Cervelo's C-shaped steerer tube on the Caledonia-5, R5, R5-CX, and Aspero-5 requires a stem that matches the profile, and the ST31 Carbon Stem delivers the factory upgrade over the alloy ST32 option. The design clamps to the steerer using a split spacer system and two-bolt interface, while the rear of the stem body tapers to match the aerodynamic lines of the fork and frame. Carbon construction keeps weight reasonable while providing the stiffness that precise handling demands.

Internal routing passes Di2 wires and hydraulic hoses from the handlebar face into the steerer tube, keeping cables hidden from view and out of the wind. The stem works with Cervelo's HB13 handlebar and the groove-routing system that channels wires along the bar's underside before they enter the stem. An integrated top cap closes off the steerer opening, eliminating the gap where wind would otherwise catch and create turbulence.

The faceplate uses a standard four-bolt pattern for 31.8mm handlebars, so you're not locked into Cervelo bars if you prefer something else. An 8-degree drop angle positions the bars slightly below the stem clamp, which works for most road and gravel fit preferences. Cervelo's BarFly mounting system integrates with the faceplate design, giving you a clean computer mount option without aftermarket adapters cluttering the cockpit.... Read More