Zipp Service Course Seatpost (20)

Better fit means better performance. If your saddle is out of position, you’ll waste energy with every pedal stroke. That was our foremost consideration in creating the Service Course® seatpost.  The secure, low-profile clamp allows the saddle to slide farther back along the rails, and with 0 mm and 20 mm setback options, it’s possible for nearly any rider to achieve the perfect fit.  This unique clamp design also features downward-facing bolt heads that allow micro-adjustment of the saddle even after it is mounted. 
For high strength, low weight, and efficient use of every gram, the shaft and head not bonded together but are 3D-forged from a single piece of 7075 aluminum. The Service Course seatpost with 20 mm of setback weighs 285 g (350 x 27.2) and is available in 275 and 350 mm lengths and 27.2 and 31.6mm diameters.