Shimano Syncro Shift – Advanced Shifting Technology

By Mitch Rosset

Oddly, my exploration into Shimano’s Syncro Shift started with a fat bike. I purchased an inexpensive fat bike to see if I would enjoy riding one. The bike was a blast, but when riding the local trails, a frustrating problem arose. Our trails have short, steep downhills that feed into abrupt, steep climbs. Flying down hills on a fat bike was a thrill, but climbing those testy steep ones that often follow was not so much fun. The components wouldn’t allow me to shift fast enough to have a proper gear in which to climb.

Being a roadie at heart, I’m not a fan of the 1x (1-by) set-up. Therefore, to climb quickly, I needed to shift to the small chainring in front and drop several gears in the back. So what would happen? I wasn’t able to shift the front and back as fast or accurately as I wanted, so I would stall out mid-climb. Thus, the walk of shame, dismounting halfway up the hill and walking up to where I could remount.

It got extremely frustrating, because I had a bike with traction enough to climb the hill – and I had the power to get up the hill if in the right gear – but instead, I was walking. So what was the answer?

Shimano’s superb off-road version of Syncro Shift in the XTR series of components. I installed the XTR Di2 group, set up Syncro Shift and couldn’t be happier with the results.

But how does this relate to road riding? Read on.

What the heck is Syncro Shift?

According to Shimano’s website, Syncro Shift “gives riders the simplicity of a 1×11 drivetrain, with the gear range and gear steps of a 2×11 drivetrain by utilizing a single gear shifter (or two shifters, if you prefer) that can control both the front and rear derailleurs through programmable gear mapping.”

That’s a lot to understand. So let me explain, and elaborate. And give you a quick thought to plant in your head: think of it as an automatic transmission, of sorts.

Syncro Shift is Shimano’s adaptation of their second-generation Di2 to allow a bike to automatically shift to advantageous gear combinations. No longer will the rider be able to shift into extreme cross-chain situations like big-big or small-small.

For example, when climbing in the large chainring and the second-largest cog in back, the next shift of the right-hand shifter (assuming the rider is looking for an easier gear) would automatically move the front chainring to the small ring and the rear cog to a preset gear combination (in this case, a gear one step easier than the combination of big ring, second-largest cog).

Syncro Shift allows you to select, within a range, what gear combinations to be utilized. This eliminates the rider worrying about if and when to shift the front ring. All front shifts can be left for Syncro Shift to control. Ultimately, the system avoids cross-chaining and achieves better utilization of power.

Is Synchro Shift Backward Compatible?

Syncro Shift is installed in both the Shimano 9100 and Ultegra 8000 Di2 series. These are current and soon-to-be released Di2 versions. For older Di2 applications, you’ll need to purchase a new battery, either BTDN110 (internal) or BT-DN 100 (external). The upgraded software is included in the battery, and when the firmware is updated in Shimano’s E-Tube Project, the two new shifting options become accessible. These older applications include the 9000 Dura-Ace Di2 and 6800 Ultegra Di2 series. (Note: Syncro Shift cannot be back-mated with 10-speed Di2 versions.)

The photo above shows the various boxed components of the “add on” system. The new battery lists for around $150. Installation is as easy as substituting the new battery for the old one. When installing the new battery, I highly recommend adding one of the new D-Fly units (sells for under $100). There are two types of D-Fly units available, the older style mounted by the rear derailleur, which is obtrusive and can be knocked off. Or a new, smaller unit that can be hidden up by the junction box or run internally (so I’m told).

The D-Fly enables the Di2 system to communicate with your Garmin (or similar) head unit. You will also need one more short Di2 cable to connect the D-Fly unit. Select Garmin models have an additional screen that displays battery strength, shift mode, and currently used front/rear gear combination. I use a Garmin Edge 1000. (See the photo, left, of my screen display.)

Syncro Shift will run whether you have the Garmin screen displaying or not. You also can add key features of Syncro Shift to your default dashboard screen.

Note: The Syncro Shift software is found in the battery and will be available for use in all new units moving forward.

Syncro Shift offers modes for ultimate system performance

Syncro Shift has two levels of system performance, as well as manual mode.

Mode #1: When the front derailleur is shifted, the rear derailleur shifts two cogs. For example, if you shift to the small chainring, it triggers the rear derailleur to move down two smaller cogs. But shifting into the larger chainring, the rear moves up two larger cogs.

If you are already in the largest cog when you shift the front chainring to the large ring, no additional automatic shifting occurs. This is useful, but not a game changer. What it mimics is your current front derailleur shifting pattern.

Mode #2: This one I found quite intriguing. When in the small chainring and you shift to pre-selected harder gears on the cassette, the bike will automatically shift into the large chainring and to a pre-set gear in the rear. This mode eliminates cross-chaining, as well as shifting two shifters at once. The result is no loss of speed and/or effort while shifting to an appropriate gear.

Now, here’s the part that truly opens up the joys of this system. Let’s say you’re climbing a hill in a 50 x 25 combination, with the 28 as your biggest cog. The next shift of your rear derailleur puts you into a cross chain 50 x 28, right. Wrong. Syncro Shift automatically shifts to the small chainring and whatever cog has been pre-set in the rear. Not sure what to run in back? Leave the default system in play, Shimano engineers have spent plenty of time figuring out what’s best.

Play around with your presets

Plug your Di2 into a laptop with E-Tube Project installed and follow the prompts. An easy-to-digest bar diagram will open, and sliding the colored tab up and down enables you to select from acceptable gear combinations. There are myriad other tweaks in the E-Tube Project, but in this article I’m focusing on those that apply to Syncro Shift. If you have a Di2-equipped bike, I highly recommend taking the time to download the E-Tube Project. Hook your bike to your computer to learn how to take advantage of all that Di2 offers.

Leverage the E-Tube Project app

The latest application ofE-Tube Project works with mobile devices (smart phones and iPad). I downloaded the app to an iPhone 7 and could easily change the parameters from my phone. (See the photo, left, from my phone.)

But why would I ever want to do that? One recent example was on a century ride. I used the gearing combinations that felt fine for me in the morning, but it felt too aggressive for my tiring legs in the afternoon. A couple of clicks in the app and I let the bike help to pick easier gear combinations that better fit my tiring legs.

Summing it all up

Is Syncro Shift a game changer? Shimano’s own marketing material states that “Syncro Shift is the kind of thing you don’t completely understand until you try it.”

Syncro Shift can eliminate the front derailleur shifter and does away with all extreme cross-chaining. I would certainly say this is a game-changing development. I’m thrilled to have this advanced shifting on both my road and fat tire bikes.