The Sirrus X offers an unparalleled combination of comfort, efficiency, and nimble handling, excelling on roads, in the terrain, and in other environments. SMOOTH, COMFORTABLE, AND EFFICIENT: Sirrus X provides the smoothest ride in its class. With larger, confident tires, a slightly more upright riding position, and a super intuitive one-by drivetrain. RIDER-FIRST ENGINEERED: Like all Specialized Performance Bikes, the geometry of each frame is unique. This means that for each frame, every tube size is specifically selected to achieve the optimal balance of stiffness, weight, and responsiveness, ensuring that no matter what size you ride, you can experience the best riding experience in the world. NIMBLE: Industry-leading lightweight, exceptional pedal efficiency, and steering precision come together for reliable, nearly telepathic handling.