Vision is FSA’s more aerodynamically focused arm, and the new 4D bar implements plenty of aero optimisation into its design. Unlike most aero flat-sectioned road bars, the 4D’s top wing section is angled forwards at 10 degrees from the clam section out to the drops. This creates a flatter forward-facing section, and when paired with a slender aero-styled stem, like Vision’s Metron, it offers drag-reducing performance.
If, like us, aerodynamics take second place to ride feel and usability, the 4D still has serious advantages. That swept-forward top-section with deep tear-dropped shape provides a comfortable on-the-tops position, with the slightly angled hand position making this a great bar when riding extended climbs on the tops. The hand position feels natural and open, so you can breathe easily and pull on the bar without feeling cramped.
The 125mm compact drop with 80mm reach is based on one of our favourite road bars, the FSA K-Force Light. With that 10-degree forward sweep, the 4D adds a bit of length to the overall reach on your bike, for a longer, lower ride position, which is great if you want to add a bit of sportiness to your endurance bike, or a touch more aggressive positioning to your racing special. The drops also have a subtle two-degree outward bend, which adds to wrist clearance when you’re down in the drops.
The bar is grooved for Di2 routing, and has an internal cable tunnel so will work with pretty much any drivetrain. The real benefit is just how well the bar rides. Vision has built the 4D using continuous fibres throughout its length, with a unidirectional carbon finishing layer, which adds a brilliant blend of stiffness where you want it, yet compliance that eliminates road buzz. The 4D is expensive, but rides beautifully, and at 229.8g for a size 44cm, it’ll improve the front-end feel of your bike.