I’ve got a 5-port SM EW90 junction box wired for both base bar and aero bar shifting, with the 5th wire going to the rear derailleurs and internal battery (with a junction box splitter). I’ve kept my main junction box inside the stem but with a change of fit (change of stem) I can no longer internally mount the main 5-port junction box.
However, I believe a 3-port junction box would fit inside the new stem (in combination with another SM JC41 splitter to accommodate the loss of 2 ports). The physical box is smaller. Can anyone tell me if the 3-port junction box retains the same circuitry or logic to handle all the base/aerobar/internal battery/derailleurs functions? No local LBS has this answer.
I’d prefer to not externally mount the junction box.
Yes, the SM JC41 will work. You just need one “A” junction somewhere in the system. This can be a 5-port, 3-port, or the little one that comes connected to the road shifters. You can then splice in any combination of the “B” boxes to get the wires where you need them.
I recently did a non-standard road setup and once connected, everything just worked. Pretty sweet.
Yes, the SM JC41 will work. You just need one “A” junction somewhere in the system. This can be a 5-port, 3-port, or the little one that comes connected to the road shifters. You can then splice in any combination of the “B” boxes to get the wires where you need them.
I recently did a non-standard road setup and once connected, everything just worked. Pretty sweet.
+1
in fact you can use JC-41 to split cables many times over so that all of the shifting cables route into JC-41 and there’s only one cable needed btwn that JC-41 and the controlling “A” junction.
this is my set up
climbing switch------------
Right extension shifter-------JC-41 (shifters take up three ports, last one go to EW-90)---- EW-90-----JC-41 (to battery, RD and FD)
Left extension shifter___/ ___Open port