Although there is no legal requirement for riders to wear a helmet, unlike in Australia, it has become the norm for road cyclists to use them. While all helmets essentially serve the same purpose, there's plenty of variation when it comes to fit, weight, ventilation and, of course, price.

If you’re racing then a helmet is required and has been since a ruling was introduced by the UCI in 2003. It therefore makes sense then that if you’re going to buy a new helmet to ensure you get a helmet that fits, meets the relevant safety standards, and suits the discipline you’ll be using it for.

The early hard shell cycling helmets, first launched in the late 1970s, were shunned by riders for a number of reasons, mostly to do with the terrible looks, along with the weight and lack of ventilation that made them extremely uncomfortable. The only form of head protection seen in the peloton in those days would be the minimal leather ‘hairnet’ style of helmet that offered so little protection as to be utterly pointless.

Today hard shell helmets can still be found, mainly used by BMX and dirt jump riders, with the majority of road riders preferring lightweight helmets that have a vacuum formed plastic cover in-moulded to a polystyrene shell. Within this format, there are helmets that cover all budgets and styles, with manufacturers offering options for different types of cycling, from casual riding and commuting through to road racing, time trialling and beyond.

In this buyer's guide, we'll run through the key options when it comes to buying a cycling helmet - otherwise, make sure you check out our video guide above for a closer look at some of the features to keep an eye out for.

RCUK Buyer's Guide - Helmets - EPS liner
Lazer Z1 MIPS Helmet

Featured product: Lazer Z1 MIPS Helmet

Some helmets do everything well and Lazer's Z1 MIPS is a good example of effective protection with a lightweight and well-vented design

Safety standards

Cycle helmets sold in the UK will be required to meet one of two European safety standards, either EN 1078:1997 or EN 1080:1997.

Given that all helmets have to meet these same standards, you would think that the price of helmets would be fairly standardised, too. Of course, this isn't the case, so what do you get for your money when paying more?

Well, like most things cycle-related, the more you pay, the less you get. Simply put, lighter and better ventilated helmets cost more. While this may seem counter-intuitive, it comes down to the fact that manufacturers have to recoup the development costs of creating every lighter and better ventilated helmets that offer the correct levels of protection.

It's worth pointing out, when considering safety, that some manufacturers offer the option of a crash replacement policy - and helmets should always be replaced in the event of a crash. Of course, no-one wants to or tries to crash but, in the case of Lazer, as one example, if you send the importer a picture of the damaged helmet along with proof of purchase you can get a healthy discount on a replacement.

RCUK Buyer's Guide - Helmets - MIPS

What is MIPS?

MIPS, or the Multi-directional Impact Protection System, is a technology that is becoming increasingly common with modern helmets. While no manufacturer is keen to publish hard numbers on the safety of helmets, MIPS is a 'slip-plane' technology said to the reduce rotational forces that can result from certain impacts.

First featuring on the most top-end helmets and now trickling down to more affordable models, MIPS is easily spotted by the yellow plastic inner shell between the expanded polystyrene and the helmet padding. The yellow MIPS liner rotates individually of the rest of the helmet in order to more effectively dissipate forces from a crash.

RCUK Buyer's Guide - Helmets - sizing

How to find the right fit

When it comes to purchasing a helmet, actually going to a shop and physically trying the various makes and models on is the only real option if you want to get the correct fit. While we all look roughly the same, our heads vary significantly in shape and size, and not all helmets suit all heads.

You may well have measured your head and know what size you theoretically want, but the measurement of the circumference of your head is not the only thing that needs to be taken into account when choosing a helmet. Different manufacturers make helmets that are different shapes. Some will produce helmets that are spherical while other will have shells that are more oval in shape. The only way to know which make suits your head is to go to a store and try a selection on.

"The importance of a good fit can't be overstated, as anyone who has ridden wearing an uncomfortable helmet will vouch for. Take the time to try on a number on options at your local bike shop"

You know you’ve got the right shape when you put a helmet on that has a snug but not tight fit all-around, with no pressure points at the edges. While you may not be able get a helmet that is an exact fit, moving the internal padding around the perimeter can help to get the fit just so. Naturally, the retention system, while we'll come on to, also plays a big part in getting a secure fit.

The importance of a good fit can't be overstated, as anyone who has ridden wearing an uncomfortable helmet will vouch for. Take the time to try on a number on options at your local bike shop.

RCUK Buyer's Guide - Helmets - fit
Lazer Tonic Helmet

Featured Product: Lazer Tonic Helmet

Just 5g heavier than the top model in Lazer's range for just a third of the price, the entry-level Tonic helmet covers all the basics in a competitive package

Retention system

Since modern helmet designs were first introduced, the way they stay in place on the rider’s head has subtly changed.

Originally, it was down to the straps that travel down in front of and behind the ears and meet below the chin to keep the helmet on. Today on most helmets it’s standard to get an additional retention system which can be adjusted to fine-tune the fit.

There are a number of variations when it comes to the design of retention systems and how they are adjusted, but essentially they all work by pulling together what is essentially an adjustable webbing system across the back of the inside of the helmet. Either way, what you should look for in a retention system is something which can be easily adjusted with one hand while on the move.

More complex systems (often on more expensive helmets) will also feature some kind of height adjustment, again allowing you to get the perfect fit for your head shape. Finally, if you ever ride with a cotton cap or skull cap, it's worth seeing whether you can comfortably fit one under the helmet and retention system.

For most riders, what retention system works for you is simply down to personal choice, but for those with long hair it can be a deal breaker as some won't work if you have a ponytail. Once again, it’s a case of try before you buy if you have long hair. Even if you don’t, it’s advisable to visit a store to get first-hand experience about how the system on the helmet you choose works and how it should feel when you have the helmet on.

RCUK Buyer's Guide - Helmets - Strap

Weight

Like all things in cycling, when it comes to getting the lightest possible helmet you have to spend more - often lots more.

In theory it should be easy to make a very lightweight cycling helmet - after all, most are essentially just a large chunk of expanded polystyrene (EPS) with holes cut through it. However, while the EPS is a very good material for absorbing impacts, it has a tendency to also split when hit hard - for this reason, modern helmets have an in-moulded, hard plastic shell, and straps that run through the helmet’s interior to hold it all together and this is where the weight starts to get added.

"Although as a general rule of thumb helmets will get lighter with a larger financial outlay, the differences are often negligible"

Although as a general rule of thumb helmets will get lighter with a larger financial outlay, the differences are often negligible, with some more affordable helmets occasionally coming within touching distance of the top models (or sometimes even lighter) as a result of fewer bells and whistles, even if the construction techniques aren't as advanced.

The £49.99 Lazer Tonic (claimed weight 230g) is a good example of that. It carries just a five gram weight penalty over the £149.99 Z1 helmet (225g). In real world terms, that's a difference of roughly one carbon headset spacer. Of course, you don't want to feel like your helmet is made of lead, but once you reach a certain weight and price, unless you want bragging rights there are significantly more important aspects of helmet design to worry about than weight.

RCUK Buyer's Guide - Helmets - Aerodynamic
Lazer Bullet MIPS helmet

Featured product: Lazer Bullet MIPS Helmet

If speed is your thing, an aerodynamic helmet like the Lazer Bullet MIPS will help you cut through the wind with more efficiency

Aerodynamics

Most riders will be familiar with the extreme aerodynamic helmets favoured by time trial riders; usually teardrop-shaped and free from vents. The lack of vents may improve air flow over the helmet but it does nothing for comfort on a long ride.

However, aerodynamics is also starting to make its presence felt in helmet designs for road racing and committed club cyclists.

The main feature of aero road helmets that have started to appear on the market in recent years is a lack of vents; not the complete lack seen in TT helmets but enough to direct airflow over the helmet rather than through it.

These aero road helmets first came to prominence when Team Sky were seen wearing aerodynamic headwear outside the realms of a time trial, but things have evolved since then and the focus for manufacturers now is to produce a helmet which gives the rider an aerodynamic advantage without sacrificing ventilation. The R&D time put into developing these helmets, as well as the advanced manufacturing techniques, means they're not cheap.

For those riders who want a helmet that can function as a regular or aero design then there are choices such as Lazer’s Z1, which has an optional aero shell to cover the vents and increase aerodynamics, but you're not going to get any air flow through there (that said, it's also good for keeping your head warm in winter). Alternatively, the Lazer Bullet is a dedicated aero road lid that features a sliding vent system, so the option is always there to boost aerodynamics or let a little air in (because it's still not going to be as well-vented as a conventional helmet).

RCUK Buyer's Guide - Helmets - Ventilation

Ventilation

We've already talked about how less helmet means more money, and how more vents (again, normally for more money) can mean a reduction in the aerodynamics of a helmet. However, there's more to a helmet’s ventilation than simply how many holes it has in it.

You might think that the more open a helmet is, and the larger the vents, the more air can flow through it. However, helmet designers don't just concern themselves with the number of vents on the exterior - good helmet designs will have channels cuts into the polystyrene that are there to pull and direct air flow through the helmet and over the rider's head; the constant flow taking away excess heat.

RCUK Buyer's Guide - Helmets - Padding

Padding and other features

Providing you've got the right shaped helmet in the right size you should only need to use minimal padding to get the helmet comfortable. If you need to use really thick pieces of padding, the helmet could well be the wrong size or shape. 

The padding should be easily removable and washable. Velcro is usually used to hold it in place and this means it can easily be taken out and washed when needed. You do remove the padding and wash it on a regular basis, don’t you? You should because not only does the padding serve to make the helmet that little bit more comfortable, it will also soak up a lot of sweat.

Finally, here's one other feature to look out for. Although not a common sight yet, a trend that is beginning to appear is lighting built into the helmet’s shell. It's doubtful the idea will go mainstream just yet as the market currently demands low weight and the addition of the LEDs and associated batteries does nothing for that, but it's an option for safety-conscious riders who always want the option of illumination.