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, our focus goes beyond just the weight. We have challenged the norms of competitive cycling because we wanted to deliver pure cycling enjoyment: the Aethos 2 is designed to virtually disappear beneath you – it’s incredibly agile, smooth, and refined. With increased tire clearance, enhanced components, and a data-driven, fit-optimized geometry, even more riders can now experience this exceptional ride quality. The Aethos 2 breaks the rules, all for the love of the ride.