Di2 Wireless Unit Install Location
 

I first installed the Shimano EW WU111 wireless unit in the stokers seat tube where the battery is, then in the captains bottom bracket down tube area where there is a connector to put the EWWU in-line. I am getting intermittent, mostly no signal to my Garmin 1030 plus head unit. My theory is the EWWU is either too far away or too shielded in titanium and carbon tubes to communicate well.

Sensing I need to install it forward at the captains cockpit I now envision the EWWU inside a handlebar end.

My questions for the forum are: 1.) Do you concur with my theory that the EWWU is too far, too shielded ? and 2.) Can I wire the EWWU in a loop from the ST-9070-L shifter Di2 leads, one wire out to the EWWU inside the handlebar end tube, and another wire back to the ST ? My left shifter has (3) leads, only one being used from the SC-M9050 junction box. From what I've seen and heard, the EWWU can be installed anywhere in-line and it will be recognized and work. I dont know if this loop idea counts as in-line or not. If not I'll get a longer wire from the SC-MT800 juction to the EWWU then to the ST, creating a true in-line scenario. Di2 wires are over $20 ea, I'd like to not buy one if I don't have too.

Thanks !

Just went through this process with our bike. I had hoped to install the unit in the handlebar end, but the openings in my bar weren't large enough to accommodate the Di2 wire. My mechanic simply tied it to the A junction, which sits out in the open anyway. FWIW I have the unit installed in the seat tube of my carbon road bike, and have never experienced a signal drop.

Mine are located in the downtubes above the BB in both Di2 equipped bikes...but we don't have the XT Di2 handlebar mounted System Info Display.

Since you're using SC-MT800 as Junction A, which is ANT+ and BT capable, the D-Fly (EW-WU111) won't work.

Note#4 in the Shimano compatibility chart, on page 1 at the linked PDF, states "The system accepts just 1 unit with wireless chip. (doesn't work if plural units with wireless chip are connected)."

Remove the D-Fly, your problems should clear right up.

Recommend setting it up as close to your computer as possible. I have mine right by my stem mounted junction box and it sits nice and clean under my computer. Never had an issue of dropouts. If you have to buy an extra E-Tube cable in order to mount it inline up front, do so.

"Since you're using SC-MT800 as Junction A, which is ANT+ and BT capable, the D-Fly (EW-WU111) won't work."

Astute observation and thank you for this. I now see that in the compatibility chart. Since my D-Fly buttons sometimes work, especially in the shop when testing after installation, it caused me to review my setup and model numbers. I realize I made a pertinent error in stating my junction A was the SC-MT800. In fact I have the older SC-M9050, which from what I can tell does not have the BT. I should be more careful when stating facts. Sorry to throw you of the scent.

As you and jadocs both noted, this will be my next move, placing the wireless unit in the open near the A junction. Easy to do and eliminates any argument for interference. More clutter up there where I have so much stuff already but what's one more ?

As far as tucking it into the handlebar end, I can defer that as a future project when bar tape is to be replaced. As I've seen in a YouTube video, to route wires I was going to drill a hole into the underside of the bars, about 3" away from the end. My know-nothing logic says I don't put much weight load at or below this point so am not risking a handlebar failure by doing this.

The EW WU111 on our Macchiatto (aluminum frame) is installed in the stoker seat tube below the battery and has performed flawlessly. You may want to verify all drivers are up to date, as out of date drivers can cause weird behavior. Just a data point.

Good luck!

Slightly different, but related question: My bike has the wireless unit installed in the stoker seat tube underneath the battery, although we are not using any wireless capability at present - i.e. no Garmin. It also has a Shimano Information Display which supposedly also has wireless capability. The Info Display was added to replace the A junction under the stem. I've been told that the system won't work if there are two wireless-capable nodes in the system, and yet it seems to work just fine.
True or false?
I suspect that the real answer is that the system will shift just fine, but will have trouble connecting wirelessly to a laptop or other Bluetooth device.

Well... it depends.
There are three (mtb) displays out there

• SC-MT800 (with BluetoothLE / ANT)
• SC-M9051 (with BluetoothLE / ANT)
• SC-M9050 (without any wireless connectivity)

Shimano does indeed state that you can have a maximum of one wireless capable unit installed.
If the M9050 is installed on your bike then I would expect everything to work just fine.

Even if you have one of the other units, I'm not sure what would happen if BLE / ANT were disabled on one of the units.. The system may still function.. I have never tried :).. I do have an SC-MT800 and EW-WU111 here, so maybe I will try that soon..

Terry, This is GREAT information! As much as I've poked around on Shimano's website, it completely escaped me that there might be three versions of the thing. But here's the question: How do I tell which unit I have installed?
Thanks for your insights...very helpful.

Well.. they all look similar, but every Di2 component has its model code written on it somewhere.
The MT800 is the XT version, M9051 the XTR version. Functionality-wise they're identical, but the case is slightly different.

M9050 is relatively old and I'm not sure what it looks like. There are a lot of images on google, but they all look similar to me ;-).

Either way, I would probably connect the bike to a windows PC, run E-Tube Project and let that tell me what component is installed.

Yep, I've discovered the wonders of E-Tube Project! It told me two interesting pieces of information: 1) It confirmed that our info display is the SC-MT800, and 2) it informed that in fact we don't have a separate wireless unit installed. That clears up the mystery about how come it is that our bike seems to work with two wireless units installed...it doesn't!
I also learned something else I hadn't known: that there is a another set of switches built in to the brake levers that I had not known existed. But the best part is that I was able to re-configure the set of switches to behave in what is (for me) a rational way. The default behavior just made no sense to me at all.
For those who are new to this (as I am), there are some valuable tidbits of info that may help you. One is that you can use the battery charger to connect your bike to your PC and you can run E-Tube Project from there.
The other thing I've learned is that Shimano's documentation sucks eggs, at least as far as downloading, installing, and using E-Tube goes. In hindsight, it all makes sense, but if it's your first time through...
Terry, thank you very much for helping me through this. Life is much better now.

Hah, no problem! Since we're talking about how the Shimano documentation is a bit lacking.. I've actually written something about getting started here: https://bettershifting.com/di2-for-d...to-di2-manual/

:)
(Suggestions / comments are always appreciated)

They're updating E-Tube Project (pc) October 13 by the way!

That's a good start! But since it's such a complex subject with so many variables (old or new battery, differences between Shimano gruppos, road vs mtb, etc), I'd suggest expanding what you have and breaking it down accordingly.
Your writeup refers to using the Info Display for MTB, but I use it on my road bike...why limit it to MTB?
It would be great to address my particular bugaboo (this go round...) i.e., how to find and download the E-Tube Project software (both on a PC and on a cell phone), and a one sentence description of the difference between E_Tube Project and E-Tube Ride (I stumbled across both when trying to figure out "E-Tube" and was lost until I understood the difference applications and how they are used). In other words, a birds' eye orientation to DI-2.
I greatly appreciate what you're trying to do ... it's badly needed. Need any help?

Makes sense! Thanks! I'm thinking there could be something on finding the software, what to use it for and similar. Perhaps Software "hub" pages that explain the basics and link to the relevant articles... we'll see.

I'm currently awaiting the new E-Tube Project "launch" next week.. when that happens I suspect I'll have to rewrite most of the E-Tube project pages (at least partially) - they're changing the way it looks to be more inline with the new mobile app.
See this video for example:
After that I think my main challenge will be how to display all the information in a way that people can actually find it (there are a lot more pages linked further down on the homepage for example).

I'll also add something on the displays to the respective 'component' pages on the site, making it clear that they can be used on any Di2 bike.

I think the most help I need is ideas and knowing what people need to learn / figure out.. Most of it is so familiar to me that some of these things are hard to think of until I spot them on a forum like this :).

(sorry for hijacking the thread ;))

I'm in the process of upgrading one of my tandems to Di2. I have etap on the other so we'll see which I like more. Your site has been really helpful, so thank you. I found your site early on and for whatever reason google directs me to your site when I'm looking for the compatibility guide so still go through your site to get to the shimano compatibility guide.

Great resource on Di2! Thank you for posting.

It's worth noting that the EW-WU111 unit does NOT need to be installed inline, so if you have a spare Di2 port on a junction or box you can use that with just one end of the wireless unit. I just tried it and it works.

Yep!. Mine is installed in the left handlebar drop, connected to a spare port on the shifter :)

Thanks for the useful Di2 tips. We're planning to upgrade from Ultegra 6870 Di2 to the new 12sp Ultegra R8100. Should the Bluetooth receiver on the RD-8150 rear derailleur work reliably on a longer tandem frame? We prefer to avoid a wired connection through the boomtube.

Interesting! I haven't thought of that.

I'm not sure, to be honest. I had an R9200 bike here last week, but didn't check the max range. I'll do some digging tomorrow.. if I find anything I'll let you know ;-)

The Bluetooth range should be ample, but I don't have a R8100 or R9200 on hand to check. I'm waiting for the Ultegra group to be available in Spring.

For those with internal wiring and a junction A at the bar end the distance from the A to B junction on most tandems is too long for the longest di2 wire. Putting the wireless unit inside the bar, between the A and B junctions makes it possible to reach with the longest di2 wire. And it put the Bluetooth up front close to the computer or your phone.