Zipp Service Course Stem
When Zipp unveiled their alloy 101 wheelset they quickly learned of the hunger in the marketplace for uber-engineered aluminum components. If it wasn't their hottest-ever product unveiling, it was up there. Given that, up until recently, Zipp worked exclusively with carbon fiber, they were perhaps less attuned than some to the fact that most folks aren't opposed to aluminum as a material, but just need a compelling reason to pick it over carbon. With their Service Course line of components -- all of it borne from their infamous engineering wizardry, but in this case all of it made from aluminum -- Zipp hasn't just compelled us, they've floored us. A core component from that line is the Service Course Alloy Stem. It provides exceptional performance, lightness, and positional flexibility, but it does so at a reasonable price in comparison to many more expensive (and often heavier) stems. Zipp 3D forges the Service Course Stem from 7075 aluminum. This forging process aligns the grain structure of the aluminum, giving the material the strength that allows a thin-walled final structure. And its smooth shaping looks good with today's sculpted carbon frames. The Service Course Alloy Stem is offered in seven sizes from 70 to 130mm in 10mm increments. Each length is available in two angle options -- the +/-6 option is ubiquitous these days, but the +/-17 models remind us of a bygone era where stems were dead flat and oh-so pro. It has a 31. 8mm clamp diameter and is a perfect match for Zipp handlebars. The 1-1/8" steerer clamp has a stack height of 42mm.