Tharsis ThreeFive Direct Mount Stem

What Our Gearhead® Experts Are Saying:

"The PRO Tharsis ThreeFive Direct Mount Stem is the stem I specify when a rider is building a full Tharsis 3Five cockpit and wants every component engineered to work together as a system. The direct mount interface combined with the 35mm oversized clamp diameter produces a front end stiffness level that a conventional stem simply cannot replicate, and the CNC machined AL-7050 construction gives it a fit and finish quality that reflects the performance intent of the whole build. Two length options at 45mm and 50mm cover the range of reach adjustments most trail riders need without requiring a different stem family."

The combination of a direct mount interface and an oversized 35mm clamp diameter represents the highest achievable stiffness specification in a trail stem, and the PRO Tharsis ThreeFive Direct Mount Stem is engineered to deliver both within a single component designed specifically to complete the Tharsis 3Five cockpit system. Where a conventional stem introduces compliance at both the steerer tube clamp and the handlebar interface, the direct mount design eliminates the steerer clamp variable entirely, anchoring the stem rigidly to the fork's direct mount interface for a front-end connection that transfers rider input to the front wheel with minimal mechanical loss.

The CNC machined AL-7050 alloy construction provides the dimensional precision and material consistency that a performance-grade direct mount stem demands, ensuring that the interface geometry between stem and fork is held to tolerances that eliminate the play and flex that looser manufacturing standards introduce at this critical junction. AL-7050 delivers a favorable strength-to-weight ratio that keeps the stem from 125 grams across the available length options while maintaining the structural integrity required for the repeated impact loads of trail and all-mountain riding. The 35mm oversized handlebar clamp diameter works in conjunction with the direct mount interface to maximize stiffness at both ends of the stem simultaneously, producing a cockpit that responds to rider input with a precision and immediacy that a standard diameter conventional stem cannot approach.

Two length options at 45mm and 50mm provide meaningful reach adjustment flexibility across the range of trail and all-mountain frame geometries and rider fit requirements most commonly encountered in performance builds, allowing the stem length to be matched to frame reach, rider arm length, and intended riding style without compromising the component's structural or aesthetic intent. The 0-degree rise maintains a clean, low cockpit profile suited to the geometry of current trail frames, and the 4mm stack minimizes the overall height contribution of the stem to the cockpit assembly on builds where headset spacer management and final bar height are closely considered. Full integration with the Tharsis ThreeFive handlebar range ensures that the complete cockpit assembly functions as a unified system engineered to the same performance and control standard throughout.