do helmets decay?

Discussion in 'Road Cycling' started by Dan Daniel, May 12, 2003.

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  1. Dan Daniel

    Dan Daniel Guest

    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.
     
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  2. Michael Ross

    Michael Ross Guest

    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
     
  3. Brian Hughes

    Brian Hughes Guest

    "Dan Daniel" <[email protected]> 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
     
  4. Pete

    Pete Guest

    "Dan Daniel" <[email protected]> wrote in message
    news:[email protected]...
    > 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
     
  5. Jon Isaacs

    Jon Isaacs Guest

    >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
     
  6. In article <[email protected]>, Dan Daniel <[email protected]> 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
     
  7. Jon Isaacs

    Jon Isaacs Guest

    >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
     
  8. Barry Gaudet

    Barry Gaudet Guest

    Jon Isaacs <[email protected]> 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
     
  9. Tony Zipple

    Tony Zipple Guest

    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.
     
  10. Dan Daniel

    Dan Daniel Guest

    On Tue, 13 May 2003 04:37:30 GMT, "brian hughes" <[email protected]> wrote:

    >
    >"Dan Daniel" <[email protected]> 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.
     
  11. Dan Daniel

    Dan Daniel Guest

    On Tue, 13 May 2003 17:45:02 GMT, [email protected] (Paul Southworth) wrote:

    >In article <[email protected]>, Dan Daniel <[email protected]> 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?
     
  12. Dan Daniel

    Dan Daniel Guest

    On 13 May 2003 19:06:46 GMT, [email protected] (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?
     
  13. Dan Daniel

    Dan Daniel Guest

    On 14 May 2003 00:07:36 GMT, Barry Gaudet <[email protected]> wrote:

    >Jon Isaacs <[email protected]> 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.
     
  14. Pete

    Pete Guest

    "Dan Daniel" <[email protected]> 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
     
  15. Barry Gaudet

    Barry Gaudet Guest

    Dan Daniel <[email protected]> wrote:
    : On 14 May 2003 00:07:36 GMT, Barry Gaudet <[email protected]> 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
     
  16. In article <[email protected]>, Dan Daniel <[email protected]> wrote:
    >On 13 May 2003 19:06:46 GMT, [email protected] (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?

    Because people frequently try to eke the last miles of life out of a tire, and they think, "well I
    might get a flat, big deal". Blowing a tire at the wrong time is actually really dangerous, risky
    like breaking a brake cable or snapping a chain. I put it at
    #1 because it's one of the most common dumb dangerous things people
    do on bikes. Cyclists should have a similar policy on tires as motorcycle users - smart people
    replace them before they are worn out.
     
  17. Dan Daniel <[email protected]> wrote in message
    news:<[email protected]>...

    > 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.
    >
    Do helmets decay?

    I think you're OK as long as you've only used sugar-free shampoo, and remembered to brush your
    hair after feeding it (you DO use one of those shampoos which claims to contain all kinds of
    nutrients?).

    But seriously, the shell of the Bell Havoc helmet I bought 3 years ago cracked the day I bought
    it, when dropped from a height of about one foot while locking up my bike. Not
    confidence-inspiring.

    The shell has become increasingly brittle, and visibly yellow (lots of UV). Cold weather riding
    may have contributed to the cracking - don't know if these are tested below 0C.

    My 20 year old V1PRO is rock solid, but I have my doubts about the effectiveness of the
    styrofoam liner.
     
  18. Barry Gaudet

    Barry Gaudet Guest

    Jon Isaacs <[email protected]> wrote:
    :>Sunlight - Assuming the 'on your head helmet' is in the sunlight and the 'shelf' helmet isn't.

    : The foam is protected by the microshell, no direct sunlight.

    It would still have some UV exposure through vents and such.

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

    : And of course depending on the model, it might actually provide better protection.

    Oh. another thing that voids hardhat guarentees is contact with chemicals even those in a
    magic marker.

    --
    'They paved paradise And put up a parking lot' -Joni Mitchell
     
  19. Barry Gaudet

    Barry Gaudet Guest

    Jon Isaacs <[email protected]> wrote:
    :> Oh. another thing that voids hardhat guarentees is contact with chemicals even those in a magic
    :> marker.

    : I see no reason to believe that the chemicals in a Magic Marker are at all benign. Those pens have
    : a strong odor of volatiles when the cover is removed.

    : Regarding UV exposure, given the small amount of time a helmet is exposed to sun light, I am not
    : concerned.

    Well I'm not suggesting it would disintegrate before your eyes, but it would affect the structure
    of the plastic over time. How much time? *shrug*

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