The new OSTRO combines the best of Factor’s renowned engineering capabilities across lightweight, aerodynamics and comfort into one bike that’s ready for anything

The OSTRO is an ‘everything’ bike, a quiver killer, a master of all trades. Searingly fast, incredibly light and supremely comfortable, it’s ready to win sprints, mountain stages and cobbled Classics. It’s the ultimate all-rounder because it refuses to compromise. If you’re the sort of rider who races with ‘the knife between your teeth’ no matter the parcours, this is the bike you’ve been waiting for. When we say you can have it all, we mean it.

Unapologetically future-facing, the OSTRO is only available for disc brakes and electronic shifting. The benefits of these technologies are now well understood and appreciated in the market and, by committing to them, Factor has enabled further gains to frame weight and integration.

Named after a southerly Mediterranean wind that sweeps through the Côte d’Azur and Nice, location of the Grand Départ of the 2020 Tour de France, the OSTRO is made for exactly the sort of mixed terrain and crosswinds that the riders of the Israel Start-Up Nation team encountered during the early stages of

this year’s Grand Boucle. The OSTRO is making its debut at the Tour de France and is being ridden by the team.

“The OSTRO concept was born from my long experience working with pro teams and riders, especially at Paris-Roubaix,” explains Graham Shrive, Factor’s Director of Engineering. “Every year there would be a couple of riders who wanted to use their aero bikes to get that advantage, no matter how poorly suited they were to the cobbles. Plus, of course, pros have always wanted an aero bike with no weight penalty, or a super light bike with no drag penalty in the valleys, as the climbers might see it. Instead of battling to get them on a bike made for the cobbles, we decided to build them what they wanted, and it turns out to be a hell of a bike.”

Key features
  • ●  Superlight frame weight – 780g for a painted frame in size 54 Flicker design, achieved throughFactor’s industry-leading carbon fibre expertise and mass-optimised aero profiles. For using the very best materials and reaching such a low weight for its class, the OSTRO carries Factor’s VAM designation
  • ●  Mid-chord aero profile – The truncated NACA profile down tube has the same cross-sectional surface area as the down tube of an O2 VAM, optimising aerodynamic performance versus weight
  • ●  Wide stance fork – Optimises aerodynamics for a pro-spec 26mm tubular by widening the gap between the fork legs and the spokes, reducing the turbulence caused by the forward rotating spokes meeting incoming airflow, and gives clearance for a 32mm tyre
  • ●  Reversing Flow Energising Channel – A Factor innovation, this channel built into the crown of the fork relieves the stagnant airflow that is drawn up by the forward rotating wheel and tyre and collects behind the fork, where it disturbs airflow around the outside of the fork onto the down tube. Incoming airflow to the fork is focused through a converging nozzle to accelerate the reversed flow out of this area, significantly reducing the pressure changes in this area, improving laminar flow and cutting drag
  • ●  32mm tyre clearance – Generous tyre clearance means the OSTRO is ready for Paris-Roubaix, super-long rides or your favourite back roads, and all without compromise to handling characteristics. Specifically, the OSTRO has ISO clearance for 32mm tyres mounted to rims of 21mm internal width
  • ●  Fully internal cable routing – Drawing on technology from the new O2 VAM, the OSTRO routes all of its cables 100% internally. Crucially, it does so while retaining a 11⁄8 upper headset bearing for minimal frontal area and drag, whereas other brands resort to a 52mm upper bearing
  • ●  Compliant rear triangle – The pencil-thin, ViSTA-style seat stays directly add compliance in two ways: with controlled vertical flex along their length, and by meeting the seat tube at a dropped angle that creates a cantilever around the seat cluster, allowing a small, controlled amount of ‘travel’ at the saddle to deal with bigger bumps
  • ●  Identical geometry to the O2 and O2 VAM – This is the optimum racing geometry for confident handling and that is unchanged by this bike’s broader role. Consistent geometry makes it easy for our pro riders to switch bikes and for our customers to choose based on the riding that they do
  • ●  Very high frame stiffness – Frame stiffness is a weak area of aero road bikes which use traditional airfoil shapes. The OSTRO achieves exceptionally high frame stiffness for the category by using truncated airfoil profiles, resulting in stiffness levels at or above that of the O2
  • ●  Cockpit options – To give customers more choice, the OSTRO is compatible with the one-piece Black Inc Barstem for fully internal cable routing, and also with all separate bars and stems (cables enter below stem)
  • ●  Electronic shifting only – In line with customer demand and enabling aero drag and weight savings, the OSTRO is built exclusively for electronic shifting groupsets
  • ●  T47 threaded bottom bracket – Used for the first time in a Factor, the T47 standard ensures a secure fit and easy maintenance
  • ●  Three different fork offsets – Ensures optimum handling characteristics across all frame sizes so that every customer has the best ride experience
  • ●  New lightweight seatpost – Mid-depth profile seatpost balances weight and aero, available in 0 and 25mm offset options.
  • ●  Launches with Black Inc FORTY FIVE wheelset – The new Black Inc FORTY FIVE is the perfect pairing with the OSTRO and launches simultaneously. The FORTY FIVE is designed with an optimal balance of aerodynamic performance and lightweight for riders who want a single wheelset to do everything from high mountain gran fondos to flat road races to long training days, and everything else in betweenWhile introducing the OSTRO as the ultimate all-rounder, Factor also continues to provide for riders with focused requirements, unlike many other brands which have diluted their offerings by blurring categories and incorporating features for their own sake. Riders looking for the fastest and stiffest road bike to race on flatter terrain and criteriums will love the ONE; those who live to climb will find their perfect partner in the ultralight O2 VAM. The addition of the OSTRO to the Factor range creates the perfect option for those who want to do it all with one bike.

    Every element of the OSTRO is optimised for aerodynamics. Broadly, this work can be split into three areas: the mid-chord aero profile tube shapes, the wide stance fork featuring our pioneering Reversing Flow Energising Channel, and the aero cockpit with fully integrated cabling. The net result is a superlight bike that is close to the aero performance of the ONE and ready to blitz the fastest road races.

    The tube profiles are derived from NACA (National Advisory Committee on Aeronautics, the godfathers of aero) shapes, oriented along the waterline (horizontal) in line with airflow and optimised for ride quality and aero-to-weight balance by truncating the aero section aggressively. Essentially, this means chopping the long tail off an airfoil shape. Done right, this makes the airflow behave as if it were still following a complete airfoil, resulting in low drag. The critical element to the performance of a truncated airfoil is the tight radius at the transition or cut point, but this is challenging to manufacture in carbon fibre. Owning our factory allows Factor to use a more expensive and time-consuming process to achieve the optimum shape without passing on that cost to consumers. As well as being lighter, stiffer and more compliant, these truncated aero sections also reduce drag in crosswinds and better accommodate bottles on the bike. In designing the OSTRO, Factor considered every aspect of the frame and applied the optimum aero profile, with particular regard to the transitions between frame sections (eg down tube to seat tube, fork and head tube to down tube) and to performance across a full range of effective wind angles.

The new wide stance fork features our highly innovative Reversing Flow Energising Channel. Both the channel and the fork’s wide stance address the aerodynamic challenge of incoming airflow meeting the ‘reversing flow’ of air carried by the wheel and tyre moving forwards through the fork. This reversed flow stagnates behind the fork and disturbs airflow around the outside of the fork onto the down tube. To solve this, Factor designed a converging nozzle into the fork crown to accelerate the reversed flow out of this area, significantly reducing the pressure changes met by the relatively clean air travelling over the outside of the head tube and fork legs, and thereby improving laminar flow and cutting overall drag. Additionally, by significantly increasing the width of the fork legs, the fork legs and the wheel rim are each able to operate in airflow that is undisturbed by the other, allowing the aero profiles to function at optimum efficiency.

The one-piece, aerodynamic Black Inc Barstem reduces drag by meeting clean incoming airflow with a clean shape. Fully internal cabling brings further gains and Factor has achieved this while maintaining a 11⁄8” top headset bearing for optimised frontal area, whereas many other brands increase the head tube size to accommodate internal cabling, cancelling out the benefits.


The OSTRO is an aero disc-brake frame which weighs just 780g (painted, size 54). For using the very best materials and reaching such a low weight for its class, the OSTRO carries Factor’s VAM designation. It easily builds to the UCI limit of 6.8kg, equipped with a power meter and mid-depth aero Black Inc FORTY FIVE wheels. Finally, here is an aerodynamic race bike with no weight penalty. Few rides or race routes are exclusively mountainous or flat roads so, naturally, you want it all: speed and lightness. The OSTRO is the ‘everything’ bike, making you fast whatever the terrain.

It achieves its remarkable lightness in three ways. The tube profiles were carefully developed to balance aerodynamics against weight. The down tube, for example, has almost exactly the same cross-section as that of the O2 VAM. Also shared are the exceptionally high grades of carbon fibre material used and the industry-leading manufacturing techniques employed to get the very best from them, all made possible because Factor owns its factory and can pass considerable efficiencies to the customer. Finally, the new integrated cabling system, which debuted recently on the revised O2 VAM, is weight neutral, which is to say it doesn’t add a single gram.


The OSTRO is an aero race bike that’s ready for Paris-Roubaix. It’s a ground-breaker on the cobbles, whereas usually it’s the cobbles that break riders. Why be aero for Roubaix? Simple. It’s a 260km race that averages around 45kph and ends with a sprint in a velodrome. Any energy saved can make the

difference to victory, and over that distance at that speed you can save a lot of energy. What’s more, the same applies to every single ride that you do.

The OSTRO achieves its remarkably smooth ride in three key ways: tyre clearance, ultra-thin seat stays, and carbon fibre layup.

Tyre clearance of 32mm is huge for an aero race bike and it opens a world of possibilities. Take on the cobbles, the back roads or your longest ride ever. This clearance is enabled by the disc-brake-only design and wide stance fork.

At the rear, the ViSTA-style pencil seat stays are designed to absorb road noise and cushion bumps. Furthermore, they meet the seat tube at a dropped angle which encourages the seat tube and seatpost to cantilever around the seat cluster to create an effective amount of controlled ‘travel’ at the saddle.

Factor has renowned expertise in carbon fibre, and because we own our factory we are able to iterate almost endlessly during the R&D phase of any project. For the OSTRO, the carbon layup was continuously refined in order to achieve a high level of frame compliance without sacrificing any of the power transfer efficiency.

“This bike is only possible because Factor owns its factory and everyone is pulling in the same direction. Many features of the OSTRO, particularly the execution of the truncation radii of the aero profiles, would have been near impossible with a third-party manufacturer like most brands use. Happily, that’s not how Factor works.”


The OSTRO is available to preorder now, MSRP $5,499 USD (UK: £5,400 inc VAT) for the frameset package which includes Frame, Fork, Seatpost, Integrated Barstem, CeramicSpeed BottomBracket and Headset.

Complete bike with SRAM Red AXS & Black Inc FORTY FIVE wheelset: MSRP $10,099 USD Complete bike with SRAM Force AXS & Black Inc FORTY FIVE wheelset: MSRP $8,199 USD

The OSTRO will be available in three designs, Flicker, Soho Mix & Sicilian Peach.


The new FORTY FIVE wheelset is the perfect partner to the OSTRO, balancing aerodynamics, lightness, strength and stiffness. Its performance is driven by a proprietary rim profile and our new ratchet driven hub. The FORTY FIVE is disc-only, tubeless-ready and optimised for 25-28mm tyres, with an internal rim width of 20.7mm. The new Black Inc hubs run on CeramicSpeed bearings and feature an aggressively machined, lightweight freehub.

The aero profile of the FORTY FIVE rim is derived from the NACA 0018 shape. It’s optimised for real-world conditions, where consistent effective wind angles (yaw, the product of wind speed and trajectory versus the bike’s speed and trajectory) rarely exceed 10o. It’s true that riders may experience gusts of wind well beyond this angle, but the sudden and brief nature of a gust means that virtually every aero profile would stall anyway (15o is generally the limit for maintaining laminar flow) and that it is not a lasting condition. Therefore, a consistent effective wind angle above 10o is very rare and not a use case for which performance in other conditions should be compromised. Whereas other brands have made the mistake of pursuing ever higher angles of flow attachment as a point of differentiation, Factor focused its attention on creating a wheel that performs best where our customers and pro riders need it to – the real world. The transition point between stalled and unstalled flow conditions is tuned to be less abrupt, which will lessen the buffeting effect in crosswinds and provide more predictable handling.

The rim shape is optimised for 25-28mm tyres, with the perfect size being the 26.4mm inflated width of the Maxxis tyres used by the Israel Start-Up Nation pro team.

The Black Inc HU-07 (24/24 spokes) hubs feature oversized flanges providing the foundation for a wheel build that capitalises on complimenting the Ostro frame. The bearings are by CeramicSpeed and their placement has been further improved for efficiency and longevity.

The FORTY FIVE wheelset will feature in complete builds of the OSTRO and will also be available separately from Black Inc, priced MSRP $2,349 USD.

For more information on the bike or to arrange an interview with Factor’s Engineering Director, Graham Shrive, please contact: tom@factorbikes.com.

Pics: Jered and Ashley Gruber

Share this post

Share on facebook
Share on whatsapp
Share on google
Share on twitter
Share on linkedin
Share on pinterest
Share on print
Share on email

newsletter sign up

Leave a Reply

Scroll to top

Stay Updated

Join our 500,000 fans, and get the latest news, updates and special offers. Sign up now & receive 5% discount at our online shop.

Skip to content