Cervelo SP33 Carbon Seatpost

Cervelo SP33 Carbon Seatpost is the frame-specific carbon post built for Cervelo's Caledonia-5, R5, and R5CX, matching the aero, D-shaped seat tube profile on those frames rather than fitting a standard round post. Built entirely from carbon fiber, it comes with a seat post head assembly included, and the clamp accepts both metallic saddle rails (7mm diameter) and carbon rails (7x9mm cross-section), so it works with the wide range of saddles riders are likely to run on these bikes. The SP33 is available in 0mm and 15mm offset, letting riders dial in saddle position without changing frame size or compromising the seat tube's aero shape. Because it's molded to the exact profile of its host frames, it integrates more cleanly than an aftermarket round post adapted with a shim, keeping the aerodynamic benefit of the frame's seat tube intact. This is a replacement or upgrade part for riders running a Caledonia-5, R5, or R5CX who need a factory-matched post — whether replacing a damaged original, switching offset to fine-tune fit, or building up a frameset from scratch.