If you ride a bike, you should wear a helmet. Normally, everyone thinks that the helmet will last forever. Sadly, the truth is for vague reasons having to do with foam degrading, or maybe corrosion from salt or sweat, the helmet will expire.
So do helmets actually deteriorate or what? They do, but perhaps not in the way you might think. Here are a couple of things to keep in mind when deciding whether or not to replace your helmet.
Check for damage and wear
Here’s a few tips on what to look for on your own helmet:
Shell – Look for cracks or abrasions. Are there any cracked edges? Check for fading because UV exposure can make the shell brittle. Any compromise to the integrity of the shell will mean it may not hold together in an impact.
Liner – The foam. Press carefully over the shell of the helmet to see if there is any movement. In some helmets there will be no movement and in others a little movement, you should look for any area where there is a variation in movement compared to the rest of the helmet. An area of greater movement indicates damage to the foam under the shell. Turn over the helmet and check the liner for cracks or compressed foam. If you suspect any area of compression, check and measure the thickness of the foam at the same spot on the other side of the helmet. If you feel any dents, indentations or gouges, it’s time for a replacement.
Straps/buckles/clips and fasteners – check for wear and tear. Any loose stitching or fraying? Check buckles/clips and fasteners. Do they work and hold? Buckle or fasten and then give them good forceful tugs and twists to check they don’t come apart. Think about the force they would be under during an impact, or multiple impacts like a car, and then the road. You want to mimic that force, you need to know that they will work to keep that helmet securely on your head in an impact.
After Crashing, Replace the Helmet
Regardless of wear, if you crash while wearing a helmet, replace it. Cycling helmets are single-use safety devices. Once you compress the foam underneath the helmet’s plastic shell, it can no longer protect you. That’s true whether your helmet is 20 years old or you just bought it yesterday.
You should realize that any physical damage to the foam means your helmet can’t do its job. You should Check for damage and wear as we stated above. However, make a habit to replace the helmet after crashing.
It seems hard to believe at first, yet when I look back on my first major accident—I barreled into a truck turning in front of me—I do not remember the hit at all, and my helmet didn’t have any obvious signs of damage. But I hit the pickup truck hard enough to crumple its passenger-side door, so it seems that regardless of my foggy memory the helmet did something to protect me, and I should have replaced it.