Available with 39/27, 40/27 or 42/27-tooth chainrings, 170mm or 175mm crank arms, and to fit BB386 or BB30 bottom brackets, the K-Force Light Compact is one of FSA’s lightest cranksets.
It boasts wide-profile carbon composite crank arms that flare into a three-armed spider with a wide chainring contact area, all designed for a combination of minimum weight and maximum stiffness. The splined axle is tough chromoly steel, the chainrings are CNC-machined 7075 aluminium with profiling to ensure super-smooth shifting, and the chainring bolts are Torx headed aluminium. It's compatible with nine- and 10-speed chains.
Durability of FSA’s superlight MegaExo bottom brackets is good. If you really want carbon cranks these are among the best available, but we've always had a problem with the way composite cranks quickly look scruffy on the surface. Cheaper and lighter alloy doubles are available that stay looking good for a lot longer and perform on a par.
Also consider: FSA SL-K Compact 386 MegaExo, £520. FSA also produce a lightweight SL-K crankset for about £80 less that uses carbon arms with an aluminium skeleton. Its weight and durability is almost identical.
This article was originally published in What Mountain Bike magazine, available on Apple Newsstand and Zinio.