The Di 2 front derailleur's operation is pioneering, smooth shifting is guaranteed thanks to a microchip communication link with the gear levers. What's more, shifting the rear derailleur automatically trims the front derailleur The biggest difference you will notice is just how much quicker & effortlessly smoother shifting on the front chainrings is, even under load The difference in the effort & time to actuate the shift between mechanical & Di 2 is truly staggering The removal of traditional mechanical cables in favour of electrical wires not only eliminates poor shifting caused by contaminates, corrosion & stretching, but provides effortless gear shifts The front derailleur also trims automatically; the cage moves in response to the position of the rear derailleur on the cassette to ensure no chain rub & a quiet unobtrusive ride, enabling you to concentrate on the road ahead