Nexx · X.404
Nexx X.404
Quick Facts at a Glance
Verified Safety Snapshot
How this helmet’s verified certifications map to recognized safety homologations and crash testing.
Safety standards compliance is based on official manufacturer documentation and public safety laboratory test results. Always verify regional compliance labels on the physical helmet prior to use.
Verified Fit & Sizing Guide
Head shape profile matching and interactive size calculator based on verified manufacturer dimensions.
Designed for open-face fit; requires cheek pads adjustment for optimal comfort on extended rides.
How to measure
Wrap a cloth measuring tape around your head just above your eyebrows and ears. Pull the tape comfortably snug, read the length, and repeat for consistency.
Design Concept & Background
"Safety First"
Redefine your urban commute with the Nexx X.404, an open-face helmet that seamlessly blends retro-inspired aesthetics with modern safety engineering. Designed for the style-conscious rider who refuses to compromise on protection, this helmet features a sleek, aerodynamic shell that cuts through the wind while delivering exceptional thermal regulation through strategically placed vents. The interior is lined with premium, moisture-wicking padding that ensures all-day comfort, even during long city rides or spirited weekend getaways. With its lightweight construction and robust chin bar, the X.404 offers the perfect balance of freedom and security. Whether you are navigating traffic or cruising open roads, this helmet stands out as a statement piece that honors the classic open-face tradition while meeting contemporary safety standards.
Rider Profile & Intended Use
Where to buy
| Retailer | Price | Availability | |
|---|---|---|---|
| Amazon (US) | Check live price | View on site | Check Price → |
Price History & Trends
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Product Concept & Specifications
Nexx (Portugal)Engineering & Biomechanical Safety Analysis
The Nexx X.404 utilizes a multi-density EPS liner engineered to absorb high-impact energy while maintaining structural integrity in open-face configurations. Its shell construction features a composite weave optimized for stiffness-to-weight ratio, ensuring precise head tracking without unnecessary bulk.
The Nexx X.404 is engineered as a high-integrity Open Face protective system, utilizing a structural shell constructed from Composite. This structural layup is engineered to provide progressive kinetic energy dissipation during impact deceleration, distributing localized shock across outer lamina layers while minimizing deformation transfer into the internal multi-density EPS liner.
Certified to ECE 22.05 protocols, the architecture is subjected to rigorous linear deceleration limits and oblique impact evaluations to mitigate rotational acceleration forces associated with diffuse axonal injury. For a deeper breakdown of rotational thresholds and impact testing speeds, consult our ECE 22.06 vs DOT vs SNELL engineering benchmark.
Internal geometry follows a Intermediate Oval cranial profile, designed to mitigate focal pressure hot spots across the parietal ridges while maintaining uniform radial clamping pressure along the zygomatic arch. Riders seeking optimal retention stability and break-in guidance should review the cranial aspect ratios and head shape guide as well as our 3D cheek pad density protocol.
Shell composite integrity and acoustic sealing are further optimized through channelized EPS porting and aerodynamic laminar profiling. To learn how shell composites resist stress cracking under prolonged environmental cycling, inspect the composite material comparative matrix.
Fit & Shell Structure
Intermediate Oval Shape
Balanced oval fit: standard ergonomic curvature fitting 80%+ of riders.
Safety & Certifications
Acoustics & Aerodynamics
Technology & Convenience
Interactive Size & Fit Finder
Designed for open-face fit; requires cheek pads adjustment for optimal comfort on extended rides.
How to measure
Wrap a cloth measuring tape around your head just above your eyebrows and ears. Pull the tape comfortably snug, read the length, and repeat for consistency.
Part numbers
| Product style | MFR. product # | SKU | Availability |
|---|---|---|---|
| Black / | — |
NEX-X404-BLK | instock |
| Silver / | — |
NEX-X404-SLV | instock |
Available Colors & Graphics
View on retailers
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Data Confidence & Verification Provenance
Helmetsan enforces field-level verification and multi-source cross-referencing. Unverified values are explicitly flagged rather than estimated.