Shift and brake cables running along the chainstay need an anchor point where housing ends and bare cable begins its final run to the derailleur. The Chainstay Cable Stop from Cervelo clips into a port on the classic S5 chainstay and provides that transition point, giving the housing a secure stop while guiding the cable smoothly toward the rear dropout. Without it, or with a cracked one, housing floats loose and cable tension becomes inconsistent as the whole assembly moves under pedaling forces.

Cervelo designed this stop with a tool-free clip mechanism that lets you pop it in and out of the frame port using a small molded lever. That's convenient when you're replacing cables or servicing the drivetrain since you don't need to fish for hex keys to access the routing. The trade-off is that the plastic retention tabs take stress every time you remove and reinstall the stop, and after enough service cycles they can crack or lose their grip. A stop that doesn't seat firmly rattles in the frame and doesn't hold the housing securely enough to maintain crisp shifting.

The quality molding creates a tight fit against the chainstay port with no gaps or play when properly installed. If your original has broken tabs, a cracked body, or has simply gone missing during a cable replacement job, this OEM part restores the intended cable routing. The stop fits the classic S5 from 2014 and earlier, so verify your frame generation before ordering since Cervelo uses different cable routing components across their model years. Sold individually, and most frames only need one, but check your specific setup if you're running mechanical shifting and rim brakes with multiple cables routed along the chainstay.