Sirrus X 2.0Sirrus X 2. 0 is Specialized's entry into the Sirrus X mixed surface fitness platform same A1 Premium Aluminium frame as the regular Sirrus 2. 0, but with wider 700c38 mm tyres and slightly slacker geometry that handle bitumen, hard packed gravel, and bike path detours equally well. Hydraulic disc brakes, 1x drivetrain. Key Features Specialized A1 Premium Aluminium frame, Fitness Geometry Hydraulic disc brakes strong stopping for mixed surfaces 1x