Installing and Adjusting Shimano Di2 Shifting Systems

3) Install Front Derailleur

The front derailleur mounts to the frame in the same manner as a mechanical front derailleur but also uses a small post bolt that butts against the seat tube to provide extra stability because the servomotor is quite strong.

• Mount the front derailleur normally, and make a mark on the seat tube where the post bolt will hit. Remove the front derailleur, and attach the included backing plate at that mark (the backing plate has adhesive tape on it). The backing plate prevents the post bolt from damaging the frame.

• Mount the front derailleur again so that the bottom of the outer cage is 1/32 to 1/16 inch (1-2 mm) above the tallest point of the teeth on the outer chainring and the cage is cocked inward slightly, not parallel with the chainrings as it normally would be. Fully tighten the mounting bolt.

• Screw in the post bolt until it hits the backing plate. Continue to screw in the post bolt until the front derailleur cage is perfectly parallel with the chainrings. The tension between the mounting bolt and the post bolt provides a stable platform for the powerful front shifts.

4) Install Rear Wiring Kit

Each frame that incorporates internal routing will have very specific ways of mounting the wiring kits, so for this book we'll cover only the external mounting kits. Choose the correct size for your bike. Shimano recommends small kits for bikes 52 centimeters or less, medium kits for bikes between 52 and 56 centimeters, and long kits for bikes larger than 56 centimeters.

• First, attach the cable junction to the bottom bracket shell without fully tightening the bolt. The cables that run to the front derailleur, rear derailleur, and the battery mount may be quite long. Slack is taken up by wrapping the extra cable around the different slots in the junction box. There is no set way to do this, just trial and error. When you're happy with the junction box setup, run the longest cable (runs to the front of the bike) through the tab at the front of the junction box, and bolt it to the bottom bracket. Double-check that the correct amount of slack is in the cables to reach the derailleurs and battery well.

• Bolt the battery mount underneath the front water bottle cage. Check that there is enough room to remove the battery when the cage is mounted. If there isn't, you'll need a bottle cage adapter, which is sold by Shimano. Use a zip tie to attach the mount to the down tube, running the zip tie over the battery wire and the front wire.

• Using a zip tie, attach the wires to the frame at the chainstay, the down tube, and the seat tube.

• Wipe down the down tube and chainstay with rubbing alcohol around where the wires are routed. Use the included adhesive covers over the wiring to prevent any snags or damage.

• Insert the wiring ends into the front and rear derailleurs. It should be readily apparent how they are inserted. Note: While it's okay to insert the wire ends into the derailleurs by hand, never pull them out by the wire. This will ruin the connection. Always use the included Shimano tool to remove the wire ends.