Upgrading to Shimano Ultegra Di2 12-speed?

Running an 11-speed disc-brake road bike and thinking about upgrading to 12-speed for summer? Now’s the time to take a look at Shimano’s Ultegra Di2.

Maybe you’re in the enviable position of having a frame that you love, but it needs a little updating? You’ve looked at Shimano’s Dura-Ace and thought “that is beautiful, but the cost!” Then maybe you should take a look at Shimano’s second tier groupset Ultegra Di2?

While some riders – myself included – are happy to race on 105, others want the best. However while Dura-Ace is Shimano’s top-of-the-line groupset, Ultegra now shares most of its technology. And with Shimano Ultegra Di2 coming in at a significantly lower price point it is well worth a look.

A new shape for Ultegra Di2 hoods and lever reach can be adjusted by 16mm

And if you’re running an 11-speed groupset, you may be thinking about changing up to 12-speed. With that extra tooth you’ll get a wider range of gears. But it’s not just that, gone are the cables, gone are the bar end chargers and junction boxes. Shifting is faster, faster is always better yes? And setting up Ultegra Di2 12-speed is much simpler than 11-speed with the E-TUBE app.

You could also switch to a 1x set-up, it’s not just for gravel bikes. While you will lose some of that wide gear range, you’ll have a simpler, lighter drive-train. With no front derailleur, lighter shifters and cranks – if you go for 1x specific cranks – you’ll drop some weight.


Both systems use wireless shifters that communicate with a wired battery and derailleurs. Shimano say that by making the shifters wireless, it makes for a cleaner cockpit. This keeps your bars clear and helps make for a simpler build-up. Ultegra Di2 shifters have all-new ergonomics and each lever has three buttons that can be programmed – two on the levers for shifting and another on the top. The top button can be set interact with Garmin and Wahoo head-units. You can also add a set of satellite shifters to your bars to fine-tune your set-up. Each shifter uses a CR1632 battery to power the shifts and Shimano say you should get 1.5 to 2 years out of each.

And being wireless you can now communicate directly with Shimano’s E-TUBE App. This will allow you to fine-tune your set-up and load updates . As part of the Ultegra Di2 customisation you can choose to alter how many gears you change with each button press: how fast your shifts happen: or switch between synchro or semi-synchro gear shifts. And if you do experience any annoying rub on your gears, you can use the app to move the derailleur incrementally.

Ultegra Di2 rear derailleur
The Ultegra Di2 rear derailleur comes in only one cage length, minimising compatibility issues

Levers & braking

The new Ultegra Di2 levers have a lighter, smoother action than previous versions. This is something that has been taken from Shimano’s GRX Di2 levers. GRX levers use ServoWave technology to speed up initial pad travel. Once they’re on the rotor, power is applied in a smoother curve. General consensus is that the modulation and power is much better with the new Ultegra Di2. The pads are also set 10% further away from the rotors, reducing the chance of annoying rotor rub. And the rotors are the lighter and cheaper MT 900 and 800 from their Mtb range.

Ultegra now uses the MT 800 & 900 rotors from their Mtb range for improved braking

New battery for Ultegra Di2

Shimano have kept with an internal battery which powers the front and rear derailleurs. A new, smaller diameter wiring loom (SD-300) carries signals to the mechs. This gives high-security, faster processing and lower power consumption. Charging the battery is now done via a port on the rear mech and thanks to the larger battery you should get 1000km out of a single charge.


The backbone to both Dura-Ace and Ultegra Di2 is Shimano’s Hyperglide+ shifting. This came originally from their mountain-bikes groupsets. This uses shaped tooth profiles to control noise and vibration in the drivetrain. Shimano also say it makes for a “shockless” shift, even when pedalling under extreme loads. The extra tooth means smaller jumps between cogs and an 11-34 cassette gives a wider range of gears. And the 12 speed cassette is compatible with older 11 speed freehubs.

Ultegra Di2 shifters on handlebars
Ultegra Di2 shifters will give you a clearer cockpit and there’s one less set of cables to worry about

So, Ultegra Di2, it has all the advantages of Dura-Ace but for a lot less. With the weight ‘penalty’ only a measly 278g and around £900 cheaper, is Dura-Ace only for money-no-object builds and Pro Team riders? Take a look at Shimano’s website for full Ultegra Di2 lowdown.

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