As much as I love all bikes, I’m a mountain biker at heart. And, I’m excited to see Shimano’s Di2 coming to XTR. Synchro-Shift operates both the front and rear derailleurs in response to input from one shifter. Or, another way, the rider only says, “I need a higher/lower gear,” and Synchro-Shift says, “Okay. We’ll move the front and rear derailleurs like this for you.” It’s like having a 1x drivetrain but with a front derailleur that you don’t have to mess with.
Shimano provides the below video showing Synchro-Shift for 2×11 and 3×11 drivetrains.
Last November, Shimano received US 8,882,122 drawn to this technology. The illustrated example provided in the patent is only for a 3×10 drivetrain, but you can see the similarities. FIG. 4 of the patent compared to 2:10 of the video:
In the 3×11, at least in these examples, less time overall is spent in the smallest chainring – 3 gears when upshifting and 2 gears when downshifting vs. 5 gears up and 2 down for the 3×10.
Application: US 13/857,570
Application Status: Patented – US 8,882,122
Assignee: Shimano, Inc.
Related Patents/Applications: N/A