Internal Junction B (SM-JC41)

The junction box SM-JC41 is used inside the frame, for internal wire routing. Not all frames will accommodate an internal junction B. The alternative is to either use the external junction box SM-JC40, or not use a junction B at all.

Details & specifications

Shimano model codeSM-JC41
Shimano model nameJunction B
Weight4 g
SeriesUltegra 6770, Ultegra 6780, Ultegra R8000, DURA-ACE 9070, DURA-ACE R9150
Downloads Junction B Manual
View on Amazon (new tab)  |  eBay (new tab) Chain Reaction Cycles (new tab)

Shopping links

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SM-JC41 installation