Product Overview

Overall rating:

Score 10


  • Works brilliantly
  • Fast, accurate shifting
  • Auto trimming of gear selection
  • Well sealed from the elements


  • Cost compared to mechanical counterpart


Ultegra Di2


Price as reviewed:


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When we first heard about Shimano’s Ultegra Di2 , electric shifting group set we were genuinely excited. Regular readers will be well aware of this as we bang on about it with such regularity, some of you may be forgiven for thinking we work for the Japanese giant – or have shares in the Ultegra factory.

The truth is, we were, or still are, supremely impressed with Dura-Ace Di2 in use, but acknowledge that it’s well out of reach for a huge proportion of the cycling market. With Ultegra’s electronic shifting (known in the office as Ui2), Shimano aims to bring all the benefits to a more cost-effective level. We in the Tech team feel it’s a pretty important step and it certainly got us thinking.

What’s it for? This is a question we have asked ourselves for the last 12 months since first being shown the groupset in a back country hotel in Warwickshire. Is it a racer’s groupset, much like its original big brother Dura-Ace Di2?

Will it be more suited to the sportive rider? Does the type of cycling done matter or is it simply suited to experienced riders who’ll be able to get the most out of it? Perhaps, conversely, it’s for the beginner, the less experienced, less mechanically sympathetic or knowledgeable rider who’ll benefit from the ability to shift whenever they choose to than rather than when gear changes should be made?

When we originally planned the test, the idea was to get a huge range of the Ultegra Di2 bikes available and conduct a big shootout-style test. When we actually thought about this we realised that the most comfortable or lightest bike wasn’t really all that relevant to the success of the groupset, so this test has ended up a little bit different.

We tested Ultegra Di2 bikes to use in races, as well as winter riding and commuting. We put the bikes under women, beginners and very experienced riders. On long rides, short rides and rollers and turbos. In fact, pretty much anywhere we could and we used as wide a range of testers as possible to try to answer the questions we’d asked ourselves previously. So, get the kettle on and come on the journey with us. Ultegra Di2 – who is it for, really?

What is it?

Ultegra Di2 is Shimano’s second tier of electronic shifting. To say it’s a cheap option would be untrue, but comparatively, it’s far more affordable than the Dura-Ace Di2 launch product. The same push button shifting system is retained, the same super-long battery life is evident, it has the same auto-trimming front derailleur, the ability to add periphery controls is coming, and to the everyman, it offers all the benefits of Dura-Ace mechanical. Here at CW, we reckon that’s a pretty big deal.

The racers choice?

When Shimano developed their first electronic shifting groupset – Dura-Ace Di2 – it was aimed fair and square at the professional racer. The top-flight product was to be used in the big races as a showcase for what the Japanese company could do.

The racers would make the most of the speed and accuracy – and had been part of the development process so this made perfect sense. We wanted to know whether Ultegra Di2 was equal in the competitive realms and if it would have as similar focus.

When STIs were invented, the quantum shift in the regularity of gear shifting was huge. No longer did you need to choose a gear before a decisive sprint or steep climb and hope you had it right. The hesitation as riders let go of bars to shift on the down tube was often enough for an attack to get a gap that couldn’t be closed. With the ability to change gear always at hand, racers changed gear far more often, and, as a result, found themselves in the correct gear more of the time.

Electric shifting offers a similar leap again in our opinion, particularly the front shift. There are often times in a racing situation where people won’t change to the smaller chain ring, and struggle up inclines in the big chain ring, slightly over-geared.

They don’t want to risk the hesitation in momentum a front shift requires as the hill is crested and an important jump has been made by rivals. The upshot of this is that riders’ legs are far more cooked than they need be from pushing a big gear early and often in a race.

When the important move goes, the wary shifter may get cramp and loose out, despite having the fitness or ability – all because they’re as hesitant as an older rider would have been with down-tube shifters. Ultegra Di2 will change the front shifter ridiculously fast, in any condition, under enormous load. The powerful worm drive motor forces the chain up onto the big ring with no need to reduce pedalling load. It’s difficult to get across how little effect this shift has to your output. For racers, this alone is worth buying this groupset. However, it’s not the only benefit.

The speed of rear shifting and pleasure of using the system meant that every single person who tested the system in a race environment changed gear more often, front and rear. Neutral service wheel change mean your gears are out? No problem with Ultegra Di2, a quick button push from the bar-mounted adjuster and you’re set – adjusted, on the fly with no loss of position. Who wouldn’t want that option? From a functional point of view, in our opinion there’s no better groupset at this price for the racing cyclist.

A women’s perspective on Ultegra Di2

By Hannah Bussey

I’m fully aware that not all females have the misfortune of having hands the size of a child on the ends of arms that are weaker than water. But if you’ve inherited physiology similar to mine, then quite frankly Ultegra Di2 is the stuff groupset dreams are made of.

In a mechanical world, without compact bars – I find reaching for the shifters and brakes from both the hoods and drops a bit of a drama.

If I can claw my fingers round the brake levers, I’m not always confident that I’ll maintain my grip. Similarly when reaching the brakes, changing gear with a mechanical mechanism can been a bit of a gamble. The non-liner spring in the derailleur requires greater force and movement as you shift up the cassette, which my small hands can struggle with. Ultegra Di2 has eradicated all of these issues.

Electronic shifting flattens this exponential shifting effort and involvement in the process is now as easy as tapping a keyboard. The smaller hood radius and adjustable reach has banished any problems I’ve previously had with reach. My fingers confidently wrap round the brake levers by at least two knuckles, both on hoods and in drop positions, giving me absolute certainty in my stopping power.

Digitalization has the potential to revolutionise how I ride and race. With shifting gear so easy and effortless, I found myself doing it more often. I’m less lazy with allowing the chain to cross because previously shifting was a struggle and ‘I’ll only be in that gear for this hill anyway’.

It also auto trims the front derailleur to prevent chain rub – again making the shifting into the right gear as unproblematic as possible. The fact that I can now reach my brakes and shifters with confidence will make a massive difference to me. Previously I’ve only trusted my grip on the levers from the drops.

Knowing that I can apply sufficient braking pressure from both the hoods and drops has suddenly given me a new found confidence in my capabilities knowing that I’m in total control no matter what my position. There is no way I am alone in feeling this way as a woman with regard shifting and braking. Ultegra Di2 will measurably improve riding for a lot of women.


How heavy is it?

There is a weight penalty over mechanical parts, but it’s small beans compared to the huge improvement in the ride experience. Its less than a couple of hundred grams – is there anywhere else on bike or rider that cannot be lost from?

How long does a battery last?

Months. Even pros get by with four or five charges a year. The reality is, twice or three times a year you’ll need to top up, and you get plenty of warning when the battery falls below 50 per cent.

Will I get stuck with no gears when it dies?

The front derailleur uses far more power, and stops working first. You’ll still have plenty of power left to get you home and be able to use the rear the whole time. If you end up on the road with no power, you’ll have ignored a LOT of warnings.

Will it short in the rain?

We have used Ultegra Di2 and Dura Ace Di2 in all conditions through terrible winter weather. We have never had any issue with water ingress. Pro cyclo-cross riders use Dura Ace Di2 (which bizarrely, isn’t as well-sealed as Ultegra Di2) and their bikes get jet-washed during races. Trust us, it’s well sealed!

Ultegra Di2: Pricing

The groupset isn’t available as a whole, but rather as individual components that can be bought to suit your needs.

Di2 Upgrades

Shifters £289.99

Rear Mech £219.99

Front Mech £199.99

Cable set (internal or external) £209.99

Drop handlebar cables with control box £74.99

Battery £59.99

Battery charger £64.99

Power cable £4.99

Sub-total: £1,124.92

Ultegra Drivetrain

Chainset £224.99

Chain £34.99

Cassette £64.99

Front Brake £62.99

Rear Brake £62.99

Grand total £1,575.87

This article originaly appeared in the February 23 edition of Cycling Weekly magazine, available every Thursday in the UK priced £2.99 and worldwide via Apple Newstand, and Kindle Fire.


The pure functionality of the Ultegra Di2 groupset was never in doubt to the CW Tech Team. From early prototypes to our first uses on production equipment, we’ve been amazed how much of the Dura Ace Di2 quality has filtered down to Ultegra Di2. When a groupset works as well as Ultegra Di2 does, in any condition, with such regularity it’s bound to gain fans and when we planned this grouptest we wanted to see what riding the groupset suited. As we progressed we realised it was just as much about the type of rider as the riding.

We’re not surprised that it suited the racer, that’s in its genes, but the suitability for other situations and users did. How quickly beginners and less experienced riders ‘got’ the idea was a bit of a revelation, as was how much difference the scale and effort required for shifting impressed those with smaller or weaker hands.

After a winter of salt, grit, road spray and general abuse, how unaffected the performance and well sealed the connection were also impressed immensely. A few forays onto cyclo-cross territory were also impressive and very well suited to the precision. Being completely unaffected by dirt ingress was a revelation to hardened racers used to finessing shifts as a race went on.

The reality is whatever bike we rode equipped with Ultegra Di2, it worked exceptionally well. Functionality and suitability of the group is all encompassing. If you’re in the market for a bike at the relevant price point, or a new groupset – or even just new shifters and mechs if you have compatible parts – we can’t see any reason why you would choose a mechanical option. Yes, it really is that good.

Full Specification

  • Nick Critchell

    Had Di2 on my Jamis Xenith Pro Di2 for the past six months – simply excellent!

    Took a little getting used to recalling the correct up/down shift button, but after a few rides it becomes second nature and the clean slick shifting is a dream to use.

    I agree with the prior comment about pricing, given I picked up the Jamis Xenith Pro Di2 from Evans for under two grand while this may be the list price I’m sure the groupset can be obtained for less.

  • Ken Evans

    The price quoted is mis-leading, as a good quality carbon-framed bike, with Ultegra Di2, can be brought on the UK high-street for £2000 ! (Which is amazing value.)