The Shimano EW-SD50 electric wire connects the individual parts of the Di2 system to each other. They're available in a bunch of different sizes. You'll need about 6 of them, depending on your specific setup and frame size. The generally available sizes are:
- 1600mm (e-bike only)
Use the Shimano tool
We recommend you use the official Shimano cable plug tool for Di2 to correctly plug in your Di2 wires. You should feel and hear a click (or 'pop') when connecting your components.
Connecting the front derailleur and the (external) SM-JC40 junction B