Shimano Di2 12V 2-port internal connection box EW-JC302 - IEWJC302

The EW-JC302Shimano is a 2-port internal connection box designed for 12-speed Di2Shimano systems using E-Tube SD300 technology. Compact and discreet, it allows two EW-SD300 electrical cables to be connected to ensure a reliable connection within the drivetrain’s electronic circuit.

This Shimano connector is particularly useful when an existing Di2 cable is too short. It allows the cabling to be extended by adding an additional EW-SD300 cable, whilst maintaining a neat installation that is fully integrated into the bike.

A 2-port splitter designed for the Di2 SD300 ‘ Shimano ’

The EW-JC302 acts as an intermediate splitter between two compatible cables. Shimano It is officially designated as a 2-port junction box for the EW-SD300. It features two SD300 ports and does not contain any control electronics or firmware update functionality: its sole purpose is to ensure the continuity of the electrical connection between the components of the Di2 system.

Thanks to its compact design, the unit can be integrated into the frame, contributing to a particularly discreet internal cable installation.

Ideal for extending a 12-speed Di2 cable

The most common use of the EW-JC302Shimano e is to extend an EW-SD300 electrical cable when it is not long enough to reach the desired component.

The principle is simple: the existing cable is connected to one of the two ports on the EW-JC302, whilst a second EW-SD300 cable is connected to the other port. This configuration makes it easier to adapt the cable routing to the dimensions and architecture of the frame.

The connector is also compatible with the EW-SD300-I cable, designed for internal routing configurations.

Shimano Di2 compatibility

The EW-JC302 is designed for components using the E-Tube SD300 standard. It is used in particular on Shimano Di2 12-speed drivetrains such as:

• Shimano Dura-Ace Di2 R9250
• Shimano Ultegra Di2 R8150
• Shimano 105 Di2 R7150

It is also listed within the Shimano E-Tube SD300 ecosystem for certain SHIMANO STEPS / EP8 and EP6 systems.

Please note: the EW-JC302 is not directly compatible with the older EW-SD50 cables. To connect different generations of cabling, Shimano provides the EW-AD305 conversion adapter.

Technical specifications

• Brand: Shimano
• Part number: EW-JC302
• Product code: IEWJC302
• Type: junction box / 2-port connection box
• Standard: Shimano E-Tube SD300
• Number of SD300 ports: 2
• Cable compatibility: EW-SD300 and EW-SD300-I
• Use: connection or extension of Di2 cables
• Drivetrain: Shimano Di2 12-speed
• Installation: integration into the wiring, particularly for internal configurations
• SD50 connectors: none
• Master unit: no

In summary

The EW-JC302 IEWJC302Shimano is a compact and reliable Di2 splice designed for E-Tube SD300 cables. It is the ideal accessory for extending a 12-speed Di2 Shimano cable, simplifying internal cable routing or creating an intermediate connection between two EW-SD300 cables.

For a neat, adaptable and perfectly integrated 12-speed Di2 ‘ Shimano ’ installation within the frame, the EW-JC302 offers a simple and effective solution.