TESTED: Shimano’s New Dura Ace Di2

Shimano’s new Dura Ace Di2 11-speed electronic groupset is even better than their first… if that’s possible. By Neil Gardiner. Photos: Julie Santoro

The Story

Way up in the stratosphere of five-figure upgrade kits, Shimano and Campagnolo are duking it out, aiming to offer the ultimate in shifting performance, whatever the cost. Notably absent from the battle is SRAM, who have yet to hint at electronic gears for road biking. Shimano’s new flagship road group comes in two different versions, mechanical and electronic; the former – tested in our November 2012 issue – is actuated by the good old-fashioned cable system, and powered by you. The electronic set-up uses a lithium-ion battery, switches and two servo motors. We were keen to see how the new electronics match up to the Italian offering.


The Tech

As with the electronics industry, in cycling, things move fast. Shimano’s first-generation Di2 was incompatible with the improved 2012 Ultegra Di2 E-Tube wiring system; but now, the new Dura Ace follows on from Ultegra, with some upgrades.

Firstly, the junction box that connects up the system is available with five ports to connect more accessories, including a charger – useful if you opt for the internal battery (Shimano are now recommending that frame manufacturers allow for an internal compartment).

It’s also wirelessly compatible via ANT+, and with a firmware update, a Garmin can display Di2 data like gear ratio or battery charge (we haven’t had an opportunity to test this yet). It’s customisable using a PC – you can decide how many shifts it makes when you press and hold the button, perform diagnostics, even determine how hard each side shifts.

The levers have been reshaped with dual compound hoods for improved grip, and the button surface area is now wider. The new smaller and lighter derailleurs are less bulky than the prototype-like previous version. At the rear, the motor housing is integrated beautifully into the design. The front derailleur housing, where the brains are kept, is now more streamlined.

The Experience

Right off the bat, some of us found the hoods to be a little small in bare hands, though marginally better with gloves. We figured that’s because the average professional cyclist (around whom much of the tech development revolves) is generally smaller than our testers were. It’s purely subjective – others really liked having a full grip of the hoods. Secondary shift buttons on the bar drops are perfectly positioned for sprinting.

As for the shifting performance, it’s even more powerful than before, though we didn’t think that was possible. While under full pedalling load, the chain moves without a hint of protest at the rear, and the front is even more impressive. When holding the button down for multiple shifts, the chain engages quickly, and allows you to find the right gear based on feel, i.e. as your pedalling returns to optimum cadence – almost like a car’s auto gearbox.

The tactility has also improved. The buttons are still quite close together, but the extra surface area and the distinction between them helps, especially with full-fingered gloves.

With EPS, there’s a definite click at the exact point of shifting which helps you to ‘feel’ when the shift happens, and lift off the pedalling power for a split second to avoid grinding. This click is less noticeable with the Di2, but again it has to be said: the shifting under load is so good, it’s a moot point.


Possibly the most impressive aspect of the new Di2 is the weight, coming in around the same as the mechanical version. This saves over 200g on the last Di2. Impressive stuff, considering how amazed we were only three years ago when SRAM released a 10-speed mechanical group of about 2kg.

The Verdict

It’s neck and neck between Campy and Shimano – after all, they’re both top-end groups, and both operated by battery. To list the negatives and positives of either system would be an exercise in hair-splitting, they’re both so good. It’ll come down to personal choice – we like the Campy shifters, with slightly more ‘feel’, but found the shifting on Shimano to be more solid. There’s no particular stand-out feature that’d persuade us either way; but the idea of an internal battery could persuade us to go Japanese.

One Response to TESTED: Shimano’s New Dura Ace Di2

  1. Raymond Cox April 24, 2013 at 1:01 pm #

    The Shimano option is programmable tho weather you want your shifting quicker/slower or if you want to “swap shifters” from left to right.

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