1. Hello
    Is it possible to run 11 speed with internal battery, EW90, RD6870 and FD6770


  2. No, both your deraillers need to be 6870

  3. Great site – new to Di2 and have 6770 setup but want to add hydraulic discs.
    Have purchased ST-R785 levers, but when connected do not operate either of the derailleurs.
    AFAIK the original 6770 has never been updated, any ideas what the problem may be?

    1. Author

      As it says in the article, make sure all of your firmware is updated to the latest version when adding new components.

  4. Hi can you advise on my di2 system. It doesn’t look like the 5 pins old generation . It has 4 pins in the rear d and 4 holes on the cable end

    1. Your Dura Ace 7970 system has connections with 4 pins going to the FD & RD, 5 pins going to the junction up front.

  5. Hello Carlton. Thanks for all those precious informations. I got now all necessary parts to convert my bike to Ultegra di2.
    Nevertheless, I got a question regarding cables length. In the dealer manual, there is informations about maximal length. For exemple, it is said to not go beyond 1500mm when adding a+c, where a is the cable length between the battery (DN110 for me) and the B junction and c is the FD to B junction length.

    What’s happen if those length limits are not & using greater total length ? Does it matters really ?

    Thanks for your help.

    Regards from Marseille, in Provence, south-est of France

    1. Author

      In my experience, if you go a bit longer than that, there is no issue. Longer cables barely add any additional resistance, well within the design margins.

  6. Can you reprogram 7970 10 speed levers to work with a 9070 rear and front mech

      1. Hi Carlton
        Hope you’re well When ichecking battery life on dura ace 9070
        Di2 both green and red lighs light up
        Why is that
        Please assist
        Reg Martin

  7. Hi, looking at the comments it appears that the conversation is about Di2 road equipment but my question is about MTB but I hope you will indulge me. I purchased a RD-M9050, SW-M9050, SC-M9050, SM-JC41 and assorted EW-SD50 cables to connect them according to the manual. I have a SM-BMR1 battery mount and SM-BTR1 battery. After connecting the components there is no shifting. Double checked the connections and tried again and still nothing. Having read some of the comments it appears that the SC-M9050 may not work with the SM-BMR1 battery mount. So, I switched to a SM-EW67A hoping to eliminate using the SC-M9050. The LED on the SM-EW67A goes green for a few seconds but still no shifting. Is there something else that I need to check or something I’m missing? I have a Fox iCD suspension installed and it works fine with the battery system and cables. Any help would be greatly appreciated. Thanks

  8. Hi, can you please confirm the exact name of the front and rear derailleur for the Dura- Ace9070 version?
    I thought they were FD-9070 and RD-9070 but, instead, you call them FD-9770 and RD-9770.
    Just want to make sure that was a typo and not different version/models.


  9. I just installed Di2 on my bike.

    BT-DN110-1 battery, ST-6870 brakes, FD and RD 6870 derailleurs, SM-JC41 4 port distribution, SM-EW90-B 5 port front hub, SM-BCR2 charger.

    Don’t have EW-WU101 yet.

    System works ok except the battery died twice after a day with a full charge.

    System isn’t accessible through app until WU101 shows up. The PC app shows all pieces “green” but won’t load.



  10. Can I run a 11/32 cassette on dura ace di2 if I change the rear derailure to Ultgrea 6870 di2 with a medium cage.
    I currently run dura ace di2 on a compact 50/34 with a 12/28 cassette
    Please advise.

    1. The other possibility is it may work with your 9070. It depends on droput design and you’d probly have to back off the B-tension scew all the way and make sure you use enough chain length or avoid the big big combo. My frame builder told me it would work on my bike and it did. Same 50/34 front 11/32 rear Di2.

  11. Hi, is it possible to run wireless unit EW-WU101 with the internal battery SM-BTR2?

    1. Author

      Ian, please read the section above: “EW-WU101 and EW-WU111 ANT and Bluetooth Wireless Broadcast Modules”

  12. Hello –

    Wonderful site and information.

    My wife and I have two bikes with Di2 installed. We’d like to be able to get them to connect with our Garmin Edge 1000 and also to be able to program synchronous shifting (if we can without replacing everything. Everything is currently working great, we’d just like the added features and functions. (ANT communications with Garmin and BT with iPad).

    One is configured with a flat bar and XTR shifters. Here’s the rundown:

    FD-6870 Front
    RD-6870GS – Rear Long cage
    SB-XTR-SW-M9050 Left
    SB-XTR-SW-M9050 Right
    SC-M9050 Display Unit (Junction box and charging port)
    SM-BTR2 Internal Battery
    Misc cables to put it together.

    Can we simply swap out the SC-M9050 with a SC-MT800?

    Second configuration is a drop bar road bike with all Ultegra and the added SC-M9050 display. Here’s the list:

    FD-6870 Front
    RD-6870GS – Rear Long cage
    ST-R785R Right Shift/Brake 11SP Hydraulic
    ST-R785L Left Shift/Brake 11SP Hydraulic
    SC-M9050 Display Unit (Junction box and charging port)
    SM-BTR2 Internal Battery
    Misc cables to put it together.

    Same question – can we simply swap the SC-M9050 for the SC-MT800 to get the extra functions?

    Thanks for your help.

  13. Hi,

    I am about to replace my Ultegra mechanical drive train to Ultegra Di2 for my road bike:

    here are my components:

    1) FD-6870
    2) RD-6870
    3) ST-6870 shifters
    4) BT-DN110 internal battery
    5) JC-41 internal Junction B
    6) SM-MT800 junction A
    7) Required amount of Di2 wire and gronets

    I am intending to use the MT-800 display as junction A instead of the SM-EW90-A.

    The display will look more elegant and will give the status of the internal battery, I prefer this to the Sm-W90-A. Besides it will also communicate with my Garmin 810 through private ANT, I am told.

    Will the above configuration work and is there anything else that I need?

    Thanks and regards,


    1. Author

      I haven’t tried this exact setup, but it should work. Just be sure to install the latest firmware on all components for cross-compatibility.

  14. Hi Guys,

    I’m collecting bits to build up a winter/gravel bike in the Spring. Basically planning on a drop barred bike with MTB (clutch) derailleurs. I’ve mistakenly (stupidly) bought a second hand XTR Di2 groupset that included a triple front mech (didn’t even cross my mind, i didn’t think they made them anymore!). Firstly, does anyone know if you can programme, or maybe using the limit screws to effectively make it a double? (I know i’m clutching at straws here!).

    Also, if I need to buy another front mech, does the XT front mech work ok with an XTR rear? I assume it does, but havent really heard of anyone mixing 6870 with 9070 on the road side either.

    As always, a great Di2 resource.

    Thanks in advance

  15. I have a cycle fitted with Di2 9070 series and would like upgrade to full SHIMANO Synchronized Shift system, could tell me what items I need to do the upgrade

  16. I have a 2013 Giant Defy with Ultegra Di2 (6770 group) with external battery mount. I called Shimano because I wanted to add Bluetooth capability. My goal was to set things up so I could use the new IPAD app. to diagnose and tune the system. I bought the EW-WU101 and the BM-DN100 but then read that the SM-EW67A front wiring unit (the one I have) might not be compatible with those two units. You say that those two parts cannot be used with the SM-EW67 Front A Junction. Shimano says the SM-EW67 Front A Junction is compatible with the two wireless units and will work. I have called them twice and each time they say the same thing. If you would, can you tell me why you say it will not work? Has that been your experience? Also, might the software have been updated to allow all three units to work together? Thank you in advance for your help. jimg

    1. Hi James,

      Have you considered replacing the front junction with the SC-MT800 display? This has three ports that can replace the junction, has a port for charging the system and provides the bluetooth and Ant communications capabilities.

    2. Author

      Jim, Shimano engineers provided the info at the product introduction event saying that the SM-EW67A would not work. But this is Shimano we’re talking about, who are notorious for confusing and conflicting information. So does it “kinda” not work (i.e. no way to charge the battery)…or “completely” not work (no shifting)? It’s hard to say until you try it and find out. And it’s not at all surprising to get different answers from different Shimano employees. Please let us know what you find.

      1. So at first I thought I would blow off the wireless conversion effort because of the cost> Now I am re-thinking things and was wondering, if I buy the SM-EW90a front junction box and use it in conjunction with the other with EW-WU101 and the BM-DN100, do you think the system will work then?

        1. What is your current BM-DN100 firmware?
          Can you update BM-DN100 firmware it to latest 4.0.4 via iPad or PC ?

  17. Hi Carlton,
    I am building a R9150 setup and am looking for information about the EW-WU111 Comms Module. Does it matter where it goes in the system, obviously better to know prior to purchasing the cables so I can get the correct lengths?
    Thanks in advance for any reply.

    1. Author

      It doesn’t matter where it goes. Any place in the system is fine. I have mine in the seat post tube with the internal battery.

      1. Thanks for the reply, yeah the seatpost tube is my favoured option too as if I put it next to the battery I can get access to it should I need to without removing the bottom bracket

  18. Hi. Does anyone know if there is an incompatibility problem between Shimano Alfine Di2 and the external battery SM-BTR1? Because I just bought an external battery and support and it does not work! But works properly with the internal battery SM-BTR2.
    Do I have to update the new battery?

  19. In order to add synchro shift capability to a 6870 system with an external battery, is it just the *mount* that has to be upgraded to the BM-DN100, the *battery* itself or both? The article seems to indicate that it’s just the mount, but a lot of the comments refer to needing a new battery so I’m not clear as to which piece carries the upgraded components.

    1. The battery mount hast the firmware battery is just power.

  20. SM-BMR1 – this mount can only be updated via SM-PCE1.
    SM-BMR2 – is it possible update this mount using SM-BCR2 ?
    BM-DN100 – is it possible update this mount using SM-BCR2 (or bluetooth)?

    1. also there is this comment that contradicts FAQ info:

      2016-September-26 at 4:37 am
      “I want to update this reply:… I think you misunderstood about the BCR2 NOT being able to update the external mounts (BMR1&BMR2) they can both be updated using the BCR2, it is not necessary to us a PCE1, although you could use both. I just updated a BMR1 to 3.0.10 using the BCR2, no problem whatsoever. you cannot charge through the external mounts but you can do all the updated.”

      1. I think your misunderstand is in the context of the thread, The question was in regards to a hacked BCR2 being used to update the mounts… its cant be done with a hacked BCR2 because of the EW67 in the system, it can be done if an EW90 in being used. Or perhaps its not clear to me what you are trying to say (?)

  21. James Grant
    2016-December-09 at 12:42 pm

    So I installed the SM-EW90a junction box along with the BM-DN-100 and the and the EW-WU101. But I can’t get the Bluetooth to pair with the junction box. The rest of my setup is 6770 Di2. I press the button on the bottom of the junction box like they say (for a second or so) and I get no indicator light signal at all. The system shifts fine and the Di2 information shows on my Garmin, but I can’t update firmware because the system won’t pair with my IPAD. Any ideas?

    1. Author

      You most likely need to update the firmware using a PC and cable first. The junction probably doesn’t contain firmware that is compatible with the Bluetooth module. Subsequent firmware update could be done over Bluetooth, but not the initial compatibility update.

  22. hello i have one groupe ultegra DI2 6770 with jonction SM EW 67 A
    can you tell me if i can upgrade my groupe on 6870 DI2 11 speed with SM EW 67 jonction and FD RD 6870 derailleurs only with upgrade etube ?

  23. Synchronized shifting for road di2 is released. Does somebody try it ? How to choose between map 1 & map 2 on the bike ? Mine is 6870 Ultegra di2 with DN-110 battery & the bluetooth adapter. All firmware up to date but no PC at home to test for the moment.

    1. I have the same setup you do and did all the Dec 9 updates. The PC E-tube program still says I need to update the FD/RD also, but no updates are available. I hear people with 9070 say the same. So it seems that synchro shifting is not quite ready yet.

      1. Author

        Thanks for the update. That’s disappointing. I have the upgrade components ready to install but haven’t installed them yet.

      2. Confirmed. Mine also says “the settings cannot be read from the following unit(s) because the firmware is not the latest version”. Update the firmware…FD-9070/RD-9070…

  24. Hi, I’m using Dura Ace 9070 and lately have problem with Junction A Led. The green and red led will light whenever I long press the shifter button and after checking battery status by pressing 2 shifter buttons.

    What’s the problem? Thanks.

  25. I have a Specialized Roubaix with (firmware level):

    Shimano Di2 SM-BMR2 Battery Mount SM-BMR2 (3.0.10)
    Shimano E-Tube Di2 Cockpit Junction Box SM-EW90-A (3.0.4)
    Shimano Ultegra FD-6870 Di2 Road bike Derailleur FD-6870 (2.6.2)
    Shimano Ultegra RD-6870-GS Di2 2x11s 28-32 RD-6870-GS (2.6.3)
    Shimano ST-R785 Di2 Hydraulic STI Lever, Left ST-R785-L (3.0.0)
    Shimano ST-R785 Di2 Hydraulic STI Lever, Right ST-R785-R (3.0.0)
    Shimano Di2 D-Fly Wireless Transmitter SM-EWW01 (3.0.6)

    To get Synchro Shift:
    What will I need besides upgrading the External Battery Mount with BM-DN100?
    Will the Wireless Transmitter SM-EWW01 be superfluous?

  26. Hi I recently bought a Di2 Ultegra 6870 Bike. It has only the STI levers and no SPrinter or TT switches.
    I updated the Firmware to the latest version: DN110@4.2.5, EW-90-A@3.0.4, Shifters@3.0.0; RD-6870-SS@2.6.3, FD-6870@2.6.2
    When I try to load the presets on the bike by read presets from the bike, I get an error:
    Error occurred while reading he settings.
    Also when I try to set up Synchronized shifting, I get error message: “The settings cannot be read because the firmware is not the latest version. Update the firmware of the units to be read. FD-6870 and RD 6870-SS”
    But I have just updated the latest firmware.

    1. The firmware for the FD amd RD synchro shift is not out yet even if you have the new battery or new battery holder which is also required even though Etube seems to be ready to configure it.

      1. Thanks.. The automatic setting up of Synchroshift fails with the said message. But I can set up a preset manually into a file with the Syncroshift options and save it to my desktop. I did not want to write the preset .ini file to the bike. I was not sure if it would go thru.
        Do u think writing the preset (.ini) file with symchroshift information might mess up the system.

        1. Not sure? Interesting thought and I’m no expert on that approach. But it might be risky if something in the firmware is also required for good synchro shift. That said, people have written hacked synchro shift stuff for Road Di2. I’m hoping the read deal comes out soon.

          1. Ken S writes that people have written hacked synchro shift stuff for road Di2. Can he point us to a link? I want to have the front shift buttons also shift the rear. I do not want what XTR synchro shift does which is have the rear shift buttons shift the front when the computer thinks it knows better than the rider.

          2. Also, the Shift Mode button is available via the SHimano MTB component: “XTR DI2 SC-M9050 DIGITAL DISPLAY UNIT”. But on a Ultegra 6870 Di2 system, I am not sure how you can switch between the 2 shift modes. or for that matter even cancel out of Syncro Shift mode to manual.
            Otherwise, if the system runs out of battery and Front Derailleur shifting is not happening, you are stuck.
            Perhaps, I am guessing the shift mode may have to be controlled via a ANT/Bluetooth interface like a Garmin 520.
            Any thoughts…

  27. Thanks Carlton et al for all of this.

    Is there a way to search the comments on this website?

    Can a sprinter switch on the rear shifter be set to shift to larger rear cogs, instead of the normal sprint goal of smaller rear cogs?

    Are there any known issues of upgrading software to the latest version on 1 or 2 year old 9070/6870 seatpost battery setups? I hate to upgrade and then see things not work; yes I am in the computer industry and this does happen.

    Is there a description somewhere of how road synchro shift is intended to work when it comes out? i.e. will it shift the rear when I shift the front? Or will it be like XTR and shift the front when I hit the rear shifter and the rear derailleur is near the limit? I want the former, not the latter. I have ideas on how to accomplish this with a PIC but I would prefer to ride the bike than go through the design and experimentation.

    Does anyone know of a similar site for Campy EPS?

    And does anyone know of Campy EPS shifters hacked for 9070 di2? Yes I can imagine how to do it, but reading about it would help.

    1. Not sure I should post the links on references to hacking Di2 for road synchro shift. Check fairwheel bikes and Arts cyclery for a start but I cant find the referenced road test I had remembered. Most all synchro shift hacks involved using XTR front der but I though I remembered one that didnt. Don’t know how it will work but hopefully its customizable for preference and hopefully its not vapor ware. It’s late in releasing.

      I have updated the previous internal battery version with no issues. E-tube knows which model you have and should load the right firmware….

      After riding Campy for decades I reluctantly went to Shimano when I decided to go to eshifting due to a left arm/hand issue. Would have liked to have stuck with Campy for looks but Di2 just seemed more refined overall and liked the cabling better and it seemed more likely that Shimano would come out with Synchro.

      1. The only synchro hack I have seen is the fairwheelbikes pre-eTube one where they built their own control module and programmed it themselves.

        I have not seen anything on Art’s cyclery, but my search techniques are not great.

        The XTR front is not easy to mount on a road bike with road chainring positions. One person did it on a Calfee tandem by modifying the mount.

    2. http://bike.shimano.com/content/sac-bike/en/home/news-and-info/news/shimano-introduces-new-dura-ace-r9100-road-components–integrate.html

      “In addition to traditional “Full” Synchro Shift, riders can optionally select “Semi” Synchro Shift. This intuitive new mode automatically reacts when the rider shifts from one chainring to another, automatically shifting the rear derailleur to minimize the gear step, thus preserving the rider’s rhythm.”

      That’s what Shimano is saying. If and when it will happen remains to be seen.

  28. I have suffered 2 SM-BMR2 unit failures. It looks like corrosion at the point where the e-wire connects. Is it possible to clean the terminal and avoid replacing the unit?

  29. I have an Ultra di2 setup with SM-BTR2 battery, SM-EW90-A junction, and 6870 shifter components. I charged the battery and updated to the latest firmware. The only firmware change was to update the SM-EW90-A junction to 3.0.4.

    Now, when I check the battery charge, the charge light goes solid green as it should, but then it momentarily goes off and comes back on simultaneously with the red trim light for a few seconds, then they both go out.

    The shifters seem to operate normally, and no lights come on when shifting.

    Has anyone seen the lights behave like this and have a fix?

    Also, not sure if it’s related, but when I try to customize the shift mode setting, I get an error that says: Settings cannot be read from the following units because the firmware is not the current version. Update the firmware of the units to be read. FD-6870, RD-6870-GS. However, the firmware is already updated.

    Any suggestions?

    1. Author

      You’ll need to wait until newer firmware is released. The current version isn’t fully compatible with the newer components.

      1. I guess they messed up by allowing the newer component to update with incompatible firmware.

        Do you know if the components will still operate properly? If not, is there a way to revert back to the previous firmware?

        1. Author

          Everything should still operate normally but you won’t get new features. Instructions for reverting to previous versions of firmware are in the post above but I don’t recommend it.

    2. hello
      Exactly the same thing since updating SM-EW90-A. Green and red after… RD-9700 and FD-9700 are waiting for a new firmware update !!
      I have also the same eroor message.
      But all is working fine !!

  30. Hello,

    I have a question?
    How can i extend the new dura ace di2 rd – r9150 11 speed (maximum cassette = 11-30) with a larger cassette 11-32 or 11-36 or even 11-40?
    Sorry for my English.


    Jean-Paul Milissen

    1. Wolf Tooth Components makes a device that lowers the rear derailleur on the frame.specifically for their large rear cogs. I have not tried it. The shifting at the small rear cog probably suffers.

    2. I think an 11-40 is going over the top but try Fit Werx in Vermont, ‘http://fitwerx.com/index.php?s=K-Edge’, for options on the long cage derailleur conversion. Haven’t needed them myself but believe they could help you. Good luck.

    3. Hello Jean

      I have 2 bikes, both with 6870 Ultegra and both running a 32-11 cassette. On one bike I have the long cage and on the other I have the short cage. I cannot fell any noticeable difference in shifting long or short cage – Many have done the same also with good results and my best guess is that you could go at least to a 36-11 with a 6870 long cage version.

      1. Shimano 6870 SS Short Cage version is compatible with a 28T Cog,
        Shimano 6870 GS Long Cage version is compatible with a 32T Cog.

        You must have two long cage derailleurs.

        1. I’ve used my ten speed Ultegra 6770 Di2 with a 32T cog. It works fine. I borrowed my girlfriends wheel once in the Pyrenees forgetting that it had a bigger cassette.

          Not sure if it would affect the longevity, but it works.

        2. Sorry but I do know exactly what I have and Google is your friend, do a search with “6870 short cage + 32-11” and you will find that many many other bikers have done the same with very good results. Shimano is very conservative with their specifications and I’m indeed running a 6870 short cage together with a 32-11 cassette with good shifting. Sometimes you will have to install a longer bolt for adjusting the RD a bit further away from the biggest cog but that was not even needed in my case.

    4. I have a similar set up but with Ultegra 10 speed. I changed the RD cage from short to an XT medium but reused the RD and changed the largest cassette cog to Wolf 40 on a Deore XT 11-36. Also removed the 11 cog and substituted an Absolute Black lock ring. I added a Wolf Tooth components “Road Link” to get clearance between the large cog and the jockey wheel. Works fine in my system.
      Using 11 speed you have an additional problem of finding a road specific cassette with 32, 40, or 42 cogs. The spacing on the 11 speed road and mountain cassettes are not the same.

  31. Hi, thank you for the very good information about the DI2 system.
    I´m running a 6770 setup. Is it correct, that if I change to the BM-DN100 I can use synchro shift?
    Thank you for your help

    1. Author

      Theoretically, that is correct. But Shinano has not yet released firmware to make it work. So we won’t know for certain until they do.

  32. I don’t see this answered above but perhaps you can answer it directly. I want to put together a 11 speed di2 system with a large cassette range. This will go on a Domane SL frame
    I am leaning right now to having di2 xt components for the RD, braze on FD, front display/junction A, B internal junction. Battery will likely be internal but according to the Trek dealer an external battery and mount, mounted internally in the down tube can be used. Brifters would be Ultegra 6870. Cassette will be xt. Crank will be Ultegra compact. Cassette will be 11-40 or 42 xt.
    The frame comes with a braze on FD mount. Will this be compatible with a braze on FD ie are the offsets the same comparing road and mtn? I know the arc of the cage will be different but I can overcome this.
    I will likely have to add a Wolf Tooth Road Link.
    Which battery and mount would you recommend?

    1. Author

      Jack, this is a very complicated setup, beyond the typical amounts of variation. I’m not sure about the front derailleur; a road version would be much more likely to be compatible. Definitely go with an internal battery due to easier recharging.

    2. The XTR front derailleur expects to use mountain chainring spacing from the frame. One person has used an XTR triple front derailleur on a Calfee tandem and a Lightning triple crank with road triple chainrings. That involved custom machining of the Problem Solvers front derailleur mount to move the derailleur closer to the frame. My guess is the XTR double front derailleur will be very hard to mount on a Domane frame and shift a road crankset. It will be hard to mount to a road braze-on unless someone has made a mount that I have not seen yet.


      Modifying the road rear derailleur and dropout for wide range is probably easier than modifying the mountain front derailleur. I would be happy to read about successful front derailleur hacks and modifications.

  33. Are there any considerations for internally routed Di2 on a travel bike with S&S couplers? Is it as easy as positioning the B junction box at the downtube coupling point and providing 20cm or so of slack in the downtube wires?

    1. You got it. It is that easy. Junction box just making sure you have enough cable for reach and ease.

  34. Is my SM-EW67A, SM-BMR2 compatible with the EW-WU101 I just bought? Nothing operates since I put on the D-Fly

    1. Make sure all your firmware is updated. I use the same equipement and all works fine.

  35. Hi, I am sorry I made a mistake. I use an EW90 B 5 port junction. So now I am not sure your setup will work after a firmware updat. Sorry for my mistake.

  36. Sorry if this question has already been answered but if the junction box A is inside the frame, how does one check the battery level easily and then charge the internal battery easily

    1. Easy? Depends on where it is in the frame. You will need to see the junction box to check the battery level, an to charge through it. You can modify the charger by splicing a connector to the input of the charger. Just buy any length cable, cut it and splice it to the charger, than buy a JC41 junction box, than you can charge through the RD cable, by plugging the spliced cable from the charger and the RD cable into the JC41 junction that way you can charge the batter without removing the EW90 junction. Than just recharge every 2-3-4 or so months depending on how much you ride. Or move the EW90 outside the frame.

      1. Or just get the d fly wireless adapter and view the state of charge on your Garmin.

        1. That looks pretty cool. Are you able to charge the battery through the d-fly? Is there a list of Garmin products that are compatible? I use the 920XT

          1. You would still need a charge connection as described before. The 920xt with latest firmware is compatible and will display battery levels and gear position.

  37. Great site, you’ve clearly invested a lot of time understanding and documenting the Shimano Di2 system. Thank you!

    I just purchased a Specialized Venge Pro with Di2. I added D-Fly EW-WU101 with the expectation of being able to 1) Add the push buttons to switch screens and do the Lap function on my cyclo-computer (Wahoo ELEMNT); 2)
    Add sprint shifters; 3) Re-program the front shifter to reverse the buttons, and 4) Be able to check the Di2 battery level. My LBS tells me that the Di2 / R785 hydraulic shifters on my bike aren’t able to do any of that. So my D-Fly investment currently only shows what gear I’m in. That’s nice, but not on my list of expected and desired functions.

    Your site says both “ST-R785 Hydraulic Road Dual Control Brake Levers/Shifters: These hydraulic road shifters are compatible with both the climbing and sprint shifters.” but also says “They do not have the special wiring port required for the SW-R610 Sprint Shifters and a SM-EW90-B 5-port junction A is required to use the SW-R600 climbing shifter.”

    A few questions I’m hoping you can help me with regarding the R785 / Di2 system:
    — Can sprint shifters be added to my system?
    — Can buttons be added to operate the cyclo-computer? Possibly the SM-EW90-B 5-port junction A — could those buttons be re-programmed to operate the computer instead of being climbing shifters?
    — Is it possible to check the Di2 battery level from my cyclo-computer?
    — Is it possible to reprogram the front shifter to reverse the buttons?

    Thanks for the help!

  38. Hi, thanks for the great reference site. I am about to replace my internal battery with the new Bluetooth model, and also add the new Bluetooth d-fly, to my 6870 setup. I’d like to check the firmware and make sure that it is all recognised by the software, using the sm-bcr1, before I do the install (which will require removal of the bb etc). Can I disconnect everything at the A-Junction, and plug the battery (and then d-fly) directly into the A-Junction? Solely for the purpose of this initial firmware check. Thanks! Grant

    1. Never mind, I went ahead and did it, of course it worked just fine 🙂

  39. I have a complete 6770 system with external battery, including the original E67A junction box. A couple months ago I about gave up after getting different error messages while trying to do a firmware update. But geez, it’s such a slick system I cringe when I think about putting out big bucks for dura ace mechanical. Anyway, my system shifts fine, but after changing the battery (thought it was dead) and plugging the bike into the SM-PCE1, E-tube kept telling me it couldn’t see the battery, or any other component, except for the right hand shifter. It showed as green on the screen (Interestingly enough, that was where I had plugged in the SM-PE1) and I could play with its settings.

    Somewhere I read that I should plug the SM-PCE1 into the battery directly, do an update on that, and then I could plug it into any of the other components with a spare port, and I could update the rest of the system components that way. Anybody know if this is the way to go about getting the firmware update done. Help, anyone!

    1. Well actually that is the correct way. First update the battery module, than the other components. Since you have the PCE1 you can update each component one at a time directualy using the PCE1. All the settings for the shifting are stored in the battery module so you can do the customization with just that one comment or st the system level. You likely have a BMR1 module and that’s the reason you ha e had this issue.

  40. Great place for information in everything Di2 – thanks so much.

    Yesterday I connected my Di2 system to do an update (SC-MT800, BT-DN110, FD/RD 6870, ST-R785 R/L). I wanted an update to the BN and SC-MT800 as it had a battery drain issue that was fixed in a firmware update.

    I connected my SM-BCR2 to the computer and the system found an update for it and installed it. Since then, it will no longer charge my system when connected to the SC-MT800 port. I have another SM-BCR2 that I am reluctant to connect to the computer at this point as it is the only method of charging for my bike. How do I un-install or fix the SM-BCR2?


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