Hood ergonomics changed substantially between the R9170 and R9270 generations, enough that fit-sensitive riders should account for it before upgrading. Shimano raised the hood peak and curved it slightly inward, creating a more secure perch when riding on the tops. The lever body itself extends 4.6mm further from the bar than the previous version, which means more clearance between your fingers and the handlebar when braking from the drops. If your current setup runs a short stem or aggressive reach, you may need to compensate with a slightly shorter stem or spacers when switching to these Dura-Ace ST-R9270 levers.

The shift mechanism communicates wirelessly via Bluetooth Low Energy to the derailleurs, which simplifies cockpit builds considerably. Modern integrated bar and stem combinations route everything internally, and eliminating shift wires from that routing makes installation cleaner and reduces potential failure points. Each lever contains its own CR1632 coin cell battery that Shimano estimates will run 1.5 to 2 years before needing replacement. Swapping the battery requires no tools beyond a coin to pop the cover, and the lever stores your pairing information so reconnection happens automatically.

Shift switches got a complete redesign for the R9200 series. The paddles are longer and easier to reach when your hands are deep in the drops, and the offset between the upshift and downshift paddles increased so you can differentiate them by feel without looking. A third programmable switch sits on top of each hood where your thumb naturally rests. Through the E-Tube Project app, you can assign this button to toggle synchronized shift modes, activate satellite shifters, or perform other custom functions depending on how you like to ride.... Read More