The Alpinestars A-4 Plasma Roost Guard is an anatomically profiled chest and back protector designed for all forms of off-road riding. This Black/Red/White M/L model combines a semi-rigid thermoplastic chest protector with a Nucleon Plasma back protector to provide lightweight, breathable, adaptive coverage without restricting movement. The protector is engineered for riders who need dependable protection against roost and impact while maintaining comfort in aggressive riding positions.
The integrated Nucleon Plasma back protector uses a viscoelastic material made with USDA-certified bio-based polymers. Its flexible structure moves in multiple directions while retaining the ability to dissipate impact energy. The lightweight, highly ventilated design provides broad coverage, impact force dispersion, and absorption. The chest shell uses a faceted construction to deliver structural strength and load performance, while flexible over-injected side wings follow the body's contours for improved comfort and freedom of movement.
Adjustable shoulder and side straps help create a secure, performance-oriented fit. Highly perforated, detachable rib and shoulder padding adds coverage against roost and impact, and the removable soft tactile thermoformed shoulder pads improve comfort. A ribbed back-protector lining promotes airflow and reduces skin contact, while the perforated 3D mesh chassis helps protect against tire roost. BNS shoulder pull tabs provide compatibility with Alpinestars Bionic Neck Support systems.
The A-4 Plasma Roost Guard is also compatible with the optional Nucleon Plasma Extended Roost Coverage Race Kit, which includes upper and lower chest extensions and a Y-strap system for using the chest protector without the back protector. Manufactured by Alpinestars, this medium/large protector is identified by manufacturer and vendor part number 6500526-132-ML.
Features:
- Anatomical off-road design: Provides chest and back protection for motocross, enduro, trail, and other off-road riding applications.
- Nucleon Plasma back protector: Flexible viscoelastic construction made with USDA-certified bio-based polymers helps dissipate impact energy.
- Semi-rigid thermoplastic chest protector: Faceted shell construction supports structural strength and load performance.
- Lightweight ventilation: Highly perforated materials and a ribbed lining promote airflow while maintaining protective coverage.
- Flexible side wings: Over-injected side panels follow the rider's body contours for comfort and freedom of movement.
- Adjustable performance fit: Shoulder and side straps allow the protector to be positioned securely over riding gear.
- Detachable shoulder and rib padding: Removable, perforated padding adds coverage against roost and impact.
- BNS compatible: Shoulder pull tabs accommodate Alpinestars Bionic Neck Support systems.
- Race Kit compatible: Works with the optional Nucleon Plasma Extended Roost Coverage kit and Y-strap system.
- Size and color: Medium/Large in Black/Red/White.
- Brand and part number: Alpinestars, manufacturer and vendor part number 6500526-132-ML.