REF: 8529383, 8529387, 8529388, 8555833, 8555838



Ventilated and adjustable, this mountain biking helmet was designed for mountain bike touring for over 2 hours.

Easy to adjust with its wheel and very comfortable, it protects your head from branches and impacts. You'll forget it's on with its comfortable foam pads. Bonus: 21 ventilation holes.

MTB Helmet Rockrider ST 500

Extend the life span of your helmet

Like all products, our helmets have an environmental impact over their life span.

So proper helmet maintenance is essential for extending its lifespan, reducing its environmental impact, and ensuring your safety.

Take care of your helmet - the planet will thank you and so will your head.

What is the environmental impact of your helmet?

We do all we can to reduce it, but we should note: our helmets have an environmental impact. Your ST 500 helmet emits the equivalent of 5.51 kg of CO2, meaning that the production of an ST 500 helmet emits as much CO2 as 33 km in an E-labelled car.

Understanding the issues around climate and use of resources, the DECATHLON teams aim for 100% of their products to undergo an eco-design process by 2026.

However, design is not the only phase in a product's life cycle that has a negative environmental impact. That's why we try to promote more durable use and a cleaner end-of-life for our products, and you have a role to play in all that!

MTB Helmet Rockrider ST 500

How to care for your helmet

After a muddy outing or an intense effort, remember to wash your helmet in fresh water and gentle soap. However, do not use any detergents or chemical cleaners. Also, to preserve your helmet from scratches, do not use the scraper side of the sponge.

Once washed, let your helmet air dry or wipe it with a soft cloth. Do not place it near a radiator or any other heat source to speed up drying.

The salt in your perspiration can attack the foam of your helmet. To prevent that, you can wash the foam parts in fresh water. This will significantly increase their life span!

Finally, store your helmet in a dry, cool place. Avoid excessive heat sources, UV rays, and winter cold.

Replacing the foam on your helmet

Many helmets that are still usable are thrown away each year because they are no longer comfortable enough to be worn. Without regular maintenance, the salt in your perspiration can attack the foam and wear it out prematurely, leading users to replace their helmets.

To prevent throwing it away prematurely, DECATHLON offers kits for replacing the worn foam of your helmet.

MTB Helmet Rockrider ST 500
Replacing the foam on your helmet

Specialised foam kit for the st 500 helmet

MTB Helmet Rockrider ST 500

Why must you stop using your helmet after a violent impact?

The outer shell of your helmet is made from polycarbonate, and the inner shell from expanded polystyrene (EPS). The former creates a stiff layer of protection to block against impacts and prevent jolts, while the latter absorbs the force of a violent impact by changing its shape. This deformation is what will provide good shock absorption and reduce the rebound effect. Keep in mind that a helmet is designed for protecting your brain from a single violent impact. 

So after a violent impact (a fall on the head or the helmet falling hard to the ground), the helmet will lose all its shock absorption abilities. Microcracks appear without necessarily being visible, and will make your helmet more fragile. As for the EPS, it is irreversibly deformed and the helmet will no longer protect your brain from future impacts. It is dangerous to wear it again!

MTB Helmet Rockrider ST 500

Why must you replace your helmet every 5 years?

It is recommended to replace your helmet every 5 years since after that, depending on the conditions of use and maintenance, the shock absorbing material can age and lose part of its absorption properties compared to its original state.

To find out the age of your helmet, just look at the production date displayed inside the helmet (often underneath the foam pads).

How you handle your helmet can also influence its life span. If your helmet is often jolted, particularly if you put it down too roughly or if it falls often, it will gradually lose its absorption properties.

Protect your helmet and it'll protect your head!

Conformity declaration


Read the conformity declaration for your MTB Helmet ST 500.