Factor LSvsOstro Gravel

The Factor LS entered the scene as Factor's initial foray into dedicated gravel, heavily influenced by its O2 VAM lightweight road bike. It's conceived as a "quiver-killer" machine, bridging road and gravel with a focus on low weight and familiar road-bike handling. Reviewers noted its "road-bike-like aesthetic, attitude, and low weight" from the outset, aiming for a subtly compliant yet stiff ride on mixed surfaces. In contrast, the Ostro Gravel, a more recent addition, takes its cues from Factor's aero-optimized Ostro VAM road bike. This is a gravel machine built overtly for speed, with every frame tube sculpted for aerodynamics and an aggressive race mentality. While the LS whispers 'fast gravel,' the Ostro Gravel shouts 'aero gravel race,' making fewer concessions for comfort or versatility in its single-minded pursuit of efficiency on loose terrain. The LS frameset weighs in at a scant 850g, while the Ostro Gravel, despite its aero bulk, still manages a competitive 950g frame weight, showing Factor's commitment to lightness even in its more robust designs.

The Factor LS delivers a ride quality firmly rooted in its road-racing DNA, often described as an "exceptionally stiff machine." It translates pedal inputs directly into forward motion, making it "super-responsive to pedal inputs" for attacking climbs and accelerating. Velo, however, noted that Factor made "careful consideration" for compliance, giving the LS a "controlled feel" that hums along on smoother gravel but "finds its limits pretty quickly once the ground gets choppy," hammering home the frame's stiffness on square-edged impacts. Moving to the Ostro Gravel, the primary descriptor is "stiff." This bike is a rigid, aero-optimized missile, built for pure speed. Reviewers found its ride "unpleasant" and "jarring and hard to handle" on anything remotely rough or technical, with the rear end offering "so little compliance" that it's physically fatiguing. On well-graded gravel or tarmac, it's a different story: the Ostro Gravel feels "like being shot out of a cannon," eager to hold speed with minimal effort. However, this comes at the cost of comfort, making long distances on varied rough surfaces a physical challenge. Handling differences are stark. The LS offers "noticeably quick" steering that lets you "carve a tight turn or rapidly change direction." It feels familiar to a road racer, easily adapting to 32mm slicks, though its tight wheelbase means "noticeable amount of toe overlap." The Ostro Gravel's handling is also quick and responsive, particularly at speed, where it picks lines precisely. But at lower speeds or on technical singletrack, its stiff chassis and road-like geometry make it "quite a handful," prone to being bumped offline by obstacles. The lack of rear-end compliance means power transfer on rough terrain can actually become harder, making you slower, a crucial detail for actual off-road racing scenarios. Both bikes rely heavily on tire choice for comfort. The LS is optimized for 40-43mm gravel tires, with wider rubber improving grip and dampening vibrations. The Ostro Gravel clears up to 45mm, and reviewers strongly recommend maximizing tire volume and optimizing pressure to mitigate its inherent harshness. The LS's Black Inc one-piece handlebar provides "a subtle amount of forgiveness," helping the front end feel more muted, while the Ostro Gravel's aero seatpost offers little comfort, leading to an unbalanced front-to-rear feel where hands are more comfortable than the seated body.