In the market for a bike helmet, but not sure where to start or what the difference is between a road and mountain bike helmet? Fret not, BikeRadar is here to help you find the best bike helmet for your needs.
There are lots of reasons to take up cycling, and once you've got your bike sorted, you'll need to get the rest of the essential kit that goes with it. After bikes, cycle helmets are next on most riders' list of important equipment.
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There are many different types of bike helmet, and the price can range from bargain basement to premium, but you don't need to spend a fortune to get a good lid that will help keep your head protected.
Our buyer's guide to finding the best bike helmet will take you through the different types of cycle helmet and what they are good for, what size of helmet you need, and even tell you when you need to replace your old helmet.
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Do I need to wear a cycling helmet?
Different countries have different laws regarding whether cyclists need to wear helmets while on the road.
In the UK, wearing a helmet while cycling is not compulsory at any age, though it is recommended by the Highway Code.
In the US, while there is no overarching law regarding the wearing of helmets, individual states and cities have laws or ordinances regarding the wearing of helmets — some for all ages, but the majority for minors under the age of 18 or 16.
Australia was one of the first countries in the world to introduce compulsory cycle helmet laws, and so wearing a bike helmet is a must.
One area where there's absolutely no debate about whether you should or shouldn't wear a bike helmet is mountain biking. If you are cycling off-road, which is inherently a risky business (that is, after all, partly why we like it so much), then you should be wearing a bike helmet.
Bike helmet features: anatomy of a bicycle helmet
Most bike helmets consist of a number of different parts: an outer plastic shell which can either be hard plastic or softer, flexible plastic, a foam section constructed from several layers to protect and cushion the head in case of impact, a fit system (often adjustable) with a chin strap to ensure the helmet stays securely in place, padding for comfort, and vents to allow air flow through. Some helmets, mostly mountain bike helmets, will also feature a plastic visor.
Certain helmets also feature Multi-directional Impact Protection System (MIPS). Developed in Sweden, this is a safety feature that takes the form of an additional layer that sits inside the shell and around the rider's head, and helps protect the head from oblique impacts.
In the case of such an impact, MIPS allows the helmet to shift a little around the head without moving the head with it, dissipating the twisting forces that can cause injury.
More and more helmets featuring MIPS are available, though there is usually a slight increase in price in such helmets to cover the cost of including the system.
You should also check to see that the bike helmet you are interested in is certified safe. These certifications, some of which are global and some of which are national or regional, act as a quality control mark that denotes the safety, effectiveness and durability of the product, and provide peace of mind that the helmet you have chosen is fit for purpose.
What size bike helmet do I need?
Bike helmets are sized according to the circumference of the head. Cheaper helmets will come in one open size or two sizes, typically small–medium and medium–large.
As the price rises, there are more sizing options, therefore providing a better and more comfortable fit — typically small, medium and large, or variations thereof. Helmet companies will list a range of circumference measurements that work for each size.
If you sit on the cusp of a size, try both sizes on to determine which one fits best. It's also worth noting that the MIPS system makes the fit of a helmet a little bit smaller, so again, if your head circumference sits at the upper end of a size range you might want to go up a size.
The first step is to find the circumference of your head. To do this, get a tape measure and measure around your head about 1cm above your ears and forehead, the whole way around the head.
The helmet should feel secure when on and should not move about when you shake or nod your head. Likewise, it should not fit too tightly; if you feel it digging in, the fit is not right. You must make sure that it's fitted correctly, sitting level across your head, around mid-forehead, with the chinstrap sitting close under your head.
Women's bike helmets
First things first: men's and women's heads are essentially the same shape, with the only differences being that women on average need smaller sizes and women also often have longer hair which can take up more room under a helmet, or need to be styled or tied back in such as way so that it doesn't get caught in the helmet workings.
So while there are women's helmets available, there are no structural or design differences between these and the unisex/men's helmets available, with the main difference being the colours the helmets come in.
That said, there are one or two exceptions. Specialized's women's helmets include what the brand calls a HairPort, where the construction of the fit system allows room for a ponytail to fit through at the back above the adjustable ratchet.
Types of bike helmet
While you can spend generous three-figure sums on a helmet, you can get a decent and certified lid at an accessibly low price. Most bike shops will carry a range of helmets at different price points.
At the entry-level end of the scale, most helmets will be fairly uniform and multipurpose. As you go up in price, helmets become much more specific for different types of cycling, and the various disciplines' comfort and protection requirements.
Skate helmet / park helmet
These helmets tend to have a rugged, simple construction, with a hard outer layer and a foam inner layer, and low coverage over the head. They usually have few or no ventilation holes, so they're fine for hanging out in the park or for shorter commutes, but will get a little hot on longer rides or when exerting lots.
They often don't have a huge amount of fit adjustability, relying instead on using different thicknesses of foam inserts.
Commuter bike helmet
Most bike helmets are suitable for commuting, though you can get ones specifically aimed at commuters and urban riders. These range from basic, vented helmets, through to ones that include integrated lights and even stowable waterproof covers.
Some commuter helmets are styled more like skate lids, with a solid outer layer and few ventilation holes, which has the added benefit of helping to keep the rain off your head if the weather isn't great. Some come with integrated peaks and removable liners, and others even have integrated lights.
Road bike helmet
The focus in the design of road helmets is threefold: to create a helmet that's lightweight, as aerodynamic as possible, and allows plenty of ventilation to keep the rider's head cool. Road cycling helmets tend to sit close to the head with many air vents.
As the price goes up, the weight goes down as a general rule, and the the ventilation becomes more sophisticated with internal channels incorporated to allow air to flow over the rider's head and vents at the rear.
Some road cycling helmets will include features such as slots or magnetic catches to allow you to rest your sunglasses on them, or removable plastic shells to increase the aerodynamic properties of the helmet.
Aero road helmet
Aero in this case stands for aerodynamics, and for certain road cyclists or types of race discipline such as time trial, this is an essential feature.
These helmets tend to eschew ventilation in favour of a smoother profile and have been wind-tunnel tested to reduce the amount of drag they produce.
These tend to sit towards the premium end of the cycling helmet market and most road cyclists would tend to have one of these in addition to a regular road cycling helmet.
Because crashing is pretty much a certainty with mountain biking, trail helmets are designed to provide plenty of protection. Mountain biking is also hard work, so venting is important too.
Trail helmets will often have a thicker shell than premium road cycling helmets, and may sit lower at the back of the head for increased coverage.
Mountain bike helmets tend to have a peak, constructed from a separate piece of plastic, which sits at the front of the helmet to help keep the sun, dirt and branches out of your face. Some also come with optional mounts for attaching lights for night riding or Go Pro cameras for filming the action.
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Enduro or all-mountain bike helmets are similar to trail bike helmets, but tend to offer greater coverage with a deeper shell providing more protection around the base of the skull, and a peak that can be raised to allow goggles to be worn.
The rise of enduro racing, which includes steep and technical descents, has also seen an increase in lightweight full-face helmets such as the Bell Super 2R, with its detachable chin guard, and the MET Parachute. These are lighter weight than downhill full-face helmets, but provide greater protection than just a trail shell on its own.
Full-face / downhill helmet
Essential for downhill mountain biking, and increasingly popular for technical enduro descents, a full-face helmet provides maximum head protection.
Very similar in design to motorcycle helmets, full-face helmets pull on over the top of the head and provide full coverage around the head including a ventilated chin guard.
They'll usually feature a long peak or visor, which is often replaceable in case of damage, and a hook or grip patch to keep the back of your goggle strap in place.
Kids' bike helmets
There are so many kids' helmets available on the market now, including full-face and skate options, that whatever colour, style or pattern your child likes, there'll be a safe and certified bike helmet to suit.
Some kids' helmets even come with MIPS for an added level of protection.
How often should I replace my bike helmet?
If you are involved in a crash, or if the helmet receives a significant blow, then it must be replaced. Even if it looks intact from the outside, there may be cracks internally that can't be seen by the human eye that compromise its safety and effectiveness.
Many helmet companies also recommend that you replace your helmet every few years if it's been worn regularly because the structural integrity of the helmet can degrade over time through wear and tear, damage caused by UV radiation from the sun, and the cumulative effects of little knocks and bumps.
Specialized suggests between three and five years for its helmets, with around three years in Australia to reflect the impact the high UV levels will have on a helmet if it's worn regularly.
So now you know what sort of helmet you're looking for why not check out all our BikeRadar helmet reviews?