PRO Tharsis XC Stem

The integrated headlock system replaces the traditional starnut or expander plug by clamping directly onto the steerer tube. This creates a more secure, unified connection between the stem and fork, which helps maintain headset tension more consistently on rough terrain.

This stem is designed for standard 1-1/8 inch (28.6mm) steerer tubes and 31.8mm handlebar diameters. If your bike uses these common industry standards, it will fit, though you should verify your current stem length and angle to ensure the fit matches your preferred riding position.

Yes, absolutely. While the stem is specifically engineered with internal routing channels for Di2 electronic shifting systems, it functions perfectly fine with standard mechanical cable setups. The routing features simply provide a cleaner look if you choose to upgrade later.

The titanium bolts are used primarily to shave weight without sacrificing structural integrity. Because the stem is designed for cross-country riding where every gram counts, these bolts help keep the overall weight down to 145g at the 100mm length.

Yes, the angle significantly impacts your cockpit height. A 6-degree stem provides a more neutral, slightly upright position, while the 17-degree option lowers your handlebar height for a more aggressive, aerodynamic, and forward-leaning posture.