Despite its smaller and lighter design, the Dura-Ace R9250 offers Shimano's fastest front shifting yet. This new, sleeker front derailleur is not only under 100 grams but also shifts 45% quicker than its predecessor, the Dura-Ace R9150. Additionally, the reduced frontal area of the FD-R9250 decreases aerodynamic drag, making it an exceptional upgrade for performance-focused cyclists. Features: Shimanos fastest front shifting, 45% faster than FD-R9150 Frontal area reduced by 33% Weight cut to 96g Top gear teeth capacity: 50-55T The biggest difference you will notice is just how much quicker and effortlessly smoother shifting on the front chainrings is, even under load 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 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 and a quiet unobtrusive ride, enabling you to concentrate on the road ahead Braze-on fit as standard; if your bike does not have a braze-on mount seat Tube adapters are available 12-speed E-tube SD300 wire compatible