Shimano's innovative Synchro Shift is now available with Shimano Dura-Ace ST-R9150 Dual Control Levers. Synchro Shift creates an intuitive experience on the bike through synchronized front and rear shifting that can be custom programmed by riders. In addition to traditional "Full" Synchro Shift, riders can optionally select "Semi" Synchro Shift. This intuitive new mode automatically reacts when the rider shifts from one chainring to another, automatically shifting the rear derailleur to minimize the gear step, thus preserving the rider's rhythm. The ergonomically-enhanced Di2 shift levers now produce a more defined shift click for a more intuitive feel and quicker shifting operation and expanded E-Tube customization allows every switch the option to independently turn on or off multi-shift. 11-speed. 230 grams pair.