Helmets Lose Effectiveness?
 

Do helmets actually lose effectiveness? When I was at my LBS last the guy asked when I last changed my helmet since they lose effectiveness after 2-3 years due to UV.

I’m aware that if a helmet ever is involved in some trauma to itself that it should be replaced, but do you actually need to change a helmet every 2-3 years if it’s never been subject to trauma?

Check out THIS article on the degradation of plastic from UV radiation. Ultimately, it depends on the quality of the plastic (specific material type and types of stabilizers used) and how the plastic is stored. I haven't personally seen a helmet manufacturer recommendation on a replacement frequency but I wouldn't be surprised. Child car seats have a printed expiration date on them but they sit in hot cars for hours daily unlike a bike helmet that may be exposed for direct sunlight for 2-3 hours at a time. I am always suspicious of bicycle industry tactics to induce spending. Somehow they do a fantastic job..... haha

I use the five year rule of thumb recommended for motorcycle helmets. I think Aria is longer. I do keep a spare helmet in the car. This one I’ll change out after three years since it is baked in the hot car.

Lightweight bicycle helmet design is probably on the absolute limit of material capability and it won't take very much material degradation at all before they fail to deliver maximum performance.
More heavily constructed Motorcycle helmets can have more leeway built into them.

almost 20years, this helmet (if worn) has kept me accident free. Good helmet. Good investment. Haven't bought body armor, yet. :rolleyes:

I have my doubts over the 2 to 3 year replacement schedule. There is, no doubt an expiration date for helmets, though nobody knows for sure where the line is. My current helmets are 4 and 6 years old.

Recommendation that I was told when I started working in a bike shop from Bell/Giro was every 5-7 years, part of this was helmet degradation, part was not realizing the underlying damage that occurs from the helmet getting kicked around (tossing it in the car, dropping it on the ground, etc.) and from the increased safety innovations of the newer helmets. So even though a helmet older then 7 years might still be good you're dealing with an unknown level of diminishing returns with how well it will still work.
Telling you 2-3 years is just trying to sell you a new helmet and really rip you off.
I'd guess that anything is ultimately better then nothing but I can recall 10 years ago a guy coming in to the shop with a bell helmet with the net over the top and I'd owned the same helmet in 1990, while that was a great helmet in 1990 it couldn't hold a candle to anything made in the last 10 years.

Let's look at a different item entirely: Trailer tires.

Have you ever been driving down the Interstate and seen a trailer sitting on the shoulder of the road with one blown out tire? Why are trailers more susceptible to this phenomenon than automobile tires? If you go strictly by the numbers, there are a lot more cars on the road than trailers; you should see cars off to the side with blowouts far more often than trailers. What's the difference?

The difference is that cars tend to wear down their tires long before the rubber has time to age out. Popup campers get used a few times a year at best. The tires are going to age out before their tread is gone. What happens when the tires age out? The sidewalls begin to crack and get brittle. Then one day the owner is heading down the highway at 65 or 70, and pow; they're in a really dangerous situation with a blowout on a thing that only has two tires in the first place.

Ok, now for helmets: Unless you crash, or ride through rain and mud every day, your helmet will look mostly new for years to come. It's like the trailer tire with lots of tread left. But the foam, plastic, and glue are all deteriorating, possibly at different rates, and due to different environmental factors. So over time, that helmet will not behave as it did the day it was purchased. And that could put the rider at greater risk should the worst happen. One document I read asserts that the foam itself deteriorates very, very slowly, but that the resins and glues can be susceptible to environmental factors that even include oils from the rider's body.

This article is excellent: https://off.road.cc/content/feature/...le-helmet-1280

I'm guilty too. I don't love paying $100+ for a new helmet when the old one seems to be working just fine. I don't even like the process of trying to find a new one that I like. Helmets become a bit like gloves, where years of use make us comfortable with the fit. But the truth is it's the right thing to do, to replace based on age. My last helmet I kept for ten years, which was way too long. My current helmet is only a few months old. Let's see if I can force myself to replace it at the 5-year mark.

Sometimes conventional wisdom isn't so wise.

Trailer tires are not helmets nor do they serve the same purpose. Tires are left outside exposed to the elements all year - why would anyone do that to a helmet. It's akin to never lubing the chain and wondering why it needs to be replaced so often. Parking your bike in the rain and wondering why everything gets so rusty. Take care of your kit?

For the average rider there's nothing miraculous about the foam in your bicycle helmet that limits its effectiveness to a couple of years. The design is simply to put something between the road and your soft noggin in low impact crashes; for most recreational riders about 30km/h max. More likely, falling over when one forgets to unclip. The helmet allows the foam to go crack instead of the skull. If you get centerpunched at 60mph no helmet will save you - the head may be intact but it will be depressed inside the thorax.

You could make an effective helmet out of 3-4 inches of compressed felt inside a shell if you wanted, but it would be cumbersome, heavy and hot. Most helmet manufacturers are really just reducing those common drawbacks by using thin, perforated foam instead. Moderately priced helmets hit the mark but people want lighter and sleeker so the compromise comes in durability.

They are a lot like construction hard hats. You don't need space age materials or to replace them every couple of years. They just keep tools from doing severe damage when dropped off the scaffolding. But if you want a fancy lightweight one it will probably be more susceptable to damage and need replacing. If you do buy the fancy one, probably leaving it to bake in the car for several years is not a good idea, as is never lubing the chain.

This has been studied, with the finding that basically helmet foam does not appreciably degrade

& 20 year old helmets test fine.

AFAS trailers, it's mostly wheel bearings and not tires that break down, and mostly boat trailers that go in the water.


https://asmedigitalcollection.asme.o...dFrom=fulltext

Foam cores were extracted from 63 used and unused bicycle helmets from ten different models spanning an age range of 2–20 yrs. All cores were impact tested...
...Based on these data, the impact attenuation properties of EPS foam in field-used bicycle helmets do not degrade with the age.


https://link.springer.com/epdf/10.10...z7MGB63zA_VQ==

Using 770 donated bicycle helmets, Alyssa DeMarco, Dennis Chimich, and Gunter Siegmund found little or no evidence of helmet age-related deterioration in impact performance.

Yep!

I keep mine until the pads are worn out (and starting to rub my skin raw), or the plastic head strap or mounts break. Oh, except for the helmet where the plastic outer shell blew off the foam innards flying down a long hill. May take three years, make take eight.

The shock absorbing foam itself? I've dissected several after replacing them because of an impact. Never saw any degradation. Of course the new MIPS foam may have better rotting properties (from the point of view of the marketers who want them to be replaced more frequently).

I generally go about 6 years before I replace my helmet. You can get a good helmet for $100 to $150. That's a lot, sort of. But, pick up a decent pair of fingerless gloves and you'll spend $30 to $45. So compare 3 pairs of gloves to a helmet and then the price of the helmet looks pretty good.

Comparing trailer tires (or any tire) to helmets is pointless.

Tire sidewalls must constantly flex. Helmets don’t. Tires fail when they can no longer flex without cracking. Helmets are DESIGNED to crack.

When old tires fail from age it is because they are starting to behave more like the shell of a helmet.

Here are two helmets from the same store:

https://www.mec.ca/en/product/5057-5...Cycling-Helmet
https://www.mec.ca/en/product/5063-4...ce-MIPS-Helmet

They both weigh the same roughly (250gm sm. vs 280gm med.).
Both have the same safety ratings (CPSC, EN1078)
Both made of the same base material EPS (foam).

One is $45, the other $300.

If I were a salesman I could just ask the question: "what's your brain worth" and let the ego take over. The marketing is designed precisely for that.

In short if it degrades over time it's useless anyway, that is mainly an issue for foam and light plastic coverings that don't do much. Foam won't save you and can cause damage when not in a hard shell. Anything with an ABS shell for example with last a thousand years in normal usage.

Wut?:foo:

I haven't been able to get more than 3 years out af a helmet for a long time. I've had to replace 4 helmets in the last 10-12 years, the latest just last week. None of the replacements had to do with age of the helmet. Two were replaced because of crashes, and 2-3 just wore out or were abused (dropped or damaged when shipping my gear on tours). As an emergency room doc was cleaning gravel out of my ear, cleaning various patches of road rash, and sewing up my arm and knee, he asked me if I planned on replacing my helmet:)

https://live.staticflickr.com/4332/3...9e138128d0.jpg


I can tell you from personal experiences that bike helmets do work as designed.

Evil Knievel was hard on helmets too! Stay safe out there :)

Irrational, but lacking poetic nuance. Should study more Fietsbob if he wants to go that route.

I did a local triathlon earlier this year and your helmet had to be less than 5 years old to pass the safety check--make of that what you will.

2 to 3 years is instituted by bike shops so they can make more money, even the 5 year rule could be the same thing. I replace my helmet when one of three things happens first, assuming no crash; one is, something breaks; two is, the padding gets worn out; and the third reason is, as the foam first starts to disintegrate it will leave tiny particles stuck onto your sweating head, that's what UV damage and or bodily oils will do eventually, and that's how you now you got to that starting point and it's time to buy another helmet. All long that will take depends on the person and the quality of the helmet, my helmets last an average of 10 years, and I buy helmets around the $80 range (on sale), I think between $70 and $100 is the sweat spot money wise for a helmet.

Hard hats are supposed to be replaced periodically too, on a pretty aggressive timetable. Every couple years I think? I might look at ours when I'm in the office tomorrow. Besides the plastic shell being exposed to UV, the webbing that keeps them in place on the head tends to become brittle and break. But these truly are an item kept in a vehicle year-round in all kinds of temperatures, so maybe replacing them is wise.

EDIT: Recommendations on new hard hats say to replace the plastic shell after no more than five years, and to replace the suspension (the webbing and cage inside the hat) annually.

Bought my one and only helmet back in 1996. My head has not grown so large that it doesn’t fit.

Just cause they work well doesn't mean you have to test them out just for s#!ts and giggles :twitchy:. Glad they're working for you though. :thumb: