On Mon, 20 Jan 2020 18:39:36 -0800, sms
wrote:
On 1/20/2020 8:09 AM, Jeff Liebermann wrote:
snip
I suspect you don't understand how most product cycles operate. I
don't have time to go through the details right now, but at some
point, a mature product (same as an over-sold product), ossifies into
a standard configuration, where all the competing products appear to
be 99% identical.
While all helmets may meet the minimum CPSC or European standards, they
are not identical in level of protection. Look at the tests performed by
Virginia Tech at
https://www.helmet.beam.vt.edu/bicycle-helmet-ratings.html where they
rate a bunch of helmets from best to worst.
Here's how Virginia Tech ran their tests:
https://vtechworks.lib.vt.edu/bitstream/handle/10919/83760/Bicycle%20STAR%20Methodology.pdf
At first glance, I'm having problems figuring out what they're doing,
what they're measuring, and how they're producing their STAR rating.
Let's just say I'm suspicious when most of the helmets cost over $100,
claim to meet CPSC, and probably meet SNELL and ASTM F1447. Yet the
report shows some variability in the STAR test results. I just might
suspect that either manufacturing inconsistencies, or wide variations
in testing methodology or results. Also, I get rather suspicious when
I can't find the raw data to see how it was generated and processed:
https://vtechworks.lib.vt.edu/handle/10919/83760
Also, note that the test report was from 5/30/2018, while more helmets
and data were added on Nov 25, 2019 which makes me wonder if any of
the conclusions changed due to the updates.
https://cyclingtips.com/2019/11/virginia-tech-add-more-helmets-to-tested-list-mips-still-trending/
Oh swell. Yet another helmet standard, this time from Australia.
https://cyclingtips.com/2019/03/australia-has-a-new-helmet-standard-on-the-way-why/
I also blundered across yet another safety publication, the
International Journal of Crashworthiness.
https://www.tandfonline.com/toc/tcrs20/current
Are you worthy of crashing?
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060
http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558