Safety remains the top priority for every cyclist, whether you are commuting daily in Paris, cycling to work in the morning via Montrouge, or going on long rides around Versailles, Saint-Cloud, or Fontainebleau. A helmet is therefore essential: it is the piece of equipment that can prevent serious injuries and protect your health in the event of a fall. How does a bike helmet work, and what criteria should you consider to choose the right one? We explain everything.
Summary:
Why wear a bike helmet
Types of bike helmet construction
Bike helmet certification
Types of bike helmets
How to choose your bike helmet
Bike helmet size
Conclusion
Why wear a bike helmet
Even in the city, a cyclist generally rides between 15 and 25 km/h, and speeds can be much higher on a downhill track. At that pace, a head injury can have serious or even fatal consequences. A reliable helmet significantly reduces the force of an impact and limits the risk of severe injuries. It absorbs impact energy and distributes it over the entire surface, thereby reducing pressure on the head and spine. The visible marks on a helmet after a fall clearly show that this investment was well worth it.
Types of bike helmet construction
The base of a helmet is a lightweight, impact-absorbing foam covered by a plastic outer shell. The shell spreads the impact energy over a larger surface area, while the foam deforms and cushions the blow, limiting its transmission to the head. Two constructions dominate: In-Mold and Hardshell.
In-Mold Helmets
In In-Mold construction, the plastic shell is fused directly to the foam under high pressure. Since the outer shell is thinner, the helmet is significantly lighter than a Hardshell model. Another advantage: in the event of an impact, deformation is clearly visible, which helps evaluate the intensity of the impact the helmet has absorbed on your behalf.
The In-Mold helmet also offers excellent ventilation thanks to its numerous vents: perfect for summer, and easy to balance in winter with a bandana or a fleece helmet liner. Its versatility makes it the most common choice among urban, road, and mountain bikers in France.
Hardshell Helmets
In Hardshell construction, the shock-absorbing foam is covered by a rigid ABS plastic shell. This type of helmet is robust, durable, and retains its good exterior appearance for a long time. However, it is heavier and may mask internal damage after an impact. Hardshell helmets are particularly popular for more aggressive forms of mountain biking and BMX.
Bike helmet certification
In France, all bike helmets must meet the EN 1078 safety standard. Another, rarer standard, NTA 8776, applies to helmets for high-speed e-bikes capable of reaching 45 km/h.
To obtain this certification, helmets are tested under loads simulating bike falls. In the laboratory, the structural integrity and shock-absorption capacity are verified. Buying a helmet from Routes and Roads ensures that it is certified.
Additional protection technologies
A glancing blow can be just as dangerous as a direct impact. This is why many brands integrate additional protection systems like MIPS, inspired by the brain's natural protection. A thin MIPS layer, placed between the helmet and the liner, allows for slight helmet movement during an impact, aimed at reducing the rotational force transmitted to the head. This technology is now featured on most sports helmets.
Since every cycling discipline has its specific needs regarding comfort and support, your helmet choice should match your riding style.
Types of bike helmets
Helmets are categorized by discipline and design. The most common categories include road, mountain bike, gravel, and commuter models. That said, nothing stops you from wearing a full-face helmet in the city if you find it comfortable. This is why we will cover the most obvious way to distinguish helmets: their design types.
Open-face helmets
These are lightweight, well-ventilated models suitable for road, city, gravel, or mountain biking. Differences lie in their shape, the presence of a visor, and the durability of the components. Road helmets are more rounded and visorless; MTB models feature a removable rigid visor; touring versions offer smaller vents and a longer, more durable visor.
Hardshell helmets
They utilize the Hardshell construction mentioned above. Their shape is rounder and the ventilation system is concealed. They are designed for tricks and stunts: dirt, skate parks, BMX, street... but remain perfectly suitable for commuting.
Never forget that a strong impact can damage the internal foam without leaving a visible trace on the shell. After a fall involving a serious impact, it is better to replace it.
Full-face helmets
These helmets resemble motocross models but are lighter and better ventilated. They offer full jaw protection and are perfect for extreme downhill disciplines and big jumps. They are essential for downhill, freeride, enduro, 4X, or technical pumptracks.
How to choose your bike helmet
In the Paris region, riding styles are very varied: leisurely rides along the boulevards, fast outings toward Versailles, forest trails in Meudon or Montmorency, or BMX tracks in Saint-Denis or Nanterre. The helmet must therefore match your riding style and activity level.
For city and daily commuting
For riding in Paris and its inner suburbs—from Boulogne to Montreuil—lightweight open-face helmets or stylish hardshell models are perfect.
The open-face helmet offers the best ventilation, ideal for warm weather or commuting. The hardshell is a bit heavier but provides excellent protection at low to medium speeds and integrates perfectly with urban style; many adopt it precisely for its look.
For trails and outdoor outings
Around Meudon, Saint-Cloud, or in the Montmorency forest, the terrain is uneven, punctuated by roots, branches, and fast descents. A lightweight, open-face In-Mold helmet with a rigid visor is therefore the most appropriate option. It protects the face better from branches, remains stable during jumps and vibrations, and ensures good ventilation during climbs.
For dirt, the skateparks of Saint-Denis or La Défense, or street riding, the rigid hardshell remains the best choice: it is highly resistant to impacts against ramps or concrete and ensures a very secure fit on the head during rotations. Despite lower ventilation, this type of helmet remains the safety standard in these disciplines.
For downhill, freeride, and enduro
If you are riding in Les Gets, Morzine, Les Deux Alpes, or at local DH spots, a full-face helmet is a must.
Bike helmet size
The right size can only be verified by trying it on. Measure your head circumference: your size should be in the middle of the helmet's adjustment range. Avoid choosing a size that is too small: the helmet might compress your head after several hours of cycling. Shake your head, lean forward: a well-adjusted helmet stays stable, sits straight on the head, without squeezing or tipping.
Conclusion
You now know the essential criteria for choosing your bike helmet. A proper fitting and advice from the experts at Routes and Roads will help you find the most comfortable model. Enjoy picking out your gear!