Shimano Dura-Ace Di2 R9250 2x12 Spd Front Derailleur With the Dura-Ace Di2 12-speed groupset, SHIMANO is literally stepping up a gear and taking its top electronic shifting group for road bikes to the next level. The electronically controlled FD-R9250 front derailleur is optimally adapted to the new 12-speed drivetrains and the SHIMANO HG+ chain and tooth profile used for it. The Dura-Ace front derailleur receives shifting commands directly from the Di2 rear derailleur via the common cable connection to the battery. This way, it supports wireless shifting with a compatible shift lever but comes without its own receiver unit. Featherweight 96 grams are the result. On the performance side, the SHIMANO FD-R9250 front derailleur impresses with precise and smooth gear changes of the proven Di2 technology, which are now said to be up to 45 percent faster than with the predecessor. Even under load, the down-swing construction reliably transports the HG+ chain to the opposite chainring with improved chain engagement. The two modes of the Synchro-Shift technology, which can be customised via the app, ensure optimally timed gear changes so that you can keep your focus high during the race. Define the gears at which the front derailleur automatically shifts, or let the rear derailleur make compensating shifts as soon as you operate the front derailleur. Whats more, the auto-trim feature automatically adjusts the front derailleur in case of unfavorable chainlines, avoiding chain rub at the cage. That's electronic shifting at Dura-Ace level that's the SHIMANO Dura-Ace FD-R9250 Di2 front derailleur! Details: Electronic front derailleur for 212-speed drivetrains Compatible with wireless Di2 rear derailleurs Mounts to braze-on sockets (SM-AD91 Di2 front derailleur clamp for frames without braze-on socket optionally available with prod. code 2238032) Compatible with Synchro-Shift: shifting front and rear derailleur with only one lever Program-controlled shifting movement: fast and smooth shifting even under high load Auto-Trim: automatic readjustment of the chain guide in relation to the rear derailleur position Increased shifting speed (approx. 45 % faster compared to the predecessor model) Reduced surface for optimised air resistance Precise fine adjustment thanks to 38 possible chain guide positions SD300 E-Tube Port: slimmer cables for less weight and easier routing Can be customised via E-Tube app (in combination with a compatible rear derailleur) Also suitable for wired setup Technical details: Material: aluminum, steel (inner connecting pin) Gears: 2 Compatibility: 12-speed/double Total capacity: 16 teeth Large chainring: 5054 teeth Chain stay angle: 6166 Chainline: 44.5 mm Compatible chains: HG 12-speed Action: Down-Swing Slots: 1 EW-SD300 E-Tube port Weight: approx. 96 g.