Product Details
This is the Shimano Ultegra Di2 Internal Junction Box. This box is referred to as the junction box "B" on a Di2 build. The SM-JC41 is for use with internal wiring setups and is the main centre of e-tube Di2 systems.. Frame Junction Box connects via SD50 E-tube wires to four different points: front derailleur, rear derailleur, cockpit junction box and battery mount
. All Di2 components on the bicycle require the same firmware version
. Using Di2 components with different firmware versions may cause malfunctions
What Sets Alchemy Apart
The best pre-owned bikes
When you buy a pre-owned bike from Alchemy Cycle Trader, you’re getting more than just a great deal. Every bike is roadworthy certified, comes with a 3-month warranty, and includes your first service free - so you can ride away with complete confidence.
Buy with confidence
In-house Active Thermography Carbon Fibre Testing for extra peace of mind on pre-owned bikes.
Learn more about our carbon testing.
Expert Servicing & Ongoing Support
Our professional workshop team is here to keep your bike running at its best long after you’ve taken it home. From routine servicing to performance tuning, our qualified mechanics ensure your ride stays smooth, safe, and ready for every adventure. Whether it’s your first free service or future maintenance, you can count on Alchemy Cycle Trader for trusted support and expert care. Learn more about our workshop services.
