Modern Di2 is basically a couple of controllers and servo motors that communicate with each other using the EW-SD50 wires. Shimano lets end-users configure their own Di2 systems using their e-tube project software. This page explains how to connect your bike to your computer.
Requirements - Road/MTB/GRX/Urban vs E-Bike
Connecting a Di2 bike to a Windows computer is done via the charging/interface port on the Junction A.
Modern road bikes, mountain bikes, and gravel bikes will all have this junction and the required interface/charge port. Some urban bikes will too.
However, STEPS E-bikes or E-MTBs generally use a display without this port. Also, most E-bikes use larger, external batteries and they do not come with the SM-BCR2 charger. If your bike is one of these I'm afraid you're out of luck - you can only connect your bike to a Windows computer using the SM-PCE1/SM-PCE02 diagnostics device.
Locate the charging / interace port
You probably know where the charging port is - but just in case you don't, have a look at this image:
IMPORTANT: E-Tube Professional
The older E-Tube Project versions can be downloaded from the E-Tube Project archive.
Connect using e-Tube Project
Plug your charger into the junction box and connect the other end to your computer – the order doesn’t really matter, but I tend to plug the connector into the bike first. Start the e-Tube Project software. Then just click the 'Next' button.
It’ll then tell you that charging has stopped because you’ve connected the bike to the computer and started the software.
Also, it will tell you to use the disconnect button when you're done and then start unit recognition.
When the connection has been made successfully you will be shown the Customize tab. This is where you can set up or tweak each component.
Cannot connect using the SM-BCR2? Need to update it?
E-Tube Project displays a message, but won't actually update the SM-BCR2:
SM-BCR2 recognition. The process is interrupted because the version of SM-BCR2's firmware is old. Connect to the Internet and download the latest version of the firmware.
Now.. the workaround is relatively simple, if not a bit frustrating.
You need to download E-Tube Project 3.4.5 and update the SM-BCR2 that way. After that it's safe to use E-Tube Project 4.
View installed components
Sometimes it is useful to see the list of installed components. When troubleshooting unresponsive components for example. By checking the list of installed and connected components you can figure out what part of the Di2 "circuit" is broken. Almost all components are listed on the Update tab.
If a component isn't listed here that means that it either isn't connected or it doesn't have any firmware that can be updated. Junction B (SM-JC41 / SM-JC40) and the external battery won't show up here for example.
Done? Use the disconnect button
When you're done please use the disconnect button as seen at the top left of the window. If you do not, the bike may not respond or may end up draining the system battery until you reconnect it. It isn't hard, but it is something to keep in mind.
Other things you can do with E-Tube Project:
- Update your component firmware
- Micro-adjust your rear/front derailleurs
- Change the Wireless passkey
- Set up Synchronize Shift
- Change button assignments and set up the switches on the shifter hoods
Questions? Leave a comment or send me a message.