The Perfect Balance of Power and Comfort, R5 Ultegra Di2 Road Bike.The Cervelo R5 Ultegra Di2 Road Bike has been designed specifically to tackle steep and warp-speed descents. The new carbon layup and refined tube sections make the frame 130 grams lighter than its predecessor, while the near-ideal bottom bracket-to-head tube stiffness ratio ensures optimal pedaling reactivity. The fork has also been refined to provide maximum weight savings, vibration damping, lateral stiffness, and strength.