Cheat Sheet: 12-speed Di2 Synchronized Shift

Updated November 7, 2022 by BetterShifting Terry

Synchronized Shifting is a huge subject, and if you'd like to know more about that I recommend reading my complete guide to synchronized shifting.

Short on time? Here is the quick summary.

Shift modes

Modern Di2 bikes have three different shift modes: manual mode, shift mode 1 (usually semi synchro), and shift mode 2 (full synchro).

In semi synchronized mode the rear derailleur will automatically shift to compensate for front derailleur shifts.

In full synchronized mode, the front derailleur shifts automatically as the rear derailleur reaches certain gears. This is great on TT/Tri bikes.

Change selected shift mode

While you can use the E-Tube Project apps to change what each shift mode does, that doesn't actually change the selected shift mode on the bike.

To change the bike to the next shift mode, press the function button twice. The LED will then indicate the selected shift mode.

On 12-speed bikes, the button and LED are on the rear derailleur. This is what the LEDs mean:

  • Blue (2 seconds): Manual shift
  • Flashing blue (2 times): Shift mode 1
  • Flashing blue (3 times): Shift mode 2

Read more on Synchronized Shifting in the complete guide to synchronized shifting.

BetterShifting Terry

About the Author - BetterShifting Terry

I enjoy playing with bike tech - both bike building and wheel building, bike maintenance and of course, Di2. Besides writing content and working on the technical side of BetterShifting, I also work as a Software Developer in The Netherlands. Read more on the About this site page.

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