Cervelo built the third-generation S5 around a modular cockpit concept where the stem and handlebar function as integrated pieces rather than interchangeable aftermarket parts. The AB08 Carbon Handlebar slots into this system as the bar component, mating exclusively with Cervelo's V-shaped stem extension to create the clean aerodynamic front end that defines the S5's appearance. This isn't a bar you can run on other frames or pair with conventional stems—it's purpose-built for one application, and that focus allowed Cervelo's engineers to optimize every interface point without worrying about universal compatibility.

The carbon construction delivers the stiffness and low weight you'd expect from a race-level component, but the real engineering lives in how the AB08 interfaces with the rest of the cockpit. Cables and electronic wiring route internally through the stem and into the bar, eliminating exposed housing runs across the front end. Once everything is routed and connected, the system presents a unified surface to the wind with no protruding cables to disrupt airflow around the head tube area. The tradeoff for this aerodynamic integration: changing bar widths or stem lengths means disconnecting the entire internal routing setup, which is why Cervelo recommends having a dealer handle cockpit swaps rather than treating it as a quick garage project.

Geometry follows a compact pattern with 80mm of reach and 128mm of drop, placing your hands in a moderately aggressive position without the extreme angles found on some aero bars. The flat aero top section provides a stable platform for resting during steady efforts on flat roads or shallow climbs, while the drops offer standard road bar positioning for technical descents and sprint efforts. Width measures center to center at both the hoods and drops, so a 44cm bar delivers 44cm at both locations—no taper or flare to account for when translating your fit numbers.... Read More