Shimano is well known for its high-end bike technology and the company has extended its range making electronic shifting available to regular bicycle riders with the Alfine Di2 Internal Electronic Shifting System.
The internally geared hub is controlled by electronic shifter via wires running through the tubes for a slick, neat look. The Alfine Di2 was designed for city bikes. Bicycles sporting the system will feature wires running from the mountain- or road-style shifter through the downtube and chainstay to the hub. A battery, mounted in the seat post or on the downtube, provides power to the shifter, hub and a small bar-mounted display that indicates what gear you’re in and how much battery is left. When the battery runs low, simply plug the bike in.
The Di2 adds an 11-speed option and the shifting system is very easy to operate. And smooth, too – a gentle tap on the trigger is followed by an electronic buzz and the hub moves quickly from gear to gear.