One of the most extensive additions is the new aero bar system featuring a unique monorail design that is sleek and incredibly comfortable. The monoextension could not be cut on the earlier versions, but here it can be cut from the front of the bar for optimum fit. Additionally, a bottle cage can be mounted between the two armrests, which is one of the most advantageous places for fuel.
The new fork shape and the new SpeedFin brake cover help riders cut through the wind. The 9.9 features premium 600 Series oclv Carbon and carbon dropouts and is compatible with all electronic shifting (namely all current Shimano Di2 and Campagnolo eps drivetrains) as well as mechanical shifting. Although Trek uses proprietary handlebars, a steerer stub is available that will allow you to use any standard 1– 1/8" stem and handlebar combination.