What Our Gearhead® Experts Are Saying: "I’ve been running the Cosmic SL 40s for fast training rides and crits—they strike a great balance between lightweight climbing performance and aero gains on the flats. They feel planted in corners and accelerate with punch, especially when paired with a quality tubeless tire setup."When we want one road wheelset that does it all—climb, corner, sprint, and descend—we trust the Mavic Cosmic SL 40. It brings the aerodynamic advantage we want for fast group rides and race day, while staying light enough to fly uphill and stay lively all ride long. Whether we’re hammering breakaways or cruising solo, these wheels keep us rolling fast with confidence-inspiring control. The 40mm deep carbon rim delivers meaningful aero savings without feeling twitchy in crosswinds, making it ideal for everyday use. A hookless, 21mm internal width rim bed is optimized for 25–32mm tubeless road tires, giving us smoother rolling and better cornering grip. Paired with Mavic’s Infinity hubs and QRM Auto bearings, the Cosmic SL 40 offers efficient power transfer and long-term reliability in a lightweight, race-ready package.