The Zipp SL Speed Seatpost has taken Zipp engineering a step further, and the result is a seatpost that is 35 grams lighter than the Service Course, with the same durability. The SL Speed features the same adjustable, low profile clamp system as is popular on the Service Course. It is a two bolt system that provides adjustment both fore and aft and in the tilt of your saddle. You'll also notice that the lower portion of the clamp is beefier than other seatposts on the market. This provides extra support for those riders who prefer a more rearward position. Meanwhile, the post itself is carbon. The main difference, which is a big one, is that the SL Speed uses carbon fiber for the construction of the post. Not just a cosmetic change, the carbon keeps the weight of the post under 190 grams and also gives you a ride that dampens road vibration and chatter. While many carbon posts feature a low maximum rider weight, the maximum weight for the SL Speed is 300lbs. The saddle sits on carbon and titanium rails for performance longevity and additional vibration dampening.