Shimano EW-JC304 Junction Box for EW-SD300

The EW-JC304 Junction Box with four slots for Shimano EW-SD300 power cables

Shimano's EW-JC304 junction box has four slots that are compatible with the EW-SD300 power cable for outdoor installation and the EW-SD300-I power cable for indoor installation. It is used for the fully wired installation of the Dura-Ace and Ultegra Di2 2x12-speed groupset. This setup is mandatory for the rim brake version, although there is also an alternative wiring option without EW-JC304. With the disc brake version, full wiring is optional and always requires this box. The distributor, which takes on the function of Junction B, is mounted internally in the frame near the cockpit, preferably in the head tube. You connect it to the shift/brake levers on one side, while on the other side a third cable leads to the battery, which is located in the seatpost. Completely wired shifting is not possible with the 105 Di2 R7150 groupset, but EW-JC304 can be used as a contact point if required. It can also be used to wire Shimano EP8 and EP6 series e-bikes, as these also work with the E-Tube platform. Older EW-SD50 cables are not compatible.

Information regarding the return of batteries and electrical equipment:

Information on the return and disposal of batteries and electrical equipment can be found here.

Guidelines for Replacing E-bike Components:

Before you replace components on your e-bike, please read through the guidelines for component replacement for CE-marked e-bikes/pedelecs with pedal assistance.

Specifications:

Number of connections:

4

Material:

Composite

Compatibility:

Power Cable:

• EW-SD300
• EW-SD300-I

E-Bike:

• EP8 EP801 for MTB / Touring
• EP8 EP801 for Urban / Touring
• EP8 EP801 for cargo bike
• EP8 EP800 for MTB / Touring
• EP8 EP800 for Urban / Touring
• EP8 EP800 for cargo bike
• EP6 for MTB / Touring
• EP6 for Urban / Touring
• EP6 for cargo bike

Shifters & Derailleurs:

• Dura-Ace Di2 R9250 (2x12-speed, 2x12-speed TT/Triathlon set-up)
• Ultegra Di2 R8150 (2x12-speed, 2x12-speed TT/Triathlon set-up)
• 105 Di2 R7150 (2x12-speed)

Features:

• B junction with 4 connections
• updated version for power cable EW-SD300

Manufacturer Number:

I-EWJC304

Contents:

• 1 x Shimano Di2 EW-JC304 junction box