It almost goes without saying that if you ride off-road, it’s an extremely good idea to wear a helmet. The odd crash is pretty much par for the course, and without a lid to protect your bonce and its precious contents, your trail riding career (along with your actual career) could well end up being a short one.

• Buyer’s guide to mountain bike knee pads - protect your pins
• When should you replace your bike helmet? We asked the experts
• Buying your first mountain bike - everything you need to know

Fortunately, these days we’re spoilt for choice when it comes to effective, good looking helmets to suit almost every budget. Helmets tend to offer better safety, comfort and durability the more you spend, but you can get a well-appointed lid from around £50. As a minimum, ensure the helmet you choose conforms to a European safety standard - denoted by BSEN, followed by a number (usually found on a sticker inside the helmet). Also keep an eye out for helmets passed with a Snell Foundation B90 rating, as this is a superior standard again.

While pricier models tend to have additional safety features, on a basic level all helmets work in the same way. A hard, thin (usually plastic) moulded outer shell serves to spread the force of an impact as broadly as it can. This force is then absorbed by a softer and much thicker inner layer (usually expanded polystyrene – aka EPS), which hopefully results in as little of the impact as possible being transmitted to your head.

How much should I spend?

Entry level helmets (£30 to £60) tend to have a smaller area of outer shell protecting the inner layer, less adjustment to the helmet’s fit and are bulkier overall. Mid-priced models (£60 to £120) have a higher quality, larger shell to better protect you and the helmet from damage, decent levels of fit adjustment on one or more planes and a more compact shape. Pricier helmets (upwards of £120) usually come with extra safety features such as MIPS (see our jargon buster below) and reinforced internal construction, multi-plane fit adjustment via a quality retention device and as light a weight as possible. Getting a proper fit is crucial when choosing a new helmet, so always try before you buy.

While pretty much any kind of bike helmet is far better than nothing, charging pedally trails in a sweaty full-face isn’t a great idea, nor is chucking yourself off big drops in a gram-conscious open cross-country lid. Basically, you need a helmet specifically designed for the type of riding you usually do.

What sort of helmet do I need?

Again, we can't stress enough that the most important thing is to get one that fits you properly and is comfortable. Try on a number of different helmets from different brands as some shapes fit some heads more comfortably and it's impossible to know which will suit you otherwise.

Off-road helmets usually fall into one of four main categories: cross-country, trail, enduro and full-face. Let’s have a look at each type in more detail…

Cross-country helmets

Designed with cross-country racing (i.e. rapid pedalling on less technical trails) in mind, cross-country helmets tend to be lightweight and very well vented, though usually offer minimal head coverage as a result. Many models come without a peak for maximum ventilation and to keep the weight down and a super-fancy XC helmet can weigh as little as 200g.

Choose if…

You want to give cross-country racing a crack, or hitting non-lethal trails is your thing.

Trail helmets

The phrase ‘trail’ is a fairly big catchall that can cover anything from gnarly cross-country to light enduro, so there’s a wide spectrum of trail helmets available as a result. You can expect an increased level of head coverage when compared to a cross-country helmet - particularly to the rear in order to protect the base of your skull - plus an adjustable peak, smaller vents and a noticeable increase in weight. A good balance of protection, weight and venting makes trail helmets solid all-around performers.

Choose if…

You ride trails with mid-sized features and you’re not overly prone to long breathless bouts of frenzied pedalling.

Enduro helmets

Typically enduro trails are more technically demanding and have bigger features than standard trails, so enduro helmets need to offer higher levels of protection than their trail counterparts as the consequences of a crash tend to be higher. On certain models you will also find additional features such as ear protection, on-helmet goggle parking and removable chin-bars (which converts the helmet from open to full-face or vice-versa), or lightweight fixed chin bars that look similar to a downhill full-face. You can also expect to find less venting and a weight penalty when compared to trail helmets.

Choose if…

• You want to race enduro or ride back to the top of gnarly trails

Full-face helmets

Offering maximum levels of protection, full-face helmets are designed for use on the most severe downhill trails. Like downhill bikes, these helmets are not made for pedalling uphill, so expect minimal venting and a comparatively hefty weight, they also have a fixed chin-bar and are designed for use with goggles.

Choose if…

• You want to ride the gnarliest downhill trails then get back to the trailhead via an uplift.

Helmet jargon explained

Cradle 

Also known as the retention system, this is an adjustable harness that wraps around the sides and rear of your head to help secure your helmet in place. On better-featured helmets, it's often adjustable for height as well as circumference.

Koroyd

A construction of short drinking straw-like tubes used instead of a traditional EPS shock absorbing layer to increase impact protection and aid ventilation. Used by Scott Optics and Endura in a number of their helmets.

MIPS

Stands for Multi-directional Impact Protection System. Essentially a MIPS equipped helmet has an additional internal low friction slip-plate which can help reduce the rotational forces that occur in certain impacts being transmitted to your brain. It's licensed to a number of brands, including Scott, Troy Lee Designs, Giro, Bell, Bontrager and others.

SPIN

Stands for Shearing Pad Inside. A technology developed by the brand POC which works in a similar way to MIPS, but uses silicone pads instead.

Straps

Essential elements of a helmet which run around your ears and secure under your chin. Thinner straps tend to be more comfortable and multiple adjustment clips can help give a better fit.

Vents

Helmets are designed with vents to increase internal airflow and stop your head from overheating. The best-vented helmets take in air at the front and let it escape to the rear.

Peak

Also known as a visor. A peak helps keep the sun out of your eyes. Ideally, it should be adjustable enough so that it doesn't impede your field of view while doing so. Many trail and enduro lids also give enough clearance to allow goggles to be stowed under the peak when not in use.

You might also like:

• Get the best mountain bike for you with our complete buyer's guide
• How to make the most of your uplift day