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With the new Cosmic SLR 45 Disc 23 mm, Mavic continues the legacy of a versatile, high-performance wheel model that has been at the top of the French brand’s lineup for nearly 20 years. This 2025 version retains an average rim height of 45 mm but features an internal width of 23 mm, offering greater stability and better compatibility with modern, wider-profile tires. How do the Mavic Cosmic SLR 45 Disc 23 mm perform on the road? Here’s our take after an extensive test ride covering over 2,000 km.
By Guillaume Judas – Photos: ©3bikes.fr
A design built for performance
In Mavic’s lineup of carbon wheels for disc brakes, the Cosmic S 42 is the entry-level model (€999), followed by the Cosmic SL, available in 32, 45, and 65 mm rim heights (€1,499), and finally the Cosmic SLR, with the same rim height options, priced at €2,249. At the very top of the range are the highly exclusive Cosmic Ultimate wheels, priced at a stratospheric €4,449—a price that reflects their entirely handcrafted production in France.
=> Buy the Mavic Cosmic SLR 45 Disc 23 mm wheels for €1,648.99 instead of €2,249
The Mavic Cosmic SLR 45 Disc 23 mm immediately stand out thanks to their UD carbon rim widened to 23 mm (internal width), a choice that reflects a commitment to optimizing aerodynamics while offering compatibility with wider tires (minimum 28 mm, up to 64 mm). The 32-mm and 65-mm versions are equipped with 21-mm and 19-mm-wide rims, respectively. This tends to demonstrate Mavic’s desire to establish a specific use for each model.
With a 45-mm profile, the Cosmic SLR 45 Disc strikes a good balance between lightness and aerodynamic efficiency, making it suitable for both flat terrain and hilly routes. The elliptical steel spokes, the result of Mavic’s aerodynamic expertise, reduce drag and, according to the manufacturer, help “save watts.”
UD Carbon Finish
The UD carbon finish isn’t just for looks: it helps reduce the rim’s weight while increasing its stiffness. Weighing 1,492 g per pair, the Cosmic SLR 45 Disc wheels are not among the lightest in their category. However, they do not compromise on the strength needed to withstand the demands of intense rides or competitions.
Optimized Tubeless System with Fore Carbon
Tubeless setup is simplified thanks to Fore Carbon technology, which has already been proven on other Mavic models. This manufacturing method eliminates the traditional rim tape. The spokes are inserted directly into the rim through a specific hole, making the wheel airtight without adding any unnecessary material. This results in reduced weight and improved tubeless sealing.
New Rim Width
The new Mavic Cosmic SLR 45 features wider rims than other models in the lineup, with an internal width of 23 mm and a maximum external width of 32 mm. This optimizes tire placement on the rim, thereby preventing the ballooning effect that occurs when a wider tire is mounted on a narrower rim. Even at the recommended pressure of 5 bar for a 28 tire, the sidewalls do not collapse during weight shifts. This width also allows the tire’s sidewalls to align with those of the rim. This provides an aerodynamic advantage, in addition to better traction on wet surfaces.
Overall, this width also optimizes the rim’s shape, making it less susceptible to crosswinds.
Infinity Hubs and QRM Auto Bearings
Infinity hubs offer increased stiffness and optimized power transfer thanks to precise spoke tension adjustment. Combined with QRM Auto bearings (Mavic Quality Auto-adjusting Bearings), they promise smooth operation and extended durability, even under high stress conditions such as those encountered on descents or during sprints. Mavic also promises reduced maintenance.
The spokes are laced in pairs, but the hub design ensures that no two spokes come into contact with each other. This is done to increase reliability and eliminate any unwanted noise.
The Instant Drive 360 freewheel system is lightweight and provides ultra-fast acceleration with an engagement point every 9°.
Disc-brake compatibility only
In line with current trends, this model is designed exclusively for disc brakes, featuring a Center Lock mount. This design reflects market trends, where disc brakes dominate due to their braking power and reliability, particularly in the rain or on technical trails.
Versatility Above All
On paper, the Cosmic SLR 45 Disc 23 mm wheels seem built to do it all: ride fast on the flats thanks to their aerodynamics, climb without too much of a penalty thanks to their modest weight, and remain stable on descents or in crosswinds thanks to their 45 mm intermediate profile.
In practice, the 45-mm profile is an ideal compromise for all-around cyclists. Compared to taller wheels (60 mm or more), it offers less resistance to crosswinds, which is an advantage on exposed routes. According to Mavic, the elliptical spokes and wider rim provide a notable aerodynamic advantage over the previous generation. While we cannot verify these claims empirically, I can confirm that these wheels with their intermediate profile are stable and reassuring, even in challenging conditions.
The Mavic Cosmic SLR 45 Disc 23 mm wheels remain lively and responsive, thanks to their well-balanced stiffness. I never felt stuck at the bottom of a steep climb when shifting to the small chainring due to excessive stiffness. At the same time, I never felt the wheels wobble in the middle of the fork or seatstays during hard pedaling.
Whether riding at a steady but sustained pace or on a more rugged course with frequent accelerations, the Cosmic SLR 45s are smooth and efficient. They offer enough inertia to make them excellent wheels for long-distance riders, while remaining light enough to adapt to the changes in pace that make all the difference in competition.
Comfort is a strong point
Although I haven’t had the chance to test the wheels in the mountains, they never felt like a hindrance on the short, more or less rolling climbs of the Chevreuse Valley. Thanks to the 28 mm tires (which actually measure close to 30 mm) and the corresponding tire pressure, I even found them quite manageable when climbing cobblestone hills.
Ultimately, what stood out most to me from this test—which spanned over 2,000 km—was the overall comfort of these wheels and the smooth ride, without compromising performance.
Some may see this as a lack of character. There are competing wheels that more radically alter a bike’s handling—and not always for the better. My experience shows that, on the contrary, for everyday use, wheels must also be comfortable and offer predictable handling to help you conserve energy.
To conclude, I should note that throughout the entire test period, I encountered no rolling issues or unwanted noise.
Verdict: Who are these wheels for?
The Mavic Cosmic SLR 45 Disc 23 mm are designed for riders looking for a high-performance, versatile, and durable set of wheels. Responsiveness and overall comfort are also among their key strengths. Even though they’re relatively expensive (you can find them cheaper HERE), these high-end wheels can take you through the entire year, on any terrain, without requiring the maintenance or usage restrictions of more exclusive models.
In 2025, as the market for high-end carbon wheels is more competitive than ever, the Cosmic SLR 45 Disc 23 mm prove that the French brand still has plenty of tricks up its sleeve.
=> Buy the Mavic Cosmic SLR 45 Disc 23 mm wheels for €1,648.99 instead of €2,249
The MAVIC COSMIC SLR 45 DISC 23 at a glance… Pros: versatility, aerodynamics, comfort, build quality Rims: 100% carbon tubeless with UD outer layer – Rim dimensions: 45 mm high, 23 mm internal width, 32 mm external width – Drilling: Fore Carbon tubeless technology without a rim liner (24 holes front/rear) – Spokes: 24 elliptical steel spokes front and rear, laced in a 2-cross pattern – Hubs: aluminum – Freehub system: Instant Drive 360 – Bearings: QRM self-adjusting – sealed cartridge – Cassette compatibility: HG, XDR, and Campagnolo (optional) – Disc mount: Center Lock – Weight: 1,492 g per pair – Warranty: lifetime – Price: €2,249 – Contact: mavic.com |
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