With Great Power Comes Great Complexity


I recently posted about my experience with SRAM’s ETAP system. It doesn’t have much by way of optionality. You click, it shifts. It will display current gear selection on an ANT+ device, and that’s about it. There is apparently a wireless communication protocol for firmware updates via a USB dongle, but SRAM has yet to issue any updates, so I’m just assuming that functionality really exists.

Anyway my friend Dan, AKA 6-0, just got a Canyon with the newest Ultegra Di2 groupset. Talk about feature-packed. It can be set up for manual, semi-synchro, or full-synchro modes. It will transmit to your display unit (Garmin et al) current gear selection, battery condition, and even a signal when it is about to change chainrings, because, yes, in Synchro mode it will change chainrings if required to get to the “next gear”.

(But as far as I know there is still no way to turn off the lockout of the last two cogs while on the small chainring, except to lie about your chainring sizes.)

With so much optionality, it behooved (behove?) Shimano to design a connection to smartphones to make configuration changes, and sure enough they did. There is even a plug-in device to upgrade older Di2 to the new capability. But setup of all the wires and signals is apparently not exactly intuitive.

Dan, being the thoughtful guy he is, wrote out some tips and hints on the setup process, including some really useful links to YouTube videos, etc. So without further ado, here are Dan’s Esoteric Observations On:



28 JUNE 2018

By Dan Denham

This guide is intended to assist persons who have Shimano Di2 shift systems that are capable of communicating with bike computers via ANT+ and Bluetooth to smart devices.  This requires the system to have Shimano [smart] batteries such as those found in the new Ultegra 8000 Di2 group set and the Dura-Ace 9100 group set.  These may be internal or external to the bike frame.  For Bluetooth communication, older Di2 systems must have their batteries upgraded to Shimano smart batteries, and install a small “D-Fly” ANT+/BT LE wireless unit in order to communicate with handheld smart devices (see Final Note at the bottom).  Communicating with bike computers enables the rider to view various data fields related to the status of gearing, shift mode, and battery condition.  The Di2 system can also be periodically and temporarily connected via Bluetooth LE (herein also referred to as Bluetooth, BT LE, or BT) to easily update firmware or make programming changes to shifting methods and to button functions.

This guide is not intended to explain the numerous ways that Di2 wiring configurations and connections may be made.  For that, the reader should consult the User Manual or Dealer’s Manual for Di2 shift system which is readily available online at Shimano’s website (see reference below).

From reading user reviews (and by personal experience), connecting a smart device to Di2 for the initial connection has a high probability of failing during the initial firmware update.  At this point, the Di2 system is likely to be unresponsive (“bricked”) and can only be restored by connecting with a PC and running the E-TUBE program.


  • Shimano Di2 Groupset – any generation
  • Shimano Smart Battery BT-DN110 (internal) or BM-DN100 (external)
  • Wireless Unit – recommend “D-Fly” Bluetooth LE / ANT+ capable unit EW-WU111 (connection ports on opposite ends) or EW-WU101 (connection ports on same end).
  • You will need an extra connection wire to insert the wireless unit into the system. Use the length appropriate to where the unit is installed.  150mm is the shortest available.
  • Cheap ($4-$7) Shimano TL-EW02 tool recommended to avoid damaging connectors.
  • Shimano USB unit and cable (Di2 battery charger SM-BCR2 or SM-PCE1 PC interface device) to connect the Di2 group set to PC computer. These connect to the Junction A box charging port and are only required to set up the system the very first time.  They are not needed again if you plan on connecting via a Bluetooth smart device thereafter.
  • E-TUBE Project program for PC. For smart phones and tablets, download and install respective E-TUBE apps (see References below).


  • Install Di2 System Required items listed above, as needed. There are various ways to install them.  Refer to appropriate manuals, diagrams, or YouTube videos for installing them.
  • Ensure that the Di2 battery has sufficient charge prior to initial connection, especially new bikes and batteries.
  • Ensure that the PC desktop will not accidentally lose power or shut down during initial connection. A PC laptop with a fully charged battery is better.
  • Download and install the E-TUBE program to the PC.
  • Ensure that the initial connection to Di2 is performed where the PC has a strong wireless signal and it is connected to the web. It will check online to find the latest firmware versions of all Di2 components and download newer versions if available.


  1. Install D-Fly wireless unit (and smart battery if necessary) in/on bicycle.
  2. Connect bike computer to the Di2 system via ANT+ to add Di2 communication between the two.
  3. Connect PC to the Di2 system via the E-TUBE Project program and run the program to view and make desired changes to Di2 gearing, shift speed, BT passkey, etc.
  4. Disconnect E-TUBE Project program via the program menu choice to turn off the Di2 system BT signal.
  5. Connect smart device wirelessly to the Di2 system via the E-TUBE app for it to view and make changes.
  6. Disconnect the smart device through the app settings as in Step 4 above. The shifters will not respond if the app and BT are still connected.  Leaving BT on in the Di2 system rapidly drains the Di2 battery.


When installing the wireless unit, do not complete the tie-down or closing up the access point until you have successfully communicated with your bike computer.  You will have to disconnect the unit and reconnect it to complete the process (according to the User’s Manual for the EW-WU111 unit).

  1. After installing the wireless D-Fly unit to the Di2 system, put your bike computer into connection mode in the same way you did to recognize other ANT+ components such as speed and cadence sensors. Let your computer search for the Di2 device and then add it to your bike computer’s list of connected ANT+ components.  You may wish to check data fields on your bike computer at this point if you have any set up.
  2. You may need to disconnect and reconnect the battery to complete the setup if you do not see any data. If you have an external battery, remove it and reinstall it.  If you have an internal battery, disconnect the wireless unit from the system (at both of its ends to ensure that it is not still connected to the battery).  Wait a few moments and reconnect it.  Wait about 30 seconds for the wireless unit to begin transmitting again.  Note:  It may also take this long for you to see Di2 data fields populate when you start a new ride.
  3. You may finish physical tie-down or mounting at this point since you should not have to make further disconnections to the wireless unit. Or you may wish to finish this after making BT LE connections to smart devices.


It is highly recommended that you make your very first connection using a PC and the PC E-TUBE program before connecting with BT using a smart phone or tablet.  If you make the initial connection with a BT-connected smart device, it often fails while updating the firmware of the individual Di2 components.  Since the PC is hard-wired to your Di2 system and there is no passkey, PIN, or code required to make the connection, there is little likelihood of failure during the initial connection setup process.  The PC program also allows you to set the BT passkey that you can use later with smart devices.  If you make the initial connection with a smart device, you will enter the default 000000 BT passkey, change it to a new one, update or attempt to update firmware, forget the BT device, connect and enter the new passkey, while risking failure and “bricking” the Di2 system.

  1. Connect your PC to the bicycle’s Di2 system with either an SM-BCR2 or SM-PCE1 to an SM-JC40/JC41 Junction A box through its charging port and a USB port on the PC, or an unused port on one of your Di2 system components.  If you have an Ultegra 8000 Di2 system with a Junction A, connect your battery charger (SM-BCR2) cable in the charging port of the Junction A (SM-JC41) and the other end into a USB port on the PC.  Other setups may require you to find an unused port on one of your Di2 components to connect an SM-PCE1 to.
  2. Run the E-TUBE Project program to update firmware and change other settings such as BT passkey code to a personal one. Note:  Each Di2 component has its own firmware version.  It may take a few minutes to check and update all components.  This allows the user to employ various vintage Di2 components (“Frankenstein” setup) and still work.  However, note the battery and wireless component requirements above for ANT+ and BT connectivity.  Shimano says that all Di2 components should work except the earliest generation.  Shimano has a compatibility chart on its E-TUBE Project website (see References below).
  3. Disconnect the program using the appropriate menu item. You should now be able to connect via smart device BT connection.  See Step 4 for this.
  4. To make a BT connection with a smart device (phone or tablet), ensure that its BT mode is turned on, start the E-TUBE app, and press the button on the Junction A box for about 1 second or until you see alternating red and green LEDs flash. The app will search until it finds the bike’s Di2 BT wireless signal and asks for the passkey.  Enter the passkey you set up in Step 2 above.  If you failed to set up a new passkey while running the program from a PC, the passkey will still be the default 000000.  Enter that number.  The app should ask you to set a new passkey.  After setting the new passkey, disconnecting BT and closing the app, go to your smart device’s settings and forget the E-TUBE Project Di2 device since that is the only way to get rid of the default passkey on your smart device.  Start the app again, press the Junction A button until its red and green LED lights alternate flashing, let the app find the E-TUBE Di2 system, and enter the new passkey.  BE SURE TO DISCONNECT THE SMART DEVICE FROM THE Di2 SYSTEM THROUGH THE APP AND CLOSE THE APP.  THE DI2 SHIFTERS WILL NOT WORK WHILE CONNECTED AND BATTERY DRAINAGE WILL BE ACCELERATED.


It is advisable to read all component manuals, user reviews, and watch videos on YouTube to educate yourself on installation, troubleshooting, and programming of Di2 wireless components and bike computers.  The wireless unit will work with Garmin, Wahoo, and perhaps other BT-capable bike computers.  Please confirm that your bike computer will work with ANT+ Di2 before purchasing a wireless unit.

  • Installing EW-WU111 to Canyon Aeroad 2018 This YouTube video shows how to install the transmitter inside the bottom bracket area of the bike on a Canyon Aeroad (Canyon Ultimate and Endurace Di2 bikes are wired the same).  Please read the comments to the video since complications can arise fishing out the junction box as well as how to upgrade the firmware and reset the Di2 system after installing the transmitter.  You will need snap ring pliers ($5 at Harbor Freight) to remove the plastic cover and a hook or needle nose pliers to fish out the Junction B box from the down tube.  You should also use the small plastic TL-EW02 Shimano tool to break and make electrical connections.
  • E-TUBE Project main page for PCs and Smart Devices on the web. You can also download the PC program here:  http://e-tubeproject.shimano.com/?lang=en
  • Best price on EW-WU111 and extension wire is at JensenUSA.com. The length of extension wire depends on where you place or mount the wireless unit and where the battery is located if you place it inside your frame.  The cheap TL-EW02 tool from Amazon for 2-day delivery (as Prime member).
  • Excellent webpage with instructions and links to other sites with documentation: https://bikepost.cc/d/55-shimano-di2-ew-wu111-e-tube-and-d-fly-wireless-module-review
  • Shimano’s website for technical manuals: http://si.shimano.com/#/
  • Shimano Dealer’s manual for the Ultegra R8050 series: http://si.shimano.com/pdfs/dm/DM-R8050-03-ENG.pdf
  • Most detailed article on Di2 setup, by Lennard Zinn: http://www.velonews.com/2017/10/bikes-and-tech/technical-faq-di2-synchro-shift-garmin-connection_450045
  • Read reviews on the EW-WU111 on Amazon.com for discussion regarding installation and troubleshooting.
  • Watch other videos on YouTube to see how to program for full synchronous shifting (using rear shifter), continuous shifting, programing shifters and hidden buttons, and connecting to bike computers.


FINAL NOTE:  I find the term “D-Fly” is confusing to me.  I ask the question, is D-Fly the wireless unit, a bike computer that can communicate wirelessly with Di2, or is it simply the capability to communicate wirelessly between Di2 and a bicycle computer.  It seems to depend on who is writing the article or manual.  I find it best just to refer to the specific components being used, i.e., the wireless unit, the bike computer, ANT+/BT capable, etc.