Choosing a mountain bike helmet: how to compare fit, protection and comfort

A mountain bike helmet needs to do more than look sporty. On Dutch MTB trails, you’ll encounter branches, mud, rain, bright sunshine and rapid changes in temperature. Yet many cyclists choose a helmet based on its colour, low price or eye-catching marketing claims. The result can be a poor fit, overheating or a helmet that’s less practical than expected.

The three most common pitfalls:

• Choosing the wrong size: a helmet that’s too loose can shift while you ride. One that’s too tight can create pressure points.
• Focusing too much on ventilation or weight: a lightweight cycling helmet is comfortable, but a good fit and adjustable chin strap are still essential.
• Unclear safety claims: terms such as “impact protection” or “dual certification” don’t tell you much unless the specific standard and product documentation can be verified.

Below, you’ll find the features to check before buying an MTB helmet.

1. Fit: measure your head circumference first

Use a tape measure to measure your head just above your eyebrows and ears. Keep the tape level and don’t pull it too tight. Then compare the result with the manufacturer’s size guide.

Not all models fit exactly the same way. For example, a size M cycling helmet may fit a head circumference of 54–58 cm, while size L may be designed for 56–61 cm. If sizes overlap, choose mainly according to your head shape and the adjustment range.

When trying on a helmet, check that:

1. It sits level and doesn’t tilt backwards.
2. The front edge sits a few centimetres above your eyebrows.
3. The adjustment dial holds the helmet securely without causing painful pressure.
4. The chin strap isn’t loose and sits comfortably under your chin.
5. The helmet doesn’t shift when you gently move your head from side to side.

A one-handed adjustment dial is handy if you wear a hat, ponytail or thin headband while riding. However, always check the fit before setting off.

2. Protection and regulations: look beyond the packaging

For an adult cycling helmet, it’s important to see a clear reference to the applicable European requirements. Check that the product has a CE mark and that the product information refers to EN 1078 for helmets for cyclists, skateboarders and roller skaters. A CE logo alone doesn’t replace clear usage and manufacturer information.

Also consider the construction:

• EPS foam is designed to help absorb energy in an impact.
• An outer shell made from PC or ABS can protect the construction during everyday use and from minor external knocks.
• A helmet that covers the sides and back of your head may be more practical for MTB riding than a model with a very open road-racing design.
• A visor helps shield you from low sun, splashing mud and branches, but doesn’t replace eye protection.

Brands may make additional performance claims. According to DKONI’s product description, the HS-062 has a PC outer shell, EPS inner layer and in-mould construction. The same description states that it has dual safety certification for US and European standards. Check the markings and documentation yourself before buying; a brand’s claim isn’t a general guarantee for every riding situation.

Replace your helmet after a serious impact, even if there’s no visible damage on the outside. The internal structure may be damaged. With regular use, it’s wise to check the helmet’s condition frequently and follow the manufacturer’s recommendations.

3. Weight, ventilation and additional protection

A lightweight cycling helmet is comfortable on longer rides, but weight is only one part of comfort. Also consider the number of ventilation holes, the shape of the inner pads and whether they can be washed.

A large visor is particularly useful on woodland trails and downhill routes. A mountain bike helmet with a visor offers extra protection from sun, rain and dirt. Check whether the visor is removable or adjustable, and whether it obstructs your view when you lean forwards on the bike.

You could also consider UV400 cycling glasses to protect your eyes. According to the Revoray X3 cycling glasses product description, the model has a PC lens, TR90 frame, weighs around 30 grams and offers UV400 protection. These details can be checked in the product specifications. Road cycling glasses can also be used for MTB rides, as long as they fit securely and the lenses provide enough peripheral vision.

Accessories such as a face mask or sleeves with finger loops can offer extra sun protection for cyclists. According to Beneunder’s product information, the AL01j has a UPF 50+ rating and adjustable ear loops. Accessories like these don’t protect you in a fall and aren’t a substitute for a helmet or sports glasses.

Recommendations for different types of cyclists

Suitable for: Budget-conscious beginners

DKONI HS-062 Adult Mountain Cycling Helmet White/Black M 54-58cm

Why it suits this rider: Size M is designed for head circumferences of 54–58 cm, and the helmet has an adjustment dial, removable visor and 17 ventilation holes. That makes it practical for leisure rides and first MTB outings.

How this product helps avoid the pitfall

The size range is clearly stated, and the adjustment dial helps reduce the risk of a loose fit. However, check the CE mark and standard information yourself before buying.

Key benefits and features

PC outer shell, EPS inner layer, 380 grams according to the product information, and a removable ABS visor.

Suitable for: Shoppers looking for premium quality

Revoray Cycling Glasses X3-Black

Why it suits this rider: If you want to complement your helmet with eye protection, this model offers a PC lens, a UV400 rating and a TR90 frame. It weighs around 30 grams.

How this product helps avoid the pitfall

The specifications state the material, weight and UV400 rating, rather than relying only on general sports claims. Check that the glasses fit your face and helmet well.

Key benefits and features

Single-piece moulded PC lens, non-slip nose pad and a fit suited to medium to large face shapes, according to the product description.

Suitable for: Specialist use and frequent riders

OutdoorMaster Full Face Mountain Bike Helmet, red, L

Why it suits this rider: According to the product information, this full-face mountain bike helmet is designed for downhill, BMX and intensive mountain biking. The chin guard and extended coverage are suited to rides where extra protection is preferred.

How this product helps avoid the pitfall

Choosing a full-face model means you don’t have to consider only open helmets when chin and face protection are important for the way you ride.

Key benefits and features

ABS outer shell, EPP inner layer, 27 ventilation channels, adjustable D-rings and a rotating visor, according to the product specifications.

Frequently asked questions about mountain bike helmets

How tight should a mountain bike helmet fit?

An MTB helmet should fit securely without creating painful pressure points. It shouldn’t shift forwards, backwards or sideways when you move your head. Adjust the rear fitting system first, then fasten the chin strap. Try the helmet on with the cycling glasses or other accessories you’ll wear while riding.

How long does a cycling helmet last?

Its lifespan depends on the materials, how it’s used and stored, and whether it has been involved in any impacts. Check the helmet regularly for cracks, deformation, loose parts and worn straps. Replace it straight away after a significant impact. If you use your helmet frequently, it’s sensible to replace it periodically in line with the manufacturer’s advice, even if there’s no visible damage.

Do I need cycling glasses as well as a mountain bike helmet?

Not always, but cycling glasses can shield your eyes from wind, dust, insects, rain and low sun. A model with a UV400 rating is designed to protect against ultraviolet light, according to the product information. Choose glasses that don’t press against the edge of your helmet and stay securely in place on bumpy rides.