Mavic Crosstrail SL Carbon 29 Wheelset

For riders who've been waiting to put carbon wheels on a trail or all-mountain build without the anxious restraint that comes with owning fragile, expensive rims, the Mavic Crosstrail SL Carbon 29 Wheelset makes a different kind of case. Mavic rates these wheels to ASTM Category 4 — the enduro and trail standard — and backs them with a lifetime warranty, which says something specific about their confidence in the construction. At 1,690 grams for the pair (745g front, 935g rear), they're competitive in weight among carbon trail wheels, but the engineering priorities here go beyond the scale.

The rim is built from 100% carbon fiber with a UD external layer — what Mavic calls UD2 — with a lower profile that reduces rotational inertia without, according to Mavic's testing, compromising impact resistance against roots and rocks. The internal width measures 30mm, which positions the rim well for 2.3" to 2.5" trail tires: wide enough to support the sidewall properly and give the tire a squared-off profile for better cornering traction, but not so extreme that it limits tire options. The rear rim is asymmetric, which addresses the uneven spoke tension that comes from the asymmetrical flange spacing on modern boost rear hubs. By offsetting the rim bed, Mavic can equalize tension across both sides of the rear wheel, which improves lateral stiffness and reduces the risk of spoke fatigue over time. Spoke count runs 24 at the front and 28 at the rear, with straight-pull, extra-flat, constricted steel spokes — the butted profile removes weight in the mid-section while the antirotation feature on the nipples resists unwinding under load. Lacing is crossed 2 at the front and crossed 3 at the rear.

The hub system is where the Crosstrail SL Carbon separates from more basic options in the trail wheel category. Mavic's Infinity hub design uses non-contact spoke lacing to eliminate the spoke-on-spoke contact that causes creaking under load on conventional crossed lacing. Front and rear spokes share the same length, and the system uses a tool-free spoke replacement approach — both details that matter more after a few seasons of trail use than they do on a spec sheet. QRM Auto bearings (Qualité de Roulements Mavic Auto) are double-sealed cartridge bearings with C3 internal clearance and an automatic preload adjustment mechanism that maintains consistent roll quality as the bearings wear in, without requiring periodic manual adjustment. The freewheel uses Mavic's Instant Drive 360 system — a wide contact-ring design with a contactless rubber seal that delivers fast engagement with low friction. The wheel ships with a Shimano HG MTB aluminum freewheel body; SRAM XD is available as an option. Both boost thru-axle standards are supported out of the box (15x110 front, 12x148 rear), with conversion kits sold separately for 9mm QR or Fox/RockShox Torque Cap compatibility.

Tubeless setup is straightforward. Mavic ships the Crosstrail SL Carbon with rim tape already mounted, reducing the setup process to installing the included UST valve, mounting the tire, and adding sealant. The rim uses a hooked bead (ETRTO 622x30TC) with the tight dimensional tolerances of Mavic's UST standard, which seats most quality tubeless tires reliably. The supported tire range runs from 52mm minimum width to 76mm maximum, covering the 2.3" to 2.6" tires that most trail riders use. Maximum tire pressure is 43 PSI at minimum tire width and 36 PSI at maximum width. Disc brake compatibility covers both 6-bolt and Center Lock standards. Each wheel ships with two replacement spokes; the rear wheel includes a multi-function adjustment wrench.

At $2,049, the Crosstrail SL Carbon 29 is a significant investment in a trail build. The lifetime warranty and ASTM Category 4 rating together address the central concern most riders have about committing to carbon under hard conditions — Mavic is certifying these for enduro and trail use, not just light trail or cross-country. For a 29er all-mountain or trail build where the rider is ready to stop treating the wheels as the weakest point of the setup, these deliver the weight and hub performance that justify the price point.