Wilier Filante SLR Road Bike Frame

Wilier Filante SLR - The Lightest Production Aerodynamic Racing Bike

Bike designers always have something they can improve. One design can use some more aerodynamic touches, while another might need to lose a little weight. With the Wilier Filante SLR, the Wilier designers have tried to create the best of both worlds: the lightest possible production aerodynamic racing road bike.

To make good on the first ambition of putting their prime aero bike on a diet, the Filante SLR sheds over 100 grams compared to the Wilier Cento10 Pro. So instead of weighing 990g, the Filante SLR comes in at 880g, which is an 11% decrease. That’s a lot, and it slips the Filante SLR into a lightweight neighborhood that is usually more occupied by other manufacturers’ climbing bikes that don’t focus on aero efficiency. They have managed to get the weight down so much by using a high modulus carbon with a liquid crystal polymer which helps increase the tensile strength and durability of the tubing.

Focusing on improving the aerodynamic properties relative to the Cento10 Pro, Wilier designers looked at how they would shape the tubes in order to make them most efficient no matter the wind direction. The Cento10 Pro and most aero bikes these days use a truncated Kamm tail shape to get the aero advantage without the weight. But Wilier discovered using a more rounded Kamm tail shape improved performance at all Yaw angles. So instead of a stem-less wine glass shape, the Filante tubing has a less pronounce “cut” appearance on the trailing edge of the tube, looking and feeling more rounded, which helps to smooth the airflow especially for side wind situations. Working with the fork, they have also widened the distance at the arch and between the fork legs, which enhances the aero properties, and makes it possible to fit up to 30mm tires. The rear triangle also can accommodate 30mm tires. The fork also makes use of an a-symmetric design to help the front end withstand the varying amounts of force that are applied on the drivetrain vs. non-drivetrain side.

Staying with the front end, Wilier engineers have also been fiddling with the steerer tube and the bearings that will fit. By using super thin bearings, they can keep the steerer tube round, instead of the D-shape found on the Cento10 Pro and other bikes, they increase the stiffness and reliability of the steerer and improve the handling. If you already have a Cento10 Pro, you may wonder how the handling could ever get any better, but it is these types of improvements that make a great bike into a super bike. They have also focused on improving the handlebar setup with an improved stiffness-to-weight ratio and multiple fit options thanks to their ACCU-Fit system.

Aero Optimization of the Filante SLR

The seatpost is not ignored in terms of aero optimization and sports a fully integrated seat clamping system. A beautifully minimal design, it’s super lightweight. Compatible with a Ritchey 1-bolt saddle clamp, it’s also very easy to adjust. The seat post itself comes in two configurations: 0mm setback and -15mm setback. Wilier has also been clever in using the Mavic Speed Release through-axle quick release design for this frame. It means that you can remove the wheel without having to pull the axle out entirely. It makes wheel changes so much faster, which matters not only to the pros in the middle of a race but also us normal folk who hate having to mess around endlessly screwing the axles in and out. Five quick turns of the lever, and the wheel is free. That’s better than a regular rim brake QR.

The whole scopo or purpose of the Wilier Filante SLR can be understood from the name. Coming from filare, which means to spin, “filante” can translate into English as “streamlined” or even “racy”, both of which aptly fit this pure racing bike with beautifully clean lines.

Also check Cinelli road bikes.