Unlocking the anatomy of the certified motorcycle helmet

Two motorcycle helmets locked with motorcycle tail frame

 Brain injury is one of the most usual causes of human deaths in motorcycle accidents.

Use of a certified motorcycle helmet can reduce the possibility of severe brain injuries due to its unique design for provision of protection against the impact with hard surfaces. Therefore, a helmet is the best measure against life-threatening injury when driving a motorcycle.

Functions of a motorcycle helmet

  • Protection to head and face in case of impact with hard surface
  • Prevention from hitting the bugs, rocks, and trash of all sorts in the face (at high speeds).
  • Protection from dirt and grime which would otherwise coat on the face while riding on muddy roads.
  • Reduction of riding fatigue
  • Protection to face from stinging raindrops during monsoon rides
  • Reduction in the volume of distracting noises


Each and every component of a motorcycle helmet keeps riders protected from possible damage to head and face. Knowing the anatomy of a helmet helps to purchase the appropriate new helmet.

(A) Outer Shell

The slender, rigid outer shell protects the head from abrasions and puncture wounds. It is the first line of defense during impact and also helps to distribute the force of impact.

The common types of outer shells are:


This hot plastic is molded to transform into the shell of a helmet. This type of shell might not be as safe as the other helmets unless there is a lot of padding.


This type of helmet is extremely lightweight, but at the cost of fragility. It will break on fall or impact. This mandates these type of helmets for ‘single-use’ only.

Carbon fiber and Kevlar

These materials are extremely strong and lightweight, but expensive.

(B) Crushable lining

“Expanded polystyrene” foam (EPS) is the thick, stiff, lightweight foam on the inner side of the shell. As it absorbs and spreads the energy of impact, it is the most critical component of a helmet in term of protection against brain trauma. Some helmets have just one layer of EPS foam, while a better helmet will have EPS foam layers.

EPS foam is designed to crush thus it limits the amount of force transmitted to the head.

Ideally, a motorcycle helmet provides protection against one crash, and one crash only.

(C) Comfort lining

The padded inner lining surrounds and holds the head and creates the snug, comfortable fit.

Most helmets have a fully-removable and washable comfort liner. Premium helmets can have anti-microbial and moisture-wicking liners that keep things cool and dry.

Cross section of a motorcycle helmet with labels

(D) Cheek Pads

These are generally thought of as part of the comfort liner. They prevent a helmet from rotating off from a front or side impact

High-end racing helmets and motocross helmets have emergency removable cheek pads. This allows first responders to remove a helmet safely without much neck flexion in the event of suspicious upper spine injuries.

(E) Chin strap

The most common closure system is the D-ring system. Some helmets feature a ratcheting system.

One convenient chin strap feature is a button, clip or Velcro attachment to hold the end of the strap after securing a helmet. This feature prevents the tail end from flapping around in the wind.

Never ride without buckling or strapping a helmet

(F) Face shield

It is the windshield through which looking out when riding. It protects from rocks, bugs and other debris that might get flung up. Face shields almost always slide up. It should operate easily and remain in position when raised.

Motocross helmets do not have face-shields, but they have a large eye port to accommodate the goggles which allow more air in and making respiration easier. This is because labored deep respiration might fog up a face shield quickly while goggles seal out rider’s eyes better than a face-shield of any street helmet.

(G) Drop-Down Sun Shield

Some helmets, specifically touring helmets, have internal drop-down sun visors. This allows the rider to flip a tinted sun visor down, instead of wearing sunglasses.

(H) Vents

Front vents bring cool air in, and rear facing vents (exhaust vents) move warm air out. Some helmets feature adjustable vents which can control the amount of airflow or can stop the airflow during cold rides.

Checklist factors

Buying a new helmet is a daunting task for any rider. But always consider these essential features before trying and purchasing a new helmet.


Always consider specific features of every helmet, if any. Because some types of helmets can be used for specific rides only.

Some manufacturers make helmets for specific head shapes while others will produce models to suit different shapes. But minor modification to an internal profile can be done by changing the internal padding to a different size. (Of course at cost of extra money!)


The helmet must be lightweight. But all lightweight helmets are not as protective as expected. Therefore, always buy a helmet which weighs enough to compromise rider’s comfort without compromising the safety of head and face.

Material (Discussed above)

Always buy a helmet with a good, clear, scratch resistant face-shield. Driving a lot underneath the sun would require a polarized face-shield or an interchangeable face-shield. A premium helmet has an internal sun visor which eliminates switching to a dark face-shield while riding in bright light. Injection molded face-shields are optically perfect. While face-shields, bent to the shape of the helmet creates distortions.

Always pay attention to the amount of peripheral vision when the helmet is on and the fogging up of face-shield. Some helmets have an anti-fog coating, otherwise, Pinlock® visor insert can be applied to stock face-shield to eliminate fogging.


A chin vent is a must along with top vents that push air around the head. Rear vents on the lower back of the helmet take the air out.

A helmet with a good ventilation system has holes in the EPS liner which line up with the vent holes in the shell.


In-helmet speakers with Bluetooth® technology can be paired with different wireless accessories. Many such accessories can be clipped to the outside of the helmet at the cost of adding extra wind drag and noise.


The best motorcycle helmet has all essential and premium features to add-on extra comfort at the cost of extra money. This does not imply that a DOT approved less expensive helmet that fits well does provide less security.

But the price of the desired helmet can be reduced by;

Choosing plain helmet instead of graphics

Selecting a similar model of helmet from the same manufacturer with simpler features, e.g. less Elaborative venting system, without space to keep/insert communication device

A used helmet

A damaged helmet might not present any visible marks. Saving a few bucks is not worth the risk of buying a helmet that won’t protect when needed.

Never purchase a used helmet



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