The Factor OSTRO gravel bike joins the brand’s existing LS and Vista platforms giving customers the choice of three distinct off-road-specific models, a rarity in the best gravel bike category.
Although aero is not one of the first considerations for many gravel bikers, it makes a difference - especially on the faster gravel races in the USA. Rolling along flat gravel roads, speeds can edge towards those you'd pedal on a road bike. Small aerodynamic efficiencies compound into energy saving and fatigue mitigation on a 100-miles off-road adventure ride.
Factor’s product planners have cleverly taken some established aerodynamic benefits of an OSTRO VAM and enabled big tyre ability. This new gravel bike is categorised as a ‘crossover’ option, capable of highly efficient road riding and gravel route exploration.
Over the last few years, the most significant comfort and performance trends in gravel biking have been increased frame and fork clearance, enabling large tyres to run at lower pressures.
Big tyres, big comfort
2022 Factor OSTRO gravel bike tyres, by Factor
The Factor OSTRO Gravel is rated to clear 700cx45 tyres without issue, compared to an OSTRO VAM’s 32mm maximum tyre width specification.
Accounting for those loose gravel road descents and greater diversity in riding surfaces, Factor’s designers shaped the OSTRO Gravel with very forgiving geometry. Compared to the VAM, it has more stack and reach, with a slacker head angle to calm steering responses.
2022 Factor OSTRO gravel bike front, by Factor
For reference, the size 56 OSTRO Gravel has 15mm more stack and 10mm longer reach than a similarly sized VAM. Its head angle is a degree slacker, too, at 72.3-degrees. To optimise these gravel riding geometry numbers fork offsets are 50mm, instead of the road-going VAM’s 43mm.
And the trick aero shapes that promise reduced riding fatigue by lowering this new gravel bike’s overall drag-coefficient? Its headtube shape is most notable, formed to reduce low-pressure zones and the resulting drag.
Threaded bottom bracket
2022 Factor OSTRO gravel bike drivetrain, by Factor
A carbon-fibre frame purposed for off-road riding duty will suffer a lot of mud and dust exposure. To prevent the dreaded bottom bracket creak, Factor’s design team relies on CeramicSpeed T47A threaded bottom bracket with aluminium cups and CeramicSpeed bearings, with a much lower prospect of dust-induced component creaking.
Aerodynamic and agile, the OSTRO Gravel is also notably light, as expected from a premium carbon-fibre frame. Factor claims that its size medium OSTRO Gravel weighs only 900g.
Factor offers a selection of build options, all featuring Black Inc integrated carbon handlebars and wheels. The Thirty Four model wheels are Black Inc’s first off-road products, featuring a hookless bead design, 34mm depth and 25mm internal diameter – making them ideal to support those larger gravel bike tyres when inflated.
The OSTRO gravel range starts at £7050 for a SRAM Force XPLR build (with a power meter). Riders desiring SRAM RED will pay £9030, with a power meter increasing that price to £9,380.
Want to migrate your current gravel bike kit to a new OSTRO Gravel fame? Factor offers its new aero gravel model as a frameset for £4,730. Keen on a rolling chassis? For £6,450 you can have that frameset with Black Inc carbon wheels.
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