How to wire up new Bar-End Junction A for Di2 (EW-RS910)

[bikerdan]

I make di2 Barend junction boxes... So the wire up is as follows

Replace your main cable from the bb with a 1400mm
Remove the 300 from the bars
Jumper the two top ports in the shifters with a 650mm cable via the internal ports
Then you need to wire your main cable with heat shrink via the internal ports to the second plug point on your rear brake side.. ( euro is right, Moto is left ) then the junction box gets the last spare port from the bar end via the intenternal rounding port..
Not very hard really

Exactly the sort of info I was after

You make it sound easy [emoji6]

The one bit I don't understand is the "heat shrink the wire...". Do you mean shrink wrap tubing that contracts when you warm it up. Or doing something directly to the di2 cable.

I would have thought I could just plug it into the second port on the shifter

Sorry for the dumb question...

Sent from my MotoG3 using Tapatalk

I think he means to use shrink cable to 'bond' the brake cable and the main 1400mm wire from where it exits the frame until the rear brake leaver for a clean look.

OK. That I was going to do anyway.
Cool...can't wait to try it out [emoji6]

Sent from my MotoG3 using Tapatalk

[Brus]

This junction works only with dura ace shifters which have more ports, right?
Ultegra shifters with one port require 3-port junction A?

[sugarkane]

Use a 4 port juction in the bar end to act as a jumper box.. Di2 is modula it doesn't care how it's wired up..

[sun]

You should also keep in mind if your handlebar will allow the bar end junction plug. I just tried to see if I can wire my Specialized Aerofly and there is something in the way of running a wire to the bar end. I believe they reinforced the shifter clamp area as I couldn't get anything to pass through that area.

[bikerdan]

Damn just checked my look ADH bars and same problem

[bikerdan]

Damn just checked my look ADH bars and same problem

So options now
1. New bars which would be a shame as the looks go well with my 695 Aerolight and they are super compact. Not sure what bars would work
2. Drill a hole somewhere on the drops. Kinda scary...
3. External junction a box. But really wanted clean looks
4. Sell the dura ace and get SRAM etap. Shame as I guess dura ace works better.

[sureal]

I'm pretty sure there will be a bunch of new handlebars support this fully integrated di2 routing which must have enough holes.

but what worries me is the stem and how cables go into the frame, before full-integrated frame come out.

The easy way is cable come out of the handlebar hole or integrated ones with stem and route as we do nowadays. The perfect routing shouldn't let ppl see cable around HT area totally.

[mr4fox]

does anyone know if i can use the EW-RS910 bra end junction box without the Y cable (EW-JC130?
i have the same bars that came on the 2016 Scott foil which has a recess in side to hide a normal 3 port junction box. so was wondering if i can just use one of the cheaper 4 port junction B (SM-JC41 which would typically reside in the BB area) and stick in inside the stem and connect each shifter to it and on cable down to the BB - which is how i currently have the 3 port junction A hooked up.

the problem is its a pita to access when i need to charge or adjsut the rear mech for clean shiftin on different hubs. there is a little hole to press the button to activat the adjustment but its har to feel when i actually pressing it...so i kinda sorta broke the button....so need a bar end junction box will be perfect

[ooo]

yes, you can

[mr4fox]

yes, you can

thanks for the info

one more Q. will the new bar end junction box fit in most drop bar ends or do they require special bars?

thanks again

[ooo]

extra hole in bar is needed for internal wiring
you can drill it in non-carbon bar,
it is a problem on carbon bar without extra holes
(but you can get long enough wire outside via opposite barend hole)

here is link to post with install manual:
viewtopic.php?f=3&t=138020&start=1155#p1284710

[Timmy269]

Is a junction A box needed for ultegra DI2? Mine is hanging on the K-edge frond mount but it would be cleaner if there was no junction box with 3 cables.
The 2 cables on the shifters I would replace with a EW-JC130 an run it to the D-fly module in the down tube.
When the battery must be charged I would take the Junction A box en connect it to de cable of the rear derailleur.

[strangely]

Is a junction A box needed for ultegra DI2

Unfotunately it does not work without it. I've tried doing exactly that myslf.

[mr4fox]

extra hole in bar is needed for internal wiring
you can drill it in non-carbon bar,
it is a problem on carbon bar without extra holes
(but you can get long enough wire outside via opposite barend hole)

here is link to post with install manual:
viewtopic.php?f=3&t=138020&start=1155#p1284710

Thanks again for the help ooo.

I think I can run the cables internally the whole way from the recess in the stem (where my junction A box is currently hidden) all the way to the vmbar ends where the new bar end junction A will live. So hopefully no drilling necessary

[Timmy269]

Is a junction A box needed for ultegra DI2

Unfotunately it does not work without it. I've tried doing exactly that myslf.

That's too bad. Is there another way to use it one another place without drilling in the frame.