Dura Ace RD-7970 10 speed Rear Derailleur

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**Compatibility warning**: none of the 7970 series components will work with other generation Di2 components. The plug is different and simply won't fit.

This 

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Di2 Rear Derailleur User Manual

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DURA-ACE 7970 service instructions

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

This page has moved to [Installation guides > Micro-adjust your 10-speed and 11-speed road bike rear derailleur](/installation-guide/micro-adjust-your-10-speed-and-11-speed-road-bike-di2-rear-derailleur/). You should be redirected automatically, but please click the link if that doesn't happen.

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Indexing, trimming, or fine-tuning Di2 rear derailleurs is done through micro-adjustment. Read how to set up your Di2 rear derailleur perfectly and ride without those grinding noises.

How to micro-adjust your road bike Di2 rear derailleur

In 2009 Shimano released the DURA-ACE 7970 series - the company's first Di2 groupset. It uses a five-wire protocol and plug and therefore none of these components are compatible with any of the other Di2 series - you simply cannot plug them in.

Rear Derailleur (10 speed)

DURA-ACE RD-7970-SS

Affiliate Links

Specifications

Related components

Related pages

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

How to micro-adjust your road bike Di2 rear derailleur

Manuals & other documents