In the world of gravel racing, speed remains crucial, although the dynamics differ from road racing. Understanding these distinctions, the OSTRO Gravel frame has been meticulously optimized to cater to the speeds encountered in gravel riding. Our team employed a strategic “zoned aero” approach, tailoring specific areas of the bike to address aerodynamic performance based on the nature of the airflow.
The front of the bike, where it encounters clean, or freestream, airflow, is focused on maximizing aerodynamics. Extensive attention was dedicated to the head tube, utilizing an entirely new tube shape that unlocks significant drag reductions. By manipulating the “laminar separation bubble” that occurs near the front of airfoils at lower speeds, our engineers drew inspiration from aerospace technology to enhance the bike’s aerodynamic efficiency.
Conversely, the rear of the bike prioritizes lightness and ride quality. Understanding that airflow in this area becomes more chaotic, our design approach shifted towards ensuring a lightweight frame that prioritizes comfort and handling.
The culmination of these design choices is the OSTRO Gravel, a bike that will propel you towards the finish line faster, with potential time savings measured in minutes rather than seconds. While the underlying technical details draw inspiration from the aerospace field, the key takeaway is that the OSTRO Gravel offers tangible performance gains, allowing you to achieve faster race times and surpass your personal goals.
Bigger Tyre Clearance
The OSTRO Gravel provides ample tire clearance of 45mm in both 700c and 650b wheel sizes, offering versatility and flexibility to conquer even the most challenging routes and events. This tire clearance figure is backed by adherence to ISO standards, with 4mm of clearance on each side. As a result, the OSTRO Gravel excels in muddy conditions, ensuring optimal performance even in demanding off-road scenarios.
The capabilities of the OSTRO Gravel were put to the test at the renowned Unbound 200 gravel race in 2022, known for its grueling conditions. Despite heavy rain making the course exceptionally challenging, riders on the OSTRO Gravel demonstrated its prowess by achieving a remarkable top-10 finish. This real-world validation showcases the bike’s ability to tackle brutal conditions and highlights its capability to deliver exceptional performance when it matters most.
With the OSTRO Gravel, you can confidently explore a wide range of terrains and take on the toughest gravel challenges, knowing that it has been proven in demanding race conditions and offers the tire clearance needed for muddy and unpredictable environments.
BLACK INC THIRTY FOUR CARBON GRAVEL WHEELS
Designed with a focus on speed in gravel riding, the new Black Inc THIRTY FOUR wheels perfectly complement the performance of the OSTRO Gravel. With a 34mm depth, these wheels strike a balance between aerodynamic advantages, lightweight construction, and crosswind stability. By avoiding excessive rim and tire side area, the THIRTY FOUR wheels maintain stability in challenging crosswind conditions.
For optimal aerodynamic performance in all-road use, a 32mm tire is recommended, providing the most aerodynamic gains when paired with the THIRTY FOUR wheels. However, these wheels are also highly effective with gravel tires up to 43mm in width, catering to the demands of varied gravel terrains. The 25mm internal width of the rim allows for larger tires to take on a better shape, enhancing their performance and providing improved traction and stability.
The hookless rim design of the THIRTY FOUR wheels simplifies the tubeless tire mounting process, often requiring only a regular floor pump. This user-friendly feature ensures easy setup and hassle-free maintenance. Furthermore, the rim incorporates a secondary shoulder that securely holds the tire in place in the event of rapid deflation, allowing riders to come to a controlled stop without compromising safety.
The Black Inc hubs, equipped with CeramicSpeed bearings, contribute to the overall efficiency of the wheels. These high-quality bearings provide smooth rolling and enhance the power transfer, further optimizing the performance of the THIRTY FOUR wheels.
With their aerodynamic design, user-friendly tubeless compatibility, and efficient hub system, the Black Inc THIRTY FOUR wheels are the perfect choice for gravel riders seeking maximum speed and performance on a variety of surfaces.
BLACK INC INTEGRATED AERO BARSTEM
The Black Inc Integrated Aero Barstem represents a significant advancement in both aerodynamics and ergonomics, proving that riding long distances and riding fast can go hand in hand. Extensive research and development, including the use of computational fluid dynamics (CFD) and wind tunnel testing, have resulted in a mid-depth aero profile that surpasses other leading brands of aero road bars, all while maintaining an impressively low weight.
Not only does the Integrated Aero Barstem prioritize speed, but it also ensures exceptional comfort. Meticulous attention has been given to ergonomics, with features that enhance the riding experience. The design incorporates a more pronounced back sweep on the tops, creating a natural wrist angle and improving comfort. The chamfered corners provide increased wrist clearance and additional hand positions. The drop shape is optimized to accommodate the longer reach of the latest Shimano and SRAM shifters. Additionally, a 7-degree flare starts below the shifter mounting point, adding 3cm of width in the drops. This carefully calculated flare provides enhanced control during descents for gravel riding, while still offering the versatility needed for road use. On the road, riders can select their preferred drop width and benefit from the more aerodynamic position achievable on the narrower hoods.
The versatility of the Integrated Aero Barstem extends to its compatibility with both the OSTRO Gravel and OSTRO VAM, offering a dual-purpose solution. For gravel riding, the wider drops provide increased control during descents, enhancing overall performance. On the road, riders can choose their preferred drop width and take advantage of the significantly more aerodynamic position achievable on the narrower hoods.
As an added bonus, the new Integrated Aero Barstem includes a GoPro-style computer mount, allowing for angle adjustment and providing a second mount for a light or action camera. This feature enhances the functionality and versatility of the barstem, enabling riders to easily capture their rides from different perspectives.
The Black Inc Integrated Aero Barstem is a true embodiment of the pursuit of both speed and comfort, offering unmatched aerodynamic performance, refined ergonomics, and added functionality. It is a component that elevates the performance of the OSTRO Gravel and OSTRO VAM, providing riders with the best of both worlds.
STEERING GEOMETRY OPTIMIZED FOR ALL TIRE SIZES
It’s true that many all-road and gravel bikes often face challenges in delivering effective and confident steering performance across different terrains. Frequently, these bikes find themselves compromising between soft handling and limited tire capacity. However, the OSTRO Gravel breaks free from this pattern by integrating tire size as a fundamental aspect of its geometry.
The width of the tires plays a crucial role in determining the bike’s handling characteristics. Wider tires have a larger outside diameter or rolling circumference, resulting in an increased “resulting” trail. Conversely, narrower tires have a smaller outside diameter, leading to a reduced resulting trail. These differences directly influence the desired handling response for each tire type. With the OSTRO Gravel, we prioritized the resulting trail as the primary consideration in our design process.
For gravel use, where speed and racing performance are focal points, we selected a trail value that leans slightly towards faster handling characteristics. This choice ensures a responsive and agile gravel bike when equipped with 43mm tires. Simultaneously, we emphasized the head tube angle during the selection of our fork rake, enhancing the bike’s precision and control.
The result is a fast-handling gravel bike that delivers a highly satisfying riding experience when paired with 43mm tires. Moreover, when equipped with 32mm tires, the OSTRO Gravel transforms into an equally enjoyable and precise all-road machine without compromising stability at low speeds.
By designing the OSTRO Gravel with tire size as an integral part of its geometry, we have achieved a versatile and high-performance bike that excels in different contexts. Whether you’re tackling gravel terrain with wider tires or seeking a precise and comfortable ride on all-road surfaces with narrower tires, the OSTRO Gravel delivers outstanding handling and an exceptional riding experience without low-speed wheel flop.