Posted in Cycle

The proverbial ‘lid’ is now an accepted and even desirable aspect of the cycling uniform. No longer just a protective cycling accessory, it has been radically redeveloped over recent decades, using next-generation materials, frontier-pushing aerodynamics, and top-tier technologies.

Far from the once clunky necessity of old, modern helmets are slick, technically sophisticated, and stylish. In this guide to cycling helmets, we look at the latest styles, features and materials, and how they've been used to create ground-breaking protection for the modern rider. 

How to choose the right cycling helmet for you

The variety of styles, sizes, purposes, and features can be bewildering for those seeking to buy a bicycle helmet, so we’ve set out a complete guide to help you make an informed choice.

Firstly, you’ll need to find your size, which can be done using the charts below. We’ve also explained the various features and safety elements of modern cycling helmets. Finally, we’ve outlined which helmets are best suited to the style of cycling you’re doing.

After that, all you need to do is work out your budget and buy accordingly.

How to find what helmet size you need

Finding the right size of helmet for you is easy and can be done alone in under a minute. Simply use a measuring tape, starting around 2.5cm (about an inch) above your eyebrows on your forehead. Now measure the complete circumference of your head, keeping the tape measure level and above your ears – use a mirror to check it’s straight.

This is the widest part of the head and the measurement on which helmet sizes are based. Ensure the tape measure is a close fit and redo the measurement a few times to ensure the result is accurate. Finding a perfectly fitting helmet is important for the helmet’s effectiveness during an impact and for general comfort. 

Once you have your measurement, use the tables below to establish the size you need to order. These measurements are a rough guide, so be sure to consult the size guide before you buy on the Wiggle product page. 

Metric X Small Small Medium Large Extra Large
Head Circumference 47 - 51cm 51 - 55cm 55 - 59cm 59 - 63cm 61 - 65cm
Imperial X Small Small Medium Large Extra Large
Head Circumference 18 1/2" - 20 1/8" 20 1/8" - 21 2/3" 21 2/3" - 23 1/4" 23 1/4" - 24 4/5" 24" - 25 3/5"

Anatomy of the bike helmet

There are many elements to the modern bike lid, with quality helmets tailoring their components, shapes and features specifically for each discipline.

Key features to consider include:

  • Ventilation – the design, number, and volume of vents
  • Retention system – style of strapping on the rear of the helmet to keep it in place
  • Chin strap – keeps the helmet on and in a fixed position. 
  • Padding – the amount of padded material in the inner lining of the helmet. Removable padding allows you to wash in inner material, which can be important for hygiene purposes
  • Weight – especially important for competition helmets
  • Reflectivity – to help riders, especially commuters, be seen at night
  • Impact protection – several technical solutions exist, including SPIN and MIPS. These are explained in more detail below
  • Visor – Some helmets, particularly those for MTB, come with removable peaks or visors. A visor on a bike helmet serves two purposes, shielding the eyes from the sun and stopping rain accumulating on goggles or glasses
  • EPS liner - The bulk of the helmet that crumples and deforms to absorb the shock of impact. This can be made of expanded polystyrene or even carbon fibre
  • Carapace - The outer hard shell which protects the EPS liner

How do I know if I need to replace my cycling helmet?

A helmet must be replaced immediately if you are involved in a collision or if it is dropped with enough force to cause structural damage. Keep a lookout for signs of ageing or wear and tear, which can cause internal weaknesses in the helmet that may not be visible.

Some manufacturers, such as Giro and Bell, offer helmet replacement schemes. Meanwhile, Wiggle is the official replacement dealer for KASK helmets. Visit our KASK Warranty page for more information

Ageing or damage will mean the helmet may not perform well in an impact situation.

How your cycling helmet should fit

Your helmet should allow for good all-around vision as well as protection.

The upper straps should form a ‘V’ shape just beneath the ear, and with the helmet on, you should not be able to fit more than two fingers between the chin strap and your chin. The buckle and chin area of the strap should fit close to the underside of the chin once fastened, but allow you to open your mouth to eat an energy bar or drink water from your bottle.

There should also be a maximum gap of around two finger widths between the front of the helmet and your eyebrow line. 

Helmet safety features

As mentioned earlier, advanced research in the industry has led to the creation of new helmet safety features. Below is some additional information on the latest advancements, which you may want to consider before choosing your helmet.


MIPS stands for Multi-directional Impact Protection System. It is described as ‘slip-plane’ technology and works by reducing rotational forces that can result from certain impacts.

See our full description on the MIPS system

Shop MIPS Helmets at Wiggle

MIPS Spherical

For their new Aether MIPS, Giro has developed a new standard of advanced protection. MIPS Spherical embeds the MIPS liner between layers of EPS foam so it doesn't sit directly against your head. This means comfort and cooling power is not compromised. 

Introduced by helmet specialist POC, SPIN was developed to counter the effects of oblique impacts. The system uses pads on the inside of the helmet that help the head continue to rotate during impact, lessening the forces on the brain.

In contrast to the post-impact support of MIPS and SPIN, SMART helmets are designed to stop impacts before they happen by ensuring you’re seen by traffic and other riders. LIVALL is one of the leading manufacturers of this tech, and you can find out more by watching the video below.

Shop SMART Helmets at Wiggle

Depending on your country, cycling on the road or competing in a race may legally require the wearing of a helmet certified to a specific standard or an international equivalent. All helmets sold on Wiggle are certified, labelled with a European CE EN1078 standard sticker, and comply with a range of international standards. If you live in the US, your helmet should conform to the US Snell B90/B95 standard, while Australians should ensure their helmet meets the AS/NZS 2063:2008 certification.

What type of helmet do you need?

Bicycle helmets are specifically designed to suit your riding style and discipline, whether that’s casual commuting, aggressive downhill riding, or searing aero speed cycling.

We’ve looked at some of the most popular cycling disciplines and the type of helmet best suited for their unique demands.

This should help you to choose the best lid for your purposes. And if you’re buying for a child, we have advice that should help you too.

How to find the best road riding helmet

Road cycling helmets are designed to be lightweight and offer an aerodynamic advantage for riding long distances. They are often built with versatility in mind and can be used in a variety of disciplines, such as cross-country riding. Road bikes also feature numerous vents to allow heat to escape during exhaustive rides or uphill climbs. Elite level helmets use ultra-light materials and offer great ventilation and protection.

Kask Mojito X Road Helmet

New and improved, the Mojito X is Kask's most comfortable flyweight helmet ever. The original was permanently a best-seller at Wiggle and this version, updated with cutting-edge technology, looks set to follow suit.

  • Made with INMOLD technology for extra durability without extra weight
  • Removable padding treated with antibacterial and antimicrobial finishes for freshness
  • 26 large vents keep your head cool 

Shop road helmets at Wiggle

How to choose the best aero helmet

Aero helmets bridge the gap between everyday road helmets and the elite time trial helmets. Designed to reduce drag while providing ease of movement, these lightweight and compact helmets are perfect for triathlon entrants, or competitive road cyclists.

POC Ventral SPIN Helmet

With an aerodynamically optimised trailing edge, the POC Ventral SPIN helmet helps limit turbulence for your smoothest ride yet. Utilising a longer linear airflow off the helmet and the rider, travelling fast should be your only priority.

  • Accelerated airflow design
  • Extreme cooling and ventilation
  • Lightweight with comprehensive size adjustment for comfort

MET Trenta Road Helmet

Designed for optimum aerodynamic advantage and super-cool comfort, the MET Trenta delivers pro-level performance for road cyclists who want to get the most out of every ride.

  • 19 vents designed for supreme cooling without adding drag
  • Works well with ponytail
  • Hand washable air mesh comfort pads

Shop Aero Road Helmets at Wiggle

Choosing the best time trial helmet

Time trial helmets are at the cutting edge of aerodynamic engineering. Designed for slicing seconds off a crucial race time, their core purpose is to give you a winning edge along with protection against a high-speed impact.

Giro Vanquish MIPS Aero Helmet

Giro Vanquish MIPS Aero Helmet

One of the most technologically advanced road cycling helmets on the market, the Giro Vanquish MIPS Aero is filled with features to streamline airflow for reduced drag and increased aero. 

  • Integrated MIPS technology
  • Magnetic Vivid shield
  • Wind tunnel ventilation

MET Drone Wide Body Helmet​​


Rigorous wind-tunnel testing has proven that the MET Drone Wide Body can deliver a saving of 10 watts at a speed of over 50KPH. One for the real speed-freaks. 

  • Internal air channels keep the head cool without sacrificing aerodynamics
  • Eyeshield held in place by powerful, low-profile neodymium clips
  • MET Safe-T Advance fit system delivers incredible comfort

Shop Time Trial Helmets at Wiggle

How to pick the best SMART helmet

SMART helmets come with in-built technology that alerts other road users to your presence and intentions. Especially effective on the road, the helmets are favoured among regular commuters.

Livall MT1 MTB Smart Helmet

Utilising wireless technology and intelligence, the MT1 Smart Helmet is designed to incorporate smartphone and Bluetooth technology, defining helmet innovation.

  • Make hands-free phone calls
  • Music player via smartphone connectivity
  • Taillight with LED turning signals

Shop SMART Helmets at Wiggle

How to pick the best commuter or leisure helmet for you

Leisure helmets tend to weigh style over substance, but good quality examples still offer excellent protection and top-tier features. Many riders will also simply opt for a good standard road helmet or even an open-face MTB option.

Giro Cormick Helmet (MIPS)

A great-looking lid for riding about town, the Giro Cormick is available in hi-viz yellow, as well as more subdued grey and black.

  • MIPS technology for additional protection against rotational impact
  • Easy-to-use Roc Loc sport-fit system for customizable comfort
  • 18 vents encourage air-flow

Shop Commuter Helmets at Wiggle

Helmets for the trail:

How to pick the best open-face mountain bike helmet

Mountain bike helmets offer protection in place of aerodynamic considerations, giving you extra coverage, and durability to meet the needs of the trail.

Fox Racing Dropframe MTB Helmet

Fox combine improved coverage with unparalleled ventilation to bring you the Dropframe MTB Helmet. Varizorb™ EPS tech within the liner spreads the energy created in an impact so you have the confidence to shred the trail as aggressively as you like.

  • Fidlock Snap magnetic buckle
  • Varizorb™ multi-density EPS
  • 8 Bog Bore intake vents plus 7 exhaust vents.

Oakley DRT5 Helmet

Boss the trails with Oakley's do-it-all DRT5. MIPS® technology delivers extra protection from rotational impact and a BOA® FS1-1 360-degree system gives you complete control over the fit. 

  • MIPS® Brain Protection
  • Innovative sunglasses stowing mechanism
  • X-Static® silicone sweat-wicking brow pad

Shop MTB Helmets at Wiggle

Full-face MTB helmets

Full-face MTB helmets are favoured by Enduro and downhill riders for their important face-protection qualities.

Bell Full-9 Fusion MTB Helmet (MIPS)

The Bell Full-9 Fusion MTB Helmet (MIPS) is specifically designed for off-road riders who relish the challenge of changing terrain. The overbrow ventilation and air-channel matrix mean you'll stay cool even on long climbs.

  • Ten helmet vents plus three brow ports
  • MIPS-equipped
  • Fibreglass shell

Fox Racing Rampage Pro Carbon Beast Helmet

Equipped with groundbreaking Fluid Inside technology to better protect against both linear and rotational impact energy, the Fox Racing Rampage Pro Carbon Beast Helmet keeps your head protected so you can concentrate on the ride. 

  • Magnetic Visor Release System (MVRS) releases in the event of a crash
  • Advanced in-mold Varizorb™ EPS balances weight & performance
  • Chinbar/eye port CAGE™ improves energy management of chinbar

Shop full face MTB Helmets at Wiggle

Picking the best XC helmet

While the less technical cross-country trails pose less of a risk of a high-speed fall, the greater demand on your stamina means you need much better ventilation to stay cool throughout an event.

IXS Trail RS XC Helmet

IXS Trail RS XC Helmet

The Troy Lee Designs A2 Decoy MIPS MTB Helmet sets a new benchmark for mountain bike helmets, providing optimum impact protection without compromising style, comfort and ventilation. If you love single-track, dirt jumps or XC, this one's for you.

  • Break-away anodised aluminium visor screws
  • Low profile fixed strap dividers for a no-fuss fit
  • High-performance odour protection

Troy Lee Designs A2 Decoy MIPS MTB Helmet

Troy Lee Designs A2 Decoy MIPS MTB Helmet

Providing every technology you need to tackle the trail. The lightweight Trail RS XC Helmet from IXS is highly breathable and provides a personalised fit for those putting comfort first.

  • InMould technology
  • External and internal vent channels with 19 openings
  • Snap-on removable visor

Shop XC Helmets at Wiggle

How to pick the best BMX helmet for you

BMX helmets also feature full face and open face. Full face helmets are more likely to be worn during BMX racing, while open face (skate style) helmets are more common on flatland riding and dirt jumping.

MET YoYo Helmet

MET YoYo Helmet

Take your tricks to the next level with the support of a MET YoYo Helmet, the ideal BMX protection for doing ripping up the urban scene.

  • ABS polymer outer shell
  • Strong fit straps
  • Anti-pinch chin strap

Shop BMX Helmets at Wiggle

Choosing the best kids helmet

Wiggle’s range of helmets for kids and youths feature industry-leading safety standards and come in a variety of colour schemes designed to encourage their use.

Giro Scamp Kid's Helmet

Giro Scamp Kid's Helmet

Good things can come in smaller packages sometimes: the Giro Scamp Youth Helmet offers grown-up protection for younger cycling heads.

  • Built-in visor
  • Pinch-guard buckle
  • Ponytail compatible

Kiddimoto Union Jack Helmet

Designed to form a lasting relationship with the trail, the Kiddimoto Union Jack Helmet strikes the perfect balance between style and safety to keep the little one protected.

  • Adjustable straps
  • Internal comfort padding
  • Rear wheel adjustment

About the author

Damien Whinnery's picture
Damien Whinnery
Published on: 23 Sep 2019

Fascinated by fitness, serious about sport, and joyous about the gym