Salomon designs its trail shoes around a precision midfoot wrap, and that single decision shapes how the whole range fits. The upper hugs the bridge of the foot and the Quicklace system cinches everything into a snug, locked-down package, which is exactly what you want when you are picking a line through rocks or hanging on through a fast, technical descent. The trade-off is that a Salomon shoe in your usual US number feels shorter and tighter than the everyday road trainer you are probably comparing it to. For that reason most wearers fit best half a size up, and the same advice holds whether you are looking at the Speedcross, the Sense Ride, an S/Lab racer, an X Ultra hiker or the lifestyle XT.
The half-size-up rule is about more than comfort off the shelf. On long efforts your feet swell, and a forefoot that felt fine on the first kilometre can press against the toe box hours later, especially on steep downhills where the foot slides forward into the front of the shoe. Adding half a size buys back that room without loosening the midfoot wrap or heel hold that make Salomon shoes feel so secure. If you sit between sizes, go up rather than down. The only Salomon silhouettes that sit closer to true to size are the wider road models, but for anything built for the trail the guidance is consistent: it runs small and snug, so size up half.