Words by Kevin Rouse || Photos Courtesy Shimano
I remember the first words I read about Shimano's foray into the world of electronic shifting. (But then there's also these, of course) In particular I remember the commonly recurring adjectives being used to describe it. "Emotion-robbing,' 'robotizing' and 'soulless'—to name a few.
Questions of reliability and durability abounded. Naysayers said their nays. But, that's not to ignore the resounding chorus of oohs and ahhs being issued as well.
Six years later I think we can safely say that those in the oohs and ahhs camp were on the right side of the fence. Look at the majority of range-topping bikes from any manufacturer and you're likely to see a bike gussied up with a Dura-Ace Di2 kit.
Thus when Shimano introduced Di2 at the Ultegra level, and at a substantial price break, they cemented electronic shifting's place at the head of the cycling technology curve, proving it was a viable option at price points other than 'stratospheric'.
Now three years later, the Ultegra Di2 group gets its first ground-up refresh, carrying down design cues and advances from its more expensive sibling.
Sporting the 6870 moniker, Shimano's second-tier electronic option follows hot on the heels of Dura Ace 9070, and adopts many of the features that group introduced earlier this year.
Already one of the more ergonomic designs out there, the ST-6870 shift levers feature a refined hood profile for better access to the shift buttons, as well as compatibility with the sprinter satellite shifters and the new Di2 multi-shift function introduced in the 9070 group.
Both the front and rear derailleurs have gone on a diet and sport slimmer silhouettes.
Perhaps most importantly, the new rear derailleur features a wide-link design to limit deflection under shifting loads as well as a mid-cage version that allows the use of up to a 32T cog.
The front sees a design change that brings in a new support bolt to ensure the proper alignment is kept while shifting into the big ring, further increasing shift accuracy and speed.
Again, taking cues from it’s Dura Ace sibling, the Ultegra 6800 crankset adopts Shimano’s latest four-bolt spider, which allows for the use of a much-wider gear range on the same crank, and, when paired with the new Ultegra mid-cage rear derailleur offers the widest 11-speed road gearing range on offer from Shimano.
Paired with the ergonomic improvements and revised component designs, the new Ultegra Di2 6870 group slims down by 126 grams (with the internal battery option; the group is 69-grams lighter with the external battery configuration), but that’s only part of the story. Adopting the next-generation E-Tube wiring and software packages, the new Ultegra 6870 group offers much easier setup and maintenance.
Modular in nature, the new E-Tube system offers plug-and-play connectivity, vastly simplifying wiring during initial setup and component changes. On the software side of the E-Tube equation the new Ultegra group adopts the new PC interface as used by the later Dura-Ace electronic group.
This new interface (which as of now does not offer support for Mac) allows users to update firmware, change functions, customize shift buttons, as well perform minor diagnostics on the system—all via a port on the updated junction box.
The new Ultegra group does something more than bring the latest and greatest in electronic shifting down to a more affordable level, it also introduces Shimano’s entrance into the world of hydraulic stopping on the road.
Utilizing much of the same technologies introduced on Shimano’s mountain-bike offerings, the new R785 system adapts them for road and cyclocross applications.
Both the calipers and rotors sport Shimano’s much-lauded ICE technologies in the form of finned brake pads for the two-piston BR-R785 caliper, and FREEZA cooling fins on the SM-RT99 center-lock rotors (available in 140mm and 160mm
The Ultegra 6870 Di2 groupset and R785 hydraulic braking system will be available beginning November 2013.