Helmet Buying Guide

Helmet Buying Guide

A bike helmet is designed for one primary purpose, to protect your head from injury in the case of accident. Whilst it is not a legal requirement in the UK to wear a helmet at all times, it is advised and we recommend you wear a helmet at all times you are cycling. You can replace the bike but you definitely only get one head. Beyond the basic function of protection from injury, helmets are then designed with other critical functions in mind. These include comfort, ventilation and aerodynamics. Some of the technologies employed in helmet design are genuinely leading edge.  Plus, it’s a fast moving world so it is important to make sure you are buying the helmet suitable for the type of riding you are going to be doing.

The good news is that Criterium Cycles sells a wide range of helmet styles and types from some of the world’s leading brands. So whatever kind of riding you are planning and whatever your budget, we will have the helmet for you. Check out some of the most important factors to be taken into consideration using this Criterium Cycle Helmet Buying Guide.


When you are considering a new helmet, you may wish to consider that one of the challenges with traditional helmets is that they are not fully effective in protecting you from angled impacts. Angled impacts can cause violent accelerations leading to increased rotational forces on the brain. This can lead to diffuse axonal injury, one of the major causes of unconsciousness and in some cases, permanent brain damage. There is however a technology that has been shown to address this issue with considerable success. It’s called MIPS (Multi-directional Impact Protection System). You can read our detailed blog on helmets and MIPS by clicking here.

MIPS is designed to mimic the brain’s own system for protecting itself from trauma. MIPS provides a liner, separate from the shell of the helmet but connected by a low friction layer. When a MIPS helmet is subject to impact, the low friction layer allows the helmet to slide relative to the head. The result is a helmet which reduces rotational acceleration on the brain by nearly 40% without impacting adversely on the energy-absorbing properties of the helmet overall.

Helmet Fit

If the most important priority is to have a helmet in the first place, the next most important thing is to have one that fits properly. This is really important for your safety. If the helmet is moving about on your head it is not protecting you as it should. It will then prove a real distraction, itself a safety concern.

To measure your head correctly, you will need a measuring tape (and possibly a friend or colleague to help!). Measure the circumference of your head by measuring horizontally around your forehead. Do this roughly 1 inch (2.5cm) above your eyebrows. Make sure you keep the tape measure both level and a close fit. Make sure as well that you stay above your ears which helps keep the tape measure level. We often find that taking three measurements and then the average of the 3 helps remove any measuring error in one.

Some manufacturers produce womens’ specific designed helmets which often have a slightly different internal sizing. On our website, you will see those helmets that are specifically designed for women in the product description.

Natalie Milne demonstrating a correctly fitted cycle helmetThis picture of Natalie Milne, the Team GB Triathlete sponsored by Criterium Cycles, demonstrates a well fitted helmet. The straps should form a v-shape with the internal angle of the V just below the ear. If correctly fitted, you should only be able to fit two fingers between your chin and the chin strap. More than that, and it’s too loose. It should feel close fitting but not uncomfortable or biting into your chin.

Helmet Types


Whilst designed primarily for road cycling, these helmets can really be used for all types of cycling. This means they are a good, all round solution. Some helmets come with advanced internal mounting systems that ensure a constant fit around the head. Others focus on lightness and aerodynamic performance. Within the product description for each helmet you will be able to find a summary of the technical features.


Mountain Bike helmets tend to focus less on lightweight / aerodynamic performance (though that is still important) and more on protection recognizing the challenges of trail and off road riding. Peaks on the front are usual features and some helmets come with full face protection. This ensures the lower jaw / chin area receives optimum protection.

Urban Commuter

These helmets are specifically designed for use in the city / urban environment. They tend to do without many of the ventilation systems of more advanced road and mountain bike helmets. This is because they tend to be used for shorter, less physically demanding rides. However, the focus is still very much on safety and protection.


It is really important to get kids to start wearing a helmet at the earliest age possible as it teaches good habits! We stock a wide range of kids’ helmets in some pretty wild colour schemes so that they can look really cool as well as stay safe.

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