S-Works Aethos 2 Break the Rules Weighing in at only 595 grams, the S-Works Aethos 2 is the lightest production road bike frame in the world. But that’s not our focus. We broke the rules of road cycling to deliver pure riding enjoyment: the Aethos 2 is designed to feel almost non-existent beneath you – it is incredibly agile, smooth, and refined. With increased tire clearance, enhanced components, and data-driven fit-optimized geometry, even more riders can now experience this exceptional ride quality. Aethos 2 breaks the rules, out of love for the ride.