for the tiny lever-throw adjuster, its position and design is much harder to use compared to SRAM’s Guide RSC brakes; midway through a cold, wet winter, it became impossible to turn without the help of a tiny blade screwdriver.

The FSAs aren’t the strongest in brute stopping force compared to Shimano and SRAM Guides, and FSA readily admits that because the target audience is cross-country and average trail riding. Absolute on/off power also isn’t the only factor. FSA created a lot of controllable modulation into the K-Force brakes that makes slowing down intuitive from brain to finger. FSA also designed its brakes to begin pad movement instantaneously when the lever begins to move—a valid reason why throw adjustment is so important. If you grab a handful, they will stop you quickly. With all this in mind, I was able to maintain complete tire control in turns without locking up the rear wheel, and performance consistently remained predictable.

Ultimately, the K-Force’s customizable features allowed me to tailor my braking style to suit, and once that happened I never gave it another thought. As much as I like the feel at both levers and their overall performance, I will say they do fit only one application perfectly, and that’s cross-country riding and racing.