What Our Gearhead(R) Experts Are Saying: "When I built up my race bike with these Crossmax SL Ultimate 25s, I instantly noticed how quick they felt on climbs. They're insanely light yet still track precisely on descents. The Adaptive Layup carbon rims save grams where it matters most, and the Infinity hubs paired with the Instant Drive 360 system make every pedal stroke count. Whether I'm hammering through an XC course or local singletrack, they deliver that crisp, connected ride feel you only get from the best."We ride the Mavic Crossmax SL Ultimate 25 29 front and rear wheels when speed, stiffness, and efficiency decide the outcome. Designed with feedback from elite racers, these carbon XC race wheels deliver lightning-fast acceleration and precise handling at the lightest weight in their class. Each 29-inch rim uses Mavic's Adaptive Layup carbon construction-reinforcing high-stress zones while trimming excess material elsewhere-to shave 70 grams per rim without compromising strength or control. The result is a wheel that feels responsive, stable, and razor-sharp on technical climbs and descents alike. The 25mm internal width rims strike the ideal balance between quick acceleration and optimal tire support for 2. 2-2. 4in XC tires. Each wheel is laced with 24 double-butted, straight-pull spokes in a two-cross pattern to maximize power transfer while maintaining vertical compliance for all-day control. Mavic's Infinity hub platform reduces weight and improves tension balance, while the Instant Drive 360 freehub with a dual ratchet system engages fast for snappy response when surging out of corners. Both front and rear wheels are hand-assembled in Europe and built for 6-bolt rotor compatibility, with 15x110mm and 12x148mm Boost spacing for modern MTB standards. Together, they form a featherweight carbon wheel pairing that thrives in cross-country races and fast, technical trail rides.