Helmet Buyer's Guide

27th July 2016 in General by Joshua Mott

A good helmet is an essential part of any rider's kit. Read through our buyer's guide to make sure your next helmet is right for you.

The perfect cycling helmet possesses the right balance of coverage, ventilation and comfort. When this equilibrium is found you're likely to forget you are wearing a helmet at all. That is until you require the helmet to perform the task it was intended for when it could be the difference between being able to make it home in one piece and something a lot more serious.

How to Size your Cycling Helmet

Having a correctly fitted helmet is of primary importance. The majority of helmets are sized by head circumference. To measure this, take a measuring tape and measure from one inch above your eyebrows all the way around your head. This should be the widest part of your head, giving you a comfortable and close fit.

How to Size your Cycling Helmet

How to Wear Your Cycling Helmet


When you have the helmet on your head it should sit centrally on your head, extending partially down your forehead to protect your temples.

Helmet guide wrong


A common mistake is having your helmet tilted too far back, leading to less protection for your face in the event of a crash. Your helmet should sit no further than two finger widths away from your eyebrows. Another common mistake (made more often than you would think) is wearing a helmet backwards, which serves no purpose than to give you the appearance of a rhinoceros.

Helmet guide right


The helmet's straps should sit comfortably under your chin; loose enough that you can fully open your mouth comfortable but not so loose that you can pull the strap over your chin. Most helmets, especially more expensive models, will have some form of adjustment dial that will allow you to adjust the helmet's internal fitting to dial in the perfect fit. Your helmet should sit firmly, yet comfortably, in place.

Safety Certifications

Bicycle helmets have to comply with one or more safety certifications. All helmets sold on SigmaSport.co.uk comply with the European CE EN1078 Standard, however, in other areas of the world helmets are legally required to comply with other safety standards. In the US this is the CPSC Standard and in Australia and New Zealand it is the AS/NZS 2063:2008 standard. Before purchasing a new helmet check your specific country requirements and check with the manufacturer to see if the helmet has received any additional certification.

Choosing Your Helmet

Standard Road Helmets

Helmet guide regular

From Left to Right; the Kask Mojito, POC Octal and the Lazer Z1


Your standard go-to helmet that fits all of your everyday usages from commuting to racing. This type of helmet tends to have a lot of vents to help keep your head cool on warmer days. Higher-end models are often exceptionally light, weighing in at around 250 grams.

Uses: Every type of riding from commuting, getting around town and training to high-level racing and sportive riding, especially in hot conditions

Hybrid Aero Helmets

Helmet guide hybrid

The MET Rivale, Kask Protone and the Giro Synthe


A recent addition to the helmet realm, hybrid aero helmets skirt the boundary between standard helmets with their multiple vents, and aerodynamic helmets with their watts-saving drag reduction. These helmets tend to have vents, are usually lightweight and found at the upper end of helmet brands' ranges.

This style of helmet has been in vogue with the pro peloton in recent seasons and you'll see pro riders wearing this type of helmet for all but the hottest of races.

Uses: Training, sportive riding or racing

Aero Road Helmets

Helmet guide aero
The Specialized S-Works Evade, Bontrager Ballista and the Giro Air Attack


A cross between the ultra-aerodynamic profile of time trial helmets and the comfort, size, practicality and versatility of standard road helmets, aero road helmets provide a low drag shell with little or no venting.

By using an aerodynamic shell, aero road helmets reduce wind resistance around your head and this ultimately saves you power (watts). Some aero road helmets, like the Specialized S-Works Evade, claim to save you up to 40 seconds of power over 40km when travelling at 40 kph. While this sounds like a case of marginal gains gone mad, this sort of saving could make all the difference in a close finish line sprint.

Light and compact, these helmets are also becoming increasingly popular with triathletes due to their lighter, more versitile profile when compared to traditional time trial helmets.

Uses: Racing, triathlons and serious sportive riding. Some riders also opt for aero helmets in particularly cold or wet weather as the provide extra protection

Time Trial and Triathlon Helmets

Helmet guide TT
The Bontrager Aeolus and the POC Cerebel Raceday


Time trial and triathlon helmets are designed to provide the wearer with as great an aerodynamic advantage as possible in time-based events. This tends to make them larger than regular road helmets, with little or no venting. To a greater extent than aero road helmets, time trial helmets are designed to provide as great an aerodynamic benefit as possible with less attention paid to weight and practicality.

Time trial helmets often integrate visors or eye shields into the helmet design as a means of further boosting drag reduction.

Uses: Time trials and triathlons

Mountain Bike Helmets

Helmet guide Mountain Bike

The Specialized Ambush and the POC Trabec Race


Mountain bike helmets provide greater coverage, retention and ventilation than road helmets. This often means more coverage around the back of your head and around the temples. They also tend to include a visor for added coverage.

Full face helmets also fall under the banner of mountain bike helmets. These provide the most all-encompassing protection with added protection around your jaw, ears and back of the head. Full face helmets are intended for the riskiest of mountain bike riding like downhill racing and enduro riding.

Uses: Off-road riding

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