How to adjust your Shimano Di2 shifting (2x12)

If the gears ever get stuck, Shimano Di2 shifting systems can be adjusted with minimal effort. We'll show you how to get your Di2 2x12-speed rear derailleur working again in three easy steps.

• Hex wrench, 2 mm
• Workstand (optional)
• Ruler

This tutorial describes how to set up 2x12-speed Di2 systems for Road groupsets. The images show a different rear derailleur model and are for illustrative purposes only. For more details, please refer to the manufacturer's manual. For other shifting systems, go to the overview and select the right model.

• H-screw (outer end stop adjustment)
• L-shaped screw (inner end stop adjustment)
• B-screw (chain wrap adjustment)
• Function button (switch to settings mode)

• Shift to the small chainring at the front and the largest sprocket at the rear.
• Turn the B-screw in or out to adjust the distance between the upper pulley wheel and the largest sprocket.
• For Dura-Ace / Ultegra:  The spacing between the teeth (measured from the tips) should be 6 mm (11-34 cassettes) or 14 mm (11-30 cassettes).
• For Shimano 105: The spacing between the teeth should be 10 mm (11-34 cassettes) or 6 mm (11-36 cassettes).
• Turn the crank arm forward and make sure the chain runs freely.

• Move up to 5th gear (fifth-largest sprocket).
• Press and hold the function button on the rear derailleur until the LED changes from blue to yellow (setup mode).
• You can now use the buttons on the shifter to move the rear derailleur in small increments to the left or right.
• Move it all the way to the left until the chain touches the 4th sprocket and until a slight noise can be heard when turning the crank forward.
• Now move the rear derailleur 5 notches to the right toward the 5th sprocket. 
• Press and hold the function button on the rear derailleur until the LED changes from yellow to blue (normal mode).
• Shift through all the gears. If the chain is rubbing in a gear, repeat the procedure in that gear.

• Shift to the small chainring at the front and the largest sprocket at the rear.
• Now turn the L-screw (clockwise) until the front end lightly touches the stop (on the opposite side).
• Shift to the large chainring at the front and the smallest sprocket at the rear.
• Now turn the H-screw (clockwise) until the front end lightly touches the stop (on the opposite side).
• Finally, turn the H-screw back one turn.

Your rear derailleur should now shift smoothly and run silently.
If it cannot be adjusted in this way, there may be various reasons such as a bent derailleur hanger. In such cases, the service workshop in your Rose store will be happy to help you.