Several of Cervelo's frameset models (Caledonia-5, Aspero-5, and 2022 R5) have a proprietary C-shaped steerer tube that require a matching stem design, and the company offers this ST31 Carbon version, as well as the ST32 Alloy option. The stout but reasonably light design is otherwise a threadless stem in how it sets up and functions, with the steerer via a split spacer system and a 2-bolt steerer clamp. It carries a 4-bolt faceplate for a 31.8mm diameter handlebar.

The ST31 Stem features access for internal routing and has a rear facing section with a mild aero taper to match the specified fork/framesets. Cervelo offers the ST31 in 70-130 mm lengths in a -9 degree drop.