Alpinestars SX-1 Plasma Knee Protector

The Alpinestars SX-1 Plasma Knee Protector is built for motocross and off-road riders who demand maximum protection with natural freedom of movement. At the core is the Nucleon Plasma protector, made from USDA Certified Biobased viscoelastic material that moulds to your knee and absorbs impact energy effectively. It’s designed to flex in multiple directions, giving a snug fit that stays comfortable all day.

A dual-density co-injected frame with soft polymer scooped edges ensures no pressure points when your boots press against it—ideal for long rides. The Dual Gear System (DGS) allows both upper and lower frames to hinge smoothly, mimicking the knee’s natural motion for better control and comfort. The ergonomic frame adapts to various leg sizes with rigid and flexible over-injected shells that stay securely in place. The Patella System provides full knee cup coverage and shields against impact, such as handlebar hits.

Lightweight, ventilated, and CE-certified (EN 1621-1:2012 Level 1), the SX-1 Plasma delivers serious protection without slowing you down. With a dual-strap hook-and-loop closure and snap-fit buckles, adjustments are quick and secure.