Cannondale C1 Aero 27 Seatpost 15mm Offset

The Cannondale C1 Aero 27 Seatpost is a full carbon post with a 27mm deep D-shaped profile that reduces aerodynamic drag compared to a round post while increasing vertical flex through the saddle. That added compliance absorbs road buzz on rough and variable surfaces, easing fatigue over longer efforts without sacrificing the stiffness needed for power transfer.

The 15mm offset positions the saddle rearward to support a more natural pedaling position on performance road and gravel frames. Hardware for Cannondale’s SmartSense system is included. Frame compatibility covers the 2025 Synapse and SuperX, the 2020 CAAD13, and the 2020 SuperSix Evo, Evo SE, and Evo CX, all of which accept the D-shaped post profile.

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