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How to Upgrade Shimano Dura-Ace 9070 and Ultegra 6870 Di2 to Synchro Shift

September 17, 2020

In June 2016, details of the new highly anticipated Shimano Dura Ace R9150 and R9170 Di2 groupsets were released. The new groupsets featured rim brake and hydraulic disc brake versions, a new aesthetic with a beefed up crank arm and angular rear derailleur, wider gear options and even a stealthy, dual-leg power meter. Despite those exciting additions, one of the most intriguing progressions was the introduction of 'Synchro-Shifting'. The synchronised shifting system has been used with great success since 2015 on Shimano's XTR Di2 groupset and through the new Dura Ace R9150 Di2 groupset, became available to road riders.

Not sure what Shimano's Synchro-Shift is? Learn all about that in our guide to Shimano Di2 Synchro Shift Modes.

The exciting news for riders with compatible older 11-speed Shimano Dura-Ace and Ultegra Di2 groupsets is that with a new battery and a firmware update, you too can enjoy the benefits of Synchro-Shift. And with Shimano’s on-bike wireless receiver you can also update your groupset to have wireless functionality, just like what new Dura-Ace R9150 offers. With the help of Dave Ross from Giant in Ormond we show you exactly how to do such an upgrade.

What you need to upgrade to Synchro-Shift

fullpage upgrade shimano dura ace 9070 ultegra 6870 di2 to synchro shift how to compatible systems

Firstly, you need to make sure your current Di2 groupset is compatible with the battery and firmware upgrade. Compatible front derailleurs include; Ultegra 6870, Dura-Ace 9070 and Dura-Ace R9150 and compatible rear derailleurs include; Ultegra 6870, Dura-Ace 9070 and Dura-Ace R9150. Simply put, any Shimano 11-speed Di2 road versions.

If you have an internal battery then you need to purchase the new BT-DN110 battery and if you have an external battery, you need to purchase the new BT-DN110 external mount, which are the critical items that allow you to take advantage of synchro shifting. The new battery contains the 'Master Unit' to the system, providing the processing power required to deal with the multiple shift patterns and customizations that synchronized shifting brings.

fullpage upgrade shimano dura ace 9070 ultegra 6870 di2 to synchro shift how to battery

The penultimate step is downloading the latest E-Tube firmware from Shimano, and connecting your bike to a PC or laptop (Windows Operating System only) to complete the upgrade. It can also be done via Bluetooth from your tablet or smartphone to your components assuming you have the plug-and-play EW-WU101 or EW-WU111 wireless receiver and have downloaded the E-Tube project app - an app that allows for complete customization of shift settings, shift button purpose, shift speed, and wireless firmware updates.

And then, of course, is the installation, which we've outlined below and featured in the video above.

How to perform the Synchro-Shift upgrade to Shimano Dura-Ace 9070 and Ultegra 6870 Di2 systems

There are different options for upgrading your old system, depending on whereabouts your 'Junction-A box' (sometimes referred to by riders as the junction box) will be. As well as having the standard Junction-A box mounted to the stem or similar, there are now options for storing new Junction-A box options within the frame (such as the Trek Madone 9-series or Pinarello Dogma F10) or inside a handlebar. Shimano’s component arm, PRO, has released a range of Vibe stems and bars that will allow the Junction-A box to be fitted and cables internally routed, creating a super clean front end of the bike. We've outlined both options below, starting with the stem mounted Junction-A box.

Upgrading with stem mounted Junction box

fullpage upgrade shimano dura ace 9070 ultegra 6870 di2 to synchro shift how to junction box a

The upgrade process is simple once you have the new battery and the latest firmware. Wherever your current battery is located (in the video example, it's in the seat post), it needs to be removed and swapped with the new battery, which is simply a matter of unplugging the old and plugging in the new. Be sure to listen for the distinct click that the sealed plug connection makes when properly installed. The Junction-A box will flash when the new battery is connected and then it's on to updating the firmware.

The firmware needs to be downloaded from Shimano if you are planning on doing it from home from a PC or laptop, otherwise, your local bike shop will be able to plug into your bike and complete the upgrade.

fullpage upgrade shimano dura ace 9070 ultegra 6870 di2 to synchro shift how to firmware 2

If you plan on performing updates and customizing settings from your phone, either the EW-WU101 or EW-WU111 wireless receiver needs to be purchased and installed onto your bike. Once it is paired with your phone, you can then customize shift settings, shift button purpose, shift speed, and perform firmware updates wirelessly. If you don't plan on purchasing the wireless receiver, the Di2 charger supplied with your bike doubles as the diagnostic plug to link with a PC, enabling you to customize your settings.

From there you can customize both Full synchro shift and Semi-Synchro shift modes to suit your riding habits and preferences. You can toggle through each mode by pushing the Junction-A box button twice. Solid red+green lights indicate you are in manual shift mode, two blinks indicate you are in Semi-Synchro Shift mode and three blinks indicate you are in Full-Synchro Shift mode. The three modes are accessible via a continuous loop, so if you press the junction box button again, it will cycle to the next mode.

Junction box inside the handlebar

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As mentioned, the latest Dura-Ace 9150 Junction-A box is housed within the bike itself or inside handlebars. Upgrading from the stem mounted Junction-A box to inside the handlebars creates an exceptionally clean front end of your bike and ensures you are utilizing the latest technology, so while it's not essential, it's certainly worth considering. The process for changing the battery and upgrading the firmware is the same, but in this case, specific handlebars that can house the Junction-A box and has internal cable routing are required. You'll also then require a specific stem that allows for the internal wiring to complete the process.

Once you have everything you need, it's a case of swapping over the stem and handlebars, and internally routing the Junction-A box wires. This whole process can be quite tricky, especially if you're don't have a lot of experience routing wires or upgrading components on your bike. Therefore, it might be best to go straight to your local bike shop to ensure the upgrade is performed properly. Once the cabling is completed, the stem and handlebar need to be installed and wrapped in some fresh bar tape to complete the build.


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