When Do Motorcycle Helmets Expire?

Helmet - Cover Page

Do motorcycle helmets expire? Do they have an expiry date? Or we can use them as long as we want?

These are the questions that run through your mind if you are using a helmet which is quite old.

As for when do motorcycle helmets expire, most helmet manufacturers do not mention any expiry date in the helmets. However, helmets face wear and tear, and technology obsolescence. As a general rule, you need to replace your helmet at least every 5 years.

Expiry Date on Helmets

Most helmet manufacturers do not mention any expiry date for their helmets.

As you can check for yourself, there will be no expiration sticker inside the helmet and nor there will be any other type of labels mentioning about the expiry date.

Simply put, if there was an expiry date, the manufacturer is obligated to include a sticker or a warning label that goes something like, “Do Not Use This Helmet After 10 NOV 2025”. Or even a simple, “Exp Date: 10 Nov 2025”.

The absence of such expiry dates implicate that the manufacturer does not believe there is an expiry date to the helmet and it should be working fine throughout its life.

This is a vital piece of information. If there indeed is an expiration date and the manufacturers have chosen to not put any label, this could lead to a huge lawsuit problem for the manufacturers. And no manufacturer would risk such liability.

So, it is safe to assume that the absence of an expiration label in helmets indicate that the helmet manufacturers do not believe in expiration of helmets.

Thumb rule for replacement

Now, despite there being no direct expiry date label from the helmet manufacturers, bikers, helmet retailers and the same manufacturers believe in replacing the helmets periodically.

As a general thumb rule, it is recommended to replace your helmet every 5 years.

This is because the resins, glues, polystyrene and other liner materials used to manufacture helmets will not be the same after 5 years of their manufacturing date.

The degradation induced in these materials over the time affect the performance of the helmet. The protective characteristics of the helmet decays over the years.

Is 5-year thumb rule – a marketing gimmick?

However, there are many doubters for this 5-year helmet replacement rule.

They do not believe motorcycle helmets expire in just around 5-years. And neither the need to replace it.

The argument here is the rule is mostly because the manufacturers and retailers want you to keep buying the helmets periodically so that they have an increased sales. And that’s why the 5-year rule is promoted.

Helmet Cover

This argument does hold its merit because of two reasons.

First, there is no strong evidence, experimental or empirical, that helmets degrade or slows down its performance after 5-years. Since there is no scientific study to back up the rule for replacement, the 5-year thumb rule seems pretty irrelevant.

Second, there is no expiry date sticker or label in a helmet. This is a huge thing. If the manufacturer is not putting it in writing that the goods prepared does not necessarily have an expiry date then how can you believe some thumb rule you heard from a friend or read on google?

So, for these valid reasons many believe helmets do not have an expiry date and the replacement thing is a sham.

Then, why should you replace your helmet?

In order to understand the mechanics of why helmets should be replaced, let us first look into the constituents of helmet.

Constituents of helmet

The three main constituents of a helmet include:

  • Outer Shell covering
  • Inner layer
  • Cloth/Fabric Liner or Comfort Liner

Apart from these 3 constituents, there is retention system, face shield and visor are present in a typical helmet.

Helmet Cross section

Outer Shell

The outermost layer of the helmet is the one which braces the impact first during a collision. The outer shell is made to be highly durable so that the impact should not result in the breakage of the shell.

The materials commonly used as outer shell of a helmet are – fibre glass, composite fibre, polycarbonate and carbon fibre.

Inner Liner

This is the most important part of the helmet since the inner liner is the one that absorbs the impact of collision a rider can face.

Inner Liner protects your head from any potential damages by reducing the rate of impact through its shock absorbing material.

The materials used in the inner lining should have excellent shock absorbing characteristics. The most commonly used material for inner lining is Expanded Polystyrene (EPS) commonly known as thermocol.

Cloth/Fabric Liner or Comfort Liner

This is the comfort padding that is in contact with your head and the skin.

Since this liner will be in constant contact with the skin, the material forming the comfort liner should be – a) comfortable; b) should not move, rotate or slip easily; c) should not cause any irritation to hair or skin; and d) should absorb moisture, sweat and oils.

For these reasons, foam is usually used in manufacturing a comfort liner.

Now, do these constituents degrade?

This is the question that will decide whether or not you should replace your helmet periodically.

The outer shell covering which is the most durable part should be working fine even after several years. However, if your helmet cover is seeing wear and tear, if there is a damage because of a past collision that has resulted in a crack or a breakage, then you should replace your helmet.

The inner lining which constitutes Expanded Polystyrene (EPS) does not degrade easily over the years. Polystyrene do degrade when subjected to high thermal stress in laboratory conditions. But in normal scenarios, it will take hundred, if not thousand years for bio-degradation.

Many people complain that polystyrene will become brittle over a period of time. However, there is no sufficient scientific data to back this claim.

The comfort lining will not suffer any damage over the years, but, the absorbed moisture, sweat and oils in the lining starts to reduce the quality of the comfort liner in your helmet.

Apart from these parts, if the bolts are loosening up consistently, if there is too much wear and tear on the helmet, then it is a sign that the years have taken toll on your helmet.

There is one more important aspect – Technology. Since helmet is a safety item, there generally is a constant technological improvement happening on the product.

As a result, over a period of time the old helmets start becoming technologically obsolete and may not be the best and safest helmet out there for you to wear.

Summing Up

Having discussed the both sides of the argument on whether motorcycle helmets expire or not, here is a quick summary for you.

Arguments against replacing your helmet periodically:

  1. No expiry date: There is no expiry date mentioned in a sticker or a label in the helmets. The manufacturers have not given any sort of expiration date to the helmet.
  2. Polystyrene: For those saying polystyrene, the shock absorber in the inner lining of the helmet, will degrade – here is the fact. Polystyrene is non-biodegradable. It takes centuries for the material to degrade, not 5-7 years.

Arguments for replacing your helmet periodically:

  1. Wear and tear: Over a period of time, your helmet starts getting worn out be it in the form of scratches, tears, bolts loosening and sometimes outright damages. Sustaining such wear for a long time will bog down the performance of the helmet especially if there are any cracks.
  2. Moisture, sweat and oils accumulation: Best helmets will come with reusable comfort liner. You can take out the fabric, clean them and put it back. Or just replace the comfort liner. However, most helmets do not have that option. Years of oil and sweat accumulated will start showing signs, even if you wash them periodically. If your helmet is smelling despite many cleaning efforts, it is time to address the issue.
  3. Technology obsolescence: This is the most important aspect. As the years progress, safety measures in the helmets see technological improvements. If you are still using a decade old helmet, no matter the performance, the helmet quality will always be subpar when compared to the newer versions. Hence, to keep up with the safety standards, you need to replace your helmet every 5 to 7 years.

Now, despite these arguments, one can choose when they should need to replace their helmet.

I am a believer of 5-year thumb rule. But that does not mean you should be too.

If your helmet is in an excellent condition even after 6 years and you feel there is no need for replacement, absolutely fine. At the same time, if your helmet is 2 years old and already has cracks, bolts loosen consistently and the comfort liner smells badly, and you want to replace that’s fine too.

So, what do you believe? Replacing the helmet around 5-years seem reasonable to you?