The option of hiding the battery inside the seat post will appeal to many.
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Shimano Dura-Ace Di2 9070 Series

In our March-April issue we had a play with the 9000 series mechanical 11 speed Dura-Ace groupset. Among its best features were the super light shifting of the front derailleur, thanks to a complete redesign and also the slender profile of the new hoods. The trick for Shimano in the new generation 9070 electronic series has been to blend the best characteristics of its new and improved mechanical system with advantages of electronic shifting.

Despite the success of Shimano’s first generation of Dura Ace Di2 and the follow up success of the Ultegra version, Shimano have not been content to rest on their laurels. It was no surprise that Shimano would follow Camapgnolo’s lead and move into 11 speed drivetrains, or, that they would subsequently integrate the 11 speed into the Di2 stable. It was also no secret that the Ultegra style cabling system would trickle up to the Dura Ace model as it had proven to be both reliable and simple to use. But when we recently visited Shimano to have a look at the Dura Ace Di2 being installed on our test bike, we realised that apart from cosmetic changes beneath the skin there were quite a few tweaks as well.

The control box is zip tied below the stem.

Apart from the uptake of the Ultegra style cabling every other component specific to the 9070 groupset has come in for a makeover. Similar to its mechanical counterpart, the hoods of the levers have been reduced in size, to a point where I think they are just about at the sweet spot for size and comfort. At a recent race day I had forgotten to pack my gloves and raced with bare hands. This made the reduction in hood size very noticeable, and will enable a better fit for a wider range of hand sizes. The length of the shift paddles has also increased to towards the top of the lever to make accessing them easier when riding on the hoods and a distinct “click” is heard and felt to signal a gear change. The shifter body has also been modified to incorporate a third port, with the bottom port being specifically allocated for sprint shifters only and the top two ports being standard to accept all other shifters. The control box is now neatly mounted under the stem and can be easily swapped out as there are no wires hard wired into the system. The control box is now also available in a three or five port configuration. With three ports in the hoods and the availability of a 5 port junction box, the possibilities are seemingly endless. As a proof of concept at release time Shimano wired up a bike with STI shifters, sprint shifters, climbing switches and TT shifters, overkill sure, but an impressive display nonetheless, with all functioning seamlessly.

Both rerailleurs have had some weight reduction.

The battery that so successfully powers the whole system is still available in the standard external mounted version but also now in an internally mounted option. The internal battery is small enough to fit in most seat posts yet still has the same recharge intervals as the external mount battery. It is also great to see so many manufacturers now putting thought into accommodating battery placement in their frame designs with many incorporating mounting points for external batteries generally under the bottom bracket area.

Brakes on the 9070 series are the same as 9000's.

Charging for the internal battery is now handled via a cable that connects into the control box and then routes through the new internal specific battery charger. The new charger connects to power via a usb cable which also enables it to talk to Shimano’s E-Tube diagnostic software which at an end user level is limited to shift setting modifications and rudimentary diagnostics. At a shop service level, the E-Tube software enables a Di2 equipped bike in for a service to receive a check to ensure that all software is current, all new firmware is applied and everything is functioning properly.

The new hoods features a trimmed sleeker profile.

With regard to shift settings, the 9070 series Di2 comes with programmable shift settings in both the speed of the shift and the number of cogs shifted per operation. The factory default settings are for normal shift speed settings and no limit to the number of shifts, this means that keeping pressure on the shift lever will see it move continuously through the cassettes range till it reaches the end if you so desire. There are five speed settings; very slow, slow, medium, fast or very fast with even the very slow being comparable to a crisp mechanical shift. The shift number can be set to 2, 3 or unlimited, and while I didn’t really see the need for unlimited with the shifting being as quick and precise as it is, I will have to admit to not taking it off unlimited and enjoying the ability to slide through the gears to find the sweet spot.

The levers have had the tactile surface extended for easier shifting from the hoods.

Both derailleurs have also received some upgrades a few grams have been shaved off each when compared to the previous generation components and the rear derailleur can now handle a 28 tooth cassette.  The front derailleur is also now able to have its trim adjusted via the e-tube software for those that move away from Shimano cranks and need to fine tune their shifting.

Battery mounts are securely out of sight below the bottom bracket.

Essentially what Shimano have done in this new version is take on board all the reasons riders would give for not choosing electronic and address them. The weight of the new Di2 is comparable with the mechanical setup, there is multi-shifting available, there is an internal battery option for those with aesthetic issues, and the battery life is really a non-issue, in fact the only problem may be that the battery charge cycle is so long that you may forget to make it part of your normal maintenance routine. As for price, well it is a premium system but with lesser known brands on the market sporting 11 Speed Di2 and some fancy carbon wheels for a touch under $4,500 the entry point for this groupset is certainly not astronomical.

The option of hiding the battery inside the seat post will appeal to many.

So not only does it match all the critical metrics of mechanical shifting, it goes well beyond mechanical in so many other ways not possible with the standard system. Not only are the speed and shift patterns changeable but the shifters can be tasked to change any derailleur in any direction unencumbered by traditional thinking or mechanical limitations. If you want all your right hand shifts to shift the chain left, sure! Want to have your front brake and front shifter on the same lever, no problems! And while these may seem like a novelty, to some who don’t have a history in cycling these “unusual” configurations may seem like common sense, not to mention the ability to enable those with physical limitations such as arm amputees to be able to enjoy the pursuit of cycling.  With the interface now being via a computer and the ease of which software upgrades can be implemented it will be interesting to see where Di2 technology will take us in the future.   

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The option of hiding the battery inside the seat post will appeal to many.

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