Factor Bikes' ONE Disc Road Frameset is as fast as it is stunning. The first thing that grabs your attention is the unconventional OTIS fork and the Evo bar/stem combo directly on top. The next unique feature is the Twin Vane bisected down tube. Of course these features could be cast aside as gimmicks except Factor is well versed in the aero game and it has a pretty narrow focus of creating the fastest bikes on pavement as possible. For instance, the Twin Vane down tube features a lengthwise cutout that Factor credits with a 100g reduction in air resistance forces as it gathers and manages the unruly turbulence rolling off of the front wheel. Those in the know refer to turbulence as "dirty" air, and the Twin Vane serves to clean up this air helping you go faster with less effort. With the inclusion of disc brakes on this ONE, we feel like it takes the frameset from an excellent aero frame to an extraordinary all-arounder.
Factor's aim with the new ONE was to create the fastest aero road bike ever. Lofty goals indeed, but with the latest advancements to the ONE, we feel the brand may well have done it. The newest ONE combines every bit of aerodynamic technology and frame construction expertise from previous Factor models including the One Total Integration System (OTIS) front end.
OTIS enjoys the obvious benefits of presenting a minimal face to the wind (it's practically two-dimensional head-on) and—with the inclusion of an external fairing that rotates with the fork and bars, it disturbs the air as little as possible. These features are designed to work in cahoots with the bifurcated downtube in order to take full advantage of the peculiar design, and without both elements, the significant claims of reduction in air resistance are void. OTIS's integrated bar/stem combo also does its part, increasing stiffness, boosting the frame's aerodynamic benefits yet further, and actually managing to reduce frontal surface area when compared to the concept bikes that the ONE owes its DNA to.
OTIS's final benefit runs contrary to everything we'd expect to see in an aerodynamic race frame: It contributes to handling that's so stable and sharp we experienced a brief adjustment period. The One never feels like it's going to drift off its line or twitch into a dangerous steering hiccup while arcing through sweeping descents, but it is definitely capable of diving for the inside line on a 90-degree crit corner and making tight adjustments at speed. There may very well be frames whose front ends more effectively balance stability and responsiveness, but we haven't found any. What we have found, though, is a minute amount of flex in a deep-dish front wheel that—until being mounted on the ONE—had felt unyielding during sprints and while redlining punchy Flemish walls.
Every bit of drag interfering with forwarding momentum represents wasted effort on your part, aerodynamics in cycling is arguably more important than in motorsport—at least, that's what we think when we're pulling the group into a headwind. Based on the brand's extensive testing, the One saves around one second for every kilometer traveled at race speeds around 24-28mph. These gains are based solely on the aerodynamic features built into the frame and its accompanying handlebar/stem construction, so any details like deep rims and a dialed rider position are just icing on the aero cake.
After the OTIS front end and bifurcated down tube, the One's most immediately obvious "aero" feature is the tube shaping, which incorporates the rounded face and truncated trailing edge that are populating the pointy end of the peloton these days. The shape babysits airflow from the point the frame encounters it till long after it's detached and dissipated into the 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 tube shapes are accompanied by a handful of classic aerodynamic features, including fork integration, an integrated seatpost clamp, a hidden, flat-mount disc brake, and internal (electronic only) cable routing.
The stiffness underwriting the OTIS fork is also general throughout the bike, with the down tube, bottom bracket, and built-up chainstays demonstrating similar efficiency. In fact, the frameset's drive spine—especially, again, the OTIS fork and head tube juncture—is so rigid that it really will expose otherwise undetectable amounts of flex in all but the stiffest carbon race wheels. Fortunately, Factor spares you the impossibility of finding an appropriately stiff stem/handlebar combination by including its own, which integrate as part of the OTIS system to further reduce drag and eliminate the possibility of a weak link anywhere in the drive spine.
The geometry is slightly tweaked from frames out of the Old World. These changes manifest as a slightly lower stack, longer reach, and a steeper seat tube than the all-purpose frames used by cycling's biggest teams. These deviations demonstrate that, though many of the Continental brands privilege tradition over innovation, Factor has no qualms about building a bike that meets the needs of scrappy fastmen like co-founder Baden Cooke, smooth rouleurs like Millar, and the current pros at AG2R La Mondiale. With carbon guru Rob Gitelis on board, Factor enjoys the freedom to continuously tweak the geometry and make unreasonable demands of the factory in order to deliver. And the brand has certainly taken advantage of it.
Ultimately, the geometry changes situate the rider more forward on the bike, helping you stay on top of the pedal stroke and rolling your hips forward to increase power output. This posture isn't about endurance-ride noodles or sportive waffle rides; it's meant for hammering to keep pace in a crit peloton or sacrificing yourself on the altar of the kind of long, grueling solo moves where the frame's aerodynamics really come into play.
The system's uncompromising efficiency is equal parts tube design and carbon lay-up, with Factor pairing the former with the latter's three-modulus blend. Two of these moduli are of the quality we see in most top-tier racing frames, but the third, Pitch Fibre (oh so British), is the lightest, stiffest material that can be shaped into a bike frame. 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.
Included with this frameset is a ceramic bearing headset and bottom bracket, and aero seatpost. The ONE Disc uses the Flat Mount standard, with recessed caliper hardware mounts for small aerodynamic gains and cleaner looks. The bolt-on Factor 12mm thru-axles keep the whole system tidy and away from the wind. Adding comfort for the ride, this frameset has clearance for 28mm tires.