Mavic

Cosmic Carbone 40 Wheelset - Clincher

If we haven't already, investing in a set of carbon clincher hoops for training and racing is something we all plan on doing at some point. It's something of a no-brainer. The speed and aerodynamic benefits of carbon rims are well-proven and worthwhile, but the one area in which carbon clinchers not only fall short of receiving glowing reviews, but outright fail at times, is braking. Mavic's Cosmic Carbone 40 Wheelset loves to go fast, but not at the expense of being able to stop. To achieve this, Mavic engineered an entirely new rim construction for the Cosmic Carbone rather than just a new braking surface or brake pads, and the French firm's quest to get it right shows in the wheelset's bombproof durability and incredibly responsive braking.

The key to a carbon rim that won't fail under braking is in its efficiency at dissipating heat. Rather than trying to mitigate the issue of heat dissipation only at the surface of the rim, Mavic chose to make an entire rim that would respond better to heat, starting with a Maxtal aluminum bed. Aluminum has long been known for its ability to dissipate heat and resist high temperatures better than carbon, enhancing the durability and braking capability of the entire structure. The lightweight aluminum 'rim bed insert' that Mavic uses also holds air pressure better than full-carbon, making it an early adapter of the aerodynamic clincher trend. The Maxtal aluminum is a higher grade than what's commonly used in aluminum bike components, offering an improved strength-to-weight ratio over its more common 6061 alloy counterpart. Atop the aluminum, Mavic then uses its proprietary TgMAX heat-treatment process to carefully hand-layer 3k carbon layers from the bead to the tip of the fairing.

The rim is next placed in a mold to permanently bond the layers together, with spoke holes drilled only through the inner rim wall, which is itself reinforced with an aluminum insert to increase structural integrity. The result is a lightweight, adaptable rim that you can depend on to handle well in the terrain you encounter in your everyday training rides as well as during your next criterium. According to Mavic, this process took three years to fully fine-tune, and common sense supported by extensive testing shows that this proprietary construction method more efficiently diffuses heat buildup at the rim surface than carbon-only rim designs. The Cosmic Carbone 40's will not win every wind-tunnel speed test, but if durability and reliability under braking matter to you, the wheelset is a resounding success.

While the rim design is a significant feature of the Cosmic Carbone wheelset, it's not the only one worth noting. As you turn the pedals, the wheels roll smoothly on Mavic's hardworking carbon-bodied hubs with aluminum flanges, equipped with Mavic's QRM+ bearings. With an allowance for micro-fine, preload adjustments and narrow tolerances, the bearings promise reliable power transfer and a customizable ride that can be adapted to different conditions. Keeping with the lightweight design, Mavic includes Force Transfer System Light in the freehub body to reinforce the contact area between the aluminum hub body and the pawls, which uses two stainless steel inserts to enhance engagement and increase the overall durability of the freehub body.

Sixteen bladed, straight-pull steel spokes lace these hubs to the front rim with radial lacing, while the rear wheel receives twenty spokes with a two-cross drive side and radial non-drive side lacing pattern. The rims are wrapped in Griplink and Powerlink tires designed by Mavic and manufactured by Hutchinson. Both tires are constructed with a race-able 127 TPI. The front-specific Griplink tire focuses more on traction and puncture protection, including a grippy tread and a Kevlar breaker to defend against mid-race flats. The Powerlink tire out back was constructed to lower rolling resistance and, instead of Kevlar, is reinforced with a nylon breaker to maximize speed. The wheelset includes compatible carbon brake pads specific to the Cosmic Carbone, as well as a multi-function adjustment wrench and BR601 quick-release skewers.