The 4.0 stem series from German manufacturer Tune offers superior stiffeness, light weight, and style. Some impressive improvements have been made over the previous generation "Geiles Teil" stem design. The most obvious improvement is the move to a four bolt design, which helps to increase stiffness and safety through wider dispersion of clamping forces. Tune also cut about 25 grams off the previous design through slightly more aggressive machining, bringing their weights more in line with mainstream competitors. Both stem and handlebar interfaces are very precisely machined then finished with chamfered edges to ensure optimum compatibility with carbon components. The stems are finished in bright polished anodized colors with laser etched Tune logos on top and bottom.
Tune makes safety a top priority in both design and testing. Their 4.0 series stems were subject to the wrath of the VR-3 Max, and passed with flying colors!
Tune stems are designed and manufactured with pride in Germany.
The 4.0 stem's titanium bolts are fastened using a 4 mm hex wrench, and the use of a torque wrench is strongly suggested. Tune's torque requirement is 5 - 6.5 Nm. When pairing this stem with carbon handlebars, we recommend using Tacx assembly paste.