The Ultegra Di2 STI Lever is Shimano's second generation electronic shifter, offering a refined wire set-up, a handful of extra grams and a much friendlier price tag compared to their original Dura-Ace model.
By eliminating the friction caused by cables and housing, the ST-6770 levers allow lightning quick shifts. Gear changes are much faster than Shimano's mechanical systems and the shift pads require just 2mm of movement for actuation. Multiple strokes can be made while coasting and the multiple shifts will catch up as soon as pedaling is resumed.
Unlike Shimano's mechanical systems, the brake lever is no longer used for down shifts -- there are two shift pads placed behind the brake lever to control gear changes. The ergonomics of the hoods are similar to the mechanical Ultegra, yet slightly slimmer since they don't need to have room for cables and housing. The brake pivot has been moved closer to the hand for easier reach and better braking power and modulation. Reach is also adjustable for different sized hands. Braking still uses traditional cable and housing (included).
The Ultegra Di2 ST-6770 STI Levers are sold as a pair without electronic wires (SM-EWC2L and SM-EWSD50 are available separately). 313g/pair.
Note: The ST-6770 Levers are not compatible with Dura-Ace 7970 series Di2 components or wires.