In current Shimano Di2 systems for Dura-Ace and Ultegra, there are two buttons on each shifter, both of which sit behind the brake lever. These buttons can be configured in a variety of ways.

In reality most true sprinters have styles that won't change with Shimano's new SW-7972 'Sprint' satellite shifter for their Dura-Ace Di2 group, but that doesn't mean the new gizmo isn't really ...