Bike helmet: how to choose (standard, MIPS, fit)

A bike helmet only works if it's the right size and properly adjusted. The rest — technologies, ventilation, weight — comes after. Here's how to choose without being overwhelmed by marketing.

The standard, the bare minimum

In Europe, a bike helmet must be certified CE EN 1078. It's the foundation. Every helmet sold commercially complies with it; beware of products without certification marking.

MIPS and anti-rotation systems

MIPS (and equivalent systems) add a thin inner layer that allows slight slipping to reduce rotational forces during an oblique impact. It's a real safety advantage, but not essential: a properly adjusted helmet in the right size already protects well. Consider it a bonus, not a must-have.

Choose by intended use

• City / commute : well-ventilated helmet, sometimes with integrated rear light and visor. Useful for lighting.
• Road : lightweight and highly ventilated, aerodynamic.
• MTB : lower rear coverage, visor, sometimes full-face for downhill riding.

Fit, the decisive step

1. Measure your head circumference and choose the corresponding size (S/M/L).
2. The helmet must be horizontal, two fingers above the eyebrows.
3. Adjust the rear dial so it fits without pinching, then the Y-shaped straps under the ears, and the chin strap (one finger should fit).
4. Shake your head: it should not move.

When to replace it

After any impact (even without visible damage, the foam has absorbed the energy) and generally every 5 years or so (foam and straps age).

A question about bike equipment? Describe your needs to the mechanic AI.