Caliper

Isn't a degradation of the materials in the helmet the root cause behind the replacement? Nobody ever claimed that helmets should be replaced because fashion trends have changed.

mr_bill

Ah, "conspiracy." What I find truly odd is that some of the very same people who claim there is a "marketing" or "legal" conspiracy at helmet manufactures uncritically read a reguritated press release of a "study" by a legal forensics company.

Snell still certifies bicycle helmets.

-mr. bill

livedarklions

I already posted that the CPSC recommends 5-10 years. Care to bet whether Snell or CPSC have better "data"? It's pretty obvious that there's a ton of guesswork going into the optimal interval as I would consider those both fairly reliable authorities.

I don't need to be a conspiracy theorist to note that manufacturers have a financial incentive to promote frequent replacement, I'd have to be a complete nitwit not to notice it.

I didn't comment on the landfill issue, I commented on what I saw as an especially stupid response to it--equating helmets with tires. Exposure to sweat, sunlight, skin oils, etc. are not the same factors as time. Those are factors that are going to vary with amount of use, not time elapsed since manufacture. Unlike tire "rubber", there is absolutely no evidence that foam is not shelf stable, and there's every reason to believe that the ill-effects of the other factors you listed would be quite obvious to even a cursory examination. Your argument quoted above is to restate your original non sequitur that tires and foam are the same because they're petroleum based and then add "seems quite logical". It's not.

BTW, is this a link to a conspiracy site? They note that the same manufacturer admits its product is still good after 8 years, but recommends 3-5 year replacement: https://helmets.org/replace.htm

Get back to me when you understand that one can suspect that marketing concerns are actually A motivating factor for for-profit manufacturers without being some sort of kook.

mr_bill

What are motivating factors of legal forensics companies to publish research?

-mr. bill

livedarklions

I'm shocked, shocked to find that gambling is going on here!

indyfabz

So....What's the answer to the question again?

livedarklions

If you wear a helmet greater than 1625 days old, an anvil will drop from the sky and hit your head.

mtbronbo

that is what they tell you; who? is it the manufactures? I replace helmets after a hard crash or after a year or two when they look like hobo attire. Is it like getting a flue shot? I would replace after 3-4 years on appearance.

livedarklions

That's pretty much the way I do it--I figure the appearance is a pretty good proxy for extent of wear.

indyfabz

Or your flue cleaned.

livedarklions

Any legal forensics research on frequency of flue cleanings you'd like to link?

Headline in search of a story:

"Avian Flu Spread When Bird Flew Through Flue"

Caliper

I would trust Snell over the CPSC, because I never trust Government to get anything right. The CPSC has been doing the bike helmet thing for 20 years now though, wouldn't it be great if they had actually done some rigorous testing of longevity? After all, they have the appropriate baseline data and facilities to run the entire test.

Of course there will be guesswork from any third party. I'm sure there is variation in the exact chemical makeup of each design from one manufacturer to the next. Hmmm.... Who might know something about that? Oh, right, we can't trust them.

I never said that helmets are tires, rather I used an analogy to tires to challenge the assertion that since helmets linger in landfills for a very long time, therefore a replacement interval is silly. Helmets aren't tires, but also time in a landfill does not equate to functional lifespan.

So you are claiming that absent any visible damage that a helmet will perform the same indefinitely? There is no evidence that foam is not shelf stable? It would be the first petroleum product I am familiar with that is. I also have no way of testing if the material in a helmet is working properly. I can check for visual damage, but have no way to confirm the impact absorbing capacity of the foam.

Your note about the manufacturer there is taking quotes from two different times. " in their 2010 catalog ... Unfortunately they now say three to five years" Maybe their helmet designs from nine years ago ARE different, I really don't know but different statements years apart is not evidence of anything other than change.

Your point about financial considerations may be true, but at the same time, what of someone who intentionally disregards the manufacturers instructions for proper use of safety equipment?

And, while you're at it, can you also admit that it's a bit silly to say that on the one hand you trust a manufacturer to make a safety product but then on the other don't trust the same manufacturer to tell you how long the product is OK to use?

livedarklions

So I take it you're not familiar with thermoplastics, then? Generally, they are considered to have an infinite shelf life. Have you guessed what kind of material polystyrene is? Yup, it's a thermoplastic. Seriously, the idea that no petroleum based product is stable is a complete howler, that's what the entire category of thermoplastics is best known for.

You're a broken record at this point, you go ahead and believe that manufacturers deserve to be treated with unquestioning obedience. If I weren't so bored with this discussion, I'd explain to you why they have financial incentives (i.e., liability) to turn out a safe product while no financial incentive to avoid making you buy too many of them Have a good day.

Caliper

Again, you're confusing something simply being present with the properties that make it useful. Really, what petroleum based product IS stable with age? They may not decompose and crumble to dust but I've yet to see a plastic that doesn't get brittle over time. I always find it a hoot when the plastic toolbox that never goes outside still gets brittle sitting in a closet. PVC pipes that have literally not seen sun in years and have carried nothing but drinking water are not as flexible when you remove them as when they are installed. Funny, those are thermoplastics also. They are still there on the shelf but they aren't quite the same as they once were.

Ad hominem attacks are usually a sign that you're out of arguments. I'll continue to believe the helmet manufacturers, but also Snell, CPSC, auto racing organizations, sports leagues, and just about everyone who uses a helmet who all recommend replacement. See ya.

livedarklions

Not an ad hominem attack to point out you're just repeating the same nonsense. You have some weird experience with plastics which is a neat rhetorical trick because it can't be disproven, I have plastic tubs for decades with absolutely no degradation.

Manufacturer recommendations have nothing to do with the shelf life of foam. Know how I know that? The helmets don't have sell-by dates. Somehow, your hypothetical degradation only starts magically on purchase.

Helmets are also not pvc pipes carrying drinking water, btw. Hydrolytic degradation is a thing, even drinking water is not Ph neutral.

Helmets wear through use, and sun and sweat on the foam is also probably a thing. But I have better information on how much exposure and wear that my helmet has undergone than anyone else on the planet.


I find the fact that I've repeated that 3-5 years has actually been too long for me and you keep accusing me of taking unreasonable risks rather funny.
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Sy Reene

That's just it.. can someone link or provide a quote of what exactly some (which?) helmet manufacturer actually said about replacement every 5 (or is it 3) years, and when they stated this? I'm just curious.

It doesn't have to be wholly or at all about foam degradation. I've already pointed out one example, in that MIPs wasn't even really around 5 years ago. So if a MIPS helmet manufacturer said today something along the lines of: "if your helmet is older than 5 years, we recommend replacing it" -- would they be wrong in stating this if they're actually of the belief that their current product (with MIPS) would be safer than any helmet they sold 5 years ago without it? There is perhaps other tech and/or design that also could be better.. the hard shell material? Maybe the foam itself has had some advancements? Buckle materials?

Another example: I think a good number of helmets recently lost the sharp edges/tails in the back, going to a smoother/rounder profile, as it was realized those sharp ridges (while looking cool) could actually grab road in a crash and twist your head in unpleasant ways.

What would have been really interesting, is if a bunch of those helmets from that 26yr study, were made available to Virginia Tech, for them to put into their relative scoring/testing process. Eg. a bunch of 5yr old helmets, a bunch of 10yr, a bunch of 15yr, etc.

02Giant 

Replace your helmet whenever you feel like it needs to be replaced.

Why all of the drama?

tagaproject6

You are not new in BF. Drama is BF.
Wait until someone steal your baby bike bolts...

indyfabz

I replace my helmet when it starts to cause chafing/bleeding "down there."

livedarklions

tmi

bpcyclist

Yikes!

Atlas Shrugged

a. Yes
b. Probably also yes but seams like reasonable upgrade and what would the downside be?

Camilo

The resistance isn't the cost, but the very idea of throwing away something that's perfectly good for no reason. Throw away culture + helmet companies' bottom lines = "it makes just sense to get a new helmet every 3-5 years, because safety!"

As has been discussed, there's a lot of very good reasons to replace a helmet - soft parts degrade, buckle breaks, occipital cradle/ retention parts break and such parts can't be replaced. Crash replacement. It gets scratched up and just looks like crap. Maybe you like the looks or fit of a different one better for whatever reason or think newer ones might be designed to safer (btw, I do think a lot of progress has been made in strap/retention systems since the 90s, and especially in the past 10 years or so. It's much easier to make a helmet fit properly now than it was back then.)

In general just don't like the idea of throwing stuff away that still works fine. Waste of money, resources and landfill space.

cyccommute 

You may know more about the use of your helmet but what do you know about the impact that use has on the polymer? The manufacturers have more knowledge about the material than you or I do. I (might) have more knowledge about the polymer than you do since it's my job to know about chemicals and chemical reactions as well as how materials change over time, i.e. "aging". My field isn't in expanded foam nor in manmade polymers but I do pick up knowledge about materials outside of my expertise from time to time for various reasons. All objects...manmade or natural...are subject to degradation through exposure to the environment. How that exposure influences those objects can be difficult to predict. A helmet that is 20 years may be perfectly fine or it could be severely compromised. Most of the compromisation is going to occur at corners and sharp edges of which helmets have a lot. Visual inspection won't tell you anything. Destructive testing might...depending on how you do the testing...but that's not going to leave you with a workable helmet.

The paper on helmet aging cited above indicates that helmet may age well but it has some flaws. We don't know the entire history of each helmet. They didn't test the helmet at the edges because it's too hard to sample there. The experiment doesn't have very good controls since the helmets are donated and don't have a specific history. Do all the helmets have UV coatings or additives to protect them? It would also be good to see a controlled, accelerated aging to see if it matches real world aging.

Perhaps it's all a conspiracy by Big Helmet or it may just be a CYA by Big Helmet to squash the little guy. Then again perhaps not. Do you have any information to address the above concerns or evidence that Big Helmet is doing something nefarious? Have you tested your helmet for degradation byproducts? Have you tested your helmet to see if it is holding up? Or do you look at it and say "seems okay to me" without any basis to say that?

As I've said above, my helmets seldom last 5 years before I biff them against the ground but, even if they did last 5 years, replacing them at that interval isn't that odious. It's cheap insurance and I can take advantage of new technologies.


Again, how do you know it "still works fine"? The only way to test it is to destructively test it. You can do that in a laboratory or you can do it by smashing it on the ground with your head in it. One way hurts a whole lot less than the other. In the end, you might have an answer but the helmet is no longer "fine". If the helmet isn't "fine" when you smash it into the ground with your head in it, it could have dire consequences. Either way, the helmet is going to end up in the landfill.

livedarklions

You have an argument that proves way too much--if inspection is essentially useless, then I have no way of knowing whether the helmet was fatally compromised in shipment or just basic handling at the store. Obviously, the only rational way to do this is to acquire a helmet right at the end of the production line after, of course, minutely observing every facet of the helmet's production.

Sorry, but if the CPSC says up to 10 years is ok, I'm finding it pretty damn hard to believe that the manufacturers have some secret knowledge that the CPSC doesn't regarding degradation over time.

Can we stop with the nonsense "conspiracy" condescension? These are all business concerns with marketing departments, I don't have to be some sort of paranoid to think that might affect their call on when replacement is needed.

BTW, I don't think anyone here is suggesting that someone use 20 year old helmets,. The question in the OP was specifically about 3-5 years. There seem to be plenty of sources more knowledgeable than thee or me that indicate that that range is not based on anything.