Open-face Helmet GIRO Ratio Mips — Hard Shell, In Form Fit, Stack Vent, Matte Black

The GIRO Ratio Mips is an open-face bicycle helmet featuring a hard shell construction, an In Form fit system for adjustable sizing, and Stack Vent ventilation designed to manage airflow. It includes an integrated Mips rotational impact protection layer and a matte black finish. Intended for urban and recreational cycling, the helmet balances protection, fit adjustability, and everyday usability while offering compatibility with select aftermarket audio accessories.

Advantages

The hard shell with an in-mold lower wrap combines a durable outer shell with a polycarbonate lower shell permanently fused to the liner, providing robust coverage without unnecessary weight. The integrated Mips brain protection system is designed to help reduce rotational forces in certain impacts while remaining part of the helmet’s adjustable fit architecture. Thermostat Control adjustable venting and Stack Vent alignment help manage airflow and reduce goggle fogging. The In Form fit system provides quick, tool-free sizing adjustments for a secure fit.

Suitable for

• Urban commuting and city cycling
• Recreational road and leisure rides
• Riders who prefer an open-face helmet with Mips rotational protection
• People who need an easily adjustable helmet fit

When it may not be suitable

As an open-face helmet, the GIRO Ratio Mips does not provide the extended chin and face coverage of full-face helmets, so it may not be appropriate for aggressive downhill or motorized off-road use where full-face protection is preferred. It is primarily designed for urban and recreational cycling rather than competitive racing where different models with race-optimized aerodynamic profiles could be preferable.

Key specifications

• Style: Open-face bicycle helmet
• Shell construction: Two-piece hard shell with polycarbonate lower wrap fused to liner
• Fit system: In Form adjustable dial fit with up to 6 cm of adjustment range
• Impact protection: Integrated Mips rotational protection layer
• Ventilation: Stack Vent alignment and Thermostat Control adjustable venting
• Finish: Matte black
• Compatibility: Designed to work seamlessly with compatible goggles and some aftermarket audio systems

How to use

Place the helmet on your head and use the In Form dial to adjust the fit until the helmet sits snugly and comfortably. Adjust the chin straps so they form a V around the ears and fasten the buckle, ensuring the strap is snug but not restrictive. Use the Thermostat Control button to open or close venting according to ambient temperature and exertion level, and align the Stack Vent with goggle vents if you use goggles to reduce fogging. Inspect the helmet before each ride for cracks or damage and replace it after any significant impact.

What to consider before purchase

• Intended use: suited for urban and recreational cycling, not a substitute for a full-face helmet
• Proper sizing: confirm head circumference to select the correct size range
• Compatibility with goggles and aftermarket audio accessories if these features are required

Usage recommendations

For optimal protection and comfort, ensure the In Form fit is adjusted each time you put the helmet on, use the Thermostat Control to regulate airflow during variable conditions, and replace the helmet after any significant impact or if visible damage appears.