SHIMANO 105 Di2: All you need to know

It is our only premium groupset with a mechanical and electronic shifting option. SHIMANO 105, often called The Groupset of the People, enables countless riders to experience premium shifting at a competitive price. The first edition of SHIMANO 105 Di2 comes with heaps of novelties and upgrades.

We asked Shimano Road Ambassador Joshua Gordon to ride up Alpe d’Huez with his SHIMANO 105 Di2 setup and share his experience.

Sidenote: We also covered our SHIMANO 105 Mechanical 12-speed groupset in the article 'SHIMANO 105: Mechanical Magic'.

105 Di2: Wireless and Elegantly Wired 

Josh kicks off: “I love the new wireless shifters because they have a super clean handlebar area with fewer cables, and my integrated one-piece bars made installation easier and gave less to worry about with cable management. Plus, shifting still feels instant and precise, so there is no noticeable loss in performance. Still having a wired connection from the battery to the derailleurs also means a super reliable power source.”

SHIMANO 105 Di2 utilizes a hybrid system with a wireless cockpit and a subtle, wired connection between a single, seat-tube-stored battery and mechanized front and rear derailleurs. The Di2 setup shifts crisply and precisely, making it a reliable companion on your journey.

With the clean cockpit comes a beautiful look. Just check out these SHIMANO 105 Di2 bikes curated by our team.

How Di2 shifting works

“Synchro and semi-synchro shifting on the Di2 system is a game changer I have used for years. I love using full synchro mode for automatic front shifting; no worrying or thinking about my gear ratio… It’s like having a virtual assistant managing my gears for me.”

It is the same system you’ll find on ULTEGRA and DURA-ACE groupsets. We have precision-engineered Di2 components to deliver smooth, fast and nearly frictionless shifting performance, meaning none of the premature wear or power loss that can come from having a misaligned drivetrain. Instead, Di2 knows the chain's location on the cassette and automatically trims the front derailleur into the optimal position to eliminate chain rub.

“Yes, I’ve used E-TUBE, and it makes setup, indexing and customization so easy! I love that I can micro-adjust by jumping into the app. It recently saved my ride when my mech hanger got bent while traveling. Rather than trying to fix it on the side of the road, I just adjusted my indexing through the E-Tube app, and it saved my ride!”

Like DURA-ACE and ULTEGRA, SHIMANO 105 Di2 is highly customizable and uses a user-friendly smartphone app, E-TUBE PROJECT Cyclist. With E-TUBE PROJECT Cyclist, you can set up your drivetrain just the way you like it, adjusting shift speed, altering the number of shifts per button actuation, or activating synchro or semi-synchro shifting functionality.

Say you’re headed up the Alpe d’Huez. Here’s how SHIMANO 105 Di2 would handle it—in great style.

How does E-TUBE work? 

Di2 is programmable to allow you to shift through multiple gears at once by holding down the shifting button. It’s the perfect set-up for wide gearing swings like a quick transition from a descent to a climb or when attempting to chase back on during a road race or spirited group ride. You can also utilize Synchronized Shift functionality, which allows you to program the system to change from your smallest gear to your biggest gear without having to do the math in your head.

Consider this scenario: You’re on rolling terrain with your chain situated in the middle of your gear range. Then you hit a steep climb. Should you move the chain into your small chainring and stay in the middle of the cassette or stay in the big ring and shift the chain to a larger rear cog? With Synchronized Shift enabled, you can skip the logic problem. Shimano Di2 automatically senses when your gearing choice requires a change in a chainring. Now that’s Digital Integrated Intelligence at work.

If you prefer more control, you can opt for Semi-Synchronized Shift where the rear derailleur makes a compensating shift when you move the chain from one chainring to the other. That means you’ll never be in too low or too high a gear immediately after shifting. You can even select the number of cogs the rear derailleur shifts up or down when you change chainrings. It’s completely up to you and your personal preferences and needs.

You can also use E-TUBE PROJECT Cyclist to pair the system with third-party cycling computers such as Garmin or Wahoo, which, for example, can allow you to monitor gear selection or track battery status. If you run Dura-Ace or Ultegra shifters, you can also scroll through your computer’s screen using the hood buttons on the Di2 dual control levers, meaning you don’t have to take your hands off the bars to check the time or monitor miles covered. Whether using Dura-Ace, Ultegra, or Shimano 105 Di2 12-speed levers, you can use Synchronized Shift, assign all shifting duties to one shifter, and use the other shifter to scroll through a GPS screen. 

105 Di2 Batteries

“A full charge lasts ages, even with lots of riding. The biggest compliment I can give the battery life is that it lasts so long that I completely forget it actually needs charging. So I have had to connect my Di2 to my cycling computer so I will get a reminder that it is running low, which gives me plenty of notice to charge it up… It also charges quickly if you are in a rush to get out.”

How many kilometers can be cycled with the new Shimano 105 Di2 group exactly? With a fully charged battery, you can ride 1,000 km without any worries. After 1,000 km, you connect the cable supplied to the port on the back of the rear derailleur. There is no need to remove the battery from the bike. 

The 105 Di2 group's shifters contain 2 CR1632 button cell batteries, which have a service life of 3 years. Does the front derailleur no longer work while cycling? Chances are your battery will need a charge. This will not stop your rear derailleur, meaning you’ll still be able to cycle home.

Here’s how you can tell whether your Di2 battery is charged.

SHIMANO 105 or ULTEGRA?

SHIMANO 105 Di2 uses trickle-down technology from DURA-ACE and ULTEGRA, providing a premium experience tried and tested by professional, WorldTour-winning cyclists. The current ULTEGRA R8100 is 300 grams lighter than SHIMANO 105 R7100 Di2. Yet, like the latest DURA-ACE and ULTEGRA groupsets, SHIMANO 105 features a revamped braking system that’s quiet, easy to maintain, and reliable.

SHIMANO 105 Di2 has new disc brakes, a new chain and cassette, new derailleurs (front and rear) and new shifter ergonomics. That's a lot of new. The new shifters stand out with a slim, ergonomic design, just like ULTEGRA. In addition, the distance from the handlebar to the grip can be adjusted for any size hand or riding style, thanks to our range adjustment technology.

Ultimately, 105 Di2 offers the electronic power of ULTEGRA at a lower price point. Top-line features include a fast initial contact point with a wider control zone and 10% wider pad-to-rotor clearance to help avoid brake noise. Home mechanics will also appreciate a more user-friendly brake bleeding process that can be done without removing the caliper from the frame.

Want to learn more? We’ve prepared a maintenance checklist to give you all the insights you need to keep your bike running smoothly.

105 Carbon Wheels

Continuing the theme of affordable trickle-down technology, Shimano is also launching two carbon road wheelsets—the C32 for climbing and C46 for all-around use. Both share DNA with the C36 and C50 Dura-Ace and Ultegra wheel options, balancing aerodynamics, lightweight and rigidity.

Here’s how Gordon rated our SHIMANO 105 Carbon Wheelset: “The 105 wheels have been absolutely rock-solid! I was using DURA-ACE C60s previously and I still own them, but I have kept the 105 wheels on my bike. I have ridden them in the Alps and flat roads, and personally I have not noticed any sacrifice using them… they also look great which is a plus!”