Shimano Tiagra ST 4600 10 Speed ShiftBrake Lever Set. The Shimano Tiagra ST 4600 ShiftBrake Lever Set is a rock solid performer on 2x10 speed road drivetrains. Shimano's Super SLR lever design delivers faster braking response and reduces operation friction to a minimum. The compact hoods, made from soft rubber for a superb grip, are anatomically shaped to enable easy braking and shifting regardless of hand position. And speaking of hands, the lever reach is adjustable via shims to tailor the ergonomics to those with smaller hands. As an added performance bonus, the Optical Gear Display enables you to determine what gear you're in without having to peak down at the drivetrain itself.