Rather than Y cable, can’t you just wire one shifter to the other, one cable to the junction box and one cable from whatever free port to the internal junction A cable? No soldering needed.
Can do, yes. It's a total bugger to run the cables, particularly if you want one cable running all the way from one shifter to a Junction A in the downtube or seattube inside the bars. It's doable though.
Can do, yes. It's a total bugger to run the cables, particularly if you want one cable running all the way from one shifter to a Junction A in the downtube or seattube inside the bars. It's doable though.