Factor says it’s blurred the lines between lightweight and aero with its updated Ostro VAM, resulting in a claimed savings of 7 watts of power at 48km/h (30mph) over its predecessor, while also tipping the scales in its favor by some 268 grams when fitted with the British brand’s in-house Black Inc wheels.
“The goal with the new Ostra VAM was to make a bike that improved on the aerodynamic performance but didn’t take away the positives of the old one,” says Factor’s director of engineering Graham Shrive. “Those positives were ride quality, ride feel, weight, usability… We wanted to make sure we retained that character while still improving the performance.”
To achieve this, Factor took advantage of UCI’s recent regulation changes; namely, the elimination of the 3:1 rule that dictated how component depth couldn’t exceed three times the width of the bike, as well as the ability to reduce main frame tube profiles to less than 25mm. This, along with wireless shifting, improved computational techniques and various other tweaks to the existing design led to the development of this latest generation Ostro VAM.
“Our engineers sought to find balance across weight, stiffness and aerodynamics; refusing to concede any one of these three critical components at the expense of another,” says Factor. “The result is a modern racing bike for riders who demand pinpoint handling, immediate power transfer, comfort on unforgiving roads and low weight for optimum performance on the climbs. Our approach to the aerodynamic development was to learn how the bike’s shape could steer the air favorably around the rider,” says Factor. “The leading edge of the bike has the greatest impact on flow behavior for two reasons. One, because it meets the cleanest airflow. And two, because it can be made to manage the air for all elements of the bike that follow. Starting with this concept, we focused on the front of the bike and worked backward. Improvements in aerodynamics at the front have a cascading effect on the elements at the rear – both positive and negative. The goal is to capture the positive gains and propagate them downstream. In some cases, changes made in the middle of the bike even influenced the drag generated upstream. For this reason, we continually reassessed the front as we worked our way rearward,” adds Factor in a lengthy explanation.
Other critical changes involved revamping the profile of the fork, along with extending the leading edge of the head tube, resulting in a fork that is placed further forward to reduce frontal drag.
“This included an exploration of flow management around the crown and down tube junctions to better work with larger tires,” says Factor. “We also found gains from the synergies between surrounding components, such as the brake caliper mount and axles. This led to localized gains and more predictable flow into the zones downstream. A reduced fork crown height coupled with the lower frontal area decreased the overall surface area of the fork, allowing us to place material in areas that would improve stiffness and ride feel while maintaining the same weight.”
Additionally, combined with the narrower seatpost and redesigned head tube, Factor says the reshaped top tube further enhances the Ostro VAM’s aerodynamic signature by some 70 grams of reduced drag.
“The variable profiling allows for much longer flow attachment and therefore reduced drag,” says Factor. “Multiple head tube profiles and sizes were simulated before landing on a shape profile that yields exceptional results at both 0 degrees [with the wind coming head on] and higher yaw angles. The lower section of the seat tube was shaped so that the tire and wheel complete the aerodynamic profile,” says Factor. “This was achieved by shaping the rear of the tube to properly nest a 28mm tire and tuning the forward shape to be the leading edge of a continuous, integrated aerodynamic profile.”
If that isn’t wind-cheating enough, Factor also developed a set of Ostro VAM cages designed to reduce even more drag.
“In the case of the seat tube bottle, I was sitting on an airplane and I’m sure we’ve all seen as we prepare for takeoff or landing that they extend the leading edge slat,” says Graham Shrive. “That allows the airflow to stay attached to the wing section a little bit better, a little bit longer at high angles of attack.”
“Most World Tour riders will throw either one or both of their bottles in the last five or 10k of the race, and I thought we had an opportunity here to sort of cheat the UCI rules a little bit and create a fairing without it actually being a fairing. In this case, what we’re trying to do is encourage flow attachment across the seat tube when the bottle is removed. The net result is that when you pull out that second bottle and toss it, the bike gets a little bit faster.”
Alongside the updated Ostro VAM, Factor also unveiled its new Black Inc 48/58 wheelset, which features a high-flange hub that’s designed to increase the lateral stiffness, while the rim’s offset spoke bed is intended to provide balanced tension across the carbon spokes. Moreover, the wheelset relies on a “mini hook” system to hold the tires in place, tipping the scales at an impressive 1,270g.
The new Ostro VAM is available in a number of different build options, across the same seven sizes and geometries as before.
Here’s how the models breakdown:
Factor
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