Alpinestars Sm3 Youth Radium Motorcycle Helmets

The all-new SM3 Youth Helmet is anatomically engineered specifically for younger riders. Optimized for MX, Enduro, and Off-road use, it integrates adult-level technologies to deliver the perfect balance of elite performance, impact protection, and long-term comfort.

Technical Specifications & Weight 

• Lightweight Performance: Engineered to minimize neck fatigue.

• ECE Version: 1060g.

• DOT Version: 1170g.

• Shell Construction: Advanced thermo-injected shell using a specialized polymer blend with varying thicknesses for optimal impact resistance.

• Size Versatility: Available in three dedicated shell sizes: Youth Small (YS), Youth Medium (YM), and Youth Large (YL).

Advanced Safety Features 

• Multi-Density Inner Liner: Ensures the correct density in key areas for superior shock absorption.

• Rotational Force Protection: Features Alpinestars’ patented low-friction coating on the EPS liner to reduce rotational acceleration during oblique impacts.

• Patented Visor Release System: Designed to release the visor with a pre-determined force, significantly reducing potential neck strain during a crash.

• Enhanced Impact Defense: The DOT version includes a composite fiber layer between the shell and EPS for maximum protection.

Growth & Ergonomics 

• Expandable Fit (YM to YL): Youth Medium and Youth Large share the same EPS size; easily upgrade to a Large as the rider grows by swapping crown and cheek pads.

• Dedicated YS Fit: Youth Small features a specific EPS size tailored for very young riders (typically 3-4 years old) for a secure, anatomical fit.

• Customizable Interior: Fully adjustable fit via spare crown and cheek pads of different thicknesses.

Ventilation & Comfort 

• High-Flow Cooling: Features 10 air inlets and 7 exhaust ports for maximum heat exchange.

• Aerodynamic Visor: Specifically designed to funnel air directly into the ventilation ports.

• Eco-Friendly Interior: Comfort liner constructed from recycled materials for a sustainable footprint.

• Hydration Ready: Integrated channels in the cheek pads for easy hydration tube routing.

• Safety Strap: 25mm soft textile chin strap for a secure and comfortable closure