Do Bike Helmets Expire
Mountain Bike Helmets Mountain Bike Helmets Advice

When do Bike Helmets Expire – Should You Replace Your Helmet?

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The short answer is yes. The longer answer is that it depends on if the material is degrading, when it was made, if it has been in a crash, and if there are any cracks or defects showing.

How long should a helmet last?

The Snell Foundation, which determines the safety ratings of helmets in the US, came up with the number of 5 years. This is based on the facts that the materials will begin to degrade over time, and that over the 5 years, the helmet will come in contact with chemicals that gradually degrade the helmet. This includes sunlight, sunblock, hair oils etc. Additionally, new technologies in helmets are upgrading every year, so one helmet from this year will be safer from the same helmet in the previous year.

Additionally, this doesn’t mean that any given helmet will last 5 years. There are a number of signs that your helmet should be replaced.

If you crash, replace it!

This is reasonably simple. A helmet with an EPS foam layer is designed for a single crash. EPS is dented permanently and tends to crack or snap under stress, making it unsuitable for multiple impacts.

If your helmet is made of EPP and EPS foam, it is more durable and can withstand 2 or 3 impacts. Many newer helmets, particularly full-face helmets, have the dual-density foam (EPP and EPS), such as the Bell Super DH, Fox Dropframe, Troy Lee Designs D3 Carbon MIPS and the Fox Rampage Pro Carbon Helmet.

Replacement Deals

Many companies, including the large helmet manufacturer Giro, have deals on their helmets where you take back your damaged helmet to get a discount on a newer helmet.

So, if you took back your damaged Giro helmet to Giro, they may discount your next Giro helmet by 30%. This allows you to get an updated helmet, which keeps your head safe, and the manufacturer gets a second purchase from you. A win-win situation!

How much force is needed to damage the helmet?

It doesn’t take much to damage a bike helmet. Just dropping the helmet may cause small cracks which weaken the structural integrity of the helmet.

As stated earlier, the foam (for the majority of the time) is designed to take only one impact. It does its job well in its first impact but may not do such a great job the next time around. And if the helmet isn’t going to do such a good job the second time, there is next to no point in wearing it!

Therefore, you need to take good care not to drop the helmet and is why you need to replace the helmet after any impact!

Inspect your helmet

You need to inspect your helmet on a regular basis for any cracks or defects which may form over time or following a crash.

A helmet must have a plastic (or carbon) outer shell for it to do its job properly. If your helmet does not have an outer shell protecting the inner foam layer, it will not provide sufficient protection in a crash.

The foam will degrade much faster from UV light, and if the foam is not held strongly together with the outer shell, it will not be able to absorb as much energy in a crash, resulting in more energy directed at the riders skull. 

Before using the helmet, check that it meets the minimum safety standards. You can tell as it will have a sticker on the inside for CPSC, ASTM, or Snell stating the standard it meets. Check that this is the most up to date standard, otherwise, it is likely that it will not be sufficient to protect your head in a crash.

Another thing we personally would look for is the presence of an anti-rotational system such as MIPS. MIPS works as a slip plane which reduces the angular momentum to your head, reducing the chances of brain damage.

Personally, we would never ride without MIPS and believe that in the near future, anti-rotational technologies will become compulsory.

The final thing to check before deciding whether to replace your helmet or not is checking the fit of the helmet. If it doesn’t fit properly, it is unlikely to protect your head well in a crash. The way that a helmet works is by distributing the energy around the helmet so that minimal energy is transferred to the skull.

If the helmet can move on the rider’s head, the energy will not be distributed evenly and can often lead to damage of the neck. If the helmet fits snugly, it will be more comfortable for riding and can reduce the damage to your head.

How long does an unused helmet last for?

If you have purchased a helmet, but never really used it, and it has just been sitting around in the garage for a few years, you are probably wondering if it is still usable. This is going to depend on a few things;

  • Has it been exposed to sunlight?
  • Has it been in contact with any chemicals, such as sunscreen etc.?
  • Has it been under pressure? Have you stacked boxes or several layers of clothes on it while it has been in storage?
  • Is it older than 7 years?

The UV light can deteriorate the outer shell, making it brittle and comprising the structural integrity of the foam. Similarly, any chemicals it may have been exposed to will also lead to deterioration of the helmet components.

If the helmet has been under some weight for some time, gradual pressure cracks may form and weaken the strength of the foam. And if the helmet is getting on in age, it may not meet the most recent safety standards, and you will be missing out on the latest safety technology which works to help save your life.


There is a fair amount of variation between manufacturers on how long a helmet can be used for. Some say between 3-4 years, others say 5-8 years. To be honest, the shorter years seem like a money-making scheme, as most helmets manufactured to meet the safety standards will last the 5 years. Look at what each manufacturer states in their product specifications, but as a rule of thumb, replacement every 5 years is a good idea.

But one thing everyone can agree on is that if a helmet has been in a crash, or dropped several times onto a hard surface, it needs to be replaced. Some companies understand that replacing every few years can be expensive and will help out in the replacement of a new helmet by providing subsidies when purchasing another helmet from them. 

In all honestly, a helmet is an investment. You pay a reasonably small amount for something that will save your life in the event of a collision.

Considering the amount of money you pay for a bike and the rest of the kit, a helmet is really not that much. Materials are being manufactured at a lower price as technology improves, allowing the price of helmets to stay relatively constant while the safety features of helmets steadily climb.

A helmet is a good investment, so treat it well, and it will last much longer. Always replace a helmet after a crash, and make sure that it fits well. You do not want to be left wishing you had replaced your helmet after suffering from some head injury.

If you are looking to purchase a new bike helmet, check out our buyers guide here.

For ideas on great helmets, check out our top 15 helmets with MIPS.

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