The Ultegra ST-6800 mechanical Dual control levers represent a considerable leap forward over the 6700 levers with many of the same improvement borrowed from Shimano's efforts which created the amazing Dura-Ace 9000 group. Shimano has been hard at work to reduce both lever throw and friction. Shifting effort has also been made more equal across the entire cassette. Less shifting force is required reducing the process of changing gears almost to the sub-conscience level with smaller, lower input hand movements for a simply wonderful shifting quality.
Changes over 6700 are significant. Lever stroke is and shifting effort required is reduced considerably over the previous generation. Shifting effort for the rear derailleur is reduced thanks in part to new pivots and cable clamp positioning on the RD-6800 rear derailleur. Front shifting on the 6700 could sometimes be a hair on the sticky side and Shimano addressed this by making the 6800 lighter, quicker and dramatically reducing friction with new shifter cables coated with an improved polymer that glides through the liner with less drag and holds grease very well. This combined with more leverage in the front derailleur produces front shifts so fast they have to be experienced to be believed.
Ergonomics have evolved with new levers and hood shapes. The carbon blades flairs slightly more outward and are a bit more sleek. Activating the levers from the drops or hoods is a little more friendly and there is 10mm of reach adjustment to fit all hand sizes for a tuned fit. Overall, the size of the body is a little smaller volume, similar to Di2 levers, and the hoods have a dual rubber compound to top off the improve creature comforts. All of these improvements come with a 22-gram weight reduction to boot.
For 11-speed mechanical systems only.