A bike helmet is an essential safety accessory that any sensible cyclist uses when riding. However, they can become compromised over time and offer less protection than they once did.
Bike helmet safety stats
In 2016:
- 835 fatal bike crashes in the U.S.
- 16 per cent wearing helmets
- 51 per cent not wearing helmets
- 33 per cent helmet use unknown (Source)
Bicycle helmets don’t expire like a carton of milk you’ve left in the fridge too long, but many manufacturers recommend replacing your helmet after a certain length of time—usually between three and eight years.
You can take these timelines with a grain of salt, since there are many other factors that determine the useful lifespan of this vital piece of protective gear.
Do bike helmets have expiration dates?
Bike helmets do not typically come with expiration dates but with a recommendation to replace them every several years. This is based on studies that have investigated the helmet’s ability to withstand impact, and its overall build quality.
Healthy skeptics believe that some manufacturers recommend arbitrary timelines to ensure their customers keep buying helmets. Of course, this is possible. But when healthy skepticism causes you to act against your own safety, it’s no longer that healthy, is it?
Gauge your helmet’s lifespan based on the brand’s credibility and how much you use the helmet. If you’re a frequent rider, you should probably replace within the 3-5 year range. If you don’t ride very often, the 5-8 year range might be OK.
It also doesn’t hurt to read reviews from others who have used the same model. Many reviews will mention how long they were able to use them before replacing.
Why bike helmets need to be replaced
Bike helmets have a specific purpose: to protect you from a crash. If you’re involved in a crash and your helmet saves you from injury, it has probably sustained the damage that would have been yours. It should be replaced.
A crash isn’t the only thing that can compromise a helmet, though. Like most items, they suffer general wear and tear from frequent use. After a time, they become less sturdy and offer less protection.
UV rays
Ultraviolet (UV) rays from the sun take a toll on your helmet’s shell. They don’t cause the interior foam to deteriorate—that’s made of polystyrene and can last as long as a styrofoam cup lasts in a landfill—but they do make the hard shell on the outside more brittle and prone to cracking.
The hard shell protects the all-important inner foam. Many manufacturers coat this shell in UV blockers to minimize deterioration from sunlight.
Keep your helmet out of direct sunlight when you’re not using it. If you notice that the exterior shell has faded considerably in color, then your helmet has probably had enough sun and should be replaced.
Sweat
Again, sweat won’t do much to the foam cushioning on the inside, but it is full of salt and acid that will gnaw at the strength of your helmet strap and fasteners. These are essential to the performance of your helmet.
When to replace your bike helmet
After a crash
Bike helmets are designed to protect you from one blow and one blow only. When they are tested, they typically pass the first impact with flying colors. But testers then require the helmet to undergo a second impact, and this is when they fail.
You want to get rid of your helmet before that second impact.
The protection comes from the polystyrene foam inside shell. It compresses upon impact, providing the cushion that saves your head. But it does not decompress. Once that foam becomes tightly packed after an impact, it can no longer provide a cushion.
Looks can be deceiving, too. Your helmet might look fine after a crash, but the foam is covered by the outer shell so you can’t really see what’s going on inside.
What makes it even trickier is that if the helmet has done its job, you might pop up from a crash thinking your head hasn’t suffered any blow at all. Head feels fine, helmet looks good—no problem, right?
Wrong. The reason your head feels fine might be because you have a helmet full of tightly compressed foam. Do yourself a favor: Thank your helmet and then go buy a new one.
Smaller impacts
Your helmet receives smaller impacts all the time. These don’t necessarily demand replacement of the helmet, but keep in mind that they add up.
You might drop it on a concrete floor while opening your backpack. You might swing it against the corner of a table in Starbucks. Every one of these little things can potentially damage to your helmet.
The prudent thing is to inspect it regularly. Look for small, hairline cracks in the outer shell. Press on the shell to make sure the foam is springing back. Look for tears on the inside liner. If you notice issues with any of this, it’s a good time to replace your helmet.
Compromised straps and fasteners
Your helmet strap and its fastening devices are an often-overlooked part of helmet maintenance. Examine the straps and fasteners yearly to make sure they haven’t succumbed to the effects of sweat. If anything is keeping your helmet from staying snug and secure on your head, you will need to replace the helmet. It cannot do its job if it’s loose or shifting around.
When technology advances
Five years is a good benchmark, generally, because research and development on bicycle helmets moves fast. Even if all else looks OK, you might consider buying a new helmet after five years simply because advances in technology may have produced, lighter, stronger helmets by then. Why not have the most protective helmet that’s available?
The Multi-directional Impact Protection System (MIPS) is the latest in brain-protection technology. Check out our post about whether or not MIPS helmets are worth it.
What if you haven’t used it?
You can prolong the life of your helmet by using it sparingly, storing it well and protecting it from the elements. That said, some studies recommend replacing your helmet after some time regardless of whether it’s damaged or not. The standard is the same: If the helmet shows any signs of physical damage on the outer protective shell or inner foam lining, it should be replaced—even if it has never been used.
If your helmet has been damaged by exposure to UV rays, solvents, or other factors in the environment, replace it. If it has been stored unused for many years, beyond the limit of safety, you should replace it.
On the other hand, if you have stored your helmet properly and it shows no signs of damage, and if it has been certified by a recent standard, then there is no need to replace it.
How to tell if your bike helmet needs replacing
Your bike helmet will certainly need to be replaced if it was made before 1990. Industry safety standards have changed since then, and most helmets from that time do not measure up.
A helmet should also be replaced if it has not been certified by a recognizable body as meeting safety standards.
How to tell if your bike helmet meets safety standards
According to the Bike Helmet Safety Institute, a good bike helmet should have the following things:
- a strong outer plastic shell with no visible signs of damage or abrasion;
- a styrofoam liner that is neither crushed nor cracked;
- strong and sturdy straps that have a tight grip and showing no signs of breaking;
- a rear stabilizer that is adjustable and shows good structural integrity;
- a standards sticker from CPSC, ASTM, or Snell sticker.
At what age can you stop wearing a bike helmet?
There is no age at which cycling without a helmet becomes safe. Helmets are for preventing head injury and death for anyone who rides bicycles. Contrary to some opinions, bike helmets are not just for kids or career cyclists.
Everyone who rides a bike deserves maximum protection in the event of an unexpected mishap. The older you become, the weaker your bones become, and the more likely you are to get hurt by even minor accidents. For that reason, everyone should wear a helmet—particularly if they are older.