The best race all-rounders in the test: The Factor Ostro VAM
The concept
Nominally, Factor has a clear division of tasks. The Ostro shown here takes its place as an aero bike, while the O2 defines itself as a climbing specialist. However, the distinction is not quite so clear in practice. The best proof of this was provided by Michael Woods (Israel-Premier Tech) at the 2023 Tour de France, when he chose the heavier Ostro despite the demanding stage profile in the Massif Central - and won on the Puy de Dome, which is up to 18 per cent steep. Why? Our test in the lab and wind tunnel explains. Hugo Houle's bike, which he used in last year's Tour of France, serves as a proxy.
In the lab
It would be an injustice to limit the Ostro to its aerodynamics. Yet 206 watts at 45 km/h is a top result in this discipline. But despite the frame set with flat tube shapes, the British-Taiwanese manufacturer manages to keep the total weight under seven kilograms. The main reason for this is the remarkably light wheelset from its own Black Inc. brand - the front wheel with a 48 millimetre high rim and carbon blade spokes weighs less than 1000 grams.
Driving experience
In the two most important categories of a competition bike - weight and aerodynamics - Factor gets a lot right. At speeds above 50 km/h, however, the Ostro reveals a weakness that can be reproduced on the stiffness test bench: The racer is not particularly laterally stiff. Sprinters might also wish for a more torsionally stiff bottom bracket.
That's what you get for your money
A fast bike for many occasions, unfortunately not very stable and not particularly comfortable. You won't find an affordable version. The four equipment variants range from 11,099 to 13,799 euros.
Factor Ostro VAM: Info & test score
- Price: 13,799 Euro
- Weight of complete wheel: 6.9 kilos
- Aerodynamics: 206 watts
- Frame sizes: 45, 49, 52, 54, 56, 58, 61 (test size bolded)
- TOUR grade: 1,9
Geometry
- Seat/top/head tube: 525/555/165 millimetres
- Stack/Reach/STR: 574/389 millimetres/1.48
- Stack+/Reach+/STR+: 627/592 millimetres/1.06
- Wheelbase/caster: 985/59 millimetres
Equipment
- Drive/gear shift: SRAM Red AXS (2x12; 48/35, 10-33 t., PM) | Grade: 1.0
- Brakes: SRAM Red HRD (160/160 mm) | Grade: 1.0
- Tyres: Conti Grand Prix 5000 S TR 25 mm (eff.: 27 mm) | Grade: 1.0
- Impellers: Black Inc. 48/58
- Impeller weights: 971/1457 grams (front/rear)
Measured values
- Weight of complete wheel: 6860 grammes | Grade: 1.7
- Air resistance: 206 Watt | Grade: 1.3
- Front stiffness: 6.6 N/mm | Grade: 2.7
- Bottom bracket stiffness: 49 N/mm | Grade: 3.0
- Rear comfort: 206 N/mm | Grade: 3.3
- Comfort front: 92 N/mm | Grade: 2.7
Advantages and disadvantages of the Factor Ostro VAM
- Plus: as fast as an arrow, very light wheelset
- Minus: not particularly stable, hard set-up
All 13 bikes in the comparison test
- Cannondale SuperSix Evo Lab71
- Canyon Aeroad CFR AXS
- Cube Litening Aero C:68 SLX
- Factor Ostro VAM
- Giant Propel Advanced SL
- Pinarello Dogma F
- Rose XLite Unltd Dura Ace Di2
- Scott Foil RC Ultimate
- Specialised S-Works Tarmac SL 8
- Stevens Arcalis
- Storck Aerfast.5 Pro
- Trek Madone SLR 9 AXS
- Van Rysel RCR Pro
- All 13 race all-rounders at a glance
How TOUR tests
Weight (25 per cent of the overall grade): The weighed complete wheel weight in the standardised test wheel size of 56-57 centimetres counts for the evaluation. However, we also show the wheel weights for orientation purposes. The grading scale is designed so that the physical effect of weight and aerodynamics on the average speed is comparable for an average route profile of 1000 metres in altitude per 100 kilometres. For orientation: The aerodynamic optimisation of the bike can compensate for up to almost four kilograms of weight on such a route. Simultaneous top marks in weight AND aerodynamics are mutually exclusive, but there are racing bikes that find a very good compromise. If the route is more hilly than our reference route, weight becomes more important; if the route is flatter, aerodynamics become more important.
Air resistance (25 per cent): Dynamically measured in the wind tunnel, with TOUR dummy, rotating wheels, moving legs and over a wide range of flow angles. Summarised to an aerodynamic grade for typical environmental conditions.
Front stiffness (10 per cent): Important parameter for steering precision and confidence in the bike at high speeds, determined in the TOUR laboratory. The overall stiffness is determined on the fully assembled frame set, i.e. including the fork. The stiffness values are capped. The aim is not an infinitely stiff frame, but one that is sufficiently stable to ride.
Bottom bracket stiffness (10 per cent): Reveals how much the frame yields under hard pedalling, for example when sprinting. This measurement also takes place in the TOUR laboratory, with realistic clamping in which the frame can deform as it would during riding.
Rear comfort (10 per cent): A measure of compliance under road shocks, measured in the TOUR laboratory. A suspension travel is measured when the seatpost is loaded. The measured value correlates very well with the riding impressions and the feeling of comfort. Good marks also mean decent riding dynamics, which have a positive effect on speed on poor roads.
Comfort Front (5 per cent): The deformation of the handlebars under load is determined in the same way as for the rear. A good score means a lot of suspension comfort, which takes the strain off your hands on long rides. However, strong sprinters who want a lot of stiffness should look for stiff handlebars.
Switching (5 per cent): The shifting characteristics are determined in the driving test. It is not the price or the quality impression of individual components that is assessed, but exclusively the function of the entire gearbox. For example, the cable routing, the quality of the cables and the mounted chain also play a role.
Brakes (5 per cent): As with shifting, the test on the road also counts here, and the experience from our countless tests of brakes is also included in the assessment. It is not the component itself that is evaluated, but the function of the interaction between brake body, pads, rims or discs and cables as well as cable routing: How well can the brakes be modulated? How durable are the brakes, how long are the braking distances?
tyres (5 percent): Rolling resistance and grip are evaluated - as far as known from one of our independent tyre tests or on the basis of driving impressions.
The overall score is calculated arithmetically from the individual scores weighted differently (percentages in brackets). It primarily expresses the sporting qualities of the bike.
Jens Klötzer
Editor
