To kick off the road racing season and the start of the Tour Down Under, Giant has launched their new Propel Advanced SL aero road bike. After years in the making, working with the likes of Theo Bos and Mark Renshaw with Team Blanco, Giant claims the Propel SL is the fastest bike yet – not just for Giant, but the fastest bike, period. Not satisfied with simply making a more aerodynamic machine, Giant was keen on developing a bike that was just as light, stiff, and responsive as their popular TCR Advanced SL, but that was able to cheat the wind offering big gains over the course of a race.
Even in today’s marketing climate, throwing around words like the “most aerodynamic bike in the world” should only be done with evidence to back it up. Giant claims to have created new, innovative testing protocols that allowed for the most complete and accurate data sets in the industry and even went as far as to create a dynamic mannequin for the wind tunnel testing rather than a static dummy or human rider. Wind tunnel testing was completed at the ACE wind tunnel in MAgny-Cours, France with the Dynamic Mannequin accurately simulating the turbulence created by pedaling on a bike. After years of designing, testing, and tweaking, the result is the Propel – Giant’s first aero road bike.
More details plus test results after the break!
Going along with the idea of creating an aero bike that rides like a typical road bike, the frame module (medium frame, uncut fork, uncut integrated seat post w/head, brake system, and headset plug) comes in at 1,675g. Broken down, it should result in the Propel being one of the lightest “aero” road bikes on the market – what Giant says is class leading weight without compromising stiffness and handling. When asked about his new ride Bos said, “It’s been almost a year since I started testing pre-production versions of the Propel Advanced SL. The first time I rode it I knew this was a bike that would give me an advantage in sprint situations where every fraction of a second counts.”
To compliment the new aero shapes of the frame, Giant also includes their proprietary integrated SpeedControl SLR brake system – essentially carbon mini-V’s built into the back of the fork legs and interestingly, the seat stays rather than the chain stays. The seatstay placement could have something to do with complications with the placement of the Di2 battery, or simply because there isn’t an aero benefit from tucking them into the chainstays. In addition, Giant also introduced a new once piece bar/stem system aimed at improving aerodynamics and offering a stiffer front end.
The top end Propel advanced SL series is built with Giants top of the line Advanced SL carbon technology and will feature Giant’s OverDrive 2 tapered steerer ( 1 1/2 to 1 1/4″ upper), and integrated seatpost (ISP), and their 88mm press fit PowerCore bottom bracket.
Like many new aero bikes and parts, Giant utilized Computational Fluid Dynamics to shape the various tubes to work together for total system aerodynamics. Giant dubbed the process their AeroSystem shaping technology which reflects their belief that each change to the frame should be viewed on how it affects the overall performance rather than just how that individual tube performs. In the end, the use of the Dynamic Mannequin and team Blanco riders helped shape the ultimate design of the frame.
Giant’s Global On-Road Category Manager Jon Swanson is quick to point out that they didn’t rush to market with an aero road bike, rather opting to take their time so that the final product truly offered an aero advantage. To guarantee the results, the Propel was tested in head to head aero tests with other top aerodynamic bikes. In their testing they found that the Propel Advanced SL was more aerodynamic than every other bike they tested, and at every yaw angle. In a 40K time trial at 40KPH, the Propel shaved as much as 36 seconds over the rivals based on drag in the wind tunnel.