Factor’s design objective with this new frame was to combine the efficiency of an advanced aero package with the robustness of a bike that could roll with confidence over some pavé.
For amateur riders the result is a true ‘quiver-killer’ road bike, possessing a breadth of ability that can theoretically replace a collection of two or three bikes.
The Ostro’s overall aero profile is influenced by Factor’s O2 Vam, with a similarly shaped down tube, whilst geometry angles also use values proven by the brand’s O2 frames.
On a size ’54 frame, the new Ostro sets its seat angle at 73-degree and heat tube at 72.5-degrees. The geometry spectrum is size specific and so are a choice of three fork offset measurements, with the smallest Ostros running a carbon fork at 53mm offset, medium sizes at 48mm and the larger frames 43mm.
Beyond the Ostro’s progressive geometry, there are compliance features engineered into the frame. The bike’s elegantly slim seat stays provide adequate engineered flex, to reduce road buzz, especially on imperfect road surfaces.
Balancing the need for outstanding aerodynamics and large volume tyre compatibility was a design challenge with this new bike. Factor’s carbon-fibre engineers solved the issue by controlling the entire process, from concept to a succession of iterations, that finally become the Ostro.
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Factor owns its carbon-fibre production asset, which means that design engineers are not constrained by a third-party supplier. This has enabled the Ostro product team to develop a frame that is preciously light (780g for a size ’54), yet shaped with impeccable aerodynamic details.
Black Inc FORTY-FIVE wheels run CeramicSpeed bearing and are 20.7mm ID (Image credit: Factor)
All about the aero
One of the most notable aerodynamic design features of Factor’s Ostro, is its generously spaced caron fork structure. This wider leg spacing reduces the influence of wake turbulence from rotating spokes, disrupting the airflow through and around an Ostro’s fork.
Stagnant air and its potential drag are addressed by a relief channel, shaped into the fork crown, which improves laminar airflow. It helps to disperse the effect of dynamic air being driven upwards by the front wheel’s rotation.
Ostro riders benefit from the lower rolling resistance, superior handling, more secure braking and greater all-day riding comfort offered by higher-volume tyres. The bike is capable of rolling 26mm tubular or 32mm width tubeless tyres, seated on 21mm internal diameter rims.
Factor is marketing its new Ostro, with a SRAM Red AXS build, at $10,099 (£9,250), while the SRAM AXS Force kit version retails for $8,199 (£7,850). Other builds roll Factor’s new Black Inc Forty Five carbon road bike wheelset.
Three colourways are available: Flicker, Soho Mix and Sicilian Peach. Riders who prefer to do a customised finishing kit can opt for the Ostro frame package, priced at $5,499 (£5,400), which includes a fork, seatpost, integrated bar stem, CeramicSpeed bottom bracket and headset.
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Lance Branquinho is a Namibian born media professional, with 15-years of experience in technology and engineering journalism covering anything with wheels. Being from Namibia, he knows a good gravel road when he sees one, and he has raced some of Africa’s best-known mountain bike stage races, such as Wines2Wales and Berg&Bush.
