S-Works Aethos 2 Break the Rules Weighing just 595 grams, the S-Works Aethos 2 is the lightest production racing bike frame in the world. However, that was not our primary goal. We aimed to redefine the rules of racing by delivering pure road cycling pleasure: the Aethos 2 is designed to feel as if it disappears 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 feel. The Aethos 2 breaks the rules out of love for the ride.