Changing handle bars on my cervelo s2

[Logan Skidmore]

Had been riding my Giant Defy 2 since 2014, got stolen in 2020. Decided to upgrade. Found a 2015 Cervelo S2 in great condition. Love the bike. Way stiffer, way faster but the handle bar assembly is super uncomfortable when getting into and staying in aero. Considering changing it out for something else (basically a set with longer bar tape area) but I’ve never done that before. Any suggestions on what to look for or big dos and donts of changing up handle bar assemblies (I will have the new ones professionally installed. Not gonna diy that!).

 

[Boogers]

Most handle bar stems these days, which I'm sure includes the stem that came standard on that Cervelo, have a 31.8mm, round clamp to attach the bars.
The 31.8mm clamp size is called "OS" or "oversize", which is simply to differentiate it from the previous standard clamp size of 26mm.

So, assuming no one changed the bar stem to something non-standard, you'll have many options of OS road bars to choose from. Even though most road bars will have that same clamp size, the other sections can vary a bit in shape. They can be different widths (as you've noticed), different shape drop section, different depth of drop, different forward extension length from the tops (where the levers attach), and different drop angle where the levers attach

This is just a small sample of the different shapes