Sirrus X 5.0Sirrus X 5. 0 is the flagship Sirrus X Specialized FACT 9r Carbon frame with Rider First Engineered geometry (each frame size uniquely engineered for optimal balance), Shimano hydraulic disc brakes, premium 1x drivetrain. The sub 10 kg fitness gravel light bike for riders who want the most performance from the Sirrus platform. Key Features Specialized FACT 9r Carbon frame with **Rider First Engineered geometry** each size individually tuned Shimano BR