As a person who is concerned about my safety on the road, and generally not dying, I have always been concerned about the sheer number of people wearing damaged or outdated motorcycle helmets. Having a background in the industry, I have regularly come across people who have kept helmets for longer than 5-6 years and, in extreme cases, 15 years plus. Visordown wrote an article on this topic and found that up to 40% of motorcyclists in the UK are wearing helmets that should have been replaced. However, I feel that I would like to expand upon this and cover the importance of replacing unsuitable helmets.
So what happens to a helmet as it ages?
Now, I can already hear many of you getting ready to comment, “Oh but the helmet I was given by a friend of a friend’s great grandfather twice removed, has been fine so far, fits and it’s only 200 years old!” Now hear me out first.
Your helmet is made up of an outer shell, often made up of polycarbonate or multi composite materials. Under the shell is a layer of foam which varies in thickness and density. This is called the Expanded Polystyrene (EPS) lining. The EPS Lining tends to be what limits the age of the helmet to 5 or so years. The EPS lining is hugely important as it compresses when the helmet takes a large impact and stops you from having what would probably be the biggest headache of your life.
Now the issue with the lining is that it degrades and hardens between 4-5% a year, this is something that happens naturally and is sped up if the helmet is used regularly, or if the person has greasy hair or uses solvents and sprays. By the time the helmet is 5 years old the EPS lining effectiveness could have decreased by 25%. At this stage there will now be a gap between the EPS lining and your head, if the helmet now takes an impact this could increase the risk that more force is transmitted through to the skull, increasing the likelihood of traumatic brain injury…. Ouch!
Ok so what happens to a damaged helmet?
When a motorcycle helmet is dropped or crashed in it could cause serious damage to the helmet. You would not necessarily know if any damage has been caused unless you own an x ray machine, unless you work for the NHS you probably won’t have one handy. For this reason, my stance on this is it's better to be safe than sorry when it comes to replacing potentially damaged helmets.
We have already covered how vulnerable the EPS lining can be, even a slight impact can cause cracks in the lining which will reduce the effectiveness of the helmet. As well as damage to the EPS lining, the outer shell of the helmet could also be compromised. Microfractures that you might not be able to see could form in the shell of the helmet once it is dropped or crashed in, this will significantly weaken the structure. Now I can hear you thinking, “What good is a helmet to me if it can’t even survive being dropped?” There is a reason helmets get damaged from slight knocks, helmets are designed to crack and spread the impact in the event of a crash, this is a safety feature not a weakness, however they are only designed to take one impact.
So how would I know if my helmet is still wearable?
Luckily most helmet manufacturers have painted EPS liners, they are painted in black so that if any cracks appear, they appear as white cracks and are easy to see against the black paint. Once these white cracks appear it's safe to assume the EPS liner is damaged or compromised in some way. I will show you an example that I have found.
This is the EPS liner on a brand new Arai RX7 V
This is the EPS liner on a 10 year old Arai RX7RR
It is quite clear to see what age has done here to the EPS lining, if your helmet looks like this REPLACE IT!
Last words
We all know the risk involved when we get on our bikes, it's an unfortunate reality. However we can all take steps to reduce the risk of injury by making sure our helmets are in top condition, if they are not, replace it simple as. Or if you are in doubt about your helmet, please do contact one of the guys at Bike Stop, they can check over your helmet and advise you.
