Item # SHI002J
Shimano Ultegra 6870 Di2 Disc Brake Groupset $1,792.39
Shift your perspective.
Di2 and hydraulic disc brakes have received their fair share of hype in recent years, and we must say, if virtually perfect shifting and increased braking modulation are important to you, Shimano's Ultegra 6870 Di2 Disc Brake Groupset more than delivers. While the numerous E-Tubes and junction boxes necessitate some serious attention to detail during setup, Di2, once installed properly, touts a host of benefits that no mechanical system has ever been able to match. Ditto the hydraulic disc brakes, which provide almost instant engagement and more modulation for better stopping in all conditions. Minimal maintenance, impressive battery life, and reliable shifting under full power make Di2 an incredibly worthwhile upgrade to your current bike or a wise investment if you're building up a new machine.
Though they're not officially labelled Ultegra, the ST-R785 Di2 hydraulic shift and brake levers are the unbranded equivalent of Shimano's best dollar-per-gram groupset. We suspect that, with the legalization of disc brakes in the pro ranks, we'll see Dura-Ace, Ultegra, and 105 all get their own official levers — but for now, the model numbers get the nod. As with the non-disc Di2 model, the levers are fully programmable to a variety of actuations. If you're switching to Shimano from another brand and aren't looking forward to adapting to a new shifting style, the ability to program how many gears up-shift or down-shift per push of the lever is an especially thoughtful touch, allowing you to still shift the way that feels most natural to you. If needed, you can also choose to reassign the lever/derailleur pairings if the standard settings aren't your style.
You'll notice that the system is constantly aware of the front derailleur's relation to the chain as you switch into the low or high ranges of the 11-speed Ultegra cassette, auto-tuning its position to allow you to use your full range of gear ratios without chain rub. Both the front and rear derailleur are almost identical to their Dura Ace cousins, with the site of manufacturing standing as the main difference between the two. Ultegra's servos, motors, and other hardware are produced in Malaysia while Dura-Ace is produced in Shimano's Japan-based facilities. We'd agree with Shimano that the gap between the two is nearly imperceptible; Ultegra offers incredible durability and dependability that very nearly matches that of Dura Ace.
This set includes all of the electronic power components that you'll need to bring hydraulic Di2 to life on any road or 'cross bike with a battery capacity that's claimed to last up to 1,000 miles. Paying attention to a few simple lights on the junction box will give you ample warning in advance as your battery slowly dips to half power, then into low power, with plenty of time to finish a ride and get charged. E-tubes, internal and external junction boxes, and an external battery mount round out the electronic portions of the kit, allowing you to mount Di2 internally or externally depending on your frame's capabilities.
In closing, we'd be remiss not to mention the gorgeous new Ultegra crankset. Shimano made improvements to its previous Ultegra crankset for Ultegra 6800, dropping 26g compared to its predecessor and adopting a cleaner, four-arm design. Dura-Ace was the inspiration for the changes, and the new crank arm design, built using Shimano's Hollowtech II construction, matches the rigidity of its Dura-Ace muse and is compatible with both standard and compact chainrings.