The FSA SL-K Light BB30 crankset is so similar to the K-Force Light version that the decision to select one or the other is nearly one of aesthetics. In terms of functional difference, it's almost a simple question of whether or not you want the ceramic bearings of the K-Force Light. If that's not a major concern, then FSA's standard steel cartridge bearings on the SL-K should do just fine. Roughly 30 grams separate the two, and the slightly heavier SL-K Light has more subtle FSA branding on the arms. The unidirectional carbon on the SL-K crank gives it a silky appearance, in contrast to the woven outer layer on the K-Force Light unit.
Both cranksets use the same mold shape. So technically, the performance attributes of the hollow carbon fiber crankarms of both the SL-K and K-Force models are most likely identical. If there's a difference in stiffness, it's measurable in the lab, not out on the road. The other major aesthetic difference is in the 5-hole chainrings. The SL-K features Storm Grey anodized 7075 aluminum where the K-Force Light uses black. Other than the color, they are identical. Though more difficult to produce , T-30 Torx internal wrenching alloy fasteners are used for the chainrings bolts to ensure strip-free, proper torquing of the hardware. A tight fit and snug fasteners means less power-robbing flex and decreased chance for strange creaking noises to develop.
The theory behind BB30 -- stiffer 30mm spindle, lighter weight, and a reduction in crankarm width for greater ankle clearance -- makes lots of sense to us. The FSA SL-K Light BB30 Crankset is a great choice whether you're interested in a standard 53/39 or compact 50/34 chainring configuration. It's compatible with all 10-speed road shifting systems. We also sell FSA produced Campy 11-speed compatible chainrings which can be fitted to this crankset. Three crank arm lengths are available -- 170, 172.5, and 175mm. Claimed weights are 640 grams for the standard and 593 grams for the compact version.