As an addition to the mechanical Dura-Ace 7900 series, the electronic Dura-Ace 7975 will deliver state-of-the-art technology that will give its users a revolutionary road riding experience. Di2 stands for 'Digital Integrated Intelligence'. This innovative shift technology is still based on the Shimano Index System (SIS) that has proved its superior gear changing characteristics over the years. The big difference is that in this case , the shifting action is provided for by electronics instead of mechanics. This electronic shifting system was tested extensively over the past two years by several professional riders in all conditions possible, such as rain, mud, low temperatures, cobble stone roads and combinations of all of these at the same time. Dura-Ace 7975 series consists of Dual Control Levers, front and rear derailleur's and a battery kit combined with remaining 7900 mechanical components. The Shimano 7975 Dura-Ace Di2 Derailleur to Battery Internal Cable Set is part of the 7970 series.
To ensure that the signal goes from the shifter to the derailleurs, the reliability of the electric cable has been proven by repeated field tests in various riding conditions, including extreme temperatures, rain, mud, and cobble stone roads. The removal of traditional mechanical cables in favour of electrical wires not only eliminates poor shifting caused by contaminates, corrosion and stretching, but provides effortless gear shifts. Dura-Ace Di2 requires 2 cables: a handlebar cable set to connect the shifters to a battery indicator junction box or FlightDeck, and the other to connect the handlebar cable to the battery and derailleurs. This battery to derailleur cable is for internal routing. External cable sets are ideal for upgrading your current bike to Dura-Ace Di2 if it does not feature the internal cable routing option. Internal cable sets are for bikes specifically designed for Di2 to ensure clean lines and minimal rider interference. External cables are available in varying lengths, there is no need (or facility) to cut these cables. Reliable and secure water resistant connectors.