Shimano now has three Di2 12-speed electronic groupset options for you to choose from. Here are the differences between the three and the surprise reasons why we think you might choose Dura-Ace for your next bike.
difference between dura ace ultegra and 105 di2 groupsets

For starters, Dura-Ace provides the largest range of gearing options of the three, with more chainsets and more cassettes available than either Ultegra or 105. There’s also a significant weight advantage. However the electronic underpinnings of all three groupsets are similar, so let’s start off with a quick refresher on what’s the same, as explained in more detail in our previous post.

What Dura-Ace, Ultegra and 105 12-speed Di2 groupsets have in common.

Shimano Dura-Ace R9200, Ultegra R8100 and 105 R7100 now offer you three electronic only, 12-speed semi-wireless options, with a wireless connection between the shifter levers and the derailleurs and a single in-frame battery powering both derailleur mechanisms. Shimano says that that’s a set-up that gives around 1,000km of riding between charges, with the shift levers each running for around two years on a coin cell. The internals of the system are the same too, with the same electronics and battery. 

Dura ace

You can customise shifting set-up and performance for all three groupsets via Bluetooth with the Shimano E-Tube app. Dura-Ace and Ultegra shifters allow you to fit satellite shifters and both have a button on the hood that you can programme to perform functions like controlling your bike computer; 105 omits this.

Whereas Dura-Ace and Ultegra use Hyperglide+ engineering transposed from Shimano’s MTB groupsets, this isn’t used for 105. It’s claimed that Hyperglide+ offers shifting that’s up to 58% faster at the rear and 45% faster at the front.

Dura-Ace and Ultegra offer both rim brakes and disc brakes, 105 only disc brakes. The discs on Dura-Ace and Ultegra now use Shimano’s Servo Wave tech that gives more progressive braking through the stroke and 10% greater retraction of the pads for less chance of brake rub.

Both Dura-Ace and Ultegra, but not 105, offer a power meter, but Dura-Ace’s claimed accuracy is 1.5% as against 2% accuracy for Ultegra. All share disc brake rotors and chains with Shimano’s mountain bike groupset ranges, with Dura-Ace working with the highest spec XTR components. 

Ultegra power meter

All that makes sense - there’s no reason for Shimano to add to its development costs by doing everything multiple times. Many pros were already using mountain bike disc rotors with the previous generation Dura-Ace for their lower weight and better heat dissipation than the in-series rotors and the MTB chains were already designed to work with Hyperglide+.

What’s the weight difference?

Here’s where there are significant gains to be made by fitting Shimano’s top-tier groupset. 

Depending on configuration we reckon that a complete Dura-Ace R9200 groupset weighs around 2438g while Ultegra R8100 comes in at 2716g, making Ultegra R8100 around 278g heavier. 105 Di2 weighs around 2995g, adding a further 279g over Ultegra and making the groupset a full 557g heavier than Dura-Ace. On a top-tier bike, where the frameset typically weighs under a kilogram, that’s a significant difference.

That weight difference is spread across the range of groupset components, with Dura-Ace using the most expensive materials.

Take the cassette for example, where there’s the largest weight gain with Ultegra. Shimano quotes a weight of 223g for Dura-Ace as against 291g for an 11-30t for Ultegra, a 68g difference. Go for the 11-34t cassette and the figures are 253g for Dura-Ace and 345g for Ultegra, a 92g difference. 

Dura Ace vs Ultegra vs Di2

You get small differences elsewhere too, with the Dura-Ace power meter chainset weighing around 748g, again dependent on configuration, 21g less than Ultegra. At 350g, the Dura-Ace shift levers are 41g lighter than Ultegra, while you’ll save 67g on a set of derailleurs, 53g on a pair of disc brake callipers and 35g if you want single pivot rim brakes. It all adds up.

Other components weigh exactly the same between the groupsets: they all use the same battery for example, and whereas Shimano now has dedicated RT-CL900 rotors for Dura-Ace and RT-CL800 for Ultegra, both are claimed to weigh around 114g for a 160mm rotor.

What are the differences in materials used?

The weight differences between the groupsets are largely due to the use of premium materials in Dura-Ace. There’s also more machining and finishing with Dura-Ace than Ultegra and 105.


For example, Shimano makes the largest six sprockets in the 11-30t cassette and the largest seven in the 11-34t out of titanium for a Dura-Ace cassette, whereas they’re made of steel for Ultegra and 105. 

Shimano uses carbon fibre sideplates for its Dura-Ace rear derailleur, saving yet more weight, whereas in Ultegra and 105 these are alloy.

What are the differences in options?

Shimano still pitches Dura-Ace as the racer’s groupset while Ultegra is its premium all-rounder. So you’ll get some options for the fast rider in Dura-Ace that aren’t available in Ultegra, like increased front derailleur capacity, making it more suitable for time trial bikes. In general, you have more flexibility in component options available in Dura-Ace than in Ultegra or 105. 



At the chainset end, while Dura-Ace, Ultegra and 105 all have 52/36t and 50/34t options, only Dura-Ace has a 54/40t available. That’s the equivalent of the old “standard” 53/39t designed to give the racer a higher geared configuration. Dura-Ace, Ultegra and 105 all offer crank arm lengths between 160mm and 175mm in 2.5mm increments, but only Dura-Ace has a 177.7mm crank length.

At the rear, both Dura-Ace and Ultegra groupsets offer the same Hyperglide+ 11-30 and 11-34 tooth cassette ranges. At launch, Shimano said that there would be an 11-28t in Dura-Ace only, but that’s still not commercially available. 

For the fitter rider, an 11-28t paired with either the 50/34t or the 52/36t chainset is likely to give adequate range for the majority of riding; racers will probably be happy with the 11-28t cassette paired with the 54/40t chainset, which gives smaller gaps between ratios in the centre of the cassette.

Shimano 105 gives you either an 11-34t option or an even wider range 11-36t cassette.

What’s the price difference?

At full retail price you’d pay around £3,500 for a complete Dura-Ace groupset without a power meter and £2,400 for Ultegra so there’s around an £1,100 price differential for a complete groupset. 105 Di2 retails for £1,700, depending on spec, so around half the price of Dura-Ace. That may seem like a lot, but in the context of the overall price of a new premium bike, it’s not enormous.


It’s a one-off cost too. Most components will stand years of use and are unlikely to need replacing quickly. The parts that do wear out faster – principally the chain and cassette – are compatible between Dura-Ace and Ultegra, although it’s worth noting that Shimano says that the non-Hyperglide+ 105 parts are not.

That means that, if you want to save a little cash and are prepared to live with the extra weight, you can opt for the cheaper Ultegra parts when it’s time to retire worn Dura-Ace components.

Which should you choose?

There’s an argument for equipping your bike with Ultegra, or even 105 12-speed. But if you want the pinnacle of Shimano’s groupset performance, and arguably the best groupset available from any brand, then there’s only one option. Dura-Ace offers the largest range of variants in gear ratios and crank arm lengths and there are other things that only Dura-Ace will provide.


Opting for Dura-Ace will give your bike the pro look too: of the 18 men’s WorldTour pro teams, 13 ride bikes equipped with Shimano groupsets, and they all use Dura-Ace.


Read: Cycle To Work Vouchers - why they are a good option for your next bike >


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