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Shimano Dura-Ace Di2 R9150 – first ride review

As Shimano's Dura-Ace Di2 R9150 groupset starts to appear on model year 2018 bikes, we get a taste of the Japanese firm's latest electronic drivetrain

Shimano launched the latest Dura-Ace Di2 R9150 groupset a full year ago, back in June 2016, but only now are we beginning to see the Japanese firm’s evolved electronic groupset on complete bikes. In fact, the pros (or rather, their mechanics) have only started getting hold of the complete groupset for their own use.

However, you can now expect to see Dura-Ace Di2 R9150 listed on spec sheets for the highest of high-end bikes and – including the 2018 Lapierre Pulsium, which we rode at the updated endurance machine’s launch in France last week.

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As well as putting the Pulsium, which is said to be up to 40% stiffer than the previous version, through its paces, we had the chance to try Shimano’s Dura-Ace Di2 R9150 gruppo.

The 2018 Lapierre Pulsium 900 Ultimate FDJ, equipped with Shimano Dura-Ace Di2 R9150 (Pic: Ashley Quinlan/Factory Media)

Dura-Ace recap

First, let’s quickly recap. Back when Shimano originally unveiled the latest Dura-Ace groupset at the start of the 2016 Tour de France, much of the buzz was about the arrival of top-tier disc brakes and a Dura-Ace power meter – which, incidentally, looks to still be a work in progress.

However, Shimano had made a number of refinements across the groupset, with a stated aim of improved ‘system efficiency’. That includes a new slim-line ‘shadow’ rear derailleur borrowed from the MTB XTR group, as well as the capability to run an 11-30t cassette with a standard length derailleur. The chainset also received a makeover, with the beefier, all-black design somewhat polarising opinion.

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Moreover, the shifters themselves received an update to the ergonomics and, on the Di2 groupset, the shifter buttons were updated to offer additional feedback and a more tactile response to shifting.

The R9150 (rim brake) and R9170 (hydraulic disc brake) Di2 software also saw an update, with Synchronised Shifting arriving, as well as an update to Shimano’s E-Tube software, which now allows the full customisation of the shift buttons. So you can completely change the shifting logic, if you want. All those changes, by the way, have now also found their way onto the recently-launched Ultegra R8000-series groupset.

For our ride, each shifter button was assigned its conventional function but we had the brains of the system setup in Semi-Synchronised Shifting mode. Otherwise, we were using the single-bolt, dual-pivot rim brake calipers (there are also direct-mount versions available), a compact 50-34t chainset and an 11-30t cassette.

First-class efficiency

The first thing that occurs when you ride Dura-Ace – in either mechanical or electronic guise – is just how well-sorted the entire experience is. Back when we rode the mechanical R9100 setup aboard the Orro Gold STC, we praised how efficient it felt, with rim brake performance that set new standards in modulation and power.

On the Di2 version, nothing has changed in that Dura-Ace remains as exceptionally good as we’ve come to expect from Shimano, and the updated shifter ergonomics are a joy to handle, with the levers really accessible from the bars..

Lever throw itself isn’t relevant with Di2, of course, but the new texture of the Di2 buttons really help the rider distinguish between each as naturally as they would between brake lever throw and paddle actuation on the mechanical setup. During my two rides on the Pulsium, I experienced zero missed shifts, and feel it’s a significant upgrade over the old Dura-Ace (and subsequent Ultegra) buttons.

Shimano have updated the textured shifters to make it easier to differentiate between buttons (Pic: Wouter Roosenboom)

Additionally, the new buttons have also been engineered to offer more tactile feedback. No longer do you feel like you’re playing a video game, literally pressing buttons, but now the shifts are far more akin to a tight and well-oiled mechanical setup. This is certainly no bad thing – fans of positive-feeling mechanical shifts now have something to upgrade to, without losing that sense of connectivity with the drivetrain. Credit to Shimano, too, because they’ve listened to feedback from riders who complained Di2 lacked the connection of a mechanical groupset.

When those buttons are pressed, it’s the same slick, efficient and near-foolproof shifting of the chain through derailleur mechanisms that whirr and zip into place with a satisfying finality. Still self-adjusting so chain rub is a thing of the now very distant past, I detect a slightly louder noise emanating from the front derailleur over the previous iteration. And, rather than being a distraction, it actually sounds reassuring.

Semi-Synchronished shifting

However, it’s the Synchronised Shifting function that really impresses. You can have Di2 setup in Full Synchro mode, where the front derailleur shifts automatically according to where the chain is on the cassette and probably of most interest to time trialists, or have it switched off altogether, but for most riders the Semi Synchro option, where the rear derailleur reacts in response to front derailleur shifts, will appeal the most.

Essentially, it’s intended to reduce the rider’s workload. When the front derailleur is shifted, the rear shifts automatically by one or two gears to move you into the next effective ratio. In practise, it’s a cinch to get used to, and a real boon when you’re really hanging it out on a climb and are forced to shift into the small ring for a lower ratio and don’t want the hassle of finding the best gear on the rear cassette. Likewise, if you decide to put in an attack, you can fire up the big ring and the rear derailleur adjusts you up the cassette so you’re not suddenly churning a gear that’s too ambitious. It’s designed to keep your gear changes smooth and progressive.

Shimano’s E-Tube software means you can also programme multi-shift and shift response times too, although on our rig we left it as supplied for these initial rides. Nevertheless, responses to inputs are razor-sharp. Even when you decide that you want an extra shift at the rear derailleur under large amounts of torque, the system responds with superb efficiency.

The latest Dura-Ace chainset is visibly beefier than the previous version, with the latest Ultegra groupset now also sharing a similar design (Pic: Jean-Luc Armand)

What can’t Dura-Ace Di2 do?

One thing to bear in mind, however, is that this isn’t a simultaneous system, instead responding to your front derailleur input by moving said derailleur, then adjusting the rear one a split second later. The effect is a slick response and Shimano obviously felt the stress of two moving points on the chain might increase the chances of a derailment or a poor shifting experience, so it’s probably a wise thing, but I can’t help wonder if the next iteration will help to address this as the Japanese giants refine the system.

Naturally, the system can’t work if you’re at extremes of the block (i.e. in 11t at the cassette and shifting into the small ring). Clearly, this isn’t a natural thing to do – instead it’s likely you’d come up the cassette instead to find an easier ratio.

But these are realities of the groupset, rather than distinct limitations. What you have here is a pro-grade groupset which, while not a wildly significant departure from the previous version, makes incremental improvements across the board, whether that be the excellent rim brakes, improved lever ergonomics, additional rear derailleur capacity or beefed up chainset. With the addition of improved button textures and actions, as well as the step forward in Di2 software technology that we’ve now seen introduced with Ultegra as well, Dura-Ace Di2 R9150 is very much a potent rival for the wireless lustre of SRAM’s eTap.

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