The Factor Ostro Gravel is an unapologetic race platform engineered specifically for high-speed gravel events. Drawing heavily from Factor’s Ostro VAM road bike, it prioritizes aerodynamic efficiency and structural stiffness over broad-spectrum versatility or plush compliance. The frame features deep, truncated aerofoil tube profiles, a distinctive head tube optimized for lower gravel speeds, and fully internal cable routing.
Designed exclusively for electronic drivetrains, the chassis clears a 45mm tire and relies on a threaded T47A bottom bracket. It is built for riders who treat gravel as a competitive discipline rather than a backcountry adventure. By focusing entirely on power transfer and wind-cheating shapes, Factor has created a highly specialized machine that thrives on fast, well-graded dirt roads and tarmac, leaving comfort-oriented exploration to more traditional gravel designs.
Where to get it.
2 retailers · size 54.
Spec sheet.
Every component shipped with this build.
Geometry & fit.
6 sizes published.
The Ostro Gravel utilizes a road-derived geometry that dictates an aggressive, forward-leaning rider posture. With steep head and seat tube angles, the frame places the rider in a position optimized for power output and aerodynamic efficiency. Factor employs size-specific fork offsets to maintain a consistent, relatively short trail figure across the size range. This results in steering that is quick and reactive, allowing the bike to dart through sweeping corners on smooth surfaces with minimal input.
The front end is defined by the Black Inc integrated aero barstem, which features a subtle flare in the drops to provide wrist clearance and a stable grip without compromising the bike's narrow aerodynamic profile. Because the brake hoses route entirely through this one-piece cockpit and into the round steerer tube, making fit adjustments to reach or bar width requires swapping the entire unit and rerouting the hydraulics. While the longer wheelbase adds a measure of high-speed stability, the sharp steering geometry means the bike requires an attentive rider when navigating slow, technical off-road sections.
Where the handlebar sits relative to the bottom bracket — the single most important fit pair.
01Fit geometry4 values
02Component geometry2 values
03Handling geometry7 values
Which size should I buy?
Slide your height to see the recommended size. GearWise's fit algorithm works from the published stack, reach, and ETT — the brand's own recommendation may differ.
→Calculated from GearWise's own stack / reach / ETT algorithm — the brand's size chart may recommend a different size, and a proper bike fit beats any calculator.
The lineup.
4 builds, ranging $9,299 – $11,399.
Factor offers the Ostro Gravel in a focused range of premium builds, all centered around SRAM electronic drivetrains. The lineup splits between the Force and Red tiers, with each level offering a choice between a standard 12-speed setup or the gravel-specific XPLR configuration. Every complete build includes a Quarq power meter integrated into the crankset, adding clear value for riders focused on structured pacing and race efforts.
Across the entire range, the supporting component specification remains identical and exceptionally high-end. Every model rolls on Black Inc Thirty-Four carbon wheels, which feature a 34mm depth and a wide hookless rim profile designed to support modern gravel tires. Factor also equips every build with CeramicSpeed bearings throughout, including the T47A threaded bottom bracket, the wheel hubs, and the solid-lubrication headset bearings.
Because the frame, cockpit, wheels, and bearing upgrades are consistent across the board, the price jumps between models are dictated entirely by the shift from SRAM Force to the lighter SRAM Red components. While the entry price is undeniably high, the inclusion of power meters, premium carbon wheels, and ceramic bearings across all builds makes the specification highly competitive within the top-tier racing market.
From the press.
12 reviews from the cycling press.
Reviewers consistently characterize the Ostro Gravel as a remarkably fast, highly efficient race bike that demands compromises in comfort. On smooth dirt and tarmac, the bike excels. Testers praise its immediate acceleration, noting that it feels "taut and lithe and responsive" (Cycling News) when putting power through the pedals. The aerodynamic shaping and rigid chassis help riders maintain high speeds with less effort, imparting a "sense of ease when going fast" (Cyclist Magazine) that closely mimics a dedicated aero road bike.
However, that same structural rigidity translates to a punishing ride on rougher terrain. Multiple reviewers describe the frame as "overly firm" (Cyclist Magazine), pointing out that the deep-section aero seatpost offers almost no rear-end compliance. When the route turns to rocky doubletrack or technical singletrack, the ride quality can quickly become "stiff and harsh" (Gravelcyclist), leading to increased body fatigue over long distances.
The consensus positions the Ostro Gravel as a highly specialized tool. It rewards fit, experienced riders who prioritize outright speed on well-graded courses, but it is less suited for those seeking a forgiving ride for multi-day bikepacking or relentlessly bumpy trails.
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