O'NEAL Sierra Adventure Helmet Black/Gray XL — Ventilated DOT & ECE Certified with Adjustable Face Shield

The O'NEAL Sierra Helmet in Black/Gray XL is a lightweight, ventilated adventure helmet with an integrated adjustable face shield, DOT and ECE certification, and a removable moisture-wicking liner for multi-terrain riding.

Built for street riders, enduro enthusiasts, side-by-side operators and adventure bikers, the O'NEAL Sierra pairs a durable polycarbonate/ABS shell with comfort features to keep long rides manageable. At approximately 1590g (±50g) the helmet balances protection and weight, while ventilation and a washable liner maintain comfort during extended use.

How does this helmet handle ventilation and comfort?

The Sierra uses strategically placed vent holes and an air-channeled comfort liner to move heat and moisture away from your head. The liner is removable and washable so you can keep the interior fresh after rough, dusty outings.

• Multiple vent holes for airflow and heat dissipation
• Air-channeled, moisture-wicking comfort liner
• Removable and machine-washable liner for easy maintenance
• Lightweight 1590g (±50g) shell reduces rider fatigue

What protective features and certifications does it include?

Safety is addressed through a robust polycarbonate/ABS shell and secure retention hardware. The Sierra meets DOT FMVSS 218 and ECE 22.05 standards, providing recognized impact protection for road and off-road conditions.

• Polycarbonate/ABS composite shell for impact resistance
• Padded chin strap with Double-D safety lock for reliable retention
• Certified to DOT FMVSS 218 and ECE 22.05 safety standards

How does the integrated face shield perform for varied riding conditions?

The molded, integrated face shield offers broad coverage and can be adjusted in height to match goggles or riding preferences. It’s ideal for riders who need quick transition between open-air and shielded setups without removing the helmet.

• Integrated face shield reduces dust and debris exposure
• Height-adjustable shield to fine-tune airflow and field of view
• Streamlined design keeps the helmet compact across conditions

How easy is it to use and maintain on the road?

The Sierra is designed for everyday use and occasional heavy-duty outings: the removable liner simplifies cleaning, the Double-D strap stays secure under vibration, and the lightweight shell keeps neck strain minimal. Regular care and correct fit will maintain performance season after season.

• Removable/washable liner for fast cleaning between rides
• Padded chin strap for comfort during long journeys
• Simple height adjustment for the shield without tools

Who is this for: The O'NEAL Sierra Helmet in Black/Gray XL is best suited for riders seeking an affordable, versatile helmet that performs well on streets, trails and utility vehicles. Choose this helmet if you want DOT and ECE-certified protection, an integrated adjustable face shield, and a washable comfort liner in an XL size for a secure, comfortable fit.