ST collective brains trust.
I have just had a new P3 build up for me using some parts from one of my older bikes and a mix of new ultegra and DA shifters etc.
The new P3 has a tri rig front cockpit which is super nice and adjustable, the only PITA is that to charge the Di2 I need to unscrew a cover which is a bit fiddly with the current set up. I am a bit anal about making sure it is always well charged before outdoor rides and races so I don’t want to be fiddling with this every few weeks.
I thought a nice clean option was to install the handlebar-end Di2 junction box on the aero bars (RS-910). I just went to do this today and it will be super clean and make life very easy…however…when I plug the junction box into the existing junction box and the shifter there is no power to anything. Remove the brand new RS-910 and the system works fine. I am not sure whether the problem I have is an out of the box dud RS-910 or that the firmware on the other Di2 gear needs updating for the RS-910 to work. I have not updated the firmware on this before…
Any advice appreciated…anyone know if the firmware needs to be at a certain level to allow the RS-910 to work? Any other ways to check that the RS-910 is working out of the box?
Cheers from down under…
If I am understanding this correctly you are plugging in the RS-910 into the existing junction A box (EW90). If so that’s your problem. System doesn’t work with 2 Junction A boxes. If you disconnect the EW90 and use only the RS-910 it’ll work.
You’ll probably need a junction B 4-port internal though in place of where the EW90 sits inside the Tririg bars in order to have everything connected. Possibly might need an extra wire or 2 to get everything routed. Search for the thread about an Di2 upgrade to a Felt IA16 on here on how to route using a Tririg alpha setup and an RS-910. It is exactly what you are trying to accomplish with your setup. Great info on that write-up and helped me make the plunge to Di2.
The RS-910 acts as the junction A box, so you don’t need the second one. You’ll probably need some of the e-tube y-cables to get everything wired properly.
The RS910 is probably on a newer firmware than the rest of your system. You can use your internal battery charger to update the firmware if you don’t have the Bluetooth transmitter installed on. Download the E-TUBE software to your PC. Plug the charger plug into the RS910 and then plug the USB into the PC.
The E-TUBE application will guide you through the steps to update it. The system will detect all plugged in parts and identify which ones need to be updated.
All my bikes are Di2. Each bike it seems like I needed to relearn everything. Although, one thing I know is not all generations play nice. Verify your old parts and new parts work together.
I should mention, I just use the junction box under the stem. I use a mount for the junction box that fits like a stem spacer (got it on amazon). I just charge on the side of the junction box.
My P2, I actually went with the battery mount under the bottom bracket area instead of seatpost by choice. Pop the battery off and charge it directly on the charger. Not sure if a lithium battery matters when flying on a plane, but I figured this solves that as well. I take the battery off and put it in my carry on bag.
And once you have it all hooked together the firmware on everything does need to match. Does your system have the wireless unit EW-wu111? Then you can update everything with the e-tube app, and also do some customization of how it shifts.
If not then I believe you’ll need a windows laptop to plug it into, but I don’t know much beyond that.
But as mentioned you only need the one junction-A, if you have the old one still connected.
ST collective brains trust.
I have just had a new P3 build up for me using some parts from one of my older bikes and a mix of new ultegra and DA shifters etc.
The new P3 has a tri rig front cockpit which is super nice and adjustable, the only PITA is that to charge the Di2 I need to unscrew a cover which is a bit fiddly with the current set up. I am a bit anal about making sure it is always well charged before outdoor rides and races so I don’t want to be fiddling with this every few weeks.
I thought a nice clean option was to install the handlebar-end Di2 junction box on the aero bars (RS-910). I just went to do this today and it will be super clean and make life very easy…however…when I plug the junction box into the existing junction box and the shifter there is no power to anything. Remove the brand new RS-910 and the system works fine. I am not sure whether the problem I have is an out of the box dud RS-910 or that the firmware on the other Di2 gear needs updating for the RS-910 to work. I have not updated the firmware on this before…
Any advice appreciated…anyone know if the firmware needs to be at a certain level to allow the RS-910 to work? Any other ways to check that the RS-910 is working out of the box?
Cheers from down under…
This isn’t firmware related. It is as Loxx laid out - you can only have one Junction A in the system. Use a Junction B in place of the original Junction A.
Thanks ST brains trust. You have hit the nail on the head. I had figured the new junction box would just function as a satellite of some description but as you all say, you cannot have two Junction A’s, I will have to figure out the wiring to make this work, hopefully not too tricky to find the correct Junction B box to make it all work.
FYI you can use as many B junction boxes (sm-jc41) as you want. They can be helpful.
Thanks ST brains trust. You have hit the nail on the head. I had figured the new junction box would just function as a satellite of some description but as you all say, you cannot have two Junction A’s, I will have to figure out the wiring to make this work, hopefully not too tricky to find the correct Junction B box to make it all work.
If you are replacing a 5-Port Junction A you’ll be short a port with the 4-Port Junction B. If you have the space the cylindrical 6-Port Junction B from the XTR Di2 external mount internal battery holder will be an option.
Thanks ST brains trust. You have hit the nail on the head. I had figured the new junction box would just function as a satellite of some description but as you all say, you cannot have two Junction A’s, I will have to figure out the wiring to make this work, hopefully not too tricky to find the correct Junction B box to make it all work.
If you are replacing a 5-Port Junction A you’ll be short a port with the 4-Port Junction B. If you have the space the cylindrical 6-Port Junction B from the XTR Di2 external mount internal battery holder will be an option.
The above link is what is referred to earlier and exactly what I need. I don’t think I will be short a port at the moment…will hopefully get some parts together tomorrow if I can escape work for an hour or so. A good job for New Years day…
Do you know if the 6 port junction B can be had separately?
I ended with 2x 4 port junction B in my tririg alpha X in order to solve the exact same problem as the OP. It works well and fits easily, but I’m just wondering about this 6 port B that I didn’t know until this post.
Do you know if the 6 port junction B can be had separately?
I ended with 2x 4 port junction B in my tririg alpha X in order to solve the exact same problem as the OP. It works well and fits easily, but I’m just wondering about this 6 port B that I didn’t know until this post.
Shimano always seems to be bad about offering small parts separately. I have not seen this Junction B offered on its own. With a lot tri installations out there I’m surprised they haven’t offered a B equivalent of the 5 port Junction A.
I had my bars set up just like yours before finding the battery holder Junction. It fit fine in my Zipp Vuka Stealth, but is fairly large diameter and may not fit very tight spaces. I imagine there are cases where two 4 Port Junction B’s and a shit e-tube connection wire could be stacked slightly more compact.
Two Junction B’s and a connection wire approach the price of the battery holder kit so if it works for your bars it is a simpler install. I was able to buy these fairly cheap online, but with Shimano cracking down on the UK and European sellers it is harder to find them. That’s also my main complaint with Shimano making this change - most US retailers don’t come close to carrying the full range of Di2 products:(
Thanks ST brains trust. You have hit the nail on the head. I had figured the new junction box would just function as a satellite of some description but as you all say, you cannot have two Junction A’s, I will have to figure out the wiring to make this work, hopefully not too tricky to find the correct Junction B box to make it all work.
If you are replacing a 5-Port Junction A you’ll be short a port with the 4-Port Junction B. If you have the space the cylindrical 6-Port Junction B from the XTR Di2 external mount internal battery holder will be an option.
The above link is what is referred to earlier and exactly what I need. I don’t think I will be short a port at the moment…will hopefully get some parts together tomorrow if I can escape work for an hour or so. A good job for New Years day…
Yes he did a good job of documenting this option. This came after I found the 6 Port Junction B option for a couple of tri builds. I mentioned the port shortage because you said you were using old parts.
Exxxviii used newer Shimano single button shifters for his build. These don’t have pigtail wires coming out of shifters so you can use the e-tube y cable if they are long enough for your install. This cuts out one junction B port.
If you are using shifters with pigtails then you can’t use the y cable directly. You could use it with inline 2 Port Junction B’s but this will add up in cost and you may have trouble routing things in the base bar.
As long as you plan it out ahead of time there are lots of Di2 installation options.
As many B boxes or no B boxes will work.