What are the best carbon wheels for the 2027 Étape du Tour?

Carbon wheels for the mountains: what the route demands

L'Étape du Tour 2027 is a mountain sportive: on 11 July 2027, it packs 154 km, 4,850 m of elevation gain and 5 major climbs between Cluses and Les Saisies. The L'Étape du Tour 2027 route tackles the Col de la Colombière from the very first kilometres, 15.9 km at 7%. It finishes with the Col du Pré, near Lake Roselend, then the Montée de Bisanne, 12.4 km at 8.3%, before a high-altitude finish at Les Saisies.

A route like this means long climbs, where the weight and stiffness of the pair count, then a descent after each pass, where stability and braking come first. A deep-section rim, designed to cut drag and hold momentum at high speed, offers less on long climbs, where the speed drops.

The Comete 45/55 aero wheels are designed for mountainous courses and big elevation gain, where long climbs, technical descents and changes of pace call for a light, manoeuvrable pair.

Carbon rim depth for climbing: 32 mm or 45/55

Carbon rim depth for climbing is chosen first for lightness and handling: the Cosmic SLR 32 carbon road wheels, with a 32 mm profile, are designed for the mountains. They are built to let you attack climbs and take corners with confidence. Their rim width is matched to the shallow profile: in crosswinds, the steering stays predictable.

The Cosmic SL 32 carbon road wheels have a 32 mm carbon rim, whose shape draws on NACA aerodynamic profiles to reduce drag. Their lighter rim keeps inertia down: in practice, you pick up speed quickly every time you accelerate.

The mixed-depth Comete 45/55 carbon road wheels pair a 45 mm front wheel, for lively steering, with a 55 mm rear wheel, for stability and cruising speed. The shallower front improves stability in crosswinds, an advantage on mountain descents.

Heïdi Gaugain won the Red Bull Cycling Survivor 2026, on 26 September at the Circuit de Charade, on Comete 45/55 wheels: her second consecutive win in the event.

Carbon rim depth for climbing: 32 mm or 45/55

Lightweight climbing wheels: weight, inertia and stiffness

For climbing, the lightest pair in this selection is the Cosmic Ultimate 45 carbon road wheels, 235 g lighter than the Cosmic SL 32 carbon road wheels. On the Cosmic Ultimate 45 wheels, the Adaptive Layup carbon lay-up makes the rim lighter, for livelier wheels that are more enjoyable to ride uphill.

The ID360 freehub is fitted to every pair in the selection. On the Comete 45/55, Cosmic SLR 32 and Cosmic SL 32 carbon road wheels, its 40-tooth ratchet engages every 9°: on hairpin bends, the power goes down almost instantly every time you accelerate.

Lateral stiffness also matters when you climb out of the saddle: on the Comete 45/55 wheels, the 21 carbon spokes in each wheel improve it. On the Cosmic Ultimate 45 wheels, each one-piece R2R carbon spoke runs from one side of the rim to the other through the hub: the wheel stays stiff whether you are accelerating, braking or steering through a bend.

Mavic's wheel lab tests at Chavanod include a fatigue bench that simulates 500 km of continuous climbing out of the saddle, like a very long Alpine pass. Based on field measurements, this test combines lateral loads on the wheel and torsion on the rear hub.

Lightweight climbing wheels: weight, inertia and stiffness

Comete or Cosmic: which pair for L'Étape du Tour 2027

The five Comete and Cosmic pairs in this guide are all disc-brake wheels, cost from €1,299 to €4,399 and are eligible for the lifetime warranty.

The Comete 50 carbon road wheels are designed for riders who want a single pair: fast on the flat, responsive on the climbs and precise in their line at high speed. Their 50 mm profile suits riders who prepare for the event on fast rides and want to keep the same wheels in July.

At the Tour de France Femmes avec Zwift 2026, the St Michel Preference Home Auber93 team rode two Mavic models, the Comete 50 wheels and the Cosmic SLR 45 carbon road wheels; Solène Muller crossed the summit of the Col de la Savine in 3rd place there, in the mountains classification of stage 3.

Model	Rim depth	Internal width	Pair weight	Price	Recommended use
Cosmic Ultimate 45 carbon road wheels	45 mm	23 mm	1,260 g	€4,399	Lightest pair in the selection
Comete 50 carbon road wheels	50 mm	23 mm	1,315 g	€2,499	One pair, from the flat to the climbs
Comete 45/55 carbon road wheels	45 mm front / 55 mm rear	25 mm	1,350 g	€2,499	Mountainous courses, big elevation gain
Cosmic SLR 32 carbon road wheels	32 mm	21 mm	1,390 g	€1,999	Mountains, climbs and corners
Cosmic SL 32 carbon road wheels	32 mm	21 mm	1,495 g	€1,299	Mountain wheel, entry price for carbon

Choosing carbon wheels for L'Étape du Tour

To choose your carbon wheels for L'Étape du Tour 2027, start from the 4,850 m of climbing: the best wheels for this route combine a light pair, a 32 to 50 mm rim or a mixed-depth profile, and good lateral stiffness out of the saddle. The mixed-depth profile of the Comete 45/55 carbon road wheels is designed for big elevation gain; if lightness is your priority, the Cosmic Ultimate 45 carbon road wheels are the lightest in the selection, at 1,260 g a pair.

On a tighter budget, the Cosmic SL 32 carbon road wheels give you a 32 mm profile for €1,299. The carbon road wheels range covers the other profiles. Further reading, on rim depth in triathlon: IRONMAN wheel set-up guide.

FAQ: carbon wheels for a mountain cycle tour

Tyre pressure for descending a mountain pass stays below three ceilings: the rim's, the tyre's and the one given by Mavic's tyre and rim compatibility chart for the tyre width fitted, with the lowest of the three applying. This ceiling drops as the tyre width increases. On the Comete 45/55 carbon road wheels, whose hooked rim measures 25 mm internal width, it is 5.0 bar with a 29 mm tubeless tyre and falls to 4.5 bar with the recommended 30 mm width. These values are maximums, not pressure settings: Mavic advises riding below them, especially with tubeless, and does not publish a pressure for descending. Before a long day over the passes, check that your starting pressure stays below the ceiling for your set-up.

With carbon disc-brake wheels, braking takes place on the disc rather than on the rim, which spares the carbon rim the direct heat of braking on long mountain descents. Braking is still a heavy load on the wheel: with rim or disc brakes, it generates very high stresses and heat. In the Chavanod laboratories, one bench runs 750 consecutive braking cycles, alternating between 0 and 70 km/h, and on the torsion bench the hub is subjected to high forces for 100,000 cycles, which reproduce acceleration and emergency braking. The five disc-brake pairs in this guide use the Center Lock disc standard: check that your brake discs match this standard before fitting them.

On carbon wheels, the tubeless tyre is chosen first on the minimum tyre width the rim accepts, from 23 mm on the Cosmic SL 32 carbon road wheels to 29 mm on the Comete 45/55 carbon road wheels. In between, the Cosmic SLR 32 carbon road wheels take a 25 mm tyre at minimum, and the Cosmic Ultimate 45 and Comete 50 carbon road wheels a 28 mm tyre. On the Comete 45/55 wheels, the recommended width is 30 mm. Fitting differs by model: the Comete 45/55, Comete 50, Cosmic SLR 32 and Cosmic SL 32 wheels come with UST rim tape already fitted, whereas the Fore rims of the Cosmic Ultimate 45 wheels need none.

Rim-brake carbon wheels remain an option for L'Étape du Tour: the Cosmic SL 40 rim-brake carbon road wheels have a 40 mm profile and weigh 1,600 g a pair. Their rim measures 19 mm internal width, the pair is priced at €1,299, and each wheel comes with brake pads for carbon rims. Like the disc-brake wheels in this guide, they are eligible for the lifetime warranty. The type of brake is chosen with the frame and fork, not with the wheels. On a course that strings together mountain descents, check the condition of the brake pads and of the braking surface before the event, as it is a wear part excluded from the warranty.

The Mavic carbon wheel warranty lasts for life for the original owner, provided the wheels are registered with the Mavic Care programme within 2 months of purchase. It covers the 2021 range onwards, sold since 1 September 2020. After a crash, Crash Replacement gives a discount on new wheels: 50% in the first two years, 40% between 3 and 5 years, 30% between 6 and 8 years. Wear parts remain excluded, including braking surfaces, rim tape, UST valves, bearings and the freehub body. Spare parts for the wheels remain available for several years after they are no longer sold. So register a new pair as soon as you buy it, before you start preparing for the event.

Registration for L'Étape du Tour 2027 opens to the general public on 2 November 2026 at 2 pm CET (French time), for an event held on 11 July 2027. Pre-registration goes exclusively through a Tour de France Club account. Riders in an L'Étape Series sportive can secure a guaranteed place through the L'Étape Reward programme. The 2027 edition is the 35th of the event. Between the opening of registration and the start in Cluses, you have more than eight months to choose your carbon wheels for the mountains and try them in training before the July climbs.