This post can effectively turn your regular road bike into a time trailing or triathlon machine it positions the saddle further forward in the same way as a steeper seat tube angle making for a more powerful aerodynamic position it changes a 73 degree seat tube angle to 78 degrees forged from 6061 t6 aluminium is shot peened for added strength sizes 272 mm or 316 mm length 300 mm offset 38 mm weight 298 310 grams