Cervelo introduced their Squoval Max tubeset with the 2018 R5. The more aerodynamic tubes feature a D-shaped or flatback seattube, hence the development of a UD carbon flatback shape seatpost, the SP-18 Carbon Seatpost. Cervelo offers the two bolt fore-aft seatpost head as a separate item. This is a post only- no head.

Cervelo requires 70mm minimum insert for safety, which is clearly marked, as is the adjustment scale for accurate installation, fit, and re-insertion. The overall length is effectively 350mm, and the setback version is a 25mm model.