Using an Older Helmet (FAQ?)

I'm getting my first bike in, oh, about 9 years. Sold my BMW R80 then,
and am getting a V-Strom 650 now (brag, brag, yeah, I know).

Anyhow, my Arai Signet full-face helmet has been sitting on a shelf in
a cupboard in my garage for all those lonesome 9 years. I got it only
a short while before I sold the R80, so it hasn't had much use, or sun
exposure.

Do helmets like this age, and should I replace it now? I think (not
sure) that this helmet is polycarbonate (not fiberglass)--the owner's
manual doesn't say.

Any opinions? I looked for a FAQ for this group, and didn't find one.
Also, the Arai web site offers no help. I'm sure that Arai (and my
dealer) would recommend replacing it, for obvious reasons.

 

Buy a new helmet.

 

Why?

 

If it's polycarb, I'd replace it. If it's glass fibre, I wouldn't
bother.

 

And they'd be right. Both the shell (assuming polycarbonate)
and shock absorbing foam (important on all helmets but
especially on polycarbonate ones as the shell does not absorb
any crash energy) will have aged. I never remember the
exact recommendations but even I will start thinking about
getting rid of a polycarbonate helmet after 5 years, a
fibre/resin one after 10 years absolute maximum.

 

AOL: The condition of the expanded polystyrene foam is far
more important than the shell, as it's this bit that absorbs
impact energy.

No shell will _absorb_ energy (to any significant degree),
just dissipate the impact over a larger area.

Interestingly, polycarbonate shells are better at
withstanding an impact than carbon- kevlar- or fiber-glass
shells, it's just their structural integrity tends to be
compromised more after the initial impact and their failure
mode is to shatter rather than crumple: not ideal when
bouncing down the road.

This is where the old chestnut "replace a dropped lid" came
from: Sure, replace a dropped lid if it's polycarbonate (or
your head was inside when dropped) but if it's a modern
fibre lid you can play football with it & it'll be fine.

 

On the contrary, fibre shells will actually absorb quite
a bit of the crash violence by delaminating, tearing the
structure to pieces. That is why it's the fibre shell
helmet that is most sensitive to seemingly small damage
from being dropped (not to speak of being used as a
football), every crack, delamination or softening of the
structure equals less crash energy absorption when you
need it most.
A polycarbonate shell on the other hand will be fine
after a small impact because there is no structure to
destroy. The toughness of polycarbonate can be
illustrated by its use as burglar proof glass. The
downside of this is that no energy is lost at impact,
the harder you hit, the harder the shell bounces back.

 

AFAIK, the Arai Signet used a fiberglass shell even back then. IMO, the
shell material is irrelevant. Replace the helmet: there's a good chance
you can get something lighter and quieter than that old helmet, with
better vision and ventilation too. I've posted my reasoning WRT helmets
here in the past, and you can look for it if you care for more than the
opinion. If you can't find it, I could be convinced to re-write it, I
guess.

 

There's an excellant article in one of the rags about helmets last month
(june motorcyclist or cycle world) that did a test on DOT v Snell standards,
fiber v poly, cheap v expensive etc. It's well worth the read. The bottom
line is non-snell, poly is marginally better than fiber and or snell and
cost isn't really a factor. The fiber and snell helmets tend to transfer
more of the impact to the noggin. That said, the article also indicates
that they type of helmet is probably going to be a factor in less than 25%
of accidents.

 

Please do.

Thanks to yours and others postings, I'll be looking into getting a
new helmet soon (like next week).

Why doncha rewrite your stuff about helmets? Lots of newbies (like me,
almost) would like to see it.

Tim Smith

 

Because telling you that I wrote the article on June 25 2003, with the
title: "Re: Arai Quantum/e helmet" after looking it up takes less time
than rewriting everything that I wrote. It's probably worth reading the
entire thread.

Not much has changed since then, other than my having replaced a helmet
that was probably not substantially damaged because it was old enough
that I wasn't happy about my knowledge of its condition. The position
stated in the final paragraph of my final contribution to that thread
sums up my attitude:

safety gear is a way of managing risk. The older gear gets the less
certain you can be of its condition, and eventually you may choose to
replace gear that isn't obviously damaged because it's too much of a
chance (that's what I do, anyway).

Mind, I'm not attempting to discourage questions, I'm just lazy. ;-)
I've also got opinions on the benefits of doing your own research, but
then I'm also a grad student.

 

This is the best advice so far. You're absolutely right.

 

OK people, guess I'll get a new one. Thanks for the advice.

Tim

 

The helmet article that LJ referred to is in "Motorcyclist", and I
think it's the June, '05 issue. I'm in agreement that the helmet
should be replaced. The outer shell may still resist penetration
pretty well, but the EPS foam will be deteriorated pretty badly in 9
years.