FSA’s new Gamma Drive MegaExo takes external bottom bracket technology to the cheapest level yet. It doesn’t do it lightly, though.
For a start there’s more metal in the cast aluminium cranks than there is in the forged pieces here, with the one piece drive-side arm and spider being a particularly bulky lump. Add steel inner and middle rings and a bottom bracket that’s twice the weight of others here and you’re adding over 1.2kg of mass to your bike. We’re not convinced the narrower integrated axle adds any significant stiffness compared to a separate splined BB assembly, either. At the end of the day though, we’d be more able to forgive the DH category weight if the Gamma Drive was obviously oversized and tough enough to handle some serious freeride-style action. FSA only rate it for XC though, and therefore we’re hard pressed to recommend it over lighter chainsets like FSA’s £50 Alpha Drive.