Est. 1982

Shimano SM-JC41 Di2 Internal BB Junction


The Shimano Di2 SM-JC41 internal junction box is where all roads meet in the e-tube version of the Shimano Di2 system.

All of the component and battery wires meet here before running out to their respective components - all of the wires that connect to the junction box use the same connector to make assembly that much easier.

This junction box is only made to be mounted internally on frames specially designed for an internally routed system.

For internal wiring setups only


Please Note:- E-tube is a two prong system and is NOT cross compatible with older Dura-Ace 7970 Di2 wiring.


  • Compatible with:-
  • Shimano Dura-Ace 9070, R9170 and R9150
  • Ultegra 6770 and 6870
  • XTR M9050
  • XT M8050
  • Alfine S705 and S505