Review: FSA SL-K Light Triple MegaExo mountain crankset
This spring, after one too many rides cursing my on-trend mountain double, I clicked to the fact that I should really be in the market for a mountain triple. Don’t get me wrong- the double was just fine for racing and in rolling terrain (though the extra front shifting I did was a surprise)- but there are some climbs that come late in a long day that just aren’t any fun with a double. Setting some more obvious choices aside, I decided that FSA’s least-expensive carbon fiber model would make for a more interesting review. After several months on FSA’s SL-K Light Triple MegaExo, it’s disappointed only by working very well and making for a decidedly uninteresting review subject.
Combining an aluminum spine and 24mm chromoly spindle with lots of unidirectional carbon fiber, the SL-K Light is a handsome looking crankset. The unidirectional carbon has a good amount of visual depth, especially in sunlight, and the silver rings seem nicely finished (though black would probably make the 42 outer look less big coming from the double). The 855g claimed weight (845g claimed) damages- if not quite breaks- carbon fiber’s promise of light weight, only managing to undercut Shimano’s FC-M780 XT triple/BB by 5g.
Mounted on 120mm and 140mm trail bikes, the SL-Ks and their rings have shrugged off the kind of rock strikes that would make anyone who remembers early carbon cranksets nauseous. They’ve suffered the indignities of my riding with surprising grace. The outsized graphics are beginning to suffer from my duck-footed stance, however, and could probably have stood a few more layers of clear coat. The FSA cranks aren’t markedly stiffer than anything else I’ve ridden recently- a shade stiffer than e*thirteen‘s and on par with most others. The 7075 aluminum chainrings, while not quite on Shimano’s level, do shift very well.
The provided MegaExo external bottom bracket spins freely, with ‘just right’ preload consistently provided by a non-drive side wave washer. One of the reasons that I was drawn to the SL-K Light was the nominal 24mm spindle size that it shares with Shimano cranksets. This I had hoped would allow me to wring some more life out of the half-spent Shimano bottom brackets in my toolbox. Unfortunately, one or both companies are fudging that measurement and preventing cross-compatibility. Given the ubiquity of Shimano (and Shimano-compatible) bottom brackets, this seems like a misstep on FSA’s part and could be a headache should a BB seize while traveling.
Really, though, the biggest argument against the SL-K Light Triple MegaExo comes at the cash register. At a suggested $520, they’re a full $200 more than the aforementioned XTs. The SL-K crankset’s extensive OEM spec also undermines the premium implied by their aftermarket pricing. I’ll be the first to admit my desire for carbon cranks (after all, I did buy them myself, albeit on sale), but absent a measurable weight or stiffness benefit, the SL-Ks really are a tough sell.