Dura Ace 9170 Di2 Hydraulic Shifters

The 9170 shift levers are designed for Di2 electronic shifting and Hydraulic disc brakes. These shifters are not compatible with rim brakes or mechanical shifting. The form of the lever body is comfortable and ergonomic. The shift paddle engages with a defined click that assures the shift has been made. Similar to previous versions, the upshift and downshift paddles are adjacent to each other. 

A Variety of 11-Speed Cassette and Gear Combinations

Since the 9170 group is 11-speed, these shifters are designed to work only with an 11-speed cassette and a double ring chainset. Dura Ace 9100 has several wide cassette gear combinations including: 11-28T, 12-28T, and 11-30T. For closer gear combinations you can choose from the traditional 11-25T or 12-25T cassettes. There are a total of 5 different cassette options at the Dura Ace level. If none of these meet your requirements, Ultegra has some slightly different ranges including an 11-32 option.

The advantage of electronic shifting over mechanical is the myriad of ways it can be customized to suit different shifting styles. Controlled by Shimano’s E-Tube Project App, various shifting functions can be programmed into the levers to accommodate personal requirements. For example, you can use the multi shift function to allow for longer lever presses to shift across multiple gears at once.

Electronic shifting is basically a set and forget installation. Once it is dialed in, it generally will not require any further adjustments. Expect precise and consistent shifting every time. Your only concern at this point is keeping the battery charged which should only require a full charge every 3-6 months.

If you have incorporated the Shimano EW-WU111 wireless unit into the Di2 connection network, it is possible to wirelessly control the Di2 derailleurs with a wireless ANT third party app. 

With the Di2 electronic components connected to Shimano’s E-Tube software or app, the electronic gear shifting system can be programmed in a multitude of ways. The app is straightforward to use and works with Windows, iOS, and Android. The software is user friendly and allows for easy customization and setup as well as firmware updates. 

Shimano’s electronic groupset for mountain bikes has been somewhat of a testing ground for features that later become available for the road groupset. This is the case for the inclusion of three different shifting options available for the 9170/9150 dura ace group. 

Manual, Syncro, and Semi-Syncro Shift – What’s the difference?

Typically, the shifter will go up one gear with the outer shift paddle, and down one gear with the inner shift paddle. This is the case for both the front and rear derailleur. This Manual shift mode is what is traditionally used for shifting. Now, with the addition of the hidden button underneath the top of the hood, it is now possible to program this upshift and downshift function to these buttons which allows for shifting while your hands are resting on the hoods as opposed to having to go into the drops to shift. This can be convenient and provide a more relaxed and smooth shifting experience. 

The second shifting setup is Syncro Shift. With this setup, you will essentially have automatic shifting with one press of the button or shift paddle. This will accommodate for cross shifting by automatically adjusting the front chainring if required. For example, if the intent is to find a lower (easier) gear than it is possible that pressing the shift lever or top hidden button will tell the system to go from the big ring to the small ring up front but maybe a smaller cog on the cassette. Where as without syncro shift, the shift will only go to the larger cog on the back and remain in the large chainring. This of course is not necessarily the optimal gear ratio which is why syncro shift has benefits in this regard in that it can find a more suitable gear but adjusting both the front and rear derailleur simultaneously. 

The third programmable shift function is semi-Synchro Shift. This shifting is more of a compromise and is better suited to road riders. In this case, shifting the front derailleur will automatically move the rear derailleur a certain number of cogs at the same time. The advantage is that it will keep the cadence more consistent when shifting just the front derailleur alone. Rather than a large jump going from the small to big chainring, the rear derailleur will also adjust such that a large jump in cadence is minimized. This is essentially identical to shifting manually by adjusting the front and rear at the same time to minimize the amount of jump in gear ratios. While pedalling and needing to go from large to small chainring or vice versa, the immediate gear change will be less significant and pedal cadence can be maintained. 

The Junction box has a button to manually switch between these three shift modes while riding. You can experiment with the best setup to suit your riding style. If you are accustomed to old shifting habits then it will take some time a patience to get used to using syncro shift or semi syncro shift. Experienced bike riders will automatically do what syncro does and it may overcomplicate their shifting habits. In this case you can leave it on manual or try to re-wire your habits to work with the more automated setup. 

The Shimano E-Tube software allows further customization of how the gears are mapped and which combinations will engage depending on current gear and whether it’s an upshift or downshift. I’m not sure about how practical all these custom settings will be but it is there if needed.  

Of course, none of the fancy syncro features are required and it works perfectly fine with normal shifting in manual mode for those that are unable to break from their ingrained, long-standing shifting habits.

Overall, these shifters were great for both shifting and braking. Everything is smooth, the fit is comfortable, and the system if light weight. It should be a low maintenance endeavor once setup is dialed in.