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Installing Shimano D-Fly Internally

Installing Shimano D-Fly Internally

Shimano introduced their D-Fly (SM-EWW01) wireless Ant+ Communication device in March. The D-Fly allows wireless data transmission between your Ant+ computer (usually Garmin) and your Di2 bike. It is helpful in showing remaining battery life and current gear selection. Shimano’s official position is that the D-Fly unit must be installed outside of the frame, but we have been getting excellent results installing it inside of the top tube on Carbon bikes. Here’s how we do it:



1. Plug in an appropriate size Di2 E-Tube wire into your D-Fly unit. For this bike, we are using a 300mm wire.


2. Remove your fork and headset. You may let the handlebar and fork hang from the bike, no need to remove the brake cables.


3. Remove the frame grommet and unplug the Di2 Wire that exits the frame and enters the junction box.


4. Feed this wire through the top of your head tube.


5. Plug in your D-Fly unit and feed the new wire out of the Di2 port in your frame.


6. You’ll have to find a way to keep the unit from rattling inside the frame. We prefer the “zip tie spider” method.


7. Push the unit into the headtube and back into the top tube.


8. Make sure the unit is pushed back far enough to not interfere with the headset or fork steerer tube.


9. Final check to make sure wires and zip ties do not interfere.


10. Re-install your fork and plug your new wire into the junction box.


At this point the D-Fly unit is installed. You will need to update your Shimano Di2 firmware with E-Tube Project software and the SM-PCE1 to gain full functionality of your new wireless transmitter!

1669917_607356996005637_1313261899_oNicholas Moroder is the everyday face of Belgainwerkx. He has been wrenching on bikes for 10 years and is a Certified Retul University fitter. He’s the kind of guy who can tell you what tire is best for your wet rides, or what brake pads will make your rims last the longest. He manages the service, product , fitting, and day-to-day operation of the shop.


  1. Hi, could you elaborate on the zip tie spider method to prevent rattling please? I would like to know if this method is effective in preventing rattles and also on how to do this, thanks!

  2. I have just mounted mine in the seat tube, wired between the battery and junction box b. Might not work on all frames but works a treat on my tarmac sl4

    • Any idea if it would work as well if mounted in a titanium tube ?

    • I do have as well in the seat, however, now with the Garmin edge 820 it looses connection in a BMC Teammachine SLR01 permanently (dropping out), and I wanna try this here to see whether works better doe to closer proximity to the Garmin unit. Fingers crossed as I do have a 30mm cable left in the BMC Granfondo GF01 Seat post which I could swap as interestingly there are not the same drop outs with the Garmin unit. Mhmmmm.

  3. Time to find a new bike shop. This works with any e-Tube Di2 group.

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