Di2 Synchro shift – how does it work?

Updated January 20, 2022 by BetterShifting

Updated content available

An improved page on Synchronized Shift has been published. I'm not taking this older page down any time soon, but recommend you read the new guide on Synchronized Shift

Read the Complete Guide on Synchronized Shift

When Shimano introduced the Dura-Ace R9150 series in 2016 they also released Synchro Shift. Then, a few months later, they made Synchronized Shifting available for Ultegra 6800 and Dura-Ace 9000 users as well.

All you need is up-to-date firmware and the current generation battery, the BT-DN110.

Synchronized Shifting requirements

Synchronized shift is available to users running current or previous generation Ultegra or DURA-ACE Di2 and a current-generation battery. This means you need one of the following series Di2 to run synchro-shift:

  • Ultegra 6870
  • Ultegra R8050
  • DURA-ACE R9000
  • DURA-ACE R915
  • XT M8050
  • XTR M9050
  • GRX

You will also need the BT-DN110 battery or BM-DN100 external battery mount.

On mountain bikes the same battery requirements apply, but you’ll also need one of SC-M9050, SC-M9051 or SC-MT800 in order to use synchronized shift. You can use mountain synchronized shift on bikes equipped with either XTR M9050 or XT M8050.

What is Synchro Shift?

According to Shimano; “Synchronized Shift is a function that automatically shifts the front derailleur when the rear derailleur is shifted, allowing the derailleurs to work together efficiently.” This means that you would never manually have to shift the front derailleur anymore. The system will do it for you when it thinks the time is right.

Shift modes

These are the shift modes you can set up:

  • Full Synchro Shift: your front derailleur will shift by itself when it has to
  • Semi Synchro Shift: when you shift the front derailleur, the rear derailleur will also shift in order to compensate
  • No Synchro Shift / turned off: No automatic shifts will happen. Full manual mode.

Synchronized shift map When shifting from 11T towards 28T the system will automatically shift from the big ring to the small ring between 25T and 21T

How to set up Synchro Shift

First you’ll need to download the e-Tube Project software. Connect your bike to your computer using either the SM-BCR2 (charger) or the SM-PCE02 (linkage device/diagnostic tool) and start the E-Tube Software. You can now customise the shifting settings using these steps:

  • Select your bicycle type
  • Do the connection check
  • Click ‘Customize’
  • Click ‘Shift mode settings

Synchronized Shift setup in etube

On this screen, you can select the number of teeth on your front chainring, select the range on your cassette, set gear position control, shift interval and the shift modes.

When riding your bike you can use three different shift modes. Shift mode 1, shift mode 2, and full manual. These shift mode 1 and shift mode 2 are set up as ‘semi-synchro’ and (full) synchro by default. However, you can set them up however you like. You could for example set both shift modes to full synchro, but have the automatic shift points differ for each mode. I'll talk you through customising the different shift modes in another post.

Change shifting modes on the bike

So you’ve got two custom and one full manual shift modes available – how do you use them? That’s easy! Just double press the button on either your Frame/Bar-end junction box or the below-the-stem junction box and you’ll change modes. In the video below reader Paul Teeter demonstrates how to cycle through the different shift modes.

This is what each light means:

  • Solid red/green lights: manual shift mode
  • Twice blinking red/green lights: shift mode 1 (default: semi-synchronized shift)
  • Three-times blinking red/green lights: shift mode 2 (default: synchronized shift)

Change synchronized shift mode using buttons

Looking for more information on Synchro Shift? Check out the other posts or the Shimano e-Tube website. Another good place to start is GPLama's youtube channel:


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