Factor Ostro Gravel

Package: Frameset
Color: Naked Grunge
Naked Grunge
White Grunge
UD Gloss
Prisma Custom

Speed is your goal. Every ride, whatever the surface, faster is what counts, and this is the gravel bike you’ve been waiting for. The OSTRO Gravel takes its ‘win everywhere’ mentality from its road racer stablemate, the OSTRO VAM, and is likewise developed to dominate its category with incredible aero, superior handling, high stiffness and low weight. With a tire capacity of 45mm, it’s ready to go anywhere, fast.

Prisma Paint options avialable, for confirgutaion check here, Prisma Paint, this can add over 8 weeks to delivery


Gravel racing is fast and aero really matters, but it isn’t as fast as road racing so the requirements are different. The OSTRO Gravel frame is carefully optimized for the speeds at which you’ll be riding. Our team used a ‘zoned aero’ strategy which focused the front of the bike on aerodynamics because it meets clean, or freestream, air flow, and the rear of the bike on lightness, where the air flow is too chaotic and ride quality is the priority. In particular, a lot of time was spent on the head tube, where an all-new tube shape unlocked significant drag reductions by manipulating the ‘laminar separation bubble’ that occurs near the front of airfoils at lower speeds. The tech is rooted in aerospace but all you really need to know is that the OSTRO Gravel will get you to your finish line faster, and by minutes, not seconds.


The OSTRO Gravel offers a generous 45mm of tire clearance in both 700c and 650b, giving you the options and possibilities to tackle the toughest routes and events. This is a real figure, with 4mm of clearance either side in accordance with ISO standards, so the OSTRO Gravel is super-capable in muddy conditions. That was proven at the queen of gravel races, the 2022 Unbound 200, where heavy rain made the course brutal and the OSTRO Gravel was ridden to a top-10 finish.


The new Black Inc THIRTY FOUR wheels are - like the OSTRO Gravel itself - dedicated to speed on gravel. Their 34mm depth maximizes aero gains while keeping weight to a minimum and avoiding too tall a combined rim and tire side area, ensuring crosswind stability. They’re most aero with a 32mm tire for all-road use, yet also very effective for gravel tires up to 43mm. The internal width of 25mm allows bigger tires to take a better shape. The hookless rim is designed to make it easy to mount tubeless tires, in most cases with a regular floor pump. The rim includes a secondary shoulder which keeps the tire securely seated in the event of a rapid deflation, allowing you to come to a controlled stop. The Black Inc hubs run on CeramicSpeed bearings for ultimate efficiency.


Aerodynamics and ergonomics - the flared Black Inc Integrated Aero Barstem takes both to new heights, because riding far and riding fast are not mutually exclusive. Its mid-depth aero profile is the outcome of tireless research and development, initially using CFD (computational fluid dynamics), then by testing prototypes in a wind tunnel. The result is that it outperforms leading brands of aero road bars and does so at an exceptionally low weight. What’s more, it’s as comfortable as it is fast, thanks to highly refined ergonomics which provide more back sweep for a natural wrist angle on the tops, more wrist clearance and hand positions thanks to the chamfered corners, a drop shape that accounts for the longer reach of the latest Shimano and SRAM shifters and a 7-degree flare that starts below the shifter mounting point. The flare adds 3cm of width in the drops, a figure carefully judged to suit all applications as the Integrated Aero Barstem is designed to pull double-duty for both the OSTRO Gravel and OSTRO VAM. For gravel, enjoy the extra control of the wider drops in descents; for road use, select your usual drop width and benefit from the much more aero position achievable on the narrower hoods. The new Integrated Aero Barstem also gains a GoPro-style computer mount, adding angle adjustment and a more supported second mount for a light or action camera.


Many all-road and gravel bikes struggle to deliver steering that’s effective and confident both on- and off-road, typically ending up with an unsatisfying compromise of soft handling and modest tire capacity. The OSTRO Gravel breaks that mold by making the tire size an integral part of the geometry. Wider tires also have a greater outside diameter (or rolling circumference) which increases the true, or ‘resulting’ trail of a bike; narrower tires have a smaller outside diameter which reduces resulting trail. These outcomes match the handling response you want when riding those respective tires, so we designed with resulting trail as the priority. We selected a trail value on the slightly faster handling side for gravel use, given the bike’s racing focus, while prioritizing head tube angle when selecting our fork rake. This leads to a fast handling gravel bike on 43mm tires and an equally satisfying and precise all-road machine on 32s, with no low-speed wheel flop.


When you’re riding full gas, there’s little time to appreciate anything about the countryside other than how fast it’s rushing by. The OSTRO Gravel was made for these rides, with an unrivalled combination of aero, lightness, compliance and integration. Put your head down and go.

    While the OSTRO Gravel pairs ideally with the Black Inc Integrated Aero Barstem, we have designed the front end to be easily compatible with various third party internal routing systems, so you can always have the exact touch points you>
    The stack height of the new O2 VAM is 10mm higher. We studied the position data of thousands of our customers and athletes to find the dimensions that would enable the most riders to achieve their optimal fit. Reach is unchanged.
    Factor engineers chose a round steerer, proven to be the most durable solution serious gravel riding and racing. The 1-½” upper and lower bearings with a modified split ring allow for the cables to pass through the bearing, easing maintenance demands.
    The T47 standard for threaded bottom brackets ensures a secure fit and easy maintenance. It allows for the use of a wide range of crank spindle diameters and helps keep the bottom bracket shell robust for exceptional power transfer.
    To be self-sufficient in the world’s hardest gravel events, you need extra carrying capacity. We have added mounting bosses to the top tube and down tube so that you can make it feed stations or gas stations, even on the toughest days.


Frame TeXtreme®, Toray®, Nippon Graphite® Pitch-Based Fiber
Fork OSTRO Wide Stance Fork
Seatpost 0 and 20mm setback available
Barstem Black Inc Integrated Aero Barstem Reach 80mm, drop 120mm. Multiple stem lengths and bar widths available
Headset CeramicSpeed SLT 1.5″ bearings
Head Tube Diameter 1.5″ upper and lower
Saddle Rail Clamps 7x7 and 7x9
Bottom Bracket CeramicSpeed T47A Aluminium cups / CeramicSpeed bearings available for DUB, 24mm, or Ultra-Torque
Cable Routing Internal
Compatible Components Electronic
Brake type Disc
Max Rotor Size 160mm front & rear
Max Chainring 52-tooth
Front Axle 12 x 100mm thru-axle
Rear Axle 12 x 142mm thru-axle
Wheelset Black Inc THIRTY FOUR
Wheel Size 700c
Max Tire Clearance 45mm measured
Weight 950g
Manufacturer Warranty Limited Lifetime Warranty


Size 49 52 54 56 58 61
Stack 515 535 555 580 605 625
Reach 377 385 394 402 412 422
Front Center 591 604 605 620 638 655
Wheelbase 999 1013 1014 1029 1047 1069
BB drop 76 76 74 74 74 74
ST angle 74.5° 74° 74° 73.5° 73.5° 73.5°
HT angle 71.2° 71.3° 72.2° 72.3° 72.3° 72.3°
TT (effective) 520 538 553 574 591 607
ST 450 468 483 500 523 545
Fork length 400 400 400 400 400 400
Fork Offset 56 56 50 50 50 50
Trail 62 62 61 61 61 61