Installation Guide: Wireless Unit / D-fly (EW-WU111)

Updated September 12, 2023 by BetterShifting Terry

The Shimano EW-WU111 and EW-WU101 bring bluetooth/ANT+ connectivity to road and gravel bikes. In this guide I’ll help you install the EW-WU111 Wireless Unit.

Where on the bike?

The EW-WU111 Wireless Unit is a small, inline component. You could, in theory, install it anywhere. Shimano have a couple of recommendations regarding the location of the Wireless Unit.

  • Install it near the front of the bicycle to ensure a good signal between the Wireless Unit and bicycle computer.
  • Install the Wireless Unit outside the frame
  • Do not install it on the side of the bicycle. If you do, it could get damaged in a crash or when the bicycle tips over.

Note that while Shimano strongly recommends you install it outside the frame, I haven't ever experienced problems with installing the unit in a seat post, handlebar or frame. Just be aware that this is not the Shimano way and you may experience a weak signal, depending on the structure and density of your frame or handlebars.

I have installed the Wireless Unit in my handlebars, tucked away in one of the drops. This makes the bike look a bit cleaner – and I like clean looking bikes.


Because the EW-WU111 is an inline component you can place it virtually anywhere. I will show you the most common choices. Note that if you already have an inline 2-port junction (EW-JC200) installed on your bike then you could replace that with the EW-WU111. They are roughly the same size and shape and doing it this way saves you from having to buy an electric wire.

Before the electric wire enters the frame

Most older 11-speed bikes feature a below-the-stem Junction A (SM-EW90). Newer 11-speed bikes usually have the bar-end junction hidden in the handlebars. In both these cases it is a good idea to put the Wireless Unit inline – right before the electric wire enters the frame.

EW-WU111 Wireless Unit wiring

The Junction A or the Y-connector cable (both colored yellow) connects both shifters. You connect the Wireless Unit (colored blue) to either component using a short electric wire. Then connect the other end of the Wireless Unit to the electric wire entering the frame.

The shortest electric wire you can get is 150mm long and Shimano make them in 50mm increments, all the way up to 1600mm. Measure the distance to make sure you order the correct length.

Underneath the handlebar tape

Another way to install the Wireless Unit would be underneath the handlebar tape. I do not recommend this method, but I’ve seen people do this.

If you’d like to try this method you’ll need quite thick handlebar tape and put the Wireless Unit somewhere your hands won’t touch. The Wireless Unit may seem small and slim, but it’s actually about the same size as a barrel adjuster and big enough to be in the way if placed in the wrong spot.

As for connecting it to the rest of the system, you can run a short electric wire from the shift lever to the Wireless Unit . The D-fly has two ports, but you are not required to connect both of them.

Hidden in the handlebars

My favorite position for the Wireless Unit is hidden away somewhere in the handlebars. If your bike has the bar-end junction EW-RS910 installed this is easy – just take one of the junction box wires out and use a 150mm electric wire to install the Wireless Unit.

Note that while this is an inline unit, you do not have to connect both ends. It is perfectly fine to just use one side of the EW-WU111, as shown in the image above. Be sure to connect a dummy plug to the unused end though.

Alternatively, run an electric wire from either shift lever into the handlebars and connect the Wireless Unit that way. Some things to keep in mind:

  • Make sure the Wireless Unit can’t rattle around your handlebars. Wrap it in foam, tape or anything else you can think of to prevent it from making noise as you ride.
  • Some handlebars allow you to easily run electric wires inside them. Some don’t. Your mileage may vary when attempting this method.

Shane Miller / GPLama did a nice video on tidying up his Giant, hiding the Wireless Unit in the handlebar nicely and also connecting the SW-R600 Di2 climbing shifter:

About that firmware update Depending on when your Wireless Unit was manufactured you may be forced to update its firmware before you can use it. There seem to be two versions out there:

  • A recent version with updated firmware. You can update this unit and change its settings using E-Tube for Windows.
  • An older version that cannot be ‘seen’ or updated in E-Tube until it has been updated using the mobile app.

Now.. if you have the second of these two you’ll know because it cannot be used until its firmware has been updated using the mobile app. This process can fail. If it does your bike will not respond and you’ll have to follow these steps to recover it.

When you use the mobile app to connect to the Wireless Unit for the first time it will ask you to change the passkey. You do not have to. You can press the ‘X‘ or Cancel.

If you do change the passkey it is very important to delete the connection information from your phone.

  • Tap the menu icon at the top right of E-Tube Project
  • Select “Disconnect BluetoothLE” from the menu
  • You can now close the app
  • Go to your phone’s bluetooth device list and ‘forget‘ the EW-WU111 / EW-WU101

These steps are necessary because the software does not store the new passkey on your phone, but rather caches the old passkey. Forgetting your Wireless Unit from the phone’s Bluetooth device list fixes this.

Know a better method? Having problems?

The methods mentioned on this page are not the only ways to install the Wireless Unit , but they are the most common. Of course each bike and rider are unique, so these methods may not work for you.

I'd love to hear your feedback, ideas and comments. Send me a message and I’ll get back to you as soon as I can.

BetterShifting Terry

About the Author - BetterShifting Terry

I enjoy playing with bike tech - both bike building and wheel building, bike maintenance and of course, Di2. Besides writing content and working on the technical side of BetterShifting, I also work as a Software Developer in The Netherlands. Read more on the About this site page.

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