Factor has proven themselves with performance-oriented, detail-focused machines that are designed to handle WorldTour racing. With years of industry, design and racing experience, Factor set out to make their lightest frame to date, the sub-800-gram O2, even lighter. 

Founded as an engineering showcase of bicycle tech from motorsports company bf1systems in 2006, UCI weight and frame regulations prevented their bikes from ever reaching the WorldTour. That all changed in 2016 when they released their first full fleet of UCI-legal bikes, including the original O2 (RBA, May 2017). In fact, after a WorldTour hiatus in 2019, Factor bikes are back on as the bike sponsor for the Israel Start-Up Nation squad.

The latest design update to the O2 comes in its name, the VAM (Velocita Ascensionale Media), a metric used to measure the speed of vertical ascent. Focused on reducing weight and improving handling for better all-out performance, the O2 VAM is designed for your inner racer.  


Factor claims a size-54cm VAM frame weighs 690 grams. Add in the 320-gram fork for a claimed frame/fork weight of nearly 1000 grams. Of course, that’s without the usual 80 grams of paint, but nonetheless impressive! Speaking of the frameset, at $5500, the price is not cheap, but it includes some of the component essentials from house-brand Black Inc. (one-piece cockpit, seatpost and a computer mount), as well as a CeramicSpeed PF30 bottom bracket and a CeramicSpeed headset. 

Factor was able to achieve the weight savings by fine-tuning their manufacturing process, in addition to some engineering innovation that starts with an all-new method of carbon compaction that uses latex-coated EPS mandrels during construction. 

The VAM frame is able to withstand higher pressurization while it’s built, which gram by gram helps in the removal of excess resin. A new carbon layup mixes varying modulus carbon mates with a new ultra-high-modulus carbon and Boron weave tactically placed around the seat tube and bottom bracket. This allowed Factor to remove unnecessary material and optimize the frame to react to regular riding forces, which means the top tube isn’t intended as a seat when you get tired.       

With weight and performance as the focus, Factor kept the aggressive geometry of the previous O2. With only minor tweaks to a size 54 like an increased BB drop and a millimeter-longer effective top tube length, a short 97.2cm wheelbase keeps things race-oriented when paired with the 73.1-degree head tube angle. 

The compact Shimano drivetrain completes the climber’s build.


Our test bike features a flagship build with a Shimano Dura-Ace Di2 kit. However, Factor doesn’t offer a set series of builds and leaves selecting components up to the customer and the dealer. 

We do endorse our setup’s compact, 50/34 chainrings paired with the 11-30 cassette. It’s an ideal complement to the climbing attributes of the frame.

Living up to its name, the 310-gram Svelte fork features some of the thinnest blades we have seen on a road bike.

A set of Black Inc. Black 50 clincher (actually 45mm deep) wheels add a greater amount of aerodynamic optimization than a pair of lighter-weight climbing wheels that some test riders expected on the build. Its narrow 17mm internal rim width is outdated, and the 25mm continental Grand Prix 5000s bulged over the rims. 


Owing to the engineered compliance, as well as increased stiffness in the bottom bracket, the VAM’s ride characteristics certainly classify it as something more than just a climber’s delight. Geared accordingly, the Shimano Dura-Ace Di2 drivetrain encouraged spinning up climbs. The reinforced bottom bracket’s CeramicSpeed bearing helped smooth the transfer of power of each pedal stroke. Out-of-the-saddle climbing efforts are also aided by
the aggressive geometry and low front end.

“What we didn’t expect from the O2 VAM was its well-rounded compliance.” 

The Factor’s cornering is responsive and allows for split-second decision-making, which is how we prefer it on race-optimized builds. Coincidentally, the VAM has similar handling traits as Factor’s One aero bike. Continental’s 25mm GP 5000s are grippy and keep the bike planted in an apex. However, we prefer the tubeless-specific GP 5000s for their ability to run lower pressure without the worry of pinching a tube.  

Asymmetrical chainstays keep the rear end short and allow for up to 30mm of tire clearance. The thin seatstays are engineered to enhance compliance.

Unlike most lightweight bikes like Trek’s Emonda SLR, the VAM’s ride is stiff in part due to the narrow Black Inc. wheels. Sprint efforts on our local group rides felt right at home on the VAM. Staying at speeds of 25 mph
seems to be the sweet spot for the Black Inc. wheelset. 

What we didn’t expect from the VAM was its well-rounded compliance. It’s compliant and strong enough to handle gravel roads, so don’t hesitate to get it dirty. We didn’t, and the VAM wore the grit well. This doesn’t mean it’s suited
for endurance riding, though. The aggressive geometry wore us down much faster than, for example, the BMC Roadmachine’s endurance-focused geometry.      



Factor made their name thanks to their meticulous engineering and performance-oriented designs. Remember when disc brake bikes were thought to be too heavy for a performance road bike? Factor continues to dispel such notions by cutting frame weight to make a 15-pound disc brake bike not just acceptable but preferable. 

Starting at $5500 for the frameset and generous parts package, owning the VAM will require a deep pocketbook, but given the advanced frame design and improved handling, the VAM’s race-oriented ride quality is hard to beat.


• Weight-optimized with disc brakes

• Not just a climber

• Made for racing


Price: $7,899 – $10,099

Weight: 15 pounds

Sizes: 49, 52, 54 (tested), 56, 58cm


Helmet: Giro Synthe               

Jersey: Bontrager        

Bib: Voler               

Shoes: Giro Empire     

Socks: Fitter       

Glasses: Tifosi          

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