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How to Shop for Mountain Bike Helmets: Matching Protection to Your Riding Style

When shopping for mountain bike helmets, the most important starting point is matching the helmet to your riding style. Casual trail riders and cross country cyclists will find a half-shell or XC helmet suits them well, offering lightweight comfort and solid ventilation for longer days in the saddle. Riders tackling more technical terrain or enduro-style descents are better suited to an all-mountain helmet, which provides extra coverage and a visor to manage glare. For those pushing into downhill or bike park riding, a full face helmet is the right choice, offering maximum protection across the face and head. Convertible helmets are worth considering if you want flexibility between open and full face coverage on the same ride. Across all styles, fit is critical. Measure your head circumference and choose a helmet that sits snug without shifting. Explore the different types of mountain bike helmets below to find the right fit for your riding needs.

Commonly Asked Questions about Mountain Bike Helmets

What type of mountain bike helmet do I need for my riding style?

The right helmet depends on the terrain and intensity of your riding. Casual trail and cross-country riders are well suited to a half-shell or XC helmet, which prioritises lightweight comfort and ventilation. Riders tackling technical descents or enduro-style trails should look at all-mountain helmets for added coverage, while downhill and bike park riders need a full-face helmet for maximum protection.

What is the difference between a half-shell and a full-face mountain bike helmet?

A half-shell helmet covers the top and sides of the head and is open at the face, making it lighter and better ventilated for climbing and trail riding. A full-face helmet adds a chin bar and extended coverage to protect the face and jaw, which is essential for high-speed or high-impact riding like downhill. Choosing between them comes down to the risk level of your riding and how much protection you want to prioritise.

Are convertible mountain bike helmets worth considering?

Convertible helmets offer a removable chin bar, allowing you to switch between open-face and full-face configurations on the same ride. This makes them a practical option for enduro riders or those who mix climbing with technical descents and want flexibility. They tend to be slightly heavier than a dedicated half-shell, so they suit riders who value versatility over minimal weight.

How do I get the right fit when choosing a mountain bike helmet?

Start by measuring your head circumference with a tape measure, typically just above the eyebrows and around the widest part of the back of the head. Use this measurement against the sizing guide for the specific helmet you are considering, as sizing can vary between brands and models. A correctly fitted helmet should sit snug and level on your head without rocking side to side or shifting when you move, and the retention system should hold it firmly in place without causing pressure points.

What should I look for when comparing entry-level versus premium mountain bike helmets?

Mid-range and premium helmets typically offer improved ventilation, lighter construction, better fit systems, and additional safety technologies that can improve comfort on longer rides and more demanding terrain. Many mid to higher-end models include MIPS (Multi-directional Impact Protection System), a low-friction layer inside the helmet that allows a small amount of rotational movement on impact, helping to reduce the rotational forces transmitted to the brain in angled crashes. Premium helmets also tend to feature more refined dial-fit retention systems and deeper coverage at the back of the head, offering a more customised fit and added protection for trail and enduro riding.

Related Categories

Helmets $100 and under

Shop for the perfect new helmet from 99 Bikes huge range of Helmets priced under $100. Choose from Mountain Bike Helmets, Recreation and Road Helmets and Kid's Helmets of all shapes and sizes. 99 Bikes offers the best brands; from Bell, Fox, Giro, Met, Pro-Tech, 100% and so many more, all at New Zealand's best prices.

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Kids Helmets

99 Bikes have a wide of kids bike helmets for all children including babies, toddlers, and youth. Shop a wide range of kids helmets including boys helmets and girls helmets in various styles like kids BMX helmets. Our great range of kids helmets bring both safety and fun designs together. When buying a baby or kids bike helmet, the same guidelines apply as if you were buying a bike helmet for yourself - it needs to be comfortable, durable and the correct size. You should also ensure that you choose a helmet colour and design that your child will love to ensure that they’ll want to wear it every time they jump on their bike. You can be sure you're buying the best helmet at the best price with our Best Price Guarantee. Shop online with click & collect and delivery, and in store at your local 99 Bikes in Auckland, Christchurch & Wellington.

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Multi-Directional Impact Protection System

The Multi-Directional Impact Protection System (MIPS) was designed by a Swedish Neurosurgeon to offer the best helmet protection against rotational forces without significantly impacting helmet weight or aerodynamics. This technology is prominent among pro teams, with Australians Richie Porte and Simon Gerrans sporting the innovative GIRO Aether MIPS in recent tours. We stock a range of MIPS Helmets for Men, Women and Kids, with different colours, shapes and sizes for all types of riders.

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Adults Bicycle Helmets

Shop 99 Bikes Extensive Range of Adults Bicycle Helmets for top-quality protection for every type of riding. Featuring a wide range of options, from Casual Sport and Leisure Helmets for everyday comfort to Road Helmets crafted for speed and aerodynamics. For trail enthusiasts, our MTB Helmets and Full Face Helmets offer extra coverage and durability, while Commuter Helmets prioritize visibility and style on urban streets. BMX riders can find high-performance BMX Helmets designed for tricks and stunts. With options to suit every riding style, 99 Bikes has the perfect helmet to keep you safe on all your adventures. Shop in-store and online now with 99 Bikes.

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Road Bike Helmets

Road bike helmets generally feature lightweight aerodynamic designs which help reduce wind resistance and provide ventilation around the rider’s head. Road bike helmets are designed to feature more air vents compared to other helmets such as mountain bike helmets, helping to improve airflow. Shop the best range of road helmets from quality brands. You can be sure you're buying the best helmet at the best price with our Best Price Guarantee. Shop online with click & collect and delivery, and in store at your local 99 Bikes in Auckland, Christchurch & Wellington.

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Recreational Helmets

Shop a great range of Recreational Helmets from the best brands like FOX, Lazer, Met, and more. Shop in-store & online at 99 Bikes

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Full Face Helmets

We have an awesome range of mountain bike helmets from all the best brands at New Zealand's best prices. Full face mountain bike helmets or downhill mountain bike helmets offer added protection to the front of the face while improving overall coverage of riders' heads. Convertible mountain bike helmets convert from half face helmets to full face helmets. You can be sure you're buying the best full face helmet at the best price with our Best Price Guarantee. Shop online with click & collect and delivery, and in store at your local 99 Bikes in Auckland, Christchurch & Wellington.

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BMX & Skate Helmets

99 Bikes have an awesome range of BMX, skate, scooter and bike helmets from all the coolest brands. BMX & skate helmets are generally designed with two things in mind; safety and style. These type of helmets generally aren’t as aerodynamically designed as other helmets, but what they lack in aero efficiency, the make up with good looks at the skatepark. Shop the best range of BMX & skate helmets from quality brands. You can be sure you're buying the best helmet at the best price with our Best Price Guarantee. Shop online with click & collect and delivery, and in store at your local 99 Bikes in Auckland, Christchurch & Wellington.

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