The first thing to understand about the all-new Propel range is that it’s built to win races. Big races. There’s a reason why this aero road machine made its public debut at the 2022 Tour de France. This is a bike that has been engineered to give pros like Dylan Groenewegen and Michael Matthews of Team BikeExchange-Jayco a competitive advantage when it matters most.
After years of engineering and development, followed by additional testing at smaller races earlier this year, Groenewegen introduced the new Propel Advanced SL to the world with one of the biggest wins of his career at Stage 3 of the Tour. The Dutchman beat some of the world’s best sprinters in a photo finish. Thirteen days later, Matthews proved that the new Propel can do more than sprint, when he won a grueling, hilly Stage 14 with a dramatic solo attack.
For fast finishers like Groenewegen and Matthews, winning or not winning often comes down to those hectic moments in the closing kilometers. Positioning, chasing, attacking. Bumping elbows, leaning hard through technical corners, blasting ahead of the field. This is where the new Propel surges ahead of the pack.
The guiding design principle behind the new Propel is its AeroSystem Shaping Technology. This is a process that can be viewed as a sum of all parts. It’s about analyzing every tube, junction, angle and component—both individually and, more critically, as a holistic system.
The goal when creating all the different parts that make up this system is to simulate real-world riding conditions. The engineering team starts this process with airflow simulation software called computational fluid dynamics (CFD). After all the numbers are crunched, the physical forms are created. Then comes wind-tunnel testing, followed by the final step, which is to produce sample bikes and test them on the road with our pro athletes.
AeroSystem Shaping is what led engineers to use the signature truncated ellipse airfoil shapes that can be found in key areas of the frameset including the down tube, seat tube and seat stays. Working with renowned aerodynamicists at the GST wind tunnel in Immenstaad, Germany to accurately simulate real-world riding conditions, they use a dynamic mannequin to analyze the aerodynamic factors of not just the bike, but rider and bike together.
This combination of CFD and wind tunnel analysis led to the frameset modifications you see on the new Propel Advanced SL. The frontal sections, where aerodynamics matter most, feature sculpted lines and that truncated ellipse shape to minimize drag. Following our holistic approach to aerodynamic design, we even created two different water bottle cages (one for the down tube, one for the seat tube) to minimize aerodynamic drag for each of these specific tubes.
When it comes to aero gains, the frame itself is part of the story, but not the whole story. The new proprietary Contact SLR Aero handlebar and stem also reduce drag, as do the new CADEX 50 wheels and CADEX Aero tires. When comparing the complete new Propel Advanced SL bike to the previous generation, the new model improves aerodynamic drag by 6.21 watts. This equates to a savings of 27 seconds over 40km at 40kph.
The new Propel Advanced SL is crafted with Giant’s most premium raw carbon fiber and cutting-edge manufacturing techniques to achieve a greater stiffness-to-weight ratio than the previous generation. For competitive racers, nothing matters more than power-to-weight, so making the new Propel both stiffer and lighter was essential.
Tests show that the new frameset is not only one of the lightest in the aero road category, but it also achieves significant gains in stiffness. Lighter weight plus increased stiffness equals better efficiency on the road. When determining the precise tubing shapes and diameters, along with the layup of the Advanced SL Composite material that’s used to create the frame and fork, Giant engineers focused on two key areas of stiffness: frame stiffness, which determines the amount of overall frame and fork torsional flex under load; and pedaling stiffness, which measures the lateral flex of the bottom bracket area under load.
Most of the gains in stiffness come from modified sections of the head tube, down tube and bottom bracket area. But just making a frameset ultra-stiff doesn’t necessarily make it faster. To optimize all-around performance in real-world conditions, compliance and control also play a role. For that reason, the rear half of the new Propel has been re-engineered to provide a smoother ride quality, which helps make it a more capable all-rounder.
The seat tube, chainstays and integrated seatpost have all been reengineered, with slimmer diameter tubing compared to the previous generation Propel Advanced SL. This new design helps reduce weight, and it also gives the new Propel improved road handling. Compared to the outgoing Propel Advanced SL, the new model has 85 percent added rear-end compliance (via the new integrated seatpost), making it more capable for long, hard days in the saddle, when its road-smoothing properties help minimize fatigue. Added frame and fork clearance also allows you to run larger diameter tires (up to 30mm) for an even smoother ride.
The cockpit has been completely redesigned with an innovative new two-piece Contact SLR Aero handlebar and stem setup that makes it easier to change components and dial in a precise fit. This new OverDrive Aero system keeps the cables and hoses hidden from the wind while avoiding the complexities associated with fully integrated handlebar/stem designs that are common with many of today’s aero road bikes.
The new Contact SLR Aero carbon handlebar has flattened tops for aero efficiency and hand comfort, along with a deeper drop for added control while sprinting, cornering and descending.