Just link the two shifters with one cable, then take a cable from the left shifter (or the right - I say left as my handlebar-end junction is on the left) and link it to the junction.
I can only see the Y-cable making cabling a lot harder/more awkward and it's an unnecessary expense.
The only problem I'm having right now is that there are no bloody bastard decent handlebars with proper internal routing. I reckon I've bought (and returned) every pair currently available apart from the Deda SuperZero, which the internal cable routing is bloody awesome in - shame they look like a turdey boomerang.
Yeah they're branded to be designed for this stuff, they're actually fucking rubbish - got both the Vibe and Vibe LTD at mine waiting to be returned if you want to have a look.
You don't need the Y-Cable
Just link the two shifters with one cable, then take a cable from the left shifter (or the right - I say left as my handlebar-end junction is on the left) and link it to the junction.
I can only see the Y-cable making cabling a lot harder/more awkward and it's an unnecessary expense.
The only problem I'm having right now is that there are no bloody bastard decent handlebars with proper internal routing. I reckon I've bought (and returned) every pair currently available apart from the Deda SuperZero, which the internal cable routing is bloody awesome in - shame they look like a turdey boomerang.