The OSTRO is the bike that encompasses Issue and its presence worldwide. It’s essentially the most recognizable (IMO) and interesting of its choices and helped form the mildew for highly effective highway machines with a slippery silhouette. The brand new OSTRO doesn’t transfer removed from the unique start line however goes all in on minute aero updates for bigger positive factors.
When it got here time to revamp the bike, the Issue design crew seemed to steadiness stiffness/consolation, real-life aerodynamics, and wonder. The crew added some cool further bits like distinctive aero bottle cages and a brand new set of ultra-fast (and really handsome) Black Ink 48/58 Wheels.
Issue OSTRO – Aero Makeover from Nostril to Tail
Growing the 2024 OSTRO, Issue checked out each tube and centered on understanding how the bike’s form might strategically information air across the rider. They began at the forefront and labored backward.
Whereas presenting the brand new OSTRO, the Issue design/aero crew defined that Enhancements on the entrance affect components on the rear, making a snowball impact of positive factors and losses. The Issue design crew divided this aero-challenge into 5 ‘zones’ to realize essentially the most aerodynamic edge whereas sustaining the bike’s total trip integrity.
Zone 1 — Fork and Headtube
The fork impacts the aerodynamics of the whole bike because the central a part of the bike’s vanguard. The CDA (drag coefficient) was decreased by minimizing the frontal space and rising form effectivity. The newly decreased fork crown peak improves the brand new OSTRO’s stiffness and really feel. The trip really feel and responsiveness are a trademark of the OSTRO, and the crew didn’t need to lose that feeling amid aero positive factors.
Issue then gave the brand new OSTRO’s headtube a extra hourglass form, lowering the frontal space. Including a nostril on the headtube allowed the crew to maneuver the forefront of the fork ahead, making a smoother transition for the nostril with the headtube.
Aero Fork on the within: Small floor particulars had been added on the within of the fork leg that work with the rotating wheel to advertise higher circulate. The dropout and brake mount surfaces are modeled to maneuver the air from the axle. All these small particulars add as much as create a pleasant chunk of aero-gains.
Zone 3 — Headtube to Toptube
The up to date head tube made manner for a take a look at the general airflow coming to the highest tube. The crew centered on smoother circulate from the headtube to the bike’s rear. A streamlined headtube-to-top-tube transition enhances circulate attachment and creates a extra slippery design. This slimmer high tube paves the way in which for an total discount in seat tube dimension for a streamlined profile.
Zone 4 — Seat Tube
Now that the UCI has eliminated the three:1 rule (about two years in the past) for elements and decreased the minimal tube thickness required, the design crew at Issue might develop a slim seat tube that labored nicely with the aggressive tapering on the highest tube.
The crew’s goal was to take care of stiffness whereas lowering frontal space. In consequence, the decrease sections of the seat tube stay as huge because the OSTRO body. It tapers into the underside bracket zone (zone 5) and requires further carbon layup magic to fight the dreaded torsional flex.
Zone 5 — Backside Bracket
The trade development is to make the underside bracket wider, taller, and barely boxy (just like the Trek Madone). Issue added their spin on this with the brand new OSTRO, making a clean but boxy backside bracket junction. The crew began, “Balancing form effectivity and sustaining quantity and rigidity is essential to energy switch. Right here, we needed to handle the pedaling forces in a single airplane whereas selling airflow retention within the different.”
As for the peak, the design crew meticulously fine-tuned the quantity above the underside bracket, balancing airflow whereas conserving it tucked away from the riders’ legs. As soon as once more, the Issue crew discovered a slight achieve in aerodynamic effectivity, including one other tick within the sooner path.
Black Ink 48/58 Wheels:
When Issue drops a brand new bike, it normally means one other cool wheelset, and the BLK Inc 48/58 isn’t any exception. The most recent BLK Inc. wheels characteristic a high-flange carbon spoke hub and weigh in at an excellent mild (for this deep) 1270g. The wheelset is aero-designed and examined for maximal efficiency with 28mm tires.
The elevated modern radius improves circulate attachment at bigger yaw angles, and the high-flange hub will increase trip really feel and lateral stiffness.
Issue design crew explains: “The elevated radius creates a extra gradual charge of curvature change, selling circulate attachment at bigger yaw angles. As well as, the rounder profile and extra gradual change in curvature implies that the aerodynamic stall onset is gentler, giving the rider a greater feeling of management in gusts and powerful crosswind conditions.”
Aero and Tube Particular Water Bottle Cages
Not solely are these new Issue/BLK Inc cages aero, however they’re tube-specific. In contrast to different aero cages, they don’t require a selected bottle or an attachment.
Black Ink–Tube Particular Bottle Cage: The BLK Inc OSTRO downtube cage bridges the hole between the downtube and the water bottle. It promotes longer circulate attachment and reduces localized drag — plus, it holds a water bottle!
Ostro Dash Cage: The Issue design crew selected a unique aerodynamic method for the Dash Cage. It acts as a high-speed circulate administration machine. It’s most aerodynamically purposeful when a rider ejects their bottle earlier than the ultimate dash. The foil profiles and exact spacing with the seat tube funnel air tightly throughout the tube and transition it to the rear wheel. Making you quicker for the instances when it’s completely wanted — like a tour stage or a city line dash.
The Full Image — Issue OSTRO 2024
So, how a lot sooner is the brand new Issue OSTRO in comparison with the earlier technology? The brand new design saves 7 watts. Now I do know what you’re considering: “All that for 7 watts?!” However that’s rather a lot in relation to an already super-aero bike.
The Issue design crew explains: “As for aerodynamics, the online achieve is roughly a ten% enchancment in aerodynamic effectivity with all variables managed and normalized in a wind tunnel. That is, on common, a 70-gram discount in drag vs. the unique OSTRO. That is about 7 watts at 48km/h, which converges with our simulation information. As well as, the aerodynamic profit will increase as yaw angles change into nearer to real-world expectations (5-10 levels).”
Issue OSTRO VAM — Costs and Availability
The brand new Issue OSTRO VAM is obtainable solely from factorbikes.com and licensed Issue sellers worldwide.
The Issue OSTRO is obtainable as a frameset, a ‘rolling frameset’ with Black Inc 48/58 disc brake carbon wheelset, or an entire bike.
Sizes: The New Issue OSTRO is obtainable in sizes 45, 49, 52, 54, 56, 58, and 61cm.
Paint choices: Gloss Chrome, and Pearl White
