The "S" in Factor Bikes' One-S Road Frameset may well refer to "steerer," as in: The One-S's fork has a traditional steerer tube instead of the unconventional OTIS fork on the brand's flagship One. Despite the different fork, the One-S incorporates the same Twin Vane bisected down tube hiding behind the One's OTIS fork. The Twin Vane down tube features a lengthwise cutout that Factor credits with a 100g reduction in air resistance forces because it gathers and manages the unruly turbulence rolling off of the front wheel. Factor refers to this turbulence as "dirty" air, and the Twin Vane serves as the aerodynamic equivalent of a cleaner to tidy up the crime scene after the fork and front wheel commit drag-inducing aerocide.
Factor's willingness to inflict violence on industry axioms isn't a case of iconoclastic vandals breaking things just for the sake of breaking things. Rather, the unconventional design elements of the One-S are the result of a collaboration between some big names in the cycling industry and a big name in automotive aerodynamics. We'll get into the details below, but it's worth interjecting here that, during its debut under One Pro Cycling's Domagalski, the One-S was ridden to two stage victories at Korea's 2.1 category stage race.
Factor is led by green jersey-winner Baden Cooke and Rob Gitelis, a carbon manufacturing guru who also happens to be a longtime two-wheel fetishist. The pair acquired the brand from bf1systems in order to adapt the erstwhile non-race-legal technology of models like the Vis Vires and 001 into race-legal designs. To help with that transition, the pair have developed a strong supporting cast that includes Matt Prior, a multisport enthusiast and the head of One Pro Cycling, and David Millar, the cycling world's most fashion-forward rouleur and the latest heir to the Millar engine. While the latter's own father remains one of the greatest Anglophone climbers, Factor's supporting cast is far more dedicated to the pure speed of sprints and TTs. The One-S bears this focus out, but—despite the impressive names behind the brand—Factor didn't do it alone.
The point of departure was bf1systems, a powerhouse of aerodynamics and the brains behind many of Europe's biggest auto-racing names. We'll avoid listing the entire roster here, but it's every bit as impressive as Factor's list of co-owners. Think back to the posters on your childhood bedroom walls or the images on your grade school folders and notebooks; chances are good those high-horsepower machines began life as a gleam in the eye of BF1's engineering team.
Aside from the Twin Vane down tube discussed above, the frameset's aerodynamic features include the bullet-nose face and truncated tailing edge that have come to define top-end tube shapes. The shape babysits airflow from the point the frame encounters it till long after it's detached and dissipated into wake. The abbreviated rear face is especially important as it reduces the negative vacuum of trailing drag that traditional tube shapes produce, but it doesn't turn into a destabilizing parachute when crosswinds and road conditions shift the yaw angle outside of a NACA profile's near-zero comfort zone.
The aerodynamic features extend to such subtleties as a hidden seatpost clamp, direct-mount rear brake caliper, tucked-away seatstays, internal cable routing, a Di2 junction box, and the inclusion of an integrated stem/bar unit that's designed to work as part of a drag-reduction system with frame and rider. Frankly, we expect this roster of wind-cheating features from high-end aerodynamic road frames. And given Factor's penchant for going above and beyond what's expected, it's no surprise that they're all represented here.
What is a surprise is that the aerodynamics don't come at the cost of comfort. The One-S isn't as buttery smooth as a classic, lugged steel frame or a heavy, carbon cobbles machine, but it does transmit a lot less harshness than the non-traditional tube shapes and seatpost would suggest. Maybe this is because of the low chainstay juncture and shape, or maybe it has something to do with the carbon lay-up. Given co-owner Gitelis' 15+ years in manufacturing, we suspect the latter might play a significant role.
The frame's contradictory balance of aerodynamics, efficient power transfer, and comfort is equal parts tube design and carbon lay-up. Factor builds the One-S with three different carbon moduli, balancing the vibration damping and compliant durability of lower and middle moduli with the unyielding stiffness of Pitch Fibre, a material that is as unabashedly stiff and light as its name is unabashedly British.
Factor isn't shy about claiming that Pitch Fibre is the lightest, stiffest material that can be shaped into a bike frame, so you might assume three things here: 1) Pitch Fibre is extremely difficult to work with, 2) it's very expensive, and 3) Factor jealously guards the exact details of its lay-up schedule. You'd be correct on all fronts. The one insight Factor gives into its process is the use of a program called Fiberism, which Factor uses to "ensure that we put the waste into the garbage can and not into the frame." Fiberism helps the brand keep material to a minimum, resulting in fabric cuts and construction as discerningly meticulous as sartorially gifted brand-ambassador Millar's wardrobe.
The included accessories demonstrate the same care. In addition to the fork, bar/stem unit, and seatpost, Factor packages the One-S with a Ceramic Speed bottom bracket, a Ceramic Speed headset, a compression plug, steering tube spacers, a spare derailleur hanger, bar tape, and a few other unlooked for but indispensable items.
- An unconventional road racing frameset with an impressive pedigree
- Aerodynamic engineering empowers long-range solo attacks
- Twin Vane down tube manages airflow coming off front wheel
- Modified NACA tube shapes are faster and more stable
- Integrated rear brake and seatpost clamp further reduce drag
- Meticulous carbon lay-up capitalizes weight loss and stiffness
- Engineered in partnership with a leading motorsport firm
- Factor Bikes breaks with tradition in pursuit of on-road gains