How to Choose a Bike Helmet

senior couple with bike helmets

How to Choose a Bike Helmet

How to choose a bike helmet? This question had never crossed my mind until one evening last January. I was on my mountain bike when an over-enthusiastic driver drove past me, causing me to lose my balance.

The next thing I remember is that I was face down. While there was no blood on or around me, I was feeling light on the head.

This scenario left me with no choice but to invest in a new helmet. Thanks to my recent brush with my own mortality, I did all I could to know more about helmets. Now I’m going to share that information with you so that you, too, would stay safe on your bike.

Looking for the Best Bike Helmet? Here’s My Top Five Picks

Why You Must Wear a Bike Helmet

Each year more than 800 bicyclists are killed and more than half a million end up in hospital emergency rooms in the US. More than 2/3rds of those killed have head or face injuries. And head injuries are a leading cause of disability, too, forcing the survivor to seek long term medical care.

Wearing a helmet could save you from becoming one of these statistics. To manage the impact of the crash, a helmet spreads the impact’s force over its surface area. This way, it makes sure that the impact isn’t concentrated on one area of the skull. That’s not all.

A helmet saves you from head injury by preventing direct contact between the impacting object (such as the road surface) and the skull. These three functions (managing the impact, distributing the impact’s force, and preventing physical contact) helps helmets reduce the risk of head injury by up to 85%.

That’s not all. Researchers in Michigan, USA have found that wearing helmets reduce hospital costs among accident victims by as much as 20%. On average, patients who were wearing a helmet at the time of crash had to pay about $6,000 fewer than those who were riding bare-headed.

How to Choose a Helmet?

The first thing you should do is to ensure that the helmet fits you properly. Apart from ensuring your safety in a crash, a properly-fitted helmet will also be more comfortable to wear. Here’s what you must to do make sure the helmet fits you properly.

Measure your head circumference. Wrap a measuring tape around the biggest portion of your head – preferably around your temples. Note down the reading in inches and then use the list below to choose the right size helmet for yourself:

  • Go for an extra-small helmet if your head circumference is between 18 ½” – 20 1/8”
  • Choose a small helmet if your head circumference is between 20 1/8’’ – 21 2/3’’
  • Opt for a medium helmet if your head circumference is between 21 2/3’’ – 23 1/4’’
  • Select a large helmet if your head circumference is between 23 ¼’’ – 24 4/5’’
  • Pick an extra-large helmet if your head circumference is between 24’’ – 25 3/5’’

How Do You Know If a Helmet Fits?

  • Once you buckle the chin strap, the helmet should provide a comfortable but snug fit. You shouldn’t be able to tilt it sideways or up and down.
  • The helmet should rest low on your forehead. It should also sit level on your head and its front-edge should be 1’’ – 2’’ above your eyebrows.
  • You could see the very edge of the helmet by looking upward. Its straps should form a “Y” that joins at the bottom of both earlobes.
  • There should only be room for one finger between buckled chin strap and the chin. Upon opening your mouth, you must feel the helmet imposing force on your head.

How to Adjust a Helmet?

  • Start by adjusting its tightness. Most helmets come with an adjustment wheel. You can open it fully to adjust the helmet until you get a comfortable fit.
  • Next buckle and tighten its chin strap. Make sure that the straps are forming a V under each earlobe. If they aren’t or the V isn’t comfortable, tighten or loosen the chin strap under both ears until the straps do.
  • Open your mouth wide. Upon opening your mouth wide, the helmet should impose a downward force against your head.

What are the Types of Helmets?

Here are the two common types of bike helmets:

Full-face helmets

Full face helmets provide facial protection as well as impact protection. You can identify them by their outward-extending chin bar, meant to wrap around your chin and jaw area. These helmets also have a vision/visor port above the jaw.

Their visor, which is mostly made of glass, allows the bike rider full range of sight. You can count on it to meet the requirements of vertical and peripheral vision. It also keeps bugs, dirt-laden air and debris out of your face. You can also tilt the visor up to drink something with a straw.

The added protection they afford to their users is the reason why full-face helmets bring fatalities down by as much as 29%. Besides, you also stay safe from harsh elements like wind, rain, hail and dust storms, all of which could jeopardize your smooth riding.

On the flip side, these helmets might not be the preferable choice for anyone wearing glasses. The condensation at the visor’s surface, when added together with the moisture on your glasses’ lens, might force you to wipe both the surfaces every few minutes.

Pros Offer facial protection as well as impact protection. Visor provides the wearer with maximum line of sight. Protect the chin and jaw area.Cons Not the most comfortable choice for anyone wearing glasses. The helmet’s interior might get too hot in the summer.

Open-face helmets

Open-face helmets come with a crushable inner liner and a hard outer shell. This allows them to provide the wearer with standard protection from impact. They are much lighter than their full-face counterparts and give you a wider-range of view, too.

Yet another fantastic thing about these helmets is they help your face stay visible. You won’t have to detach the hook and take off the helmet to fill up at service stations or enter establishments that require passersby to reveal their identity by showing their face.

Open-face helmets help you feel cooler and make you look much cooler, too. The same cannot be said about the close-face helmets which tuck your face away behind an outer shell and a visor. Those of you who want to impress others with their looks would do well to go for these.

That’s where the good news ends for open-face helmets’ fans. These helmets won’t protect your chin and jaw area. Neither will they afford much protection to your face. The absence of a glass visor means you’d have to wear glasses to protect your eyes and a face mask to protect your face from dust, rain, etc.

Pros Much lighter than full-face helmets. Help you stay cool by allowing greater passage for air. Give you an ultra-wide range of view.Cons Won’t protect your face from the impact. May require you to wear glasses and face mask.

What are Bicycle Helmets Made of?

Bike helmets are made of an outer shell and inner crushable liner. While the outer shell is made of Acrylonitrile Butadiene Styrene (ABS), Poly Propylene (PP), Poly Carbonate (PC), or fiberglass, the inner shell is made out of Expanded Polystyrene (EPS) or, in rare cases, Expanded Polypropylene (EPP).

Here’s how each of these materials fare when compared with each other:

Outer Shell

  • Acrylonitrile Butadiene Styrene (EPS): ABS plastic has high tensile strength, is incredibly resistant to physical impacts and can withstand adverse environmental conditions. It can resist scratches as well. On the flip side, ABS has poor UV resistance.
  • Poly Carbonate (PC): Polycarbonate helmets cost more than their ABS counterparts and can get scratched easily, too. However, they have better UV-resistance, extremely high impact resistance and can work down to as much as -40*C.
  • Fiberglass (FG):  Fiberglass helmets are much stronger than ABS or polycarbonate helmets. Surprisingly, they are much lighter as well. Their main drawback is that they are prone to cracking on impact, meaning you’d stay safe but would need a new helmet.
  • Poly Propylene (PP): Poly propylene helmets have a semi-crystalline nature that imparts them with high strength. They’re also very resistant to moisture, have good fatigue resistance and good impact strength. But they’re also susceptible to UV degradation.

Inner Foam

  • Expanded Polystyrene (EPS): EPS inner liners compress during an impact, ensuring that the brain experiences as few deceleration forces as possible. However, once compressed in an impact, an EPS liner won’t re-expand. So you must discard the helmet.
  • Expanded Polypropylene (EPP): EPP foam looks similar to EPS liner but there’s one difference between both. This foam rebounds after impacts and can thus withstand multiple impacts. However, it’s much pricier than EPS and not as commonly available.

Pro Tip: Make sure you invest in a liner with a Multi-Directional Impact Protection System (MIPS). Helmet with MIPS have a low friction layer separating the outer shell from the inner liner and the MIPS can move 10 to 15mm in relation to the helmet in the event of an accident, preventing brain damage.

What Features to Look for in a Bike Helmet?

  • Sizing adjustment wheel: Don’t want to get a helmet that would wiggle sideways or up/down when you wear it? Then you might want to invest in a helmet with a sizing adjustment wheel on its back.
  • Carefully engineered vents: Helmets with no vent holes tend to be less expensive because they are easy to manufacture. However, they’re difficult to wear because they tend to get hot on long rides.
  • Vent mesh guards: Decided to act upon our advice? Then make sure your helmet’s vents are guarded by mesh coverings. Those that will allow air to pass through but keep tree debris and bugs out.
  • Impact Protection: Helmet manufacturers that provide added protection use either MIPS or SPIN to provide the same. Both these systems work differently to achieve the same objective: protecting your brain from serious injury.
  • Light-colored appearance: Think the helmet’s appearance doesn’t matter? Think again. The World Health Organization has found that white helmets reduce the risk of crash by at least 19% when compared with dark-colored helmets.

How to Care for Bike Helmet?

  • Store it in a cool, dry place: Helmets should never be stored in extreme heat, which means you must avoid tucking them away in your car’s boot. The temperature inside the boot can reduce the helmet’s ability of absorbing impact.
  • Don’t expose your helmet to chemicals: The outer shell and inner foam on a helmet can be damaged by exposure to certain chemicals such as ammonia or bleach, which could possibly degrade the helmet’s materials.
  • Replace it after a crash: Even the best bike helmets are designed to withstand a single impact. One. This means once you’re in a crash, you must buy a new helmet and trash the old one.
  • Don’t accessorize your helmet: Steer away from the temptation of mounting an action camera on your bike helmet. In the event of an injury, the camera could focus the impact’s force to your head, increasing the risk of a fatal injury.


Finding the right bicycle helmet might not be the sexiest topic, but it is certainly one of the most important.

A bike helmet is one of those things you never truly appreciate until you actual find yourself in a crash, like I did. I hope this guide helps point you in the right direction to find the perfect bike helmet for your safety.

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