This article was produced in association with Vision.
Like an airfoil in a wind tunnel as yaw angle increases, progress in wheel design has threatened to stall as we head towards a peak of aerodynamic performance. The difference between the top wheelsets in the WorldTour has narrowed as brands have gone beyond bike racing and looked to nature for the smallest watt savings, copying the shapes of humpback whales’ fins and the textures of fish scales.
This is why the focus is back on reducing weight – always the goal before the importance of aerodynamics was fully understood. Are we seeing a reversal of Dollo’s Law, which states that evolution is not reversible, played out in cycling? With bike science seemingly returning to the sea, it could easily appear that way. But Vision’s all-new Metron RS, its first all-carbon wheelset, proves that we absolutely are not. At 1,290g for the Metron RS 45 and 1,390g for Metron RS 60, these new wheels are a full seven per cent lighter than the Metron SL, Vision’s previous pro-level range, but crucially they also outperform them in the wind tunnel. Furthermore, they are laterally stiffer for improved acceleration and pedalling efficiency and are built onto a new hub, the V-1000, which has been upgraded for faster engagement and has a lighter CNC-machined freehub. Vision is describing the launch of the 2025 Metron RS range as a “new era”. And the new era has already begun – the Metron RS wheels have already been ridden in the professional peloton at the biggest early-season races, including Paris-Nice, Strade Bianche and Milan-Sanremo. Let’s take a closer look at how Vision has achieved performance gains in every area.
Vision has been at the forefront of cycling aerodynamics since it was founded as Vision- Tech USA in 1993. In the early 2000s it was the first brand to produce integrated carbon bars for time trialling, the envy of the other teams in the Grand Tours of those years. In the following decade Vision applied its knowledge and expertise to wheels, equipping Peter Sagan and the Cannondale team in 2014, a partnership that continues to this day with EF Education-EasyPost. Other pro teams riding Vision components in 2025 include XDS-Astana, Bahrain Victorious and Arkéa-B&B Hotels. Vision is one of the few component brands able to complete every production step internally, from R&D to assembly, with a meticulous level of quality control carried out in its own factory.
So with three decades of experience in carbon technology at the top level of cycling, it was a natural progression for Vision to introduce carbon-fibre spokes for the new pro-level Metron RS wheels. However, although these save 108g compared with steel spokes, the challenge Vision’s engineers faced was to equal or exceed the aerodynamic performance of the Vision Metron SL, which has steel spokes. Notably, in 2024 a certain US bike and component brand launched a new WorldTour-level aero wheel with steel spokes, finding that carbon spokes helped to save weight, but the steel bladed spokes made them faster. This is because carbon spokes require more material despite being lighter, which increases their surface area. In frame tubes, more surface area helps the airflow to stay attached for longer, helping a bike move more cleanly through the air, but in the case of spokes more surface area can create extra rotational drag.
Vision’s engineers set themselves to the task, factoring in an increased internal rim diameter of 23mm compared with the Metron SL’s 21mm. Optimised for 28mm tyres and above, this not only facilitates lower rolling resistance and increased vibration absorption, but the wider external rim created a more aerodynamic shape combined with the tyre sidewalls. Validating the final prototype of the Metron RS at the San Diego low-speed wind tunnel, Vision demonstrated that it was superior to the SL. Overall, the Metron RS 45 was six per cent faster while the Metron RS 60 was nine per cent faster while keeping the same handling characteristics and stability as the Metron SLs. The problem was solved – the Metron RS wheels are lighter and more aerodynamic.
Meanwhile, in stiffness testing, the combination of the direct-pull carbon spokes and updated rim width ensured that the Metron RS wheels outperformed the Metron SL laterally and torsionally. With the superior tensile strength of the carbon spokes, there was less deflection in tests which applied a weight perpendicular to the rim surface, simulating force applied under load.
And the new V-1000 hub is designed to apply that force earlier. Vision’s own PRS (power ratchet system), first introduced in 2021, deploys a 72-tooth ratchet ring, giving a five-degree engagement angle for super-fast pickup. Additionally, the spoke head area has been redesigned for the new T-shaped heads of the direct-pull carbon spokes; weight is saved at the freehub by new computer-controlled machining and, as you’d expect of a pro-level wheel, ceramic bearings come as standard.
And finally, thanks to ongoing investment in Vision’s state-of-the-art carbon factory, the production method itself has also been enhanced: through an improved lamination process, the rims are made more accurately than ever, with the defective rate minimised. There are continuous fibres around the spoke hole area, which improves strength and durability over drilled spoke holes, and the graphics are applied during the moulding process, which saves a further 22g compared with decals.
Vision says the new Metron RS wheels are “engineered beyond limits” and, having seen the white paper, we can confirm they indeed represent a new peak of speed, aerodynamics and pure performance. There is no stalling.
