It's hard to believe that electronic shifting has been in our vocabulary, let alone on our bikes, for less than half a decade. And while electronic perfection has now become the en-vogue aspiration point for engineers, it's easy to forget that Shimano got the bandwagon kick-started. We still remember the dropped jaws and even the skeptical and naysayers at the advent of 7970. We understood: it was relatively unproven technology. But now, we've already witnessed the unbranded prototype power of the Dura-Ace Di2 RD-9070 Rear Derailleur under the legs of pro teams throughout the 2012 season. Accordingly, we hold no reservation in saying that 9070 is perfection perfected.
Starting at the question that's on the tip of everyone's tongue, is it lighter than 7970? The answer is yes, but only by around eight grams. However, if you're like us, 9070's enhanced shift precision is more important than comparing lightweight to lighter weight. But, as long as we're making comparisons, you'll immediately notice that 9070 is far more compact than 7970, and the cable routing is simplified and cleaner. In fact, Shimano based the shape and connection points in tow with the Ultegra 6770 rear derailleur. And along these lines, we find that the relatively confusing setup and wire cluster of 7970 has been replaced with Shimano's newest generation of its E-Tube electronics system.
Now, with your PC computer, you're able to make rear derailleur adjustments and setting alterations without even picking up a wrench. So, while you're manually rotating the cranks, E-Tube allows you to direct and adjust the guide pulley up or down, as well as to shift the gears up or down the cassette. You can even program the number of gears that you're running, a vital application given that 9070 operates with both 10- and 11-speed cassettes. Of course, E-Tube also performs a complete system and problem diagnosis, pinpointing any possible human error as a result of improper setup or riding. This removes the slightest hint of shifting inaccuracy, essentially keeping your shifting system running on-point at all times, even if you don't possess a fiber mechanical aptitude.
Extending this sense of power-to-the-user functionality is 9070's ability to shift up to a 28 tooth cassette capacity. Now, with 11-speeds and a high gear capacity, your available gear range will propel you through the fastest and steepest conditions that the road will throw at you. And when speeds become fearsome, and a crash unfortunately occurs, the derailleur cage will move itself out of harm's way, protecting at least one of your investments.
The Shimano Dura-Ace Di2 RD-9070 Rear Derailleur is available in one color and in one size.
Confused about how to build your Di2 Kit? Read our Learn Article.
- 11-speed derailleur with a 28-tooth maximum cog
- Programmable shifting
- Simplified cable routing over 7970
View more Road Rear Derailleurs
Reviews & Community
Zero issues, exactly what you want
Having used Ultegra Di2 on a couple of other bikes, I was ready to step up to the Dura Ace version. Lighter, crisper and more durable. Can't wait to use it this spring.
does this component come with the shimano tool that is needed to plug / unplug the wiring from the component?
No, but the shifters come with the tool.
- Familiarity: I've put it through the wringer
Need I say more? A little tight on the clearance with my Tune DC14 skewer nut but that DA doe...
Is it actually correct to state that "9070...
Is it actually correct to state that "9070 operates with both 10- and 11-speed cassettes"? Emailing Shimano directly resulted in the advice from their Technical Support team that the only way to run the new 9070 Di2 system with a 10-speed drivetrain is to use the Ui2 derailleur. RD-9070 only works with a 11-speed drivetrain. Can you confirm what's the actual situation and how, if possible, 9070 Di2 can be made to run 10-speed?
I believe I'm correct that there is no way to configure it to run with a 10spd cassette. However, that said, I think you could probably "hack" it, by adjusting the high or low limit screw to stop at cog # 1 or 10, either highest or lowest. If you then shifted beyond that, the derailleur will hit against the screw and not go anywhere. You would then have to push it twice to shift in the other direction. but why don't you just buy an 11 cog cassette? If you're wheel hub won't accept an 11spd cassette, you can probably buy a new cassette body from the hub manufacturer. I did that for my wife's American Classic wheel. (Note: the wheel will need to be redished if you install a larger cassette body.)