System Information Display - Junction A
The SC-M9051 System Information Display shows you what gear you're in, has a battery level indicator, charging port, synchronized shift mode display and also doubles as a Junction A - it has 3 e-Tube ports for you to connect components to it. The displays lets you charge the system and also connect to it using Bluetooth or ANT+.
It supports both 31.8mm and 35mm diameter handlebars.
If you're thinking of using this display on your road bike to replace your Junction A (SM-EW90 / EW-RS910) and Wireless Unit - you can! Be aware that you can only have one component with wireless/bluetooth functionality connected. If you connect both this and a Wireless Unit the Di2 system won't function.
Functionality wise this unit is identical to its cheaper XT sibling, the SC-MT800. The casing is not, but that is the only difference.
Synchronized shifting on mountain bikes
You will also need a System Information Display. It is not clear why exactly you need one, but I've asked Shimano and they have confirmed that a display is required for synchro shift on mountain bikes.
Pairing the SC-M9051 - when the 'C' doesn't show
If you've been trying to pair one of these displays to a mobile phone you may have run into the issue of the 'C' (connection mode) not showing. Some of these units do this, depending on the firmware version. This generally isn't a problem, because they do actually go into connection mode. They just don't show it.
I have written more on this in the SC-M9051 Installation guide.
Details & Specifications
|Shimano model number:||SC-M9051|
|E-Tube Port type:||SD50|
|Component series:||XTR M9050 (MTB)|
|Downloads:||XTR M9050 Dealer Manual|
Information Display User Manual