Evolution of the Factor O2

Jamie Wilkins uncovers the story behind Factor's O2 bike

This article was produced in association with Factor

Factor Bikes first came into existence as a brand in 2013 and introduced itself with the radical Vis Vires, a battle cry of a bike. When Factor was bought in 2015 by former professional Baden Cooke and Rob Gitelis, a key figure in carbon fibre bike manufacturing as well as a former racer, job one was to develop the wild Vis Vires into the aero One. Job two was to expand the range with a superlight bike for the mountains – that bike was the O2 and this is its story.


“We all ride bikes in this company and it’s hilly around here,” says Rob Gitelis. “We asked ourselves, ‘What bike do we want to ride here?’ Our answer was the O2.”  The O2 was conceived as a multi-talented race bike, drawing on all of the combined experience of Baden Cooke and Gitelis to balance comfort and stiff ness with low weight.

A precedent was set from the start, with an investment made in using the best materials available. Highly efficient power transfer came via a large downtube and chunky, asymmetrical chainstays, all with maximised junction areas at the bottom bracket.

Aerodynamics were not overlooked in the first generation O2: the downtube featured a truncated airfoil shape to substantially reduce drag versus a round-tube  frame, the seat stays were skinny, and the fork blades were made as thin as possible while retaining rigidity. In short, no corners were cut. It was only possible because Factor Bikes owns its factory and was determined to reinvest the margins saved to make every choice for engineering reasons rather than costs. This remains a defining principle.

The O2 received a rave reception from both the press and customers alike. Better yet, it also caught the eye of one of the world’s top riders and put Factor Bikes on a fast track to the pinnacle of the sport.

The competitive spirit runs deep at Factor. As well as the influence of Baden Cooke, a Tour de France green jersey winner, Gitelis also raced professionally in Europe and the US. It means they insist upon the very highest performance from the bikes and greatly value the exposure and feedback that a pro team brings “Right from our first conversations about Factor, we always said that it was a goal to be in the WorldTour,” says Gitelis.

Racing improves the breed. “The AG2R team hadn’t been happy with their old bikes,” notes Gitelis, “and Romain Bardet in particular. The team asked him what bikes he wanted to try, and he said Factor. At that point the O2 had only been out for a few months, so it was cool that he knew about it.”

Bardet loved the bike and the rest is history. The partnership paid off in style at the 2017 Tour de France, where Bardet achieved a podium finish in Paris and a dramatic win on stage 12, a monster 214 kilometre trek across the Pyrenees from Pau to a summit finish at the Peyragudes ski station’s altiport, with six major climbs. The finish line atop the cruelly steep runway was the ideal launch pad for Bardet, who kicked away from an elite group to win the stage on his Factor O2.

THE O2 VAM, 2019

The success of the O2 in racing, media reviews and sales gave Factor a strong platform from which to push ahead. “I always wanted to make a frame with no budget constraint,” says Gitelis. “The very best it could be.”  

At times, the development process bordered on the obsessive, fully exploiting the  opportunities that come with owning their own factory. “The development of the O2 VAM took around a year,” says Gitelis. “We were able to design the shapes pretty quickly, but we did about 50 different iterations to achieve the ride quality we wanted in a sub-700g disc brake frame.”  

Achieving this level of performance required new manufacturing techniques and  special materials, access to which involved its own challenges. “We knew from the start what materials we wanted to use, but a lot of them we’d never used before. I knew that I wanted to use boron, but just importing it into Asia is very difficult because it’s a controlled item. You need to do a lot of paperwork to show that you’re not making missiles, because that’s where a lot of it goes.”

Boron is a rare and expensive fibre with very specific properties. It’s very strong in compression without being fragile. While it isn’t suitable for widespread use in a bike frame, the design team identified the opportunity to create an extremely thin-walled seat-tube with some compliance for comfort and using the boron to maintain the buckling resistance.

As a factory owner, Gitelis had been able to create his cost-no-object super-bike. For the same reason, he was able to limit how much of that cost reached Factor customers, as he explains: “Based on the production costs, the O2 VAM should be a $10k frame, but I know that’s not going to help us get more people onto great bikes. We threw out traditional industry ideas of acceptable margins, which  I’ve always wanted to do. We’re selling frames for what we think represents great value to get more people buying and riding them, and it’s all possible because we own the factory.”

THE O2 MKLL, 2020

The second-generation O2 arrived in 2020 as an all-round road bike, with a sublime balance of comfort, speed, handling, stiffness and lightness. It's based on the architecture of the O2 VAM and benefits from a trickle-down of that bike's revolutionary manufacturing technology to a more accessible price point. Tyre clearance was pushed out by 30mm, which was big at the time, and a lighter system of internally routing both mechanical and electronic groupsets was introduced. At launch, a rim brake version was still offered. Key performance-driving frames features include the very precise Svelte Fork, the super-stiff Power Drivetrain's asymmetrical downtime and BB, and the Wide Stance seatstays which boost comfort. 

THE O2 VAMI, 2021

 The next step for the O2 VAM was evolution in its truest sense: a change in response to environmental stimulus. Acknowledging shifting customer demand in the market, the O2 VAMi introduced fully internal cabling. Naturally, this was done the Factor way. While other brands increased the size of the head tube to accommodate internal cabling, thereby increasing the frontal area and adding drag, Factor designed a system that retains both a 11/8” upper headset bearing and the O2 VAM’s elegant profile. 

THE NEW O2 VAM, 2023

This year, evolution made way for revolution as the O2 VAM underwent its biggest ever overhaul, gaining a massive boost to both aerodynamics and stiffness to become the world’s fastest climbing bike. Factor claims: “Nothing else this light is as fast and nothing this fast is as light.”

With complete builds weighing from 6.2kg (size 54, Dura-Ace Di2), very few bikes are as light. It’s designed to be the ultimate choice for riders seeking performance on big days in the mountains, whether you’re riding the Étape du Tour or the Tour de France, when lightness is the priority but aero and stiffness are still essential for full-course speed. And if you’re not concerned with going faster, the energy you save will help you to go further instead.

None other than seven-time Grand Tour winner Chris Froome was closely involved from the earliest phases. “I had a conversation with Rob in early 2022,” he told us, “talking about what the next bike is going to be. I put forward a lot of ideas at that concept stage and we’ve been in touch a lot since.”  

Graham Shrive, Factor Bikes’ Director of Engineering, explains how the project goals were defined: “We asked the riders of the Israel-Premier Tech team, ‘On what terrain do you get your results and how can we help that?’ They wanted a bike that would be under 7kg in race trim, with pedals, transponder and number.

“Then we asked, ‘What’s stopping you from riding the previous O2 VAM?’ They said aero and stiff ness. So, we made the new O2 VAM as stiff as the OSTRO VAM, a 35 per cent increase, and 12W faster than the old O2 VAM in the wind tunnel, which is around half the difference to the OSTRO VAM.

“The new O2 VAM is right on the UCI weight limit when race-ready and faster than any other bike this light.”

The most visually obvious differences between the new O2 VAM and its predecessor are all found around the seat cluster, with ride comfort the objective. The toptube exploits the latest UCI rules to taper down to an ultra-thin 10mm just ahead of the seat cluster; the seatpost is now external, which also saves weight; and the seatstays have dropped down the seat-tube and become even thinner, which benefits aero, comfort and lightness. Together, these features promote controlled deflection at the saddle over bumps.

The riding position has also evolved, with the stack height up by 10mm in all sizes in response to customer fit data analysis. The second-generation O2 VAM is complemented by the all-new, 1,146g Black Inc 28//33 wheelset. Its carbon fibre spokes greatly benefit in two ways: they reduce both static and rotating weight, and they greatly boost tensile rigidity, and therefore responsiveness, over steel spokes.

The combined effect with the new frame is spectacular. The riders of Israel-Premier Tech contributed a lot more than ideas. Factor views the team as an essential part of bike development. In May, Shrive personally delivered the first rideable prototype to a high-altitude training camp in Andorra. Over the next few days, Dylan Teuns was charged with testing the prototype O2 VAM during a big block of training. There was no scientific process, the test simply involved riding the bike hard on the roads for which it was designed. The feedback process is equally straightforward – pro cyclists are not expected to be engineers.

“I like to be there in person so I can ask follow-up questions,” says Shrive. “That’s more informative than comments on a form. But sometimes it comes down to the simplest possible question: do they want to keep riding it?”  

The idea of an aero climbing bike can seem confusing to some people. Aren’t aero bikes and climbing bikes opposites? Don’t you need one or the other? It’s about an order of priorities. For mountainous riding, lightness takes precedence but aero doesn’t become unimportant, it just shuffles down the list. The climbs are only part of the ride and on the rest of any route aero is as important as ever. Furthermore, the speed at which the pros climb means that aero remains a significant consideration even at gradients of eight per cent. The goal, then, is to add as much aero as possible for minimal added grammes.

A focus on some complicated aerodynamic principles has made the new O2 VAM especially fast in low yaw conditions, that is, when there is either no wind, a straight headwind, or a slight crosswind. “We gained a lot of knowledge about low velocity airfoils while developing the OSTRO Gravel to be the world’s fastest gravel bike,” says Shrive. “We built on that with the O2 VAM, gaining the ability to manipulate the formation of the laminar separation bubble and subsequent reattachment of the airflow, thereby reducing the form drag.”

In layman’s terms, the new O2 VAM is formed to control precisely how the air flows over it, including a deliberate and managed flow separation close to the leading edge which encourages the airflow to return to closely follow the frame’s shape, in turn saving its rider watts.  

At an effective wind angle of 0-5 degrees, the new O2 VAM is only 5W behind the OSTRO VAM, which itself is claimed to be the fastest aero bike on the market. Factor says that, by its own testing, this makes the new O2 VAM faster than some brands’ much heavier dedicated aero offerings. In short, this is having your cake and eating it.

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