A new challenger for the throne?
Factor has announced the new Ostro VAM, its second-generation all-rounder aero road bike.
The 2024 Ostro VAM is claimed to be seven watts more aerodynamic (at 48km/h) and 267.8g lighter than the first-generation Ostro VAM.
Factor also claims it’s more aerodynamic than two of its key competitors, the Specialized S-Works Tarmac SL8 and the Cervélo S5.
The 2024 Factor Ostro VAM is said to hit the UCI’s 6.8kg minimum bike weight limit thanks to improvements to the frameset and a new 1,270g Black Inc 48/58 aero wheelset.
Prices for complete builds start at £8,999 / $9,199 / €8,849 for a bike with the Black Inc wheels and a Shimano Ultegra Di2 R8100 groupset. The top-of-the-range model is equipped with SRAM Red eTap AXS and costs £11,399 / $11,499 / €11,049.
The modern race bike
According to Factor, the first Ostro VAM represented its ultimate take on “the modern race bike” – “the manifestation of our story” and “everything that Factor Bikes stands for”.
The second-generation version, then, has big shoes to fill.
The brand says its primary goal was to make the new Ostro VAM faster and lighter without compromising on handling or comfort.
The story here, then, is one of refinement rather than reinvention. It’s evolution, not revolution, as the cliché goes.
As with many WorldTour race bikes, aerodynamic improvements were a key focus.
Factor says it considered how the frameset could “steer the air favourably around the rider”, and how the front end of the bike affected everything downstream of it.
The frameset was then split into five ‘zones’, each of which was optimised according to the latest UCI equipment regulations.
Improvements to aerodynamics were made in four out of the five zones, while weight was reduced in three out of five areas, Factor claims.
It also says stiffness levels were maintained across every zone, despite the aerodynamic and weight improvements.
Zonal optimisations
Zone 1 – Fork
Factor designated the fork as Zone 1, because it forms (along with the head tube) a significant part of the leading edge of the bike.
The brand says it was able to improve the fork by making each leg narrower and deeper. This reduces frontal area while also making the aerofoil length longer and therefore more efficient.
Factor says it also optimised the fork crown to improve stiffness and aerodynamic efficiency with wider tyres, without increasing weight.
The brake caliper mounting point and thru-axle integration were also refined.
Cryptically, Factor says ”very small surface details were added to the inside of the fork legs to promote better airflow next to the rotating wheel.”
Exactly what form these “surface details” take remains to be seen, but we hope to get a test bike soon and will break out the magnifying glass if needed.
Zone 2 – Head tube
The head tube on the new Ostro VAM has taken on a more shapely, hourglass profile.
Factor says this causes the airflow to stay attached to the bike for longer, therefore reducing drag.
It’s also said to direct the airflow from this area between the rider’s legs, for a reduction in overall system drag.
Multiple profiles were developed and simulated using CFD modelling to attain a head tube shape that’s slippery in both low- and high-yaw situations (or headwinds and crosswinds).
The slimming down of this area also reduced the amount of carbon fibre required to build it to the same stiffness level, which helped save a small amount of weight.
Zone 3 – Top tube
The goal for the top tube was to “capture the smoother flow” from the updated head tube and carry it through to the rear of the bike as efficiently as possible.
A new, slimmed shape also helps reduce weight, though Factor says this hasn’t come at the expense of stiffness, because the new shape can “dissipate loads over a greater distance”.
Zone 4 – Seat tube and seatpost
Thanks to updates to the UCI’s equipment regulations that came into force for the 2023 season, Factor says it was able to redesign the rear end of the bike for significant improvements to aerodynamics and weight.
Specifically, the removal of the 3:1 rule (which meant frame tubes and components could have a length-to-thickness ratio no greater than 3:1) and a reduction in the minimum thickness required, enabled Factor to slim down the rear end significantly.
The new seatpost, for example, is 36 per cent slimmer than before, while the upper section of the seat tube is 20 per cent thinner.
Factor has also remodelled the bottom half of the seat tube to include a more prominent cut-out for the rear wheel.
The new shape now arcs rearwards to ‘nest’ a 28mm-wide tyre and the rear rim into a single, continuous aerodynamic shape.
Factor has also updated the seatpost clamp, replacing the wedge system at the underside of the top tube with a plate-based one at the rear of the seat tube.
This saves weight, according to Factor, but also appears to address one of our key criticisms of the first-generation Ostro VAM (the design of the previous wedge system required the use of a special tool to access it).
Zone 5 – Bottom bracket area
At the bottom of the bike, Factor says it avoided making changes simply for the sake of it.
“Subtle refinements” were made to the shape that bridges the down tube and seat tube, which resulted in small aerodynamic improvements, but Factor focused on maintaining stiffness in this area for a responsive ride feel.
Faster than the rest?
A painted, size-54cm 2024 Ostro VAM frame is claimed to weigh 820g, compared to 865.2g for the previous version.
Curiously, when the previous-generation Ostro VAM launched, Factor quoted a frame weight of 780g in a size 54cm.
The 780g figure related to Factor’s ultra-light ‘Flicker’ paintjob, though, whereas the 2024 weights are based on Factor’s new ‘chrome/black’ paint.
As many hill climb racers know, a lightweight paintjob – or forgoing one altogether – can be an effective way to make your bike lighter, so this may account for the discrepancy.
Overall, Factor says the 2024 Ostro VAM is 267.8g lighter than the previous version. This includes the frame, fork, updated seatpost, a Black Inc integrated aero handlebar and the new Black Inc 48/58 wheelset.
| | Factor Ostro VAM 2024 | Factor Ostro VAM v1 | Weight change |
|---|---|---|---|
| Frame (grams, size 54, ‘chrome/black’ paint) | 820 | 865.2 | -45.2 |
| Fork (grams) | 463 | 454 | 9 |
| Seat post with hardware (grams) | 168.6 | 182 | -13.4 |
| Small parts (grams) | 268.4 | 267.6 | 0.8 |
| Black Inc Aero Barstem (grams) | 376 | 376 | 0 |
| Frameset package(grams) | 2,096 | 2,144.8 | -48.8 |
| Black Inc 48/58 wheelset / Black Inc 45 wheelset (grams) | 1,270 | 1,489 | -219 |
| Frameset package with wheels (grams) | 3,366 | 3,633.8 | -267.8 |
As a point of comparison, Factor’s latest 02 VAM – its dedicated climbing bike – has a claimed frame weight of 730g, though that includes its integrated seatmast.
The aerodynamic improvements, meanwhile, are claimed to confer an advantage of seven watts (measured at 48pkh) over the original Ostro VAM.
Factor also says the new Ostro VAM is, on average, more aerodynamic than both Specialized’s Tarmac SL8 and Cervélo’s S5 across a range of yaw angles.
Factor says it tested both bikes “as sold” and with “normalised components”, and claims the only area in which the new Ostro VAM is outclassed is by the S5 at close to 0 degrees of yaw.
2024 Factor Ostro VAM geometry
Factor says the geometry of the 2024 Ostro VAM is unchanged from the previous generation.
The 2024 Factor Ostro VAM is available in seven sizes, from 45 to 61cm.
| Frame size | 49 | 52 | 54 | 56 | 58 | 61 |
|---|---|---|---|---|---|---|
| Stack (mm) | 503 | 523 | 542 | 565 | 587 | 611 |
| Reach (mm) | 370 | 376 | 384 | 392 | 401 | 409 |
| Seat tube angle (degrees) | 74.5 | 74 | 73 | 73 | 73 | 73 |
| Top tube (effective, mm) | 511 | 527 | 550 | 566 | 582 | 597 |
| Head tube angle (degrees) | 71.7 | 72.5 | 72.5 | 73.3 | 73.3 | 73.3 |
| Fork offset (mm) | 53 | 48 | 48 | 43 | 43 | 43 |
| Trail (mm) | 57.1 | 57.3 | 57.3 | 57.5 | 57.5 | 57.5 |
| Seat tube length (mm) | 456 | 480 | 502 | 525 | 548 | 570 |
| Bottom bracket drop (mm) | 72 | 72 | 70 | 70 | 70 | 70 |
| Front centre (mm) | 574 | 575 | 587 | 591 | 607 | 622 |
| Fork length (mm) | 373 | 373 | 373 | 373 | 373 | 373 |
| Wheelbase (mm) | 968 | 968 | 982 | 985 | 1,005 | 1,023 |
Black Inc 48/58 wheels
Developed in tandem with the new Ostro VAM, the Black Inc 48/58 wheelset features a new set of 48mm- and 58mm-deep rim profiles optimised for 28mm-wide tyres.
These are paired with new hubs and carbon fibre spokes, with Factor claiming a complete wheelset weight of 1,270g.
Both rims share an internal width of 23mm, and are hooked (as opposed to hookless) to enable compatibility with clincher and tubeless road bike tyres.
As the name suggests, the Black Inc 48/58 wheelset includes a shallower, 48mm front rim and a deeper, 58mm rim at the rear.
Factor says the rims have been shaped to create a “true airfoil shape” optimised for 28mm-wide tyres, with a wider shape that is claimed to improve aerodynamic performance at wider yaw angles.
While Factor’s wind-tunnel tests suggest its previous Black Inc 45 wheelset (claimed weight 1,542g) is more aerodynamically efficient at lower yaw angles, the new 48/58 wheelset offers better handling in crosswinds and gusty conditions, increasing its usefulness.
Factor also says the addition of carbon spokes and the new ‘high-flange’ hubs also increase the lateral stiffness of the wheelset, which improves ride feel.
Black Inc aero bottle cages
Factor has also developed a set of aerodynamically integrated bottle cages, which are said to confer a “small but measurable” improvement to efficiency. At a glance, these appear similar to those seen on the latest Giant Propel.
The Black Inc Ostro VAM down tube bottle cage, for example, is said to help “bridge the gap” between the down tube and a water bottle, which helps the airflow stay attached for longer and reduces areas of drag caused by gaps.
On the seat tube, meanwhile, the Ostro VAM Sprint cage is designed to be most aerodynamic when a rider discards their bottles in the run-up to the finish line.
The shape of the cage is claimed to work “like the leading-edge slats found on light aircraft”, helping to smooth the transition of airflow from the cage onto the seat tube and beyond.
Factor Ostro VAM 2024 specifications and pricing
2024 Factor Ostro VAM frameset
- Price: £5,449 / $5,499 / €5,799
- Frameset: 2024 Factor Ostro VAM
- Seatpost: 2024 Factor Ostro VAM
- Handlebar: Black Inc integrated aero barstem
2024 Factor Ostro VAM frameset Black Inc 48/58 wheelset
- Price: £8,900 / $8,099 / €8,799
- Frameset: 2024 Factor Ostro VAM
- Wheelset: Black Inc 48/58
- Seatpost: 2024 Factor Ostro VAM
- Handlebar: Black Inc integrated aero barstem
2024 Factor Ostro VAM Shimano Dura-Ace Di2 R9200
- Price: £10,799 / $11,199 / €10,749
- Frameset: 2024 Factor Ostro VAM
- Wheelset: Black Inc 48/58
- Drivetrain: Shimano Dura-Ace Di2 R9200
- Tyres: Goodyear Eagle F1 R
- Seatpost: 2024 Factor Ostro VAM
- Handlebar: Black Inc integrated aero barstem
- Saddle: Selle Italia SLR Boost Superflow
2024 Factor Ostro VAM SRAM Red eTap AXS
- Price: £10,999 / $11,099 / €10,699 or £11,399 / $11,499 / €11,049 including a power meter
- Frameset: 2024 Factor Ostro VAM
- Wheelset: Black Inc 48/58
- Drivetrain: SRAM Red eTap AXS
- Tyres: Goodyear Eagle F1 R
- Seatpost: 2024 Factor Ostro VAM
- Handlebar: Black Inc integrated aero barstem
- Saddle: Selle Italia SLR Boost Superflow
2024 Factor Ostro VAM SRAM Force AXS
- Price: £9,299 / $9,399 / €9,049
- Frameset: 2024 Factor Ostro VAM
- Wheelset: Black Inc 48/58
- Drivetrain: SRAM Force AXS, including power meter
- Tyres: Goodyear Eagle F1 R
- Seatpost: 2024 Factor Ostro VAM
- Handlebar: Black Inc integrated aero barstem
- Saddle: Selle Italia SLR Boost Superflow
2024 Factor Ostro VAM Shimano Ultegra Di2 R8100
- Price: £8,999 / $9,199 / €8,849
- Frameset: 2024 Factor Ostro VAM
- Wheelset: Black Inc 48/58
- Drivetrain: Shimano Ultegra Di2 R8100
- Tyres: Goodyear Eagle F1 R
- Seatpost: 2024 Factor Ostro VAM
- Handlebar: Black Inc integrated aero barstem
- Saddle: Selle Italia SLR Boost Superflow