The Factor OSTRO VAM is Factor's aero all-rounder: one frame meant to be fast on flat roads and light enough for climbing. The current version, which Factor calls "the next generation" (the OSTRO VAM v2 in its store), launched at the 2024 Tour Down Under. Stevie Williams won on its race debut. For 2026 the frame is unchanged, but Factor has added two new colours, Arctic Chrome and Terracotta Orange.

This is a specification-based review, not a ride test. All figures come from factorbikes.com and eu.factorbikes.com, Factor's news and history pages and the 2024 OSTRO manual, checked in October 2026.

What Factor changed in this generation

Factor says the new OSTRO VAM is 250 g lighter and 7 W quicker than the previous model, with its Black Inc 48|58 wheels. Factor doesn't state the test speed for the 7 W figure. The main design changes, as Factor describes them:

• Front-end aero work. Factor simulated dozens of head-tube profiles using what it calls a Rapid Iterative Design process (111 simulation runs, according to its 2026 news post) to create a "true airfoil-type profile along the waterline".
• A 15 mm wide aero seatpost, designed to the latest UCI rules. It was made possible by moving the Shimano Di2 battery into the seat tube, mounted from behind the bottom bracket, so the battery can be reached without removing the seatpost.
• An ultralight rear seatpost clamp. A pusher-type clamp at the back of the seat tube that needs low torque and allows a narrower seat tube.
• Aero integrated bottle cages. Location-specific Black Inc cages. Factor says the down-tube cage steers air over the bottle, and that the bike is faster with the seat-tube cage fitted and no bottle than with no cage at all.
• Revised fit. A new 45 cm size and a seat angle 0.5° steeper than before.
• Handling carried over from the previous model, with higher stiffness and, Factor says, greater compliance.

Factor's own brand summary says the OSTRO VAM was named Cyclingnews's 2026 best overall road bike, and that its O2 VAM climbing bike is "5W behind the OSTRO VAM" at 0–5° yaw in the wind tunnel.

Frame specification

Factor builds its frames in its own factory in Taiwan, according to its brand summary.

Builds and prices

Factor sells the OSTRO VAM as a frameset package or a complete bike. Every option includes Black Inc's Integrated Aero Barstem (AB02), the seatpost in 0 or 20 mm setback and a CeramicSpeed T47A bottom bracket. Complete builds use Black Inc 48|58 wheels in black or silver.

Prices are Factor's "from" prices. Options add cost: Prisma custom paint is +$600, and the AB03 barstem with extensions is +$190. Complete builds offer 165, 170 or 172.5 mm cranks. Factor's build pages don't specify tyres; the product renders show Goodyear Eagle F1.

The Black Inc 48|58 wheelset has a 48 mm front and 58 mm rear rim, a 23 mm internal width and mini-hook rims, and is optimised for 28 mm tyres. Factor quotes 1,250 g as tubeless clinchers.

The AB02 integrated barstem comes in 36, 38, 40 and 42 cm widths with stem lengths from 80 to 140 mm. Factor lists 80 mm reach, 120 mm drop and drops flared by 30 mm.

Geometry

Factor offers seven sizes, from 45 to 61. Official geometry:

One detail stands out: Factor changes fork rake by size (57 mm on the 45, down to 43 mm on the 56–61) to keep trail almost constant at 58–58.6 mm across the range. That aims to make steering feel consistent whether you ride the smallest or largest frame. Many brands, including Giant and Pinarello on their race bikes, use a single fork rake across all sizes. Factor doesn't publish head-tube lengths.

In size 56, a stack of 565 mm and reach of 392 mm gives a stack-to-reach ratio of about 1.44, a race position that isn't extreme for its size.

Integration and practical details

A few practical points for owners:

• Di2 battery access. On Shimano builds, the battery mounts inside the seat tube from behind the bottom bracket, so you don't need to remove the seatpost to reach it.
• Threaded bottom bracket. The T47A standard and CeramicSpeed bearings are compatible with DUB, 24 mm or Ultra-Torque cranks, depending on version.
• Integrated cockpit sizing. Width and stem length are chosen at purchase, so get your fit right before ordering.
• Seat clamp. The pusher-type clamp needs low torque; use a torque wrench.
• Electronic only. Factor lists compatible components as "electronic". Campagnolo compatibility isn't stated on the pages we checked, so confirm with Factor if you plan a Campagnolo build.

Where it sits in Factor's range

Factor's current road range, according to its brand summary, is the OSTRO VAM, ONE, MONZA and O2 VAM. The older LS endurance bike is archived.

The most direct comparison is with the O2 VAM, Factor's dedicated climbing bike. Factor lists the O2 VAM frame at 700 g, against 900 g for the OSTRO VAM. Factor also says the O2 VAM is 5 W behind the OSTRO VAM at 0–5° yaw in its wind-tunnel testing. In other words, the OSTRO VAM gives up about 200 g of frame weight in exchange for better aerodynamics. On most rolling and flat terrain, that makes it the faster all-round choice. The O2 VAM makes sense for riders who climb almost exclusively and want the lightest possible frame.

The name reflects that balance: Factor explains that VAM stands for velocità ascensionale media, the climbing-speed metric. On the OSTRO VAM it signals an aero bike intended to climb well too.

Wheels and tyres

The Black Inc 48|58 wheels use different depths front and rear: 48 mm at the front, where a shallower rim helps in crosswinds, and 58 mm at the rear. With a 23 mm internal width and mini-hook rims, Factor says they are optimised for 28 mm tyres. The frame clears up to 32 mm measured, which leaves room for slightly wider tyres on rough roads. Check the measured width on your rims, because wide internal rims make tyres measure wider than their label.

Racing and team use

Factor's 2026 news says the OSTRO VAM is raced by Human Powered Health in the Women's WorldTour, Modern Adventure Pro Cycling in the men's ProTour and Factor Racing at Continental level. Maggie Coles-Lyster won the Santos Tour Down Under Women's One Day Race on the bike in January 2026.

Factor's history page also notes earlier milestones: AG2R raced Factor in 2017, when Romain Bardet won a Tour de France stage and finished on the podium on the O2. Chris Froome became an investor and co-owner from 2021.

Who the OSTRO VAM suits

A strong fit if you:

• want one fast race bike for flat and hilly roads, rather than separate aero and climbing bikes;
• value consistent steering across sizes, thanks to Factor's size-specific fork rake;
• like integrated details such as the aero cages, slim seatpost and internal Di2 battery;
• want a threaded T47 bottom bracket on a high-end race frame;
• want a power meter included (SRAM builds).

Consider something else if you:

• want tyres wider than 32 mm;
• prefer a separate bar and stem for easy adjustment;
• want a mechanical groupset;
• prioritise the lowest possible weight. Factor's own O2 VAM climbing frame is lighter (700 g vs 900 g, according to Factor's summary).

Buying checklist

1. Choose a package or complete build. The Premium Package includes the barstem, seatpost and BB; complete builds add wheels and a groupset.
2. Pick barstem width and stem length carefully, since it's integrated.
3. Choose crank length (165, 170 or 172.5 mm) and seatpost setback (0 or 20 mm).
4. Decide on paint. Six standard colours are offered, or Prisma custom paint at extra cost.
5. Plan tyres. The wheels are optimised for 28 mm tyres; the frame clears 32 mm measured.

Frequently asked questions

How much does the Factor OSTRO VAM weigh?

Factor lists a 900 g frame (no size stated) and describes complete bikes as "sub-7 kg". It doesn't publish an exact complete-bike weight.

How much does the OSTRO VAM cost?

In the US, from $5,999 for the Premium Package frameset to $12,599 for the SRAM Red build with power meter. In the EU, €6,599 to €13,699.

What tyre size fits the OSTRO VAM?

Factor quotes a maximum clearance of 32 mm (measured). The Black Inc 48|58 wheels are optimised for 28 mm tyres.

Is the 2026 OSTRO VAM a new frame?

No. The current frame launched in 2024; for 2026, Factor added Arctic Chrome and Terracotta Orange colours.

What bottom bracket does it use?

A CeramicSpeed T47A threaded bottom bracket with aluminium cups.

Can I fit a normal bar and stem?

Factor offers the OSTRO VAM with its Black Inc integrated barstems (AB02, or AB03 with extensions). A two-piece option isn't listed on the OSTRO VAM pages.

Which teams race the OSTRO VAM?

In 2026, Human Powered Health (Women's WorldTour), Modern Adventure Pro Cycling and Factor Racing, according to Factor.

Final verdict

On paper, the Factor OSTRO VAM is a well-thought-out aero all-rounder. It has a 900 g frame, Factor's claim of being 7 W faster and 250 g lighter than before, size-specific fork rake for consistent handling and a threaded T47 bottom bracket. The integrated cages and seatpost show real attention to detail. The trade-offs are a 32 mm tyre limit, an integrated-only cockpit and premium pricing. If you want one race bike for every type of road, it deserves a place on your shortlist.

Official sources

• Factor OSTRO VAM (US store) and EU store
• OSTRO VAM Shimano Dura-Ace build and SRAM Red with power meter
• Factor news: Celebrating the OSTRO VAM
• Factor: Our history
• OSTRO 2.0 manual (PDF)

Equipment mentioned in this guide

• CeramicSpeed T47 bottom bracket
• Hammerhead Karoo GPS bike computer
• 700x28 tubeless road tyre

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