The Zipp Service Course SL stem pulls out all the stops and gives up a lightweight stem that is feature-heavy. When you break down the name of the stem, Service Course, you will see the etymology of the product fits what it was designed for. A rough translation of Service Course is: in the service of racing.
The Service Course SL is a true work of technology, it is no surprise coming from a company like Zipp. It features high-strength 3D-forged construction using 7075 aluminum. This design with this type of alloy give a stiff and light stem with little to no flex. The face plate is heavily scalloped using material only where it is absolutely necessary. 4 titanium bolts securely fast the plate to the stem and hold the bars with total security.
Cosmetically, it has some of the smoothest lines we have seen that nicely complement the aesthetics of modern frames and handlebars. During production, Zipp takes extra steps to ensure precise length and alignment for an absolute precise product. The Service Course SL is available in a range of lengths from sizes from 70mm to 130mm. Each length is available in either 73°/17° or 84°/6° rise options. Bar clamp diameter is the industry standard 31.8mm.
Great looking stem, however, when paired with a Zipp Carbon bar and recommended torque, the bar slipped continuously. Also, the little tiny torx bolts tend to strip easily.