The Di2 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 derailleurThe biggest difference you will notice is just how much quicker and effortlessly smoother shifting on the front chainrings is, even under loadThe difference in the effort and time to actuate the shift between mechanical and Di2 is truly staggeringThe 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 shiftsThe 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 and a quiet unobtrusive ride, enabling you to concentrate on the road aheadBraze-on fit as standard; if your bike does not have a braze-on mount seat tube adapters are available10-speed Ultegra E- tube Di2 compatibleFront derailleur weight is 162 grams