Understand Di2

Bought a new Di2 bike, or are you thinking about it, and want to actually understand how the system works? You're in the right place. This is the learning hub for everything Di2 – what it is, how it shifts, how to talk about it, and how to look after it.

Di2 stands for Digital Integrated Intelligence – Shimano's electronic shifting. Instead of cables pulling your derailleurs, small servo motors do the work, triggered by a button press.

The result is fast, accurate shifting that doesn't drift out of adjustment over time, and never needs a new shift cable. Di2 is available on road, gravel, mountain and e-bikes.

The system all components talk over is called E-Tube (think "Electronic Tube"). Depending on the generation, your bike is fully wired, semi-wireless (wireless shift levers, wired derailleurs), or – on 1x12 MTB and gravel – almost fully wireless. You configure all of it using Shimano's E-Tube software on a computer or the E-Tube Cyclist app on your phone.

Not sure where to start? Pick the guide that matches your bike below, then dig into the topics that interest you.

Something not shifting right?

This page is about understanding the system. If your bike is actually misbehaving – not shifting, not charging, or stuck after a firmware update – head to Fix your Di2 bike instead.

And if you can't find what you're looking for, or you've got a question I haven't answered, send me a message. I'm always happy to help.