When converting to Di2 or eTAP from a standard cable-based setup, holes are left in the frame and bottom bracket. The bottom bracket hole can let water and debris into the bottom bracket contaminating the bearings and flooding Di2 connections.
The bottom bracket cap replaces the plastic cable guide that falls out when the shift cables are removed. The cap forms a water tight seal for the bottom bracket that will prevent contaminants from entering the inside of the frame.
Weight: < 3g
When installing the bottom bracket cap, always attach it from the rear of the bike first (hook back, clip front). Gently clip in the front using your thumb as shown in the pictures. If not installed correctly, the tab can break. This is due to the angle the hole is cut in the frame.
To remove the BB cap, use the small ridge in the rear center of the cap, to pop off the rear of the cap first. This is the opposite direction used in the installation. The front of the cap faces the front of the bike and is indicated by arrows on the inside.
New Sizing Helper
We created a new sizing template to assist with the selection of mounts, extensions, and arms. Use it to estimate the positioning of components.
Sizing Template KB Article