Setting up the Shimano Di2 EW-RS910 Bar End Junction A Charging Point 2 Port

[melchionda]

I'm setting up a Tarmac and rather than having the Di2 junction box stuck to the bottom of my stem I would like to use the new Shimano Di2 EW-RS910 Bar End Junction Box for a cleaner install. However, this new junction box is only a two port box. So my question is, does anyone know how you wire up this system? If you use one port on the bar end box for a brake lever, and then is the other port intended to go to a junction box in the handlebar for the levers? That would mean there would be a third junction box in the frame. Seems like a lot of boxes, so I was wondering if I was missing something. Im also considering installing remote shifters for sprinting... that would mean yet another box. I want this to be a clean install so any guidance anyone could provide would be appreciated!

[grouk]

conect one shifter to other and from one shifter leave one cable to the junction box

[strangely]

Its pretty flexible to set up as everything on the e-tube bus is kind of series parallel and none of it really cares how its setup so long as its plugged in somewhere.

As @grouk says, the simplest way is to go direct from the Bottom bracket junction (SM-JC41 4 port passive B junction) to one brifter and then another cable to the other and then a third cable to the RS-910.

If you don't have a long enough wire and or don't want to replace this, then you can use the new Y-cable or even a second B junction (SM-JC41) to connect it all and to extend any cables that are too short. You could also use the new inline D-fly (if you have use for it), as a coupler with a smaller e-tube wire as extension for your down tube wire.

Again, connect it how you like as it doesn't care, just so long as the parts connect somehow!

[cyclespeed]

Here you go;

https://www.youtube.com/watch?v=fg1X8G2pn_I

I've just done exactly that, so thought a video might help others.

[Stueys]

On my all 9070 group set can I just plug an RS910 straight in? I don't need new battery, d-fly, etc, etc?

[TurboKoo]

Yes you can do that. Just make sure to update everything.

[Stueys]

Yes you can do that. Just make sure to update everything.

Great, thanks

[melchionda]

Thanks guys... That setup does make sense and looks really simple.

Any recommendations on the cable lenghts I need to buy?

I'm thinking I need to determine these cable lengths...

1.) From the bar end to the lever?
2.) From lever to lever?
3.) From the Downtube junction box all the way up into the handlebar and connected to a brake lever.

I want it to be tidy, but if I get wires too short it could be a real pain in the neck to get these connected.

(I'm running a 56cm frame and 44cm bars.)

[cyclespeed]

In the vid, I say what length wires I used for all those that you mention. I can't remember off hand what they were, but you might want to use a 1400mm i/o 1200 for the long one.

[sugarkane]

Thanks guys... That setup does make sense and looks really simple.

Any recommendations on the cable lenghts I need to buy?

I'm thinking I need to determine these cable lengths...

1.) From the bar end to the lever?
2.) From lever to lever?
3.) From the Downtube junction box all the way up into the handlebar and connected to a brake lever.

I want it to be tidy, but if I get wires too short it could be a real pain in the neck to get these connected.

(I'm running a 56cm frame and 44cm bars.)

1. 350mm
2. 600mm
3. 1400mm ( 1200 will do in a pinch )

[AGRider]

I've just done the same thing, but I've also added in the new 2-port inline wireless junction. Depending on the width of your bars, I would err on the long side for the cables. I got a good deal on the y-jct (EW-JCT130 cable) but it wasn't long enough to go all the way down to the RS910 box, so I have a wire going from the RS910 box to the right shifter (Ultegra 6770), then the EW-JCT130 connects the other open port on the right shifter to the left shifter, and the short (50mm) tail connects to the wireless box (EW-WU111), which then connects to the cable going into the downtube. Routing the cables into the handlebar was a little bit of a challenge, but I was using the new park tool routing kit, which really helped.

The other option you may want to look at is to do the following if you're just using regular cables:

1) Run a cable from left shifter to right shifter
2) Run a cable from right shifter to RS910 box
3) Run a cable from RS910 box to exit out of handlebars, and then
4) Use EW-JC200 Junction B (https://www.bike-components.de/en/Shima ... el-p51465/) to then connect to your downtube cable.

This way, it's a clean install, but you've got some flexibility with the downtube cable, if you don't want the D-fly / bluetooth transmitter.

I would recommend that you have bluetooth transmitter in the system though as it allows you to update the firmware and adjust settings using the iOS or Android app.

[sugarkane]

if you want dfly cable tie it too the 4 port in the bb area.. adding the JC-200 to the bars is well... a crap idea.

[AfromD]

To use wu111, d-fly must be external.
It needs to be exposed to the outside, but the signal is good.

I have the wu111 in the down tube behind the fork. Works fine. It is a carbon frame.

[sugarkane]

To use wu111, d-fly must be external.
It needs to be exposed to the outside, but the signal is good.

Yeah nah... I've installed a lot of them and never on the outside of the bike...

[Roeieber]

Does the WU111A (D-fly) to be between cables to work or is connecting on one side enough?
I want to use it in combination with the RS910 and place the d-fly on the open connection of the RS910 and place it in the handle bar.

Setup: Long cable from bracket to shifter, cable from shifter to shifter, cable from shifter to RS910 and a short cable from RS910 to WU111A.
Will it work?