Quarter-turn mounts have become the default standard for cycling computers, which means most riders already have compatible out-front mounts on their handlebars from Garmin, Wahoo, or third-party manufacturers. The Hammerhead Quarter-Turn Adapter bridges the Karoo's proprietary mounting interface to this universal standard, letting you use existing mounts rather than replacing your entire cockpit setup when switching head units.

The adapter attaches to the back of the Karoo and provides the quarter-turn tabs that slot into standard mounts. This makes the Karoo compatible with aero bar extensions, integrated cockpits, and specialty mounts designed around the quarter-turn interface. If you're running multiple bikes with different handlebar configurations, the adapter lets you use whatever mount works best for each setup while moving one Karoo between them.

New Karoo purchases include a Quarter-Turn Adapter in the box alongside the 31.8mm Hammerhead Mounting System, so this is primarily a replacement part or a spare for multi-bike setups. At 5.3 grams, the adapter adds negligible weight to your configuration. The compact profile measures 57.7mm by 36.1mm by 11.5mm, sitting flush against the Karoo body without creating unnecessary bulk or altering the viewing angle.