A function which allows riders to concentrate on only up or down shifting the rear derailleur while the Di2 system automatically picks the ideal gear combination from both the front and the rear derailleur. Even in Synchronized Shift mode riders still have full control over the front derailleur. Synchronized Shifting is designed to complement rather than replace manual shifting, and is especially useful when you are using auxiliary sprint, climbing or TT shifters, or, for Dura-Ace, the shifters on the top of the hoods.
With one press of the rear shifting lever, the function can achieve the optimal front/rear gear for your personal riding style. The E-TUBE PROJECT app or website can be used to pre-set exactly when changes take place.