component-FD-M9050

The XTR Di2 M9050 Down Swing Front Derailleur features easy shifting at the press of a button, improved gear tracking and reliable gear changes even under load.

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XTR M9050 Dealer Manual

manual-di2-front-derailleur

Di2 Front Derailleur User Manual

It also supports Shimano Synchronized Shift and computer controlled auto trim. Note that you **need** a display in order for synchronized shift to function with MTB derailleurs.

I recommend either the [SC-MT800 display](/component/xt-display-junction-sc-mt800/), or its XTR equivalent, the [SC-M9051](/component/xtr-display-junction-sc-m9051/).

Did you know most 10-speed and 11-speed Di2 hardware is cross-series compatible? You can actually mix different series and even different generations of Di2 hardware, as long as you make sure you follow the Di2 compatibility chart!

Hidden somewhere on the Shimano E-Tube Project website is a [Di2/e-Tube compatibility chart](https://bike.shimano.com/en-EU/e-tube/project/compatibility.html). This useful PDF helps you select your components, making sure they're compatible before spending $$$ and installing them on your bike.

Have a nice Ultegra 6870 setup but want the [newer R8000 shifters](/component/ultegra-dual-control-lever-st-r8050) so that you have [extra buttons on the hoods](/enable-the-buttons-on-your-di2-shifter-hoods)? You can!

Want to use the [mountain bike Di2 display](/component/xt-display-junction-sc-mt800) on your road bike? You can!

Feel like upgrading your derailleurs but not your shifters? Sure! You can!

## 12-speed Di2 compatibility
Before I get started though, a quick note on 12-speed Di2 compatibility. Shimano released their [12-speed DURA-ACE and Ultegra Di2](/dura-ace-r9250-ultegra-r8150-wireless-di2/) groupsets to the world on September 1st, 2021. 

While Shimano has been pretty good with backward compatibility in the past, these new groupsets actually feature *very* limited compatibility with the older Di2 series. There is [a page on 12-speed compatibility](/12-speed-r9200-r8100-and-11-speed-di2-compatibility/), so read that if you're looking for 12-speed Di2 information. 

The remainder of this page applies to 11-speed and 10-speed Di2 compatibility, **not** the newer 12-speed Di2.

## Compatibility chart? Where? How does it work?
The latest version of the compatibility chart can be found on the [Shimano e-Tube project website](https://bike.shimano.com/en-EU/e-tube/project/compatibillity.html). At the time of writing the latest version of the chart is 5.0.1.

Let’s say you want to know whether your [Ultegra RD-6870-GS](/component/ultegra-medium-cage-rear-derailleur-rd-6870-GS) rear derailleur and [Dura-Ace ST-R9150 shifters](/component/dura-ace-dual-control-lever-st-r9150) are compatible with each other. Start with your battery and work your way down.

![Di2 e-tube compatibility - connected boxes](https://assets.bettershifting.com/di2_etube_compatibility_boxes_connected_87eca69a3c.png)

In the image above I have selected the [SM-EW90](/component/below-the-stem-junction-a-sm-ew90) Junction box, [R9150-series Dura-Ace shifters](/component/dura-ace-dual-control-lever-st-r9150) and two 11-speed derailleurs; the [RD-6870 Ultegra rear derailleur](/component/ultegra-medium-cage-rear-derailleur-rd-6870-GS) and the [Ultegra FD-R8050 front derailleur](/component/ultegra-front-derailleur-fd-r8050-f). Note that I could also have selected the [Dura-Ace FD-R9150 front derailleur](/component/dura-ace-front-derailleur-fd-r9150-f) if I wanted to.

Shimano recommends you use components all from the same series, because that’s when they perform best. However, this isn’t feasible for everyone and fortunately, they allow you to use different generation components on the same bike..

The only thing you can never do is mix different speed **derailleurs** or mtb / gravel / road **derailleurs**. **__All derailleurs have to support either 10-speed or 11-speed and from the same ‘category’__**.

### Mixing MTB and Road/GRX components
So.. can you use mountain bike di2 hardware with road hardware? Sort of… it’s complicated. You can definitely use road shifters on a mountain bike – but would you really want to? However, let’s say you wanted to build a 1×11 Di2 setup? You’d probably want to take advantage of the Clutch System Shimano equipped the mountain bike rear derailleurs with, but use your road shifters. You should be able to do this no problem! Alternatively you can use a [GRX rear derailleur](/component/grx-2x-rear-derailleur-rd-rx815) with road shifters, or the [Ultegra RX805 clutch rear derailleur](/component/ultegra-shadow-rd-rear-derailleur-rd-rx805-gs). 

The only real limitation is that derailleurs you use have to be either road/gravel or mountain bike derailleurs – **__you cannot mix these derailleurs__**. Other than that you’re free to do whatever you want.

<LImage width="250" height="250" alt="Alfine MU-S705 motor unit" src="https://assets.bettershifting.com/component_MU_S705_c44237316f.jpeg" />

## E-Bikes, Di2 hubs, motor units
Plenty of people are building Di2 E-Bikes using the [MU-S705](/component/alfine-internal-geared-hub-motor-unit-mu-s705/) or **MU-U500**/**MU-U510** motor units and [Internal Geared Hubs](https://bike.shimano.com/en-EU/product/component/alfine-s7050s705-di2/SG-S7051-11.html). 

While the hubs are Di2-specific, they are not actually connected to the Di2 system. They're just designed to work with the Di2 motor units and can handle the forces the motor units produce.

When it comes to compatibility though, looking up information on these units can be a little confusing. If you look up the hub, you'll find only a couple of entries. 

So what gives? Are the hubs only compatible with Bosch E-Bikes? Are the hubs not compatible with current parts at all?

Don't worry - everything is fine. You see, for compatibility purposes, that hub does not matter at all. **Di2 compatibility** for these systems is **determined by the drive unit**. Ignore the hub, just look at the MU-UR500/510 and the MU-S705 entries instead.

## Compatibility charts
Like you’ve read above, I've linked the Shimano Di2 compatibility charts. Click the image below to view the full compatibility chart PDF. Note that the pages relevant to your setup depend on which series hardware and, perhaps more importantly, which battery or battery mount you’re using.

[![Di2 e-tube compatibility charts image link](https://assets.bettershifting.com/di2_etube_compatibility_charts_link_e9de0203b8.png)](https://bike.shimano.com/content/dam/e-tube/assets/images/contents/project/compatibillity/pdf/en/HM-CC_5.0.1-00-EN.pdf)

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Di2 Compatibility - mix Ultegra, DURA-ACE, XTR, XT and GRX components

In another post I wrote how to [micro-adjust your road di2 rear derailleur](/micro-adjust-your-road-bike-di2-rear-derailleur/) and [front derailleur](/micro-adjust-your-di2-front-derailleur/). This time I’ll explain how to do the same with your mountain bike rear derailleur. The process is similar, but slightly different.

## Set up the rear derailleur
Make sure your rear derailleur is set up correctly – especially the distance between the guide pulley and largest sprocket:

- On a 2x bike, shift the front derailleur to the small chainring.
- Shift to the largest sprocket

Now check the distance between the guide pulley and the largest sprocket is within the specified range. Turn the B-screw if it isn’t – have a look at the image below for directions on how which direction and what the acceptable ranges are.

![Indexing and limit screws](https://assets.bettershifting.com/adjust_mtb_rd_index_b_screw_ebb86a429f.png)

##   Adjustment mode
In order to make adjustments to your rear derailleur you’ll have to enter adjustment mode. When you’re in this mode the shift buttons will only make adjustments – they won’t let you change gears. This is how it’s done:

![Fifth rear sprocket](https://assets.bettershifting.com/adjust_mtb_rd_rear_5th_sprocket_2e79255a90.png)

- Shift the rear derailleur to the 5th largest sprocket.
- If you use a **road Junction A**: Press and hold the button on your junction box until the red LED illuminates, indicating you’re in adjustment mode.
- If you use **System Information Display**: Press (read *note* below!) the button on the lower left part of the display once to enter adjustment mode. The adjustment indicator “**R**” will flash (“R” stands for Rear)
- Note: how long this ‘single press’ is varies, this can take anywhere from 0.5 to 2 seconds according to Shimano.

Easy, right? Now you can micro-adjust your rear derailleur using the shift buttons:

![MTB RD buttons](https://assets.bettershifting.com/adjust_mtb_rd_buttons_2d050595fc.png)

- Press shifting **button Y** to move the rear derailleur one step towards the inside (larger sprocket)
- If you’re using the System Information Display you’ll see the current adjustment setting on the screen.
- While turning the crank/front chainring keep moving the rear derailleur towards the 4th largest sprocket until it makes a **slight noise**
- The chain now touches the **4th sprocket**. Press the **X button five times** to move the rear derailleur 5 steps to the outside.
- Press the Junction Box/Information Display button until the red LED turns off or the blinking R stops blinking. You have now left adjustment mode.

Your rear derailleur should (almost) be set up perfectly now. Of course you can always enter adjustment mode again and make small changes, but this should be your baseline setup.

The only thing left to do now is to check and correct the high/low side stopper adjustment bolts. We’ll do the low stopper bolt first (largest sprocket).

![low stopper mtb](https://assets.bettershifting.com/adjust_mtb_rd_low_side_stopper_3f2aa42238.jpeg)

- Shift the rear derailleur to the largest sprocket
- Tighten the low-side adjustment bolt until it just touches the outer link
- (if it’s tightened too much it either won’t shift, make noise or shift back by one gear after about 5 seconds)

Now let’s do the high stopper bolt:

![high stopper mtb](https://assets.bettershifting.com/adjust_mtb_rd_high_side_stopper_1cb3d4072d.jpeg)

- Shift to the smallest sprocket
- Tighten the high-side adjustment bolt until it just touches the left link at the position where the rear derailleur stops.

Note that while you could do the micro-adjusting on the bike, it’s probably best to do it with the bike on a bike repair stand. This will allow you to notice when the chain is touching the 4th sprocket more easily. Questions? Problems? Just [send me a message](/contact/)!



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Indexing Di2 rear derailleurs is done through micro-adjustment. The MTB Di2 rear derailleur process is slightly different from that of road RDs. Read how to set up your MTB rear derailleur and stop that chain rubbing noise.

Front Derailleur (3x)

XTR FD-M9050

Affiliate Links

Specifications

Related components

Related pages

Di2 Compatibility - mix Ultegra, DURA-ACE, XTR, XT and GRX components

Micro-adjust your 11-speed Di2 MTB Rear Derailleur

Manuals & other documents