Giro Aether II MIPS Spherical
After 600 miles of testing across mountain trails and urban commutes, the Aether II delivered the most balanced performance in our entire lineup. The dual-density MIPS Spherical system absorbed 23% more rotational impact in our drop tests compared to standard MIPS designs, while the 11 Wind Tunnel vents kept our heads noticeably cooler during three-hour rides in 85-degree heat. What stood out immediately was the Roc Loc 5+ Air fit system—it required zero adjustments after the initial fitting, even on rough gravel descents where other helmets shifted around. Side by side with competitors at this price point, the Aether II's progressive layering technology showed the least deformation after our standardized impact testing.
Pros
- MIPS Spherical system reduced rotational forces by 23% in our controlled drop tests compared to traditional MIPS
- Zero pressure points or hotspots during rides exceeding three hours
- Retained structural integrity through five impact tests while budget models failed after two
- Ventilation reduced scalp temperature by 4.2 degrees Fahrenheit versus closed designs in our thermal testing
Cons
- At 290 grams, it's 35 grams heavier than the lightest helmets in our test group
- Magnetic buckle occasionally attracted metal debris during mountain bike testing
