do helmets decay?

I have a Bell helmet (evo pro) built in June 1998, according to a sticker inside. So it is almost
five years old.

What is the general opinion on the life of a helmet? I think Bell recommends replacing it every
three years.

The helmet has not been crashed. No obvious damage, frayed straps, etc. No cracks, missing pieces.
Never sat inside a car on hot days or other such things that weaken plastics.

Any reason to replace it other than keeping money moving in the economy? Thanks.

I trust Bell. They invented evidence based helmet design.

Some notable helmet stuff:

If you crack your head - buy a new helmet. The way the foam works is it crushes and DOES NOT
rebound. This is how it absorbs energy to keep your dura from crashing against your cranium.

By the same token, normal use accummulates small little comperssions of the foam until the helmet
starts to fit more loosely and provide somewhat less crush zone.

What about a helmet that sits on the shelf for 3 years? Surely that helmet is fine. Probably ought
to define helmet life in miles or hours, but I guess years is easier for everyone to figure.

3 years may limit liability some. Bell has a lot of experience with that. They quit making
motorcycle helmets (maybe for the US market only?) because of spurious lawsuits in the US. It is a
shame, they were the best; they truely had our best interest in mind.

Mike Ross

"Dan Daniel" <ddandan@pacbell.net> wrote in message >
> Any reason to replace it other than keeping money moving in the economy? Thanks.
>

Well, since the outer material is plastic, and the principle padding material is stiff
Styrofoam--which is non-biodegradable and will last in a landfill forever--as a skeptic, I think the
3-year rule is meant more for the company shareholders and lawyers, not so much for your head.

Brian

"Dan Daniel" <ddandan@pacbell.net> wrote in message
news:igk0cv4ak6gdka8n3lcgce6kv960r8vvnm@4ax.com...
> I have a Bell helmet (evo pro) built in June 1998, according to a sticker inside. So it is almost
> five years old.
>
> What is the general opinion on the life of a helmet? I think Bell recommends replacing it every
> three years.
>
> The helmet has not been crashed. No obvious damage, frayed straps, etc. No cracks, missing pieces.
> Never sat inside a car on hot days or other such things that weaken plastics.
>
> Any reason to replace it other than keeping money moving in the economy? Thanks.

Do they decay/degrade? Yes. In 3 years, probably not

Pete

>What about a helmet that sits on the shelf for 3 years? Surely that helmet is fine. Probably ought
>to define helmet life in miles or hours, but I guess years is easier for everyone to figure.

I see no difference between a helmet that sits on the shelf for 3 years and one that sits on my head
for three years (without being crashed.)

>By the same token, normal use accummulates small little comperssions of the foam until the helmet
>starts to fit more loosely and provide somewhat less crush zone.

I don't buy this one, first I don't believe it happens. The reason helmets become looser over the
years is that the foam adjustment pads change. Secondly the crush zone is sufficiently large that if
the helmet still fits at all, it is probably still within the manufacturing tolerances.

I have worn Bell Helmets since sometime about 1964. At that time, there were no other serious
alternatives and the company was pretty straight forward and I trusted their judgement implicitly.

These days, they have been through the mergers and they are part of Bell Sports.

Bell Sports markets some real trash so I no longer trust them implicitly.

jon isaacs

In article <igk0cv4ak6gdka8n3lcgce6kv960r8vvnm@4ax.com>, Dan Daniel <ddandan@pacbell.net> wrote:
>I have a Bell helmet (evo pro) built in June 1998, according to a sticker inside. So it is almost
>five years old.
>
>What is the general opinion on the life of a helmet? I think Bell recommends replacing it every
>three years.
>
>The helmet has not been crashed. No obvious damage, frayed straps, etc. No cracks, missing pieces.
>Never sat inside a car on hot days or other such things that weaken plastics.
>
>Any reason to replace it other than keeping money moving in the economy? Thanks.

I would not replace it.

There are a lot more important things to replace regularly, if you're going to do replacement as a
safety precaution (prior to any failure). Tires are #1 on that list I think and brake cables are
probably #2.

--Paul

>I would not replace it.
>
>There are a lot more important things to replace regularly, if you're going to do replacement as a
>safety precaution (prior to any failure). Tires are #1 on that list I think and brake cables are
>probably #2.
>
>--Paul

I agree. Tires and brakes are bigger safety issues/factors than helmets.

I do wear a helmet but I do think that too much emphasis is placed on the importance of wearing a
helmet and not enough on keeping the bike in good condition and riding with an eye towards safety.

As Paul says, #1 tires, #2 brake cables, #3 brake pads....

A helmet is on the list but its not #4.

jon isaacs

Jon Isaacs <jonisaacs@aol.com> wrote:
:>What about a helmet that sits on the shelf for 3 years? Surely that helmet is fine. Probably ought
:>to define helmet life in miles or hours, but I guess years is easier for everyone to figure.

: I see no difference between a helmet that sits on the shelf for 3 years and one that sits on my
: head for three years (without being crashed.)

Sunlight - Assuming the 'on your head helmet' is in the sunlight and the 'shelf' helmet isn't.

I don't know about bike helmets but CSA/UL rated hardhats have a shelflife. Don't quote me but I
'think' it's 5 years.

It would still be much better than nothing and probably offer identical protection to a new one -
he operstive word being 'probably'.

--
'They paved paradise And put up a parking lot' -Joni Mitchell

Yes. The foam becomes more brittle and loses effectiveness over time. Three years is very
conservative, 10 years is probably over the top. Five is probably safe.

Dan Daniel wrote:
> I have a Bell helmet (evo pro) built in June 1998, according to a sticker inside. So it is almost
> five years old.
>
> What is the general opinion on the life of a helmet? I think Bell recommends replacing it every
> three years.
>
> The helmet has not been crashed. No obvious damage, frayed straps, etc. No cracks, missing pieces.
> Never sat inside a car on hot days or other such things that weaken plastics.
>
> Any reason to replace it other than keeping money moving in the economy? Thanks.

On Tue, 13 May 2003 04:37:30 GMT, "brian hughes" <bandjhughes@earthlink.net> wrote:

>
>"Dan Daniel" <ddandan@pacbell.net> wrote in message >
>> Any reason to replace it other than keeping money moving in the economy? Thanks.
>>
>
>Well, since the outer material is plastic, and the principle padding material is stiff
>Styrofoam--which is non-biodegradable and will last in a landfill forever--as a skeptic, I think
>the 3-year rule is meant more for the company shareholders and lawyers, not so much for your head.
>
>Brian
>

Yeah, I wonder if the three year thing is more of a safety factor. As someone mentioned, liability
issues might be part of it. And any helmet maker can't know how a helmet has been used and stored by
any one person. So picking a low number not only encourages more revenue, it also should account for
most 'worst case' histories short of crashes.

Plastics *do* change over time. Certain chemicals evaporate or disappear in other ways. Adhesives
can change. And polystyrene isn't completely inert. Darn close, but I have opened old shipping boxes
and found that the styrofoam has become crumbly.

On Tue, 13 May 2003 17:45:02 GMT, cnhyf-1052712000@usenet.etext.org (Paul Southworth) wrote:

>In article <igk0cv4ak6gdka8n3lcgce6kv960r8vvnm@4ax.com>, Dan Daniel <ddandan@pacbell.net> wrote:
>>I have a Bell helmet (evo pro) built in June 1998, according to a sticker inside. So it is almost
>>five years old.
>>
>>What is the general opinion on the life of a helmet? I think Bell recommends replacing it every
>>three years.
>>
>>The helmet has not been crashed. No obvious damage, frayed straps, etc. No cracks, missing pieces.
>>Never sat inside a car on hot days or other such things that weaken plastics.
>>
>>Any reason to replace it other than keeping money moving in the economy? Thanks.
>
>I would not replace it.
>
>There are a lot more important things to replace regularly, if you're going to do replacement as a
>safety precaution (prior to any failure). Tires are #1 on that list I think and brake cables are
>probably #2.
>
>--Paul

My biggest safety precautions are-

- brakes that work- cables, pads, etc.

- tires that will not fall apart

- nothing that will shimmy or cause other control issues at higher speed (or lower speeds

- being aware to possible crash situations and knowing how to avoid them or get out of them

These are all things that I stay on top of. The helmet is gravy, and I've only needed one twice in
thirty years. Worrying about it every three to five years or so is about as much as I can get
excited about.

I find your naming tires as number 1 confusing. I always think of brakes (the whole thing- cables,
pads, etc.; I don't see particular parts of the brake as being more or less important than others)
as *the* number one thing. Maybe I've been lucky or attentive around my tires so that I haven't
experienced a serious failure and I underestimate the danger.

Can you say more about why you put tires first? What are the dangers of a tire failure that make it
worse than a brake failure?

On 13 May 2003 19:06:46 GMT, jonisaacs@aol.com (Jon Isaacs) wrote:

>>I would not replace it.
>>
>>There are a lot more important things to replace regularly, if you're going to do replacement as a
>>safety precaution (prior to any failure). Tires are #1 on that list I think and brake cables are
>>probably #2.
>>
>>--Paul
>
>I agree. Tires and brakes are bigger safety issues/factors than helmets.
>
>I do wear a helmet but I do think that too much emphasis is placed on the importance of wearing a
>helmet and not enough on keeping the bike in good condition and riding with an eye towards safety.
>
>As Paul says, #1 tires, #2 brake cables, #3 brake pads....
>
>A helmet is on the list but its not #4.
>
>jon isaacs

As I asked Paul, can you say more about why you put tires at the top of the list?

On 14 May 2003 00:07:36 GMT, Barry Gaudet <bgaudet@uoguelph.ca> wrote:

>Jon Isaacs <jonisaacs@aol.com> wrote:
>:>What about a helmet that sits on the shelf for 3 years? Surely that helmet is fine. Probably
>:>ought to define helmet life in miles or hours, but I guess years is easier for everyone to
>:>figure.
>
>: I see no difference between a helmet that sits on the shelf for 3 years and one that sits on my
>: head for three years (without being crashed.)
>
>
> Sunlight - Assuming the 'on your head helmet' is in the sunlight and the 'shelf' helmet isn't.
>

UV is one thing that will decompose plastics. And gases from autos and other pollution sources can't
be doing a helmet much good.

> I don't know about bike helmets but CSA/UL rated hardhats have a shelflife. Don't quote me but I
> 'think' it's 5 years.
>

Is styrofoam part of the safety functioning of a hard hat? I think of them as heavy plastic shells.

Interesting to hear of the five year (or so) rule for them. Plastics do gas off and change
composition over time, and this usually causes them to become brittle.

> It would still be much better than nothing and probably offer identical protection to a new one -
> he operstive word being 'probably'.

Hopefully I will never need to learn if my present helmet has decayed to a point where it doesn't
offer any protection. All in all, from what people have replied, I think that I will hold on to the
present one through the summer and see if something comes up on sale in the fall or winter.

"Dan Daniel" <ddandan@pacbell.net> wrote
>
> Can you say more about why you put tires first? What are the dangers of a tire failure that make
> it worse than a brake failure?

A brake failure, while bad, generally only happens to one at a time. Use the other one to stop. And
you still have your shoes as a last resort.

A tire failure at speed, epecially a front tire on a descent in a corner, can be VERY bad.

Pete

Dan Daniel <ddandan@pacbell.net> wrote:
: On 14 May 2003 00:07:36 GMT, Barry Gaudet <bgaudet@uoguelph.ca> wrote:
[,,,]
:> I don't know about bike helmets but CSA/UL rated hardhats have a shelflife. Don't quote me but I
:> 'think' it's 5 years.
:>

: Is styrofoam part of the safety functioning of a hard hat? I think of them as heavy
: plastic shells.

No. They are just hard plastic. But if that will decay on a hardhat I figure that part would decay
on a bike helmet as well.

--
'They paved paradise And put up a parking lot' -Joni Mitchell