Shimano Ultegra and Dura-Ace Di2 Electronic Shifting – Everything You Need to Know

Shimano Di2 Groupset

Shimano Di2 Time Trial Triathlon GroupsetI learned quite a bit about Shimano Di2 when I installed one of the first available Time Trial/Triathlon groupsets on my Cervelo P2. I’ve subsequently answered a lot of questions on forums and article comments, and elsewhere. In doing so, I realized that people have a lot of questions about Di2 and the answers are difficult to find. This lead me to create this article, to consolidate everything I know and have been asked into one location so people can find answers. If you can’t find what you’re looking for below, please leave a comment and I’ll do my best to help.

Index: There’s lots of info in this post, so here’s an Index to help you find specific sections:

System Overview: Shimano Di2 Dura-Ace 9150 and 9070 and Ultegra 6770 and 6870

The second generation Shimano Ultegra 6770/6870 and Dura-Ace 9070  “E-Tube” electronic bicycle shifting systems consist of battery-powered electric derailleurs activated by handlebar mounted push buttons.  Power and shift commands are sent via a 2-wire CAN (Controller Area Network) datalink contained within a single cable housing. This design has several advantages over conventional mechanical shifting systems, the most notable of which are:

  1. Extremely low shifting effort, which generally results in more frequent shifts and therefore better gear ratio selection.
  2. Greatly improved shift quality, especially for the front derailleur chainrings, allowing shifting under full power with almost no chance of a dropped chain.
  3. Shifting is available at multiple positions on the handlebars, for example, at the end of the time trial aero bars, on the brake levers, up to in climbing position, and down low the sprint position.
  4. Automatic trimming of the front derailleur position as the rear derailleur moves back and forth between the smaller and bigger gears.  This eliminates unintended contact (and noise) between the front derailleur and the chain.
  5. Lighter weight vs. equivalent mechanical system. The Shimano Dura-Ace Di2 9070 electronic groupset with internal battery weighs 2047 grams; the Shimano Dura-Ace 9000 mechanical groupset weighs 2074 grams (27 grams more than Di2.)
  6. Multi-Shift: Pressing and holding a rear derailleur shift button results in shifts through multiple gears. The rate of shifts can be configured using the PC computer interface cable and the free Shimano E-tube Project software.
  7. Synchronized Shifting: Starting with Dura-Ace 9150, automated Synchronized Sifting of the front derailleur is an option. Two SHIMANO Synchronized Shift modes will be available:
    • Full SHIMANO Synchronized Shift: the front derailleur reacts based on the rear derailleur’s shift action. This essentially means that, when activated, there is no need for two separate shifters to control front and rear derailleurs, the two buttons on one shifter will control both derailleurs.
    • Semi SHIMANO Synchronized Shift mode: the rear derailleur reacts based on the front derailleur’s shift action, shifting to the next most appropriate rear gear when the rider makes a front shift.
    • R9120, R9170 – syncroshift enabled with firmware 3.2.0 or newer
    • 6870, 9070 – syncroshift enabled with firmware 3.2.1 or newer
    • 6770 – no syncroshift firmware update will be offered

Shimano_di2_Wire_ComparisonHistoric Info on the older first generation 5-wire Shimano Dura-Ace Di2 DA-7970 system and how it compares to the new E-tube 2-wire system:

Released in 2009, the 7970 operated using a very basic 5-wire electronic system. Each shift button was connected to a different wire; shorting the specific wires together controlled the derailleur upshifts and downshifts. Because the first generation 7970 used completely different technologies than the newer 2-wire systems, none of the components are cross-compatible. At this point, Shimano is not expected to offer any updates or new components using the first generation 7970 architecture; everything from now on will be based on the newer 2-wire E-tube design. The second generation design offers several advantages, which include: 1) smaller wire size, smaller connector size, waterproof connectors; 2) all switches can be reconfigured in software to send upshift or downshift commands to either the front or rear derailleur; 3) firmware updates can add new features (such as multi-shift) and compatibility with new components.

Compatibility: Dura-Ace 9070 and Ultegra 6770 / 6870 (and old 5-conducter 7970)

The confusing naming system used by Shimano makes it difficult to figure out what each component is, much less what is compatible between systems. Here are some compatibility guidelines:

  • Nothing from the first generation (4-conductor / 5-conductor) Dura-Ace Di2 7970 system is compatible with any other newer system. It was replaced by the (2-conductor) E-tube systems. No parts are inter-operable between 7970 and any other Di2 System.
  • In general, every electronic Di2 component is compatible between the Ultegra 6770, 6870, and Dura-Ace 9070 systems (see exceptions below.) This means that all of the road bike Ultegra/Dura-Ace dual control brake levers/shifts, time trial shifters, and climbing shifters can be used with either Ultegra 6770/6870 or Dura-Ace 9070 front and rear derailleurs. Any of the Ultegra/Dura-Ace controllers (A Junctions) can be used with either system. All components use the same cables and connectors.
  • Firmware Update Required to Make Older Components Compatible with Newer Components: If you add a new component and it doesn’t work, update the firmware using the PC USB adapter and the Shimano E-tube Project Software for Windows.
  • Synchronized Shifting and Bluetooth Wireless Units can be added to all E-tube Ultegra and Dura-Ace systems but the battery has to be upgraded to the BT-DN110 Internal Battery or BM-DN100 External Battery Mount. To add Bluetooth capability, a EW-WU101 or EW-WU111 inline transmitter must be added to road bikes and for mountain bikes, the SC-MT800 or SC-M9051 display/transmitter unit must be added.
  • Compatibility Exceptions:
    • Note 1 – Sprint Shifter Exception: The Sprint Shifter is the only exception for shifter incompatibility. It has a different wiring connector (and internal components) that can only plug into a unique/dedicated third port on the Dura-Ace ST-9070 Dual Control Brake Levers/Shifters and also the ST-6870 Levers. There is no sprint shifter port on the ST-R785 Hydraulic Levers.
    • Note 2 – Can’t mix 10-speed/11-speed front/rear Derailleurs: It is no longer possible to use a 10-speed front derailleur with an 11-speed rear derailleur (and 11-speed front with 10-speed rear.) See note farther below to read the history on this if you want all the messy details.
    • Note 3 – Front A junction and Internal Battery: Since the February 2015 firmware update, the older SM-EW67-A-E Front Junction A is no longer compatible with the BTR2 Internal Battery because it does not have the charging port to charge the internal battery. The SM-EW90 Front Junction (with integrated charging port) should be used instead. The SM-EW67 still works with the external battery.
    • Note 4 – Update the Firmware to make components compatible: If the firmware on all components is not updated to the latest version, some components may be not operate correctly with one another. So download the latest E-tube software and update everything and it should work.
    • Note 5 – All Shifters work with all 10-speed and/or 11-speed Rear Derailleurs: All of the shifters are compatible with either the 10-speed Ultegra 6770 or 11-speed Ultegra 6870/Dura-Ace 9070 systems as long as they all have the latest firmware. The rear derailleur is the only component that “knows” or “cares” how many rear gears are available. The shifters only send upshift/downshift commands and do not “know” or “care” which gear is currently selected and how many total gears there are.
    • Note 6 – SM-BTR1 External Battery and SM-BMR1 Mount firmware updates: The more expensive dedicate service tool (SM-PCE1 PC Interface) must be used to upgrade the firmware on the external battery/mount.The external battery and battery mount can not receive firmware upgrades via the SM-EW90 Front Junction A and the SM-BCR2 PC Interface/Battery Charger. (The SM-EW90 will work in a system with an external battery, but a firmware update can cause them to become incompatible until both are updated independently using the appropriate PC Interface and the Shimano E-Tube Project software.)
  • See the Shimano E-tube compatibility chart version 3.4.3 for more details

Compatibility: 11-Speed Rear Derailleur and 10-speed sprockets/wheels

The 11-speed Dura-Ace 9070 and Ultegra 6870 rear derailleurs are designed exclusively for 11-speed rear sprockets and 11-speed Front Derailleurs. Shimano does not provide a way to recalibrate/reprogram them for a 10-speed setup. The sprocket spacing is slightly smaller and the overall range of travel slightly longer on 11-speed systems. If you have 10-speed wheels and 10-speed sprockets, you should use the 10-speed RD-6770 rear derailleur and a 10-speed FD-6770 front derailleur.

Similarly, a 10-speed RD-6770 rear derailleur should not be used with 11-speed sprockets. There will be chatter in some gears, and there might be slow-shifts or self-shifts.

It doesn’t matter which shifters are used; the shifters send upshift/downshift commands regardless of which derailleur config is being used. Shifters do not “know” or “care” which gear is currently selected and how many total gears there are.

Front Chain Rings: In general, most any front chain rings will work, rigid forged rings work best with Di2 due to high front derailleur shift forces. Shimano chain rings tend to be the best, but most others work as well. A 10-speed specific or 11-speed specific chain should be used, but the differences between them are minimal and can generally be mixed/matched without issue.

How to convert “non-upgradeable 10-speed only” wheels such as Zipp 900/Sub9 Disc Wheels to 11-speed: “the spacing between a Campy 11 and Shimano 11 is close enough that you can use the cassettes interchangeably. If you get a Campy free hub body, the 2 shims (part# is on the Zipp website, just search for Campagnolo 11) and a Campy cassette and you’re ready to ride with all 11 cogs available to use.” via slowtwitch.com

But it’s an emergency and I need to use a 10-speed wheel. . . In emergency situations, 11-speed rear derailleurs can be used with 10-speed sprockets. There will probably be chatter in some gears, and there might be slow-shifts or self-shifts. To setup an 11-speed rear derailleur for a 10-speed sprocket setup, adjust the mechanical limit screw so that it can’t shift into the missing 11th sprocket position, then follow the rear derailleur adjustment procedures listed below.

Included for very motivated individuals only: 10-speed front derailleurs can be used with 11-speed rear derailleurs if the shifters and battery have firmware installed from E-tube software version 2.5.2 or earlier. Shimano disabled support for this 11-speed and 10-speed cross-matching with later firmware updates. For informational purposes only, the details of how to regain compatibility are detailed below.

  • Important Notice 2014-07-14: There is a compatibility issue with Shimano e-Tube software/firmware versions v2.6.0 and later that prevents 10-speed front derailleurs (FD-6770) from working with 11-speed rear derailleurs (RD-6870) and 11-speed front derailleurs (FD-6870) from working with 10-speed rear derailleurs (RD-6770).  DO NOT UPDATE FIRMWARE using Shimano e-Tube software v2.6.0 or later if you are mixing an FD-6770 front derailleur and a RD-6870 11-speed rear derailleur, or a FD-6870 with a RD-6770.
    • The problem component is the battery (external battery mounts SM-BMR1 and SM-BMR2, internal seat post battery  SM-BTR2.) If you keep battery firmware at v2.0.6 or earlier, the system will continue to function properly.  Shimano e-Tube Software v2.6.0 will update battery firmware to v3.0.5, and will not allow the RD-6870 to work with a FD-6770 setup.
    • If the battery firmware is updated to 3.0.5, it CAN NOT be rewritten back to the older version. You will need to need to replace a derailleur so that both are 6770 10-speed or so that that both are 6870 11-speed. (The other option is to get get a battery with the older firmware and never update it.)
    • Here’s a link to the “last known good version” of the Shimano e-Tube software to work with a mixed 10-speed/11-speed system: E-tube_Proj_V_2_5_2.zip Use this version and do not connect to the internet when using it so that E-tube can’t check for updates when open.
    • To roll-back newer versions of battery and shifter firmware, install E-tube version 2.5.2 and made a copy of “C:\ProgramData\E-tube Project\FW” which has all the firmwares packaged in that version of E-tube. Next, install the latest version of E-tube. Then copy all the firmwares from the the 2.2.3 version back to the same location “C:\ProgramData\E-tube Project\FW” for the latest version (note: ProgramData is a hidden directory, click here for details on how to view it.). Next, the trick is to find the firmware you want to downgrade (pretty easy from the name and version in the file name), and then rename it to the same name as the latest version, but increment the last version digit by one. Then connect to the bike with E-tube (without an internet connection) and it will identify that a firmware upgrade is available for that component and allow you to do the firmware “upgrade” to the older version of firmware. Now exit E-tube and then rename the firmware file back to original to prevent the issue in future. E-tube will then try to upgrade again but just don’t let it do that. This should get a bike that did nothing (not even enter adjustment mode) to a fully working state by reverting the battery and shifters. Running latest firmware in derailleurs seems to be fine. (thanks to commenter vosadrain)
    • It will not be possible to charge the BTR2 internal battery using the BCR2 USB charger unless you also downgrade the firmware of the BCR2 USB charger as well.
    • Note however that latest E-tube software will say the setup is unsupported and will not allow programming. To do programming, disconnect the internal battery and connect a spare external battery. This allows making settings changes. To program the BTR2 itself, I just connect to the BTR2 by itself (no other components) and the E-tube software will allow firmware changes to it. Or try using the 2.5.2 version of E-tube.
    • Alternatively, buy a Di2DIY internal seat post battery kit and you will not have to go through the firmware downgrading. The kit makes it possible to run all components with the latest E-tube firmware. Also worth noting some firmware updates were done to fix power distribution errors in the FPGA’s that would allow the batteries to drain down when the bike was just sitting.

Checking Battery Charge Level:

A single battery charge should give at least 1500 miles of riding. Most riders will not need to charge the battery more than twice a year.

To check the battery charge remaining, press and hold any shifting switch for 0.5 seconds or more. The amount of battery charge remaining will be indicated by the light on Front Controller A Junction.

  • 100% remaining: Illuminates green (for 2 seconds)
  • 50% remaining: Flashes green (5 times)
  • 25% remaining: Illuminates red (for 2 seconds)
  • 0% remaining: Flashes red (5 times)

When the battery charge is low, first the front derailleur will stop operating, and then the rear derailleur will stop operating. When the battery charge has been fully spent, the derailleurs will be fixed at the last gear shifting position. If the battery indicator is illuminated red, it is recommended that you recharge the battery as soon as possible.

Adjusting the Rear Derailleur Trim:

If you switch between multiple rear wheels, it’s very likely that the sprockets on different wheels won’t be in exactly the same relative position to the rear derailleur, resulting in that annoying clicking sound as the chain makes contact with an adjacent sprocket. Follow the steps below to properly align the rear derailleur with the rear sprockets.

  1. Shift the rear derailleur to the 5th sprocket position. Press the button at the junction (A) of the SM-EW67-A-E until the red LED illuminates in order to switch to rear derailleur adjustment mode. Note that if you keep pressing the button after the red LED has illuminated, protection recovery operation will begin.
  2. If shifting switch is pressed once while the initial setting condition is active, the guide pulley will move one step toward the inside. If shifting switch (Y) is pressed once, the guide pulley will move one step toward the outside.
    • Note: The guide pulley can move 15 steps inward and 15 steps outward from the initial position, for a total of 31 positions.
    • Note: When adjusting, the guide pulley will overrun slightly and then move back in an exaggerated movement so that you can check the adjustment direction. When checking the positions of the guide pulley and the sprocket, check at the position where the guide pulley finally stops.
  3. While turning the front chainwheel, operate shifting switch to move the guide pulley toward the inside until the chain touches the 4th sprocket and makes a slight noise.
  4. Next, operate shifting switch 4 times to move the guide pulley toward the outside by 4 steps to the target position.
  5. Press the button at junction (A) until the red LED turns off in order to switch from rear derailleur adjustment mode to gear shifting mode. Shift to each gear and check that no noise is generated at any gear position. If fine adjustment is needed, switch back to adjustment mode and readjust the rear derailleur.
  6. Note: if you have customized your shifters and swapped buttons, this will change which shifter and buttons control the micro-adjustments. Also, if you hit the wrong buttons while trying to set the FD trim, you can actually alter the setup of your RD. Be certain that you’re hitting the correct adjustment buttons.
  7. If you have a Garmin or similar head unit and a SM-EWW01 ANT module, the display will automatically switch into derailleur trim display when you activate that mode (i.e. by pressing the button at the junction (A) of the SM-EW67-A-E.) It will give you the trim position in either + or – 12 positions. When switching wheels, simply take note which position suits which wheel/sprocket/trainer, and trim to that level each time you change. This removes the guesswork and makes changing from wheel to trainer simple.

Note on FD-6870 Front Derailleur Trim:

The FD-6870 trim adjustment effects the auto-trim positions. The adjustment feature is accessible via either the A-Junction box, or the “Front derailleur adjustment setting” in the e-tube software, and should be used only after you have already set the physical inner/outer limit screws. So for example, if the FD outer plate rubs the chain when using the 6th largest cog, you would want to adjust the FD trim outward a couple ticks. However, you can only perform this adjustment while in the big-ring/big-cog combination. Etube forces the derailleurs into this maximum cross-chained position, whereas during the manual method you must shift to these positions yourself. (Thanks to commenter Bryan B for the info.)

Dealer Manuals:

The dealer’s manuals contain the most detailed information available from Shimano. If you’re looking for detailed installation instructions, check here:

Shimano E-tube Project Configuration and Firmware Update Software for Windows:

Shimano E-tube Project Wireless for iOS and Android: Announced on April 15, 2016 but as of yet unreleased, these apps will allow configuration of shift profiles (multi-shift on/off, multi-shift delay between shifts, shifter button assignments) and firmware updates over Bluetooth. To function, a Shimano Di2 Bluetooth Adapter, such as the MT800 digital display, is required.

Shimano E-tube Project Windows PC Software: This free software is used to update the firmware of all components. It works with the SM-BCR2 Charger + USB Adapter and the SM-PCE1 Diagnostic Adapter. The software is used to change the configuration of each shift button / lever (any can be programmed to upshift or downshift either the front or the rear derailleur.) It can also be used to enable multi-shift (multi-shift is where the shifter is held and the rear derailleur shifts through multiple gears until the shifter is released.)  The delay between of the gear changes during multi-shifting can also be adjusted. The software is available from http://e-tubeproject.shimano.com/
Older versions of the e-tube software are available from these links: 2.5.2

PC & Mobile Interfaces, Chargers, and Software:

SM-BCR1 Battery Charger: This is used to charge the external battery. The part number for the battery charger wall cord is SM-BCC1.

SM-BCR2 Charging and PC Connection: for SM-EW90-A 3-port and SM-EW90-B 5-port A Junctions. This plugs into a special port on the side of the A junctions (which is covered by a rubber flap.) This adapter charges the internal battery when first plugged into the A junction; it must be powered by a standard USB Wall charger (such as that used for an Apple iPhone) or a PC that is powered-on. If the Shimano E-Tube Project Software is launched on the Windows PC with the SM-BCR2 attached, the SM-BCR2 will switch from charging mode to configuration mode. It must be detached from the computer and reattached to switch back to charging mode.

  • It takes about 2 hours to charge the internal battery.
  • Amber light=charging.
  • Light turns off when done.
  • If the Amber light does not come on when plugged in, this indicates battery is not discharged enough to charge.
  • Light flashing indicates something is wrong, like trying to charge a external battery through a BMR.

shimano_SM-BCR2_overview

Shimano_di2_junction_a_charger_pc_interface big
Junction A Charger Port and Charger/PC Diagnostic Cable

Hacking the SM-BCR2 to have a standard Di2 cable connector: If your 3-port or 5-port junction is inaccessible for charging, there is an alternative hack method to connect it to the system through a standard Di2 port. With basic soldering skills you can hack the BCR2 to be used with any setup. Buy any length EW-SD50 wire, cut off one end. Cut the wire on the output side of the BCR2. Splice the two wires together, so that the output wire of the BCR2 is now a standard Di2 connector.  The charger has an inner (white) and outer (shield) wire; connect the inner white wire to the  SD50 red wire; connect the charger outer shield wire to the SD50 black wire. You will then be able to plug the BCR2 into any Di2 port. Or use a SM-JC40 junction B and another length of EW-SD50 wire and go through the RD (by using the SM-JC40 to connect the rear derailleur, new output wire of the EW-SD50, and the wire that ordinarily connect the rest of the system to the rear derailleur.) Thanks to @Di2diy for the info.

SM-PCE1: This PC Configuration and Diagnostics adapter will not charge the internal battery. It offers the same configuration options as the SM-BCR2, but also add some advanced diagnostic and troubleshooting features that the SM-BCR2 does not have. It attaches to via the standard E-tube wire (just like the EW-SD50 cables) rather than to a dedicated port on the side of the front A junction.
shimano_SM-PCE1_overview

Bluetooth and E-tube Apps for Apple iOS and Android: Bluetooth wireless modules are available to allow system settings to be adjusted via the mobile applications that connect via Bluetooth Adapters.

Component Overview:

The confusing naming system used by Shimano makes it difficult to figure out what each component is, much less what it does and how it fits into an a complete Di2 system. Here’s an overview of all the major Ultegra and Dura-Ace Di2 components.

Dual Control Brake Levers/Shifters (a.k.a. Brifters):

ST-6770 Ultegra Road Dual Control Brake Levers/Shifters: The Ultegra version can be used with the climbing shifters. They are sold in in left/right pairs and are also available separately.
Shimano_ST-6700_Brake_Shift_Dual_Control

ST-9070 Dura-Ace Road Dual Control Brake Levers/Shifters: The main advantages these have over the ST-6770 version is slightly lighter weight and compatibility with the low-mount sprint shifters. As like the Ultegra version, they are compatible with the climbing shifters. They also have hidden button under the rubber hoods that can activate screen changes on cycling computers from Garmin, Magellan, Pioneer, and Shimano (Shimano SM-EWW01 ANT Wireless Broadcast Module required.)
Shimano_ST-9070_Brake_Shift_Dual_Control

ST-9071 Dura-Ace Time Trial/Triathlon Dual Control Brake Levers/Shifters: These levers provide shifting from the pursuit bar position on time trial bikes. There is no Ultegra option offered at this time. These are available as left/right pairs, or can be ordered separately. These do have a permanently attached wire with a male end for connection the the SM-EW90 front “A” junction. Combined weight both levers: 117 grams.
Shimano_ST-9071_with_wire

ST-R9160 (standard cable brakes) and ST-R9180 (hydraulic brakes) Time Trial Dual Control Brake Levels/Shifters: These are the lower-profile shifters offered with the newer Dura-Ace R9150 groupset.

ST-6871 Ultegra Time Trial/Triathlon Dual Control Brake Levers/Shifters: Ultegra version of the ST-9071 Dura-Ace shifters. Slightly heavier and much less expensive than the Dura-Ace version. Combined weight both levers: 142 grams.
shimano-st-6871-ultegra-di2

ST-R785 Hydraulic Road Dual Control Brake Levers/Shifters: These hydraulic road shifters are compatible with both the climbing and sprint shifters. These are compatible with the SM-RT99 centerlock 140mm and 160mm rotors and WH-RX31 wheelset (which as no standard rim brake track.) These require the BR-785 dual piston hydraulic disc calipers. 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.
shimano_st-r785 shimano_r785_br-r785_sm-rt99

ST-6870 Ultegra Road Dual Control Brake Levers/Shifters: These road shifters are compatible with both the climbing and sprint shifters.
shimano_ultegra_6870_st-6870

Dedicated Shifters:

SW-R671 Dura-Ace 2-Button Time Trial/Triathlon Bar End Shifters: These shifters are installed on the end of time trial aero bars. By default, the left shifter upshifts/downshifts the front derailleur; the right controls the rear derailleur. For both, the lower button upshifts into a harder gear and the upper button downshifts to an easier gear. This can be changed using the Shimano E-tube Project software; the functions of the left and right sifters can be switched with one another as well. These are available in pairs or separately.
Shimano_SW-R671_Bar_End_Shifter_Dual_Button

SW-9071 Dura-Ace 1-Button Time Trial/Triathlon Bar End Shifters: These shifters have only one button each and are intended to control only the rear derailleur, with one sending the upshift command and the other the downshift command. (I personally think this version is absolutely worthless. Why have 2 SW-9071 shifters at twice the price and twice the weight, when you can just buy a single SW-R671 Right shifter instead.)
Shimano_SW-9071_Bar_End_Shifter_Single_Button

SW-R600 Climbing/PAVE Shifter: This shifter is for road bikes and is mounted on the upper horizontal portion of the handlebar, or any other location comfortable for the rider. They can be used in addition to the Dual Control Brake Lever/Shifter, or can be used on their own by plugging directly into a SM-EW90-A 3-Port Junction or SM-EW90-B Dura-Ace 5-Port Junction.
Shimano_SW-R600-climbing-shifter

SW-R610 Dura-Ace Sprint Shifter: This is the only component using a unique wiring connector; it is only compatible with the ST-9070 Dura-Ace  and Ultegra ST-6870 Road Dual Control Brake Levers/Shifters. Unlike all of the other shifters, the sprint shifters do not contain a circuit board; they do not show up as components on the CAN bus network. Instead, the sprint shifters are simple momentary switches that activate the circuit board on the host Dual Control Brake Lever/Shifter. The host dual control lever is what sends the shift command. (Note: Any momentary switch can be attached to the sprint shifter port on the Dual Control Levers by splicing into a standard EW-SD50 wire to act as remote shifters.)
Shimano_SW-R610_Sprint_ShifterShimano_SW-R610_sprinter_shifter_mounted

Alfine SW-S705 Right Flat-Bar Shifter: Reported to work with other non-Alfine setups.
shimano_alfine_sw-s705

SW-R9160 Time Trial bar-end shifters (pair): These are-end shifters directly control the rear derailleur, with one for the upshfit and one for the downshift. The front derailleur is controlled automatically via automatic Synchronized Shifting. These shifters require the BT-DN110 Internal Battery for synchronized shifting.
shimano_sw-r9160_shifter

SW-R9150 Climbing shifters (pair): These tiny climbing shifters are about as small as the sprint shifters, but can be directly connected to a junction box and do not have to be connected as slave buttons to a brake/shift lever special port. They come with plastic mounts to make it easier to attach to bars beneath bar tape. They are ideal for synchronized shifting, with one controlling the upshifts and the other downshifts. These shifters require the BT-DN110 Internal Battery for synchronized shifting.


Front Derailleurs:

FD-6770: Ultegra Front Derailleur

FD-6870: Ultegra Front Derailleur, pretty much identical to the FD-6770 but with a slightly larger diameter adjusting screw (to better dissipate the shifting forces).
shimano_ultegra_6870_fd-6870

FD-9070: Dura-Ace Front Derailleur
FD-R9150: Dura-Ace Front Derailleur for 9150 systems; features slightly reduced weight vs. 9070.

Rear Derailleurs:

RD-6770: Ultegra 10-Speed Rear Derailleur, compatible with gears up to 28 teeth.

RD-6870: Ultegra 11-Speed Rear Derailleur, compatible with gears up to 32 teeth (for the GS version).
shimano_ultegra_6870_rd-6870

RD-9070: Dura-Ace 11-Speed Rear Derailleur, lighter weight version on which the RD-6870 is based.

RD-R9150: Dura-Ace 11-Speed Rear Derailleur with 30-tooth sprocket compatibility and modified “Shadow RD” geometry to keep the mechanism close to the rear wheel to help avoid damage in the event of an accident.

Alfine SG-S505 and SG-S705: The Shimano series targets comfort and urban bikes. It uses an 8-speed (505) or 11-speed (705) internal epicyclic rear hub. It is believed to be compatible with other Di2 ETube components but this has not been verified.
shimano-alfine-s705-di2-11-speed-internal-gear-32-hole-hub

Display / Wireless Communication:

SM-EWW01 ANT Wireless Broadcast Module: This module wirelessly broadcasts Di2 data (front and rear gear selection details, gear ratio, battery life) to a cycling computer using the ANT protocol. It is compatible with Dura-Ace 9070, Ultegra 6870 Di2 and Ultegra 6770 E-tube road shifting systems. SM-EWW01 plugs into the E-tube wiring system between existing components. It has an 2 wiring ports, so it can be connected between a front shifter and the Front Junction A, or at the rear derailleur (between rear derailleur and Etube wire.) It transmits through a proprietary private ANT wireless protocol, which may eventually become a standard public ANT+ protocol. It is powered by the same Di2 system battery. It is currently compatible with the Garmin Edge 1000, Mio 505, and the PRO SCIO cycling computers (with more to come.) The hidden buttons under the hoods of the 9070 shifter levers will switch screens on the cycling computer when paired with this module. It does not currently allow for shifting control from a cycling computer/device and it is not clear that this functionality will ever be offered. The SM-EWW01 is 38mm long, 25mm wide, 12.5mm high, and weighs less than 5 grams. It does not come with any wires; 1 wire would have to be added if adding this module to an existing Di2 system.
shimano_sm-eww01

EW-WU101 and EW-WU111 ANT and Bluetooth Wireless Broadcast Modules: These modules are similar to the SM-WEE01 but also include Bluetooth capabilities in addition to ANT capabilities. They require the BT-DN110 battery or the BM-DN100 Battery Mount and cannot be used with the SM-EW67 Front A Junction.

shimano_ew-wu111_ant_ble_wireless_unit

shimano_ew-wu101_ant_ble_wireless_unit
Shimano XT Bluetooth Wireless Required Components

SC705 Alfine Display Unit: This unit displays the battery level and the rear derailleur gear selection. It is powered by the system battery and has a port for the SM-BCR2 internal battery charger / USB diagnostic tool. It is primarily designed for Alfine systems (both 8 505-series and 11 speed 705-series). It is compatible with Ultegra and Dura-Ace Di2.
shimano_alfine_705_display_unit

MT800 Digital Display with Bluetooth: Primarily aimed at XT mountain bike applications, this display allows toggling between the 3 synchronized shift modes (where both derailleurs are intelligently coordinated in unison by one pair of buttons, so no need for discrete shifting of the front derailleur.) It also shows battery level, gear position, shift mode and FOX iRD suspension position. The Digital Display required the new BT-DN110 battery. Existing Di2 XT systems are upgradable to be compatible with the new digital display after battery upgrade and firmware upgrade. This display has 3-port Di2 Cable junction and charging port integrated into the back and serves as a Front A Junction.
Shimano mt800 Digital Display with Bluetooth

Batteries and Battery Mounts:

The batteries contain the main controllers for the system. It is therefore required to upgrade the battery to get features released in new versions of Di2 (such as Synchronized Shifting that automatically controls the front derailleur based on rear derailleur shifting.)

SM-BTR1 External Battery: This external battery must be used with the SM-BMR1 battery mount. It is removed from the mount and charged using a dedicated charger.
Shimano_SM-BTR1_external_battery

SM-BMR1 and SM-BMR2 External Battery Mount: This mount attached to bottle cage mount points or other dedicated frame mounts. It is available in  3 different mount lengths: -I (intermediate length), -S (short length), -L (long length). The SM-BMR2 is an updated version of the SM-BMR1.
Shimano_SM-BMR1_External_Battery_Mount

SM-BTR2 Internal Battery: This battery is typically mounted in the seat post or seat tube of the frame. It is charged by plugging the SM-BCR2 Charging Cable/PC Adapter into the SM-EW90-A or SM-EW90-B Front A junctions.
Shimano_SM-BTR2_Internal_Battery

BT-DN110 Internal Battery: This battery is required for Bluetooth wireless units and road groupset Synchronized Shifting functionality.
shimano_bt-dn110_internal_battery

BM-DN100 External Battery Mount: This battery is required for Bluetooth wireless units and road groupset Synchronized Shifting functionality.

Front A Junctions:

SM-EW67-A-E Ultegra 3-Cable Junction: This is the original front junction with 2 integrated cables to connect to the dual control brake lever/shifters. The male cable ends on this Front A Junction will not mate directly to the male cable ends on any of the Time Trial/Triathlon dual control brake shift levers or shifters; SM-JC41 Rear B Junctions can be used to connect this front A junction to TT/Triathlon shifters. This Junction works only with External Batteries, not Internal Batteries.
Shimano_SM-EW67-A-E_A_Junction

SM-EW90-A Dura-Ace 3-Port Junction: This front “A” junction is most commonly used in road bike setups. 2 ports connect to the dual control brake / shift levers; the third port is for the cable that leads to the bottom bracket junction.

Shimano_SM-EW90-A 3-port and Shimano_SM-EW90-B 5-port Front "A" Junctions
Shimano_SM-EW90-A 3-port and Shimano_SM-EW90-B 5-port Front “A” Junctions
Shimano_di2_junction_a_charger_pc_interface big
Junction A Charger Port and Charger/PC Diagnostic Cable

SM-EW90-B Dura-Ace 5-Port Junction: This front “A” junction is primarily used in the Time Trial / Triathlon setups. 2 of the port are for the brake/shifter dual control levers, 2 of the ports are for the aer0 bar bar-end shifters, and the 5th port is for the cable that runs to the bottom bracket (where the B junction joins the wires from the front A junction, front derailleur, rear derailleur, and battery.)
Shimano_SM-EW90-B_JunctionShimano_SM-EW90-B_Junction_bottomShimano_SM-EW90-B_Junction_all

EW-RS910 Internal Bar-end Junction: This junction is installed into the end of a bar or in a dedicated frame port. It facilitates internal cable routing.

Image source: http://www.matosvelo.fr/index.php?post/1912/le-groupe-shimano-dura-ace-r9100-officialise
Image source

B Junctions:

SM-JC41 Internal Junction: This version has the exact functionality as the SM-JC40 external version, but doesn’t have the mounting tab for being bolted to the bottom bracket or wrapping the extra cable lengths. It has 2 ports on one end and 2 on the other, making it more compact. In addition to being located at the bottom bracket to connect the A junction, battery, front derailleur, and rear derailleur, it can be used at the handle bars to join multiple shifters prior to being connected to the A Junction.
Shimano_SM-JC41_B_Junction

SM-JC40 External Junction: This version is intended to be attached to the frame using the bolt that is commonly located underneath the bottom bracket housing. This junction contains no electronics; it’s sole purpose is to join 4 connectors together, which are usually the wire from the front A junction, the battery, the front derailleur, and the rear derailleur. There are wire holders above the housing to capture the extra wire length by wrapping it back-and-forth.
Shimano_SM-JC40_external

Cables, Grommets, and Cable Remove/Install Tool:

EW-SD50 Cables: These cables connect the front A junction, the battery, the front derailleur, and the rear derailleur to the rear B junction, which is typically located near the bottom bracket (near the cranks.) These are available in lengths of 300mm, 350mm, 400mm, 500mm, 550mm, 600mm, 700mm, 750mm, 950mm, 1000mm, 1200mm, 1400mm.

SM-GM01 Grommet: These round grommets are used when drilling round holes for internal cable routing, or with existing round holes. The required hole diameter is 6mm (6mm  = .236 inches. Use a 7/32-inch drill bit and then “wallow-out” the hole to make it a little bigger; a 1/4-inch drill bit will work but is just slightly larger than necessary.)

SM-GM02 Grommet: These 7mm x 8mm oval shape grommets are used in some situations / frame designs.

Shimano TL-EW02 Ultegra DI2 E-Tube Tool: This tool is used to connect and disconnect the Etube wires. They are extremely difficult to connect/disconnect by hand, and pliers or other tools can damage the wires. Don’t get this confused with the TL-EW01 tool, which is for the older 5-wire 7970 cables. (My Dura-Ace TT Dual Control Levers came with one of these tools, but no other components did.)
shimano_tl-ew02_tool

Common Questions (via Shimano):

shimano_di2_faq1
shimano_di2_faq2
Note: it is not necessary to replace the FD from upgrading from 10-speed to 11-speed.

What Components do I need to put together my own Di2 system?

Because of the huge number and variety of components, it’s very difficult to figure out what is actually necessary and what is optional. So here is a list, for the setup I recommend: Ultegra 6870. It starts from the handlebars and works backwards. (This assumes both front and rear derailleurs, but you actually don’t have to have both; you can pick one or the other and only the corresponding front shifter to go along with it.)

  • Any Type of Shifters / Shift Buttons. The Dual Control Brake Levers/Shifters are not required. You can get the just the climbing shifters or Triathlon/TT bar-end shifters, and then potentially add the Dual Control Levers/Shifters at a later point. (The only exception is the Sprint shifters, which require specific Dual Control Levers/Shifters with special ports as noted elsewhere in this article.) Amazon.com link
  • EW-SD50 Wires 1 and 2 between the front shifters and the Front Junction A (0nly for some shifters). This is a bit confusing, because some of the front shifters come with wiring attached to them and some of them require purchasing separate wires. In general, most of the stand-alone shifters come with wiring, as do the TT/Triathlon dual control shifters/levers, but the road dual control levers do not. Amazon.com link
  • Front Junction A. I recommend the SM-EW90-B 5-port front junction A as it provides the most upgrade flexibility; get the 3-port option only if you’re positive you’re never going to add more shifting components. The older SM-EW67-A-E has 2 wires built-in to connect with each of the dual control shift/brake levers; it doesn’t offer much flexibility or compatibility with a TT/Triathlon setup or adding additional shifters. Amazon.com link
  • EW-SD50 Wire 3 between the Front Junction A and the 4-port Rear Junction B connector. Amazon.com link
  • EW-SD50 Wire 4 between the Rear Junction B and the Front Derailleur. Amazon.com link
  • EW-SD50 Wire 5 between the Rear Junction B and the Battery. Amazon.com link
  • EW-SD50 Wire 6 between the Rear Junction B and the Rear Derailleur. Amazon.com link
  • Rear Junction B: This is where the wire from the front of the bike is connected to 3 output wires leading to the front derailleur, rear derailleur, and battery. SM-JC40 is for external wiring, SM-JC41 is for internal. Amazon.com link
  • Grommets for any place where the wire goes into the frame through a drilled hole. Amazon.com link
  • Front Derailleur. I recommend the Ultegra FD-6870 for 11-speed builds or the FD-6770 for 10-speed builds. The Dura-Ace FD-9070 is pretty much identical, just slightly (41g) lighter and 11-speed only. (I do not recommend the Ultegra FD-6770 unless you have a 10-speed setup, because of firmware compatibility issues with 11-speed rear derailleurs. Also, it is an older design than the FD-6870, so it is larger and offers slightly less shifting force.) Amazon.com link
  • Battery and Charger. Internal or external, depending on the build. If you have to skill/time/money-to-pay-someone to get everything internal, I highly recommend that option. The SM-BTR2 internal battery has more advanced integrated electronics and is better for firmware upgrades with the SM-BCR2 internal battery charger/PC tool. If you go with the SM-BTR1 external battery, you will need the SM-BMR1 external battery mount and SM-BCR1 external battery charger. Amazon.com link
  • Rear Derailleur. I recommend the Ultegra RD-6870 for a new build if you have 11-speed compatible wheels with 11-speed sprockets, or the Ultegra RD-6770 if you have 10-speed wheels/sprockets. The system must be match front and rear derailleurs (both 6870 11-speed or both 6770 10-speed.) Amazon.com link
  • TL-EW02 Etube Wire Remove/Install Tool: It takes quite a bit of force to snap the wires in/out. You may think you can get it seated properly with just your fingers, only to then have the wire come loose because it wasn’t fully seated. It’s a good idea to keep one in your saddle bag. Amazon.com link

What wire lengths do I need? This question is impossible to answer correctly, as it’s highly dependent on the frame size and configuration. What I recommend is running string between the component mounting locations to measure the lengths. Be sure to add some extra length, as I find that wires seem to come up short pretty frequently, even when “adding a little extra” to start with. Nothing is more frustrating that having a wire that is 25mm too short. I recommend ordering a few extra wires of multiple lengths and then returning the unneeded/unused wires. As noted above, the standard wire lengths are 300mm, 350mm, 400mm, 500mm, 550mm, 600mm, 700mm, 750mm, 950mm, 1000mm, 1200mm, 1400mm. Do not  cut/splice these wires; the connectors on the end of the wires are very small in diameter to start with and you’ll end up with a splice that is larger and less waterproof than you started with.

Acknowledgements: Special thanks to Di2diy for his continued help in the comments. Check out his Ebay store for custom Di2 batteries, harnesses, and components.

Technical Details of the Di2 CANBUS protocol and signaling

Thanks to commenter Ghislain for the details: “I reversed engineered the signal going to the RD. Since I did not have a special tap connector, I could only look at the actual signals in open loop (RD wire disconnected) on the wire going to the RD using an oscilloscope. First, I found that shift up and down are multiplexed on the same wire. A shift down would generate a positive 100 msec clean 8 volt pulse (varies between 50 msec to 500 msec depending on how long you hold the shifter). On the same wire, a shift up would generate a series of 2 msec pulses that would last the same time of a shift down pulse. Therefore, the RD has enough intelligence to discriminate between the 2 types of pulses. When you hold the button on junction A, a 140 msec pulse is generated. But since my RD wire was disconnected, the RD would not go in adjust mode.”

2020-07-24

2,485 Comments

  1. I’m considering upgrading my existing new P3 from mechanical to Di2. I’m comfortable with what I believe should be the hard steps but it’s some of the simple steps (that I’ve never done) that have me questioning whether or not this is a job I can do. I’m comfortable with what parts are needed, wiring everything through my frame, hooking the system up to the computer, firmware updates, etc. What I’m not comfortable with is the actual installation of the front and rear derailleur – I’ve never installed a derailleur before. How easy is it to screw this job up by installing the derailleurs wrong? Is there an art to it that only a bike professional is going to be able to do well?

    1. Replacing a derailleur is easy, Di2 is easier than mechanical. Watch a couple of youtube videos about it and you will know what to expect. If you can turn a wrench and follow written instructions, it’s a snap.

      For both FD & RD, install adjust strictly according to the Shimano Dealer Manual. For the FD, pay particular attention to setting the height of the FD (gap between large chainring and bottom of FD) as well as lining up the FD cage with the large chainring. On the RD, adjust the “B” screw carefully. When you are done, you will think it was easy.

      1. Thanks for the reply. It’s really the b-screw adjustment that I have no idea about. Can you elaborate on what is required there for a successful install? My cassette is typically 12-25 but I may run an 11-23 sometimes.

  2. Looking at the EW-SD50 wires it appears that they have something attached that almost looks like a zip tie a few inches long. Can anyone comment on the purpose of these?

    1. So it won’t rattle in the tube.

  3. Hi Carlton – are you still monitoring this post? My Shimano Ui2 6770 is working properly outside of the SM-EW67-A-E Ultegra 3-Cable Junction not luminating to display battery life – is there a rest? Or what am I missing? Thanks

    1. Author

      Hi James. You’re not the first person who’s complained of this. I haven’t heard of someone specifically solving the problem, so I’ll give you my best guesses. It could be firmware related, but I don’t think so. It’s most likely an issue with the SM-EW67-A-E Junction A. Replacing it would verify that it’s the problem. Another possibility is battery degradation causing the system to be unable to accurately measure charge level, but I doubt this would be the case unless you were experiencing very poor battery lift.

    2. Yep, I’ve had the same issue – looking to upgrade junction box to the SM-EW90 as a result.

  4. I just ordered a new cervelo P 3 in the Ultegra 11 speed Di2 version. It has. Magura Rt6 brakes on an Auro bar. Is there a way to install dura ace brake levers with Di2 shifters?

    1. Author

      Tammy, the short answer is that it’s not possible to use the Di2 brake/shifters without switching your brakes from hydraulic to conventional cable brakes.

      If you are extremely motivated, it’s possible to attach cateye-style remote push buttons to the magura brake leavers and then hack/solder them onto a Shimano control board (inside an existing Shimano Di2 shifter). Several people have done it, but it’s not an easy mode and it’s definitely not a “stock” configuration. In general, I wouldn’t recommend this.

      Shimano will probably offer hydraulic Di2 Triathlon in the next year or two. In the mean time, most people find cable brakes to offer great performance. Or just stay with the bike as delivered.

  5. Hi – great site…Ive got an SWorks Roubaix SL3 running Ultegra Di2 6770 and want to upgrade some of the components. I want to go from an SM-EW67-A-E junction box to a 5 port SM-EW90 and also go from external battery to the SM-BTR2 or similar. I’m assuming that this will be straight forward with just the purchase of the above mentioned items? – I’ll upgrade the software through e-tube project as well prior to commencement if its a straight forward upgrade. Look forward to your advice….

  6. James,

    I have a take of SM-EW67 that works perfectly that I will sell cheap. send me your email addy if interested.

  7. I got my Di2 install completed. I have a 10-speed system but i used your recommendation to go with the FD-6870 and RD-6770. Everything seems to be working but when running the Shimano Etube software I get a warning “The combination of FD-6870(RD11 gear specifications) and RD-6770(10 gears) does not allow the bicycle to function properly”. I assume this wearing can be safely ignored? The software does let me update firmware on all components and customize the settings.

    1. It will work just fine. The FD will autotrim for a 10 speed and you may or may not get some chain rub in 53×28 or 39×11, combos you should not be using anyhow.

  8. Trouble shooting question.
    I hit a pothole today and my Ultegra Di2 stopped working. I hit the reset button and it is still not working. Any ideas would be helpful thanks.

    1. I would take the cable insertion tool and remove and reinsert each cable end. Also reseat the battery, then reset the button

      1. This is why you need to leave a loop of slack at the lever. The lever moved when you hit the hole, and the connector came loose at the lever port, almost guaranteed.

  9. Hi Carlton,
    I’m having problems pairing the SM-EWW01 wireless unit to my Garmin 1000. I put the Garmin in pairing mode (select add a sensor – select Di2) as I have an internal battery I then remove and reconnect both cables from the wireless unit (as per instruction) and then press a gear up and down as instructed on the Garmin screen. The Garmin doesn’t find the unit. Tried numerous times. Wireless unit is connected via the original cable going to RD and cable from wireless unit now goes to RD.

    Steve

    1. Problem solved internal battery need upgrading to firmware 3.2.1. Use battery charger plugged into PC and download Shimano’s E-Tube Project Application.

      Steve

      1. Hi Steve,
        having the same issue with pairing, what do you mean by the internal battery needed upgrading? which internal battery?
        Thanks
        TOM

  10. Hi there I’m am using the 6770 di2 group set and would like to add tt shifters too .Do I just need a 5 port A junction an 2 cables for my drop down shifter as the tt shifters a have cables all ready on them. Cheers john

    1. if you are adding just TT extensions to your road levers you can just plug them into the open port on the shifters, you will need to update the firmware and set them up

      1. The open port is that the extra hole where the cable goes in to the levers also the junction A I’m using is the one with the twin cables built in, will the shop be able to update my firm ware from this?

        1. You may need to do one side at a time sines the shifter ports on the levers will be full.

          1. Brilliant thanks for your help

  11. My dI2 system worked without problems and than I had a frame crash. It took me a month to get the frame replaced and during that time the di2 was in a box in the garage. After building up the frame, the battery was daily empty. After charging it had 8.39V, after several hours 7.4V and after a day 0V. After eliminating 1 by 1 the components, it turned out that the battery mount was responsible for this. The seller wanted to send it to Shimano for replacement but as I had to do a 12 days stages ride i dsided to return it on my return, i took it with me and charged every day. ( measured the voltage before). The suddenly on day 6 it had 8V after the ride instead of 7.4V and on day 7 suddenly it was 8.3V. Thus a normal use load. The problem had disappeared, did not need to recharge anymore daily. The days before the improvements it was pooring rain and than hot sunshine.

    Can anybody explain to me what exactely in the mount can give this behaviour? And should I go for a replacement anyway or should it be allright now? The mount without cables attatched but with the battery inserted discharged the battery. The battery without mount kept simply its voltage.

    Tnx for explaining this to me.

    1. is water…..protect you battery ; )

      1. If you are asking about the kit I sell on ebay if it’s water proof, yes it is.

  12. I have a new bike with the Ultegra Di2 etube setup and my charge status light blinked green so I thought it was time to charge it. When I hooked it up, and with either AC adaptor for USB or direct to computer, I get no charge indicator or error indicator light. Does the charge status need to flash red before you can charge it or am I wrong in thinking that the charge indicator light should come on? Great site, really have to hunt for useful info on this stuff.
    Paul

      1. I’m not following you, try what adaptor? I tried a USB adaptor with no light. Am I correct that I should have a light on when charging?

        1. A USB charger adaptor like what came with an iPhone takes a few seconds for the indicator light to come on after it’s plugged in to the battery.

  13. Is it absolutely necessary to have a backing plate or something for front derailleur to push against on the DA 7970 systems? I am trying to install the system on a Dahon folding bike now. It has a front derailleur hanger, but it is not positioned to allow the back of the front derailleur to even allow the angle adjustment screw to push up against anything. Thanks..

    1. Author

      You don’t need the backing plate, but you will need to align the front derailleur per the installation instructions. So you may need to bend or otherwise adjust the bracket to get proper alignment.

    2. If this is on a carbon frame use the plate if the screw will be on a carbon surface. There is quite a bit of pressure and it can easily damage the carbon if for example the chain gets jammed a little during a shift to the big ring. The screw is there to brace the FD during shifting to the big ring and will dig into unprotected carbon.

  14. Problems downshifting:

    Hey folks..I was in the middle of a century ride this weekend and during the last 25 miles has multiple issues downshifting the DA rear Derailleur. This was very sporadic and would work once every ~10+ attempts while it would work every time at other moments.

    Now, i can’t get it to downshift at all. It upshifts (smaller cogs) every time but not down.

    Has anyone had this experience?

    Thanks

  15. I have the 6700 di2, just got the 6870 RD, 6800, cassette, and chain to go to 11 speed. After updating firmware – the e-tube software complained of incompatibility between the 6770 FD and 6870 RD. Result, when pressing shift buttons, nothing happens. However, when I disconnect one of the derailleurs, the other works and vice versa. It seems people have gotten it to work, called Shimano, and wasn’t surprised that the official response is that I have to buy a 6870 FD. Thoughts? I was hoping to save a bit of coin but if Shimano is forcing to upgrade by putting a virtual “off” switch in the software, don’t know what to do…Have some challenging climbs coming up that the 32t will come be nice to have, which was the main reason for the upgrade…

    1. try disconnecting the battery for ~ 1 minute, and than recheck the update be sure all components are updated, not just the RD.

    2. I did see that there are new updates for the components from the e tube project site, it may be possible they have made mods to the FPGA’s to make them not compatible. Please let me know if you still can’t make it work.

      1. Tried your first suggestion with the battery, no go. All components were updated with the most recent firmware. if you look at the firmware history for the components the only unit that is recent in 2014 is the PCE. If Shimano made firmware/software mods to prevent compatibility this is def an example of planned obsolescence. It’s like printer manufacturers having a counter on their printer telling it to stop functioning after so many prints. I’m lost at this point. My local LBS said they’ve performed the same upgrade path (6770 FD with 6870 RD) and it’s worked. Any other thoughts out there?

        1. So again basically if the 6770 FD and 6870 RD are plugged in – nothing happens when shift commands are sent. If I unplug one the derailleur plugged in responds to shift commands. This has been frustrating, especially if this were a deliberately designed off switch injected into the system by Shimano (sorry for the rant). Thanks again for the additional brain power. Any other thoughts are welcome…

          1. I’ll get back to you on this. I need to go test it out and see if it’s the new firmware.

          2. Ok so the new version 2.6.0 has 3 new updates, one for the PCE1/BCR1, one for the batteries, BMR1-2, BTR2 (3.05), and one for the FD 9070/6870. and the result is you can no longer change just the RD to go to 11 speed, you will need to buy a FD6870. I did find a way around this, but I think its too late for you. If you do not update the battery to 3.05 and just the rest of the components, then it will work.

          3. I do not know if its possible to change the battery back to the previous version (doubtful), but you could give it a try if your LBS has the older version

          4. Thanks. I just did some additional checks on older versions of the eTube software and it appears that the battery as you indicate is may be the culprit. Spend money on Battery or Spend money on FD? Going to check with the LBS to confirm the battery is the culprit. Thanks for helping out!

          5. Lets be clear, its not the battery, its the battery mount, SM-BMR1 or SM-BMR2, or SM-BTR2 (seat post battery) as long as the written version is >= 2.0.6 and not 3.0.5 you can run the RD6870 with a 6770 setup. for 9070/6870 the new e tube update (v2.6.0) will update the battery source to 3.0.5 and update the FD, as well as the SM-PCE1/BCR1. However an updated SM-PCE1/SM-BCR2 will still work with the older version of e tube V2.5.X. Also once the battery source has been updated to 3.0.5 you CAN NOT rewrite it back to the older version. You will need to buy the FD6870.

          6. Another little tid bit – 2.3 is the first version to support 6870. eTube v2.3 through 2.5.1 – you get a nag screen saying their may be compatibility issues between 6770 and 6870 but it allows you to still customize. v2.6 nags, then stops you from doing anything but continue to check connections. Also, it appears that if your BMR1 has the most recent firmware, those other versions will not detect the BMR1 and will prompt you to upgrade to the latest eTube 2.6 version.

  16. Hi Carlton, Do you know if the SM GM01 and GM02 rubber grommets fit the older DA 7970 wires? Thanks, Don

    1. You can make the 02 fit if you enlarge the hole with a grout bit and the drummel on slow. The 01 in for 6mm holes.

  17. So swapped out battery holder and system worked right away. My opinion – DO NOT 1) update the battery holder to the 3.0.5 firmware released in July 14, 2014, and DO NOT 2) update eTube software to 2.6.0. All should be fine. I have a rant over at bike radar, but that’s the short of the long.

      1. there will be a bunch of angry people who have converted 6770 systems to 11 speed who will update (e tube 2.6.0) their systems unaware, and then no longer be able to ride their bikes after the update. There may be another reason for Shimano to make this change, but it looks like they have targeted people who have just been upgrading to 11 speed by just changing the RD from 6770 systems.

    2. just understand that you will not be able to use e tube project with that mount, since it will not allow you to enter into updating without a battery source >=V3.0.5, so save the old mount.

      1. yup. I am definitely wiser at this point. Outside of people having accidents (which I haven’t read anything related to safety issues) can’t see a valid reason for a virtual “off” command to be inserted into the firmware code in the event the system detects different versions of hardware when it’s been working since the release of the 6870 etube support. Nuff said- I completely agree, there will be some very upset people. Thanks again for your input and participation in this…helped trouble shoot, point me in the right direction, and confirm suspicions.

      2. Author

        Thanks for the info on this issue. I updated the post to include details on the problem. Please make sure I’ve captured it correctly:

        Important Notice 2014-07-18: There is a compatibility issue with Shimano eTube software version v2.6.0 that prevents 10-speed front derailleurs (FD-6770) from working with 11-speed rear derailleurs (RD-6870.) DO NOT UPDATE FIRMWARE using Shimano eTube software v2.6.0 if you are running an FD-6770 front derailleur and a RD-6870 11-speed rear derailleur.

        The problem component is the battery (external battery mounts SM-BMR1 and SM-BMR2, internal seat post battery SM-BTR2.) If you keep battery firmware at v2.0.6 or earlier, the system will continue function properly. Shimano eTube Software v2.6.0 will update battery firmware to v3.0.5, and will not allow the RD-6870 to work with a FD-6770 setup.
        If the battery firmware is updated to 3.0.5, it CAN NOT be rewritten back to the older version. You will need to either replace the FD-6770 with a FD-6870 (or get a battery with the older firmware and never update it.)

        1. That covers it. As a note people who have 9070/6870 systems who use v2.6 the FD will also be rewritten as well as the battery system, and everything will play well together. Also people who for the first time down load v2.6 e tube project,will need buy FD, and RD 6870’s to go to 11 speed.

          1. My bike currently has 6770 fitted. I’m planning to replace the FD and RD with 6870 and update the firmware on all components to 2.6.0. Will this work?

          3. Just completed a partial Di2 upgrade from Ultegra 6770 to Ultegra 6870. Left the original shifters, wires, junction boxes and battery on the bike. Replaced everything else. Nothing worked until I updated the firmware. Everything worked after the firmware update. Thanks Di2diy for correctly suggesting that this would work.

          4. You are very welcome, thanks for the followup.

        2. Ditto – covers it. Additionally, if users need the eTube Software – v2.3 through 2.5.2 can be downloaded using the following links:

          http://e-tubeproject.shimano.com/download/E-tube_Proj_V_2_3_0.zip

          http://e-tubeproject.shimano.com/download/E-tube_Proj_V_2_4_0.zip

          http://e-tubeproject.shimano.com/download/E-tube_Proj_V_2_5_0.zip

          http://e-tubeproject.shimano.com/download/E-tube_Proj_V_2_5_1.zip

          http://e-tubeproject.shimano.com/download/E-tube_Proj_V_2_5_2.zip

          Though Shimano does not enable any links, there is a pattern in their naming convention, and the old files still exist on their servers (at least when I went through my trouble shooting).

          But again, DO NOT update the software when prompted to v2.6.0

          1. Author

            Thanks, I added the links to older software versions in the post.

        3. Just so I’m clear…I’m running 6770 (10 speed stuff all around) on 2 of my road bikes & one of my tri bikes (tri bike has 2 sets of SW-R671 due to Magura brakes). Since I’m not running anything 11-speed I’m OK to upgrade my firmware when an updates is available?

          1. Author

            You can upgrade, but if you do, you’ll never be able to switch to 11-speed rear derailleur if you do. I don’t know of any features added by the recent software that would be worth giving up that capability. It only updates the battery / battery holder firmware, I don’t know any issues with the old firmware. I wouldn’t go past e-tube 2.5.2 at this point.

          2. Yes, as long as you do not mix 10 speed with 11 speed you will be fine.

        4. My battery firmware is 2.1.1. Will that be OK with the RD-6870 and FD-6770?

          1. only one way to find out… plug the RD in and see if it works. I’m not sure what all the compatibility versions are for each component, but as long as the are up to date with the e tube version you are using it should be fine, as long as you do not update with v2.6.0

          2. Everything worked fine. I did not need to update the firmware in new derailleur. I was lucky in that I updated the 6770 firmware the day before Shimano posted the new E-tube software that would have made impossible without a new front derailleur. The only problem the wrench had was getting the old freewheel hub off.
            I am still confused about the distinction between the version of the E-tube software and the versions of the firmware data files. Wouldn’t any of version of the software go looking for the latest version of the battery mount firmware and try to install it?

          3. Author

            I’m not positive, but I think each version of e-tube software is specific to each firmware release. Otherwise, the firmware might have more features than that version of e-tube could support, and/or the update might not apply correctly. (I’m not positive on this though…)

          4. e tube project versions is the software used to update/wright to the FPGA in each component, the firmware version for each component is what is written to the FPGA of each component. when Shimano adds new products i.e. Road 6870, MTB, Comfort, and now Ebike, the older components need to have the controller area network (CANbus) updated so they can be identified on the network by all components, however sometimes the current firmware version does not need to be changed and can keep the current version, so thats why the numbers do not match, and sometimes do not change each time a new version of e tube project is updated. the battery system is the most often updated because it handles power distribution for every node on the network, and is common to each Shimano product.

        5. I keep seeing reference to this new update messing up bikes that are running the 6870 rear (11-sp) with the 6770 (10-sp) front. I have the opposite configuration as recommended by this site. I am running 6870 front and 6770 rear since my bike is 10-sp and I don’t plan to upgrade to 11-sp for a while. Will this update break my bike as well?

          1. That’s a good question, I doubt it because I think it’s shimanos way of making people buy both to go to 11 speed. I will test it out when I get home and let you know.

          2. Thank you! I would really appreciate your testing it. I’ve got my first full ironman next month and would hate to brake my bike with just weeks to go.

          3. No it will not work, if its working now do not update it,

          4. Author

            Thanks for info on FD-6870 not working with RD-6770. Post updated with latest info.

          5. Sure Carlton, I must say I was a little suprised, but only a little.

          6. Seriously, thank you guys. My last charge (and check for updates) was on 7/13…the day before this update dropped. I surely would have updated had the software told me to and I would have been in a world of hurt. 2 of my 4 rear wheels cannot be converted to 11-sp but I will convert to 11sp eventually. That’s why I bought the 6870 FD and 6770 RD. I’m hoping there are no important firmware updates in the future that I will have to miss out on.

          7. Of course you could buy a FD6770, and not have to worry. You also need to be careful when starting e tube project, even if you say no to updating e tube project it wi still download the support files for the compotes if the computer is on line.

  18. I have the ultegra 6870 DI2, and today while out riding my rear shifter stopped working to shift the rear cassette. I did some reading and thought I may have hit a pothole to throw the rear derailleur into crash mode. I performed the crash recovery and the rear derailleur responded by moving up and down the rear Cassette, But I am still unable to shift. This is all internal routing. any suggestions?

    1. Check the cable on the shifter unplug and plug it back in using the connector tool. be sure there is a relief loop.

      1. Still no power to the rear. I wonder if the cable came loose at the connector by the bottom bracket.

        1. This is when the PCE1 comes in handy for diagnosis, the BCR2 will do nothing to find what may be wrong, so checking the connection manually is the only way to see if there is a connection issue, otherwise check the RD with a PCE1 and see if something has failed. BTW do you have a mix of 11 speed and 10 speed drivetrain?

  19. Hi Di2diy I need information,
    I making a connection to one cable from the shifter left to the shifter right after connecting only one cable in The Junction A, continue perfect function for derailleurs front and derailleurs rear?

    Thx

    1. If you mean a Y connection with each end going to a shifter, and the tail going to the junction A, yes that will work, it will work with the EW90 or EW67

  20. no exactly….I want first connect shifter left one cable in shifter right and after one cable in junction A. Continue perfect function for derailleurs front and derailleurs rear?

    1. I don’t understand what you are trying to accomplish, buy just give it a try and see.

  22. DI2- Doing nothing. I recently had problems with my RD only shifting to a smaller cog, well when I brought it to my local mechanic it worked, somehow. He suggested putting the system on the PC to see if there was anythnig evident. Once firmware was update, nothing has worked- no lights, only an error light when I connect it to my charger. I have an IM in two weeks and am starting to panic. Any suggestions? If i don’t resolve this soon i will be forced to borrowing a friends bike and setting ip up similar to mine.

    Thanks

    1. what is the Di2 setup on the bike, 9070,6870,6770? what version of e tube project was used to update? what components were updated?

      1. 6070 shifters, 6070 FD, 9070 RD, 5-port JB, seat post battery. Not sure what was updated by mechanic bit when he runs it through the software it shows the incompatabilty of the FD and RD (highlighted in yellow) then doesn’t allow anything else to be done. I plug it into my charger and I get the blinking trouble light. This is very odd as everything has been up and running for 6 months. At this point I really don’t want to sink another $300 for a new battery and JB

        Thanks

        1. If you have a mix of 10 speed like FD 10 speed and 11 speed RD it will no longer work if it’s updated with the latest firmware v2.6. You will need to buy a new 11 speed FD. To test the this is the problem unplug the FD and see if the RD works, than unplug the RD and see if the FD works. The shop who did this for you should sell you what you need at cost aince they did it. Also the problem with the charger updater /BCR2 may be because it’s a different version, you will need to down loas the latest version of e tube 2.6.0 to make it be able to update with it. I assume you have been using your charger to update your firmware.

          1. Di2diy….No, the system was updated using the mechanic’s charger, so i guess my charger needs to be updated…?

            Also, I unplugged the FD and the read did not work. I will try unplugging the RD this evening and see if the front works. T- 12 days and counting and I’m afraid that if I order the 11-speed FD the system still might not work.

          2. Author

            Mark, it doesn’t seem that you have the firmware compatibility problem; RD would have worked if that was the cause. If I were you, I’d get 4 extra di2 cables (and a Junction B to connect them together) and run external lines from your cockpit Junction A to your components to see if you can isolate the problem. It will be easy to plug into the FD/RD, not sure how accessible your battery is.

          3. Mark.. you need to get your hands on a PCE1 to do diagnoses the BCR2 is worthless, and I have seen them fail to update for no reason, there are links to older versions of e tube project on this above try 2.5.2, but I have a feeling that its the RD gone bad… thats what started this problem.

          4. Di2diy, Carlton…Thanks for the help. Unfortunately I do not think I will be able to resolve this issue by July 31 (when I have to leave for my IM). What is really confusing is the sequence of events:

            1. At the end of the century ride derailleur was very inconsistent with downshifting to bigger cog
            2. Crash mode recovery, RD shifted up and down with no issues, however would still not let me downshift once completed
            3. Upon arriving at mechanics shop, everything works perfectly…..?
            4. The bike gets hooked up to the mechanics PC and nothing now works.

            On his PC, once the software recognizes the incompatibility between derailleurs (highlighted in yellow) the following page does has function buttons that are not active (option not available)

            At this point I am very disappointed and am considering selling components after the IM race

          5. Well it’s your call, but seems like you are giving up without much action, as a minimum you could download e tube 2.5.2 and see what happens when you plug it in, if it’s a firmware issue you will know pretty quick, even without doing that you could ask the guy who did the updat what e tube version he used, if not firmware than look at hardware, cables, RD.

          6. Di2diy…This brings to light another complication- I only have Macbooks and can’t find a driver for Mac. My concern is sinking hundreds more into cables, 5-port junction box, and Front derailleur then having Shimano require shifter upgrades soon after. No one local carries the cables so it’s several days before i can get the cables in and test which puts me close to leaving for my race

          7. sounds like a rock and a hard place…have you checked that the battery is charged. good luck!

    2. Mark M – I have a Mac as well. I run Windows 7 on VMWare Fusion and load eTube on it as well as other Windows only applications. There is no Mac support for the eTube project that I’m aware of. There’s several options (some free virtual apps and others paid), but you essentially have to either run a virtual machine or install Windows via Bootcamp. If you’re unfamiliar with this, I’ve never asked them, but I’m sure the apple Genius bar can help (they will probably recommend Parallels, VMWare or Bootcamp. Parallels and VMWare are virtual environments with other OSs (Windows, Linux) that can be run simultaneously along with your Mac OS where Bootcamp only allows you to be in one environment or the other. There are times where some environments have issues with some USB peripherals, I only have experience with VMWare Fusion, so know for certain the eTube software and the PCE-1 works, pretty sure Boot camp will work as well because of that is not a virtual environment. You will however need a Windows install disc/license.

      1. What happened to me was that the derailleur was slightly corroded and therefore it had resistance and would not change to another cog. I could hear the motor trying but it did nothing. Smaller cog worked now and then (less force) bigger cog not. After manually fractioning the cage with some wd40 it started working again. Maybe this is your problem too. Mine corroded when i did not use it for six weeks and it stayed in the garage after wintertime. The pins are apparently not gold bladed…

  23. I am about to have the RD-6870 installed on my bike (I have the 6770 components currently installed). I have already updated the firmware on the 6770 components using e-Tube 2.5.2. When I plug in the RD-6870 should every thing just work or do I need to do any further work with the SM-PCE1?

    1. The RD may need to be updated, but as long as you DO NOT use the new V2.6 e tube you will be fine.

  24. Hi Carlton, would you know if the white Ultrega Di2 wire cover fits the 7970 wire? Thanks again ! you are the best !

    1. Author

      Don, I don’t know for certain, but based on my experience, there is probably enough room to accommodate the larger cable diameter.

  25. I have a 6770 FD that all of the sudden will not shift to the small ring. It will auto trim in the big ring. It acts as if there is no small ring to shift too. I have checked connections, removed and reinserted the battery. Checked the controll box for crash protection. Still will not shift down. Anyone experience this problem and no how to fix it?

    1. buy a SM-PCE1, or go to a LBS that has one, and do a diagnosis on the system, to see if the FD has failed.

    2. Im having the same problem. can you tell me what happened?

  26. I discovered a single hidden button underneath the rubber hood on the very tops of each 9070 lever. What do folks typically configure these for?

  27. About to upgrade my 2013 Felt B12 to Di2 6870 and found this site. Carlton, thank you for the great research and insights into the Di2 offerings/workings. Your site is on par with DC Rainmakers tech site. Excellent work!

    1. Author

      Thank you Dennis! Unfortunately, I believe Ray posts a little more frequently than I do. . .

  28. Hi Carlton. Great write up. I have been offered the Di2 7970 groupset to buy. I see you outlined this model is not compatible with the second generation models. Do you perceive difficulties down the line obtaining parts for the 7970? or any other future problems going with an out of production model?

    1. Author

      Will, everything you said is true about purchasing older non-current products. Just make sure the lower price of the older components justifies the level of risk when compared to the price of newer (and potentially more robust) designs.

    2. Had a guy give me back my SL4 cos of this that I sold on eBay.tosser. there are going to be parts knocking about for a bit yet just not sold on new bikes and possibly not under warranty which is the worst part.

  29. Hi there, you have probably been asked this a thousand times but need to be 100% sure before I purchase. Ok here goes I currently have Di2 6770 system and I would like to upgrade to the DA 9070 11 speed. For this to happen do i need to buy the DA 9070 FD, DA 9070 RD and the DA STI 9070 obviously the 11 speed cassette and chain. Can i use all existing wiring, handle bar control box and the existing battery from the 6770 for this to work. If i have to update firmware how do i do this? Any help or advise would be very much appreciated. Cheers Dan

    1. Carlton. I bought the new shimano di2 disc brakes and a pro mechanic built it up albeit not entirely confidently. After a few rides I noticed the brakes were terrible compared to my 7970 di2 bike. I got the bleed kit and messed up and couldn’t improve it so off to my local evans cycles it went. They said the right shifter was faulty and uk shimano wouldn’t replace so had to return it to a german shop where I bought it. Evans fitted the new one and I picked it up today. It doesn’t appear any responsive than at first? I’ve never had disc brakes so not sure how responsive they should be. The 7970 were very responsive.

  30. Thanks to all for this excellent post and comments. I have a Silverback Scalera 2 which comes with a full Ultegra Di2 build. I just changed over the cassette to 11-32 which has worked fine despite the short cage. I love the wider range gearing which suits my hilly area. The derailleur hanger is quite long on this bike which may help a bit. I just thought others contemplating the same change would like to know it works fine.

  31. Hi guys – I’m trying to do the upgrade of the RD-6770 to a RD-6870, but I’m having issues.
    I downloaded the 2.5.2 e-tube software and ran it. It shows that my SM-PCE1 firmware version is 1.4.0, and my SM-BMR1 is 1.1.2. However, every time I try to update the SM-BMR1 to the higher version I get an error message that says “A unit other than SM-BMR1 is connected. Connect only SM-BMR1 to the PC on its own.”
    I then uninstalled the 2.5.2, installed the 2.5.0, and tried again. Same result.
    My PCE1 connection to the bike is through the left shifter. I have looked at the battery mount, but I can’t see a way to connect the PCE1 directly to the BMR, and just clicking the check marks off at the connection window does not seem to work. Am I missing something? Do I need to take the mount off to find the connector?
    Also, I should comment that the e-tube project software shows in the log window that it is trying to update to firmware 3.0.5. even though I have the 2.5.0 version of the software installed. The first time I saw that message, I cancelled the update. I then disconnected my PC from the internet and tried again hoping a lack of internet connection would prevent the 3.0.5 update. That resulted in an error stating that the software requires an internet connection.

    1. What FD do you have on the bike? The e tube version has nothing to do with the battery version 3.0.5 now that it has been downloaded to your computer. The only thing you can do is uninstall e tube, and reinstall 2.5.2, and make sure your computer is not on line when you start e tube up, or it will still download 3.0.5 for the battery. It you have a 6870 or 9070 FD than download e tube 2.6 and just update the battery. You will need to update the battery by pluging it directally to the PCE1 no matter what version you use. I would recommend you buy a 11 speed FD if you do not have one, since you will have issues everytime you try and update or customize the settings.

  32. Carlton, just looking for your POV on this issue I have. I have a fully equipped BMW w DI2 (9070). Had for more than 1.5yr and everything has been working fine till a couple of weeks ago when I rode through fresh street paint and I had to use a pressure washer to get all the paint off. The battery still works fine but dies REALLY fast… like after a couple of rides and it goes from ‘blinking green’ to full-on dead-empty. Thoughts? And how should I go about checking what is wrong? Thanks Carlton… as always I very much appreciate your thoughts and response! Best, Yoeri

    1. PS: I have built full (Di2) bikes from scratch… so decent from a bike mechanic POV.

    2. Internal battery BTR2.You need open battery and leave dry. After protect with plastic;

      1. Thanks! Any other feedback? Will def give this a try…. should I also I let the junction B box dry out?

        1. No need dry Junction B because principal problem is water vapor in integrated circuit inside internal battery.For better result use hair dryer( no hot option!) for dry all inside battery

          1. Thanks, so you guess that the battery will be just fine after a solid dry? Thanks again for the help… this was very helpful!!
            Yoeri

          2. Hi Sandro, just wanted to let you know that your solution worked brilliantly! Thanks again for the advice! Best, Yoeri

  33. Hi to all
    can somebody tell me if by having a ICD (implantable cardioverter defrillator) fitted to my heart?
    Any advice would be really appreciated, many thanks

  34. I have the Di29070. I added the EWW wireless to it (LBS) My Garmin Edge 1000 cannot see it. I ahve updated the firmware on the Di2. Still, changing gears while searching for the DI2 on the Garmin, not found. Ideas?

    1. Do you make updated firmware the D-Fly ?

    2. Go to settings, sensor, di2, settings and the configure as suits

    3. Build 2.5.0 added support for SM-EWW01 (which is the D-Fly). Your local Di2 reseller can do this or you can get the special connector SM-PCE1 and update the software yourself.

      1. I’d already updated the firmware myself. I did get it working on the Garmin. Seems unrelated, but after disconnecting the rear de-railer and the D-Fly and reconnecting, it worked.

  35. Hi, In need of help with di2 9070 been working all ok no issues, started a ride on sunday in light rain ,20 miles in stopped for a comfort break then resumed ride to fine nothing working no battery lights or any sign of life ? Got home checked battery 8.32v removed all connectors and checked for water, nothing. Stripped out internal wiring and removed heat shrink from all internal plugs expecting to find water, nothing. I then checked voltage into the ew7975 connector all ok but no voltage commin out to thd outer loom. Can I assume this junction box is a known issue ? It appears to be sealed so can I cut the wires and solder manually ? Or has any one got a good one for sale? Thanks Gordon

    1. If this is a new build than be sure the connectors in the levers were installed with the cable tool, it’s impossible to plug them in all the way without it. On the 7970 stuff most often if a cable fails it will turn out to be the junction cable, also check that the junction cable is complety clicked in the junction box plug, you should hear a snap when plugged in, again the cable tool is needed to remove and plug these connectors.

      1. The Junction Box is completely sealed with potting. and the wires are molded in.Part number is ew7975
        7DF JH0N0932 ?

        1. Yes junction box B on a EW7975 harness is sealed doubt that is the issue. Did you check the connectors? How long was the system working befor the probelum.

          1. Finally traced the fault to the EW79A junctionA pin out all connections but no output to switches or no lights on indicators.
            battery voltage and ground reaching the connector and both front and rear mech.Suspect water may have got in to the electrics ? Have you got any second hand good dura ace looms? Thanks Gordon

    2. BTW I do sell a modified EW7975 harness with a seat post battery on ebay. You will not find any others for sale.

  36. Mmm, possible expensive mis-guided purchases. Set up; ST-R785 shifters/brakes, SM-A-E Ultegra 3-Cable Junction:SM BTR1 battery, SM BMR2 battery mount, SM-JC40 External Junction, FD-6770 and RD-6770.

    Everything is connected, long press on the button on the SM-EW67-A-E Ultegra 3-Cable Junction makes the FD-6770 and RD-6770 move throughout their range, but when returned to normal the shifters don’t move the FD-6770 or the RD-6770.

    Any ideas? First time with Di2, nothing to compare it to.

    1. Did you update the firmware with e tube project?

      1. Not yet, FD is new, RD second hand, battery new, battery mount second hand. Shifters new.

        This set up requires the SM-PCE1 to upgrade? Is that right?

        1. And if I do get hold of a SM-PCE1 where do I plug it into, currently all ports are full.

        2. you need to update the components to the same firmware version, PCE1 will do that, also buy an EW-SD50 cable and JC40 junction box if all the ports are used up than its easy to plug it in at the RD.

          1. Everyone can relax, setup fixed. No updates required, I had just failed to correctly insert the wires into both shifters. Feel like a dick, but thank you for all your help, and my setup with the hydro brakes definitely works, that is of some interest perhaps….

  37. Mmm, possible expensive mis-guided purchases. Set up; ST-R785 shifters/brakes, SM-A-E Ultegra 3-Cable Junction:SM BTR1 battery, SM BMR2 battery mount, SM-JC40 External Junction, FD-6770 and RD-6770.
    Everything is connected, long press on the button on the SM-EW67-A-E Ultegra 3-Cable Junction makes the FD-6770 and RD-6770 move throughout their range, but when returned to normal the shifters don’t move the FD-6770 or the RD-6770.
    Any ideas? First time with Di2, nothing to compare it to.

  38. Hi Carlton, great site.

    I have a question about using e-tube with a 11spd FD-6870.

    Previously I had a full Di2 10spd FD-6770 setup and no electronic FD adjustment, but now that I’ve upgraded everything to 11spd, there is a section regarding “Front derailleur adjustment setting” that has me scratching my head.

    I’ve done the usual manual inner and outer limit screw adjustments, but do not understand the intent of using the “Front derailleur adjustment setting” while the rear is in cog 1 (innermost) and front is in the big/outer ring. Can you elaborate?

    1. Hi Carlton,Finally traced the fault to the EW79A junctionA pin out all connections but no output to switches or no lights on indicators.
      battery voltage and ground reaching the connector and both front and rear mech.Suspect water may have got in to the electrics ? Have you got any second hand good dura ace looms? Thanks Gordon

    2. clarification of my question above… when using the etube FD cage position adjustment (after adjusting the limit set screws), should that tuning feature be set so that the inner plate or outer plate is closest to the chain?

      1. Ok, after phoning Shimano Tech Support and experimenting, here’s my understanding…

        The FD-6870 trim adjustment effects the auto-trim position. So for example, if the FD outer plate rubs the chain when using the 6th largest cog, you would want to adjust the FD trim outward a couple ticks. However, you can only perform this adjustment while in the big-ring/big-cog combination. Etube forces the derailleurs into this maximum cross-chained position, whereas during the manual method you must shift to these positions yourself. The adjustment feature is accessible via either the A-Junction box, or the “Front derailleur adjustment setting” in the etube software, and should be used only after you have already set the physical inner/outer limit screws.

        That you cannot perform this adjustment while in the 5th or 6th rear cog or the small chainring, is a bit of a nuisance. I have no idea why Shimano created this restriction.

  39. I have 9070 group with 5 port junction. It had been working flawlessly previously. I moved it to a new bike and now I get at least a 1-5 button press hesitation before the rear derailleur shifts. When it begins to shift, it does shift well and rapidly. If I don’t shift for some period of time (at least 1-2 minutes), it hesitates again and takes 1-2 button presses to shift. Ive taken the wires out and inspected them and even replaced the RD cable. Strangely when I have the system charging there’s absolutely no hesitation with initial button presses no matter how long I leave it (longer pause from shifting = more nonactive presses of the button before shift occurs). The battery level was at least 50% when I started and now fully charged. I went to Etube and it doesn’t recognize anything. It somehow tried to update firmware of the battery and FD, and I went through those procedures. It still doesn’t recognize any components. I also did a crash reset and unplugged the battery. Help?!?!! Thanks.

    1. Interesting, I have the exactly the same problem since last week. Hope somebody can help as I am also running out of ideas.

      1. The PCE-1 said possible battery error (the brains of the system). I have ordered a new battery and will update you.

        1. I did some testing last night and I come to the same conclusion. Let me know if a new bat fixes the issues for you.

          1. I spoke with Shimano who said that they’ve never seen a battery go bad. They suggested I hook the battery DIRECTLY to the PCE-1 and it immediately recognized it and TOTALLY FIXED the problem. Previously I had hooked the PCE-1 to the junction rather than directly to the battery.

            BTW: I did order a new battery and it worked fine.

  40. Hi Carlton, I just finished installing an older (I think, I don’t know how to tell, I just got a comment on one of the forums that it was 1st generation) 7970 di2 system on a folder and it works great. I was lucky enough to get an extra 7970 rear deraileur that needed a part and fixed it !. Would it be too expensive to put together a Di2 system around the rear deraileur with 6770 and 7970 parts or do they have to be 7970 specific? I won’t need the front shift levers as I am using flat bars and cateye shift buttons. Would I just need a front / rear harness and battery? Since I already have the charger base I won’t need it.

    1. Whoops, sorry I wasted everyone’s time. I just read Carlton’s article and answered my questions. I just still have one, are all the 7970 parts interchangeable?

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