Zipp Speed Weaponry SL Speed Seatpost: 31.6mm Diameter, 400mm Length, Zero Offset, B2, Matte Black, B2Zipps SL Speed Seatpost has become a favorite of pro road and cyclocross racers because of its light weight and dependability. UD carbon post, head and clamps Minimum insertion length is 100mm Single bolt adjustment Product Specifics Defined Color: Black Weight: 170 Offset (mm): 0 Diameter: 31. 6 Max Height: 240 Color: Carbon Min Height: 100 Material: Carbon Clamp Style: Standard Rails Clamp Style: 7x9 Rails Length: 400 Today's Stock Status Currently