Trickle down at its finest.
Ultegra has long been the workhorse group in Shimano's road lineup. But there is also beauty in strength, functionality, and fortitude. Shimano did not just rename the 6700 tier, however. Instead, just as the Dura-Ace groupset was completely redesigned for the 9000 series, so too has the Ultegra 6800 line been given a similar makeover so that it mimics the 11-speed functionality and aesthetics of its older sibling.
Beginning with the most visible and noticed portion of the groupset, the ST-6800 levers feature a refined hood shape. They borrow the look and feel of Dura-Ace 9000, which, in turn, borrow their aesthetics from the venerable Di2 levers. The new design allows for improved grip and comfort, combined with crisper shifting. The hoods are molded from a dual-compound rubber composite. Below the hoods you'll find a sleek carbon lever with a more exaggerated outward curve than on the 6700. This makes for a more pronounced interaction with your hands from either the hoods or drops. Ten millimeters of reach adjustment for the levers accommodates a large variety of hand sizes and shapes. Although the redesign of the shifters is eye-catching, Shimano's "Rider-Tuned" philosophy is what gives the newly redesigned Ultegra such a solid rider experience. "Rider-Tuned" is the philosophy of providing added touches throughout the group, such as a shortened lever stroke. This shortened lever stroke increases the speed with which your shift moves up or down the chainrings and cassette.
Moving through the drivetrain, the redesign of the front derailleur matches the new shorter stroke lever action of the shifters. To achieve this, Shimano had to revise the actuation ratio and pull yet another page from the Dura-Ace manual. The derailleur body was given a more heightened profile, with the leverage point at the top of the body. This creates a larger pull arm with more leverage, which strengthens the pull and eases the actuation, and thus lessens the shift stroke. In a similar manner, the rear derailleur was redesigned to be more compact, lightweight, and to ensure equal shifts across the cassette's entire 11-speed range. The new 6800 was designed with the same attention to the shorter stroke at the lever as Dura-Ace. This was done using a newly designed spring mechanism. The new spring mechanism ensures an equal, positive sensation regardless of the direction of shifting, unlike the more familiar Shimano "snap" moving up the cassette, and "drop" sensation on the way down. The combination of new levers and re-engineered derailleurs creates a reduction of 35% in shifting effort in the front. Add Shimano's proprietary, polymer-coated shift cable and mechanical drag is nearly eliminated.
Even though the 11-speed shifters are initially the most noticeable component of the Ultegra groupset, it is the 6800 crankset that really steals the show. Once again, using Dura-Ace as its inspiration, you'll notice there is no comparison between the prior iteration of Ultegra and the new crankset. The 5-arm spider is absent and in its place is a 4-arm crankset, which not only matches rigidity of Dura-Ace while saving 26 grams of weight, it also is compatible with both standard and compact chainrings. Gone are the days of needing two sets of cranks for two sets of chainrings. Additionally, they were built using Shimano's Hollowtech II construction — the same method used in its big brother. The groupset includes Shimano's SM-BBR60 English Bottom Bracket.
The Shimano 6800 brakeset is no exception to the makeover, either, and it has taken stopping power to a whole new level. Shimano began the design from the ground up. They used a dual-pivot design, so the mounting bolt is no longer also the pivot. As a result, the brake arms are now located symmetrically over the wheel and work independent of the mounting due to an integrated rolling cam. The cable stop is still to the side, but the new dual-pivot design allows any pull to apply equal tension to both arms. In addition, the arm placement is closer to the rim, which, coupled with the equal pull, drastically increases modulation. And if you run larger tires, Shimano is now producing a thinner brake pad for tires up to 28mm wide. Shimano claims that the new brake design has 10% more stopping power than its 6700 series.
The Shimano Ultegra 6800 Groupset is available in three crank lengths: 170mm, 172.5mm, and 175mm, with either standard or compact chainrings. Each is available with either 11-25t or 11-28t rear cassettes.