12-speed Di2 New User Guide
Just bought a new 12-speed Di2 bike? This page explains what the buttons do, how to charge, and what synchronized shfit does.
This DURA-ACE Rear Derailleur is part of the 12 speed system, semi-wireless, and uses a new battery, the BT-DN300.
It features a charge port, LED, button, and an EW-SD300 type port used to connect the derailleur to the battery. Both the rear derailleur and the front derailleur connect to the battery using a wire.
The shift levers send their shift commands to the rear derailleur wirelessly.
These 12-speed derailleurs use the same charger as the new Di2 power meters, and perhaps even better: the port cover can be replaced when broken.
Keep having to go back to the manual to read what the LEDs mean or what the button does? Download my Cheat Sheets, print them, and keep them close to your bike. That way you'll never have to look for the manual again.
Since the main junction functionality has moved to the rear derailleur, Shimano also changed the method of getting out of crash mode. Pressing the button on the rear derailleur would be hard during a race, so you can now shift out of crash mode.
To get out of crash mode on 12-speed road bikes, shift up and down the entire cassette. This video by Rides of Japan explains it well:
Early versions of the RD-R9250 had an issue where on some occasions the chain would at times touch the chain guard - that small tab between the two jockey wheels. This didn't impact shifting, but it did cause excessive drivetrain noise and clicking.
Shimano quietly updated the RD-R9250 outer plate to include a slimmer chain guard, fixing the issue.
If you are experiencing excessive drivetrain noise on your R9250 bike, be sure to check the chain guard for impact marks. Your bike shop will be able to get a new one from Shimsno. Alternatively, you can file a bit off so that the chain no longer hits the tab.
The updated chain guard looks like this:
The part number for the new outer plate is Y3GK98040 - exactly the same as the original version of the outer plate. However, sometimes the new part is also referred to as "R9250pcage".
Just bought a new 12-speed Di2 bike? This page explains what the buttons do, how to charge, and what synchronized shfit does.
Sizing and installing a new chain for your Di2 bike isn't hard, you just need to follow the right steps. Read this page to learn more.
This page shows you how to install your 12-speed Di2 rear derailleur, set the B-screw, limits, and fine-tune the shifting using micro-adjust
Synchronized Shifting - what is it exactly? What does it do and how can you set it up? This page will guide you through the process of setting up synchro shift.
Shimano front derailleur and rear derailleur specifications... what do they mean, really? This page explains all of them, and why they matter.
Below is an overview of all known firmware updates for this component. The changelog texts are Shimano's, and quite often they're a bit cryptic - sorry!
4.2.3
■ ChangesSecurity performance for wireless communications between the shifter and rear derailleur has been improved.Click here to view FAQs for more information. https://bike.shimano.com/faq/DI20A#D-7030*The firmware for both the shifter and rear derailleur must be updated for proper operation of the Di2 system.■ OthersGeneral bug fixes.
4.2.0
- The FRONT SHIFT NEXT function is now supported.- General bug fixes.
4.1.1
The issue where the rear derailleur cannot be adjusted on E-bikes with a third-party drive unit has been fixed. - The issue where the rear derailleur cannot be adjusted using E-TUBE PROJECT Cyclist has been fixed. *If you are experiencing this issue, SM-PCE02 and E-TUBE PROJECT Professional are required to perform an update. Please contact your place of purchase.
4.1.0
- EW-EX310 is now supported. - Fixed identified issues.
4.0.7
Stabilized the wireless shifting operation and optimized the LED display.
4.0.4
Firmware released.