Specialized Aethos Shimano Dura-Ace Di2 Disc Road Bike 2022, Size 61cm Posted March 10, 2024 Specialized Aethos Shimano Dura-Ace Di2 Disc Road Bike 2022, Size 61cmExtra Large (6’3 and above). View our in-depth size guide here. Shimano Dura-Ace, 52/36t – 175mm. Fast Forward Ryot 55.