Shimano Headset

On Tue, 16 May 2017 22:19:53 +0200, Emanuel Berg
wrote:

Radey Shouman wrote:

By requiring a head injury, you exclude the
cases where helmets actually prevented head
injury (or where helmets caused a head injury
that would otherwise not have happened).

By requiring an accident, you exclude the
cases where a helmeted rider took more risk
than she otherwise would have, and had
a crash she would have avoided without
a helmet.

By comparing bikers with and without helmets,
you risk comparing two populations that are
quite different, in ability, in age, in their
tendency to follow traffic rules or to seek
medical attention, in economic status, and
many other factors.

Still, it is bikes, helmets, accidents, and
head injuries, as opposed to pedestrians,
MCs, etc.
Take note of the information I posted from the Netherlands in one of
my last posts.

On Tuesday, May 16, 2017 at 10:58:22 PM UTC-4, Sir Ridesalot wrote:

In fact a lot of people would not ride a bicycle in traffic if they weren't wearing a helmet. Why? Because they wear the helmet for that just in case moment.

Yes, Sir. That's what Risk Compensation is all about. "I feel protected enough
to do something I wouldn't otherwise do."

- Frank Krygowski

On 5/16/2017 11:31 PM, wrote:
On Tue, 16 May 2017 15:30:05 -0400, Frank Krygowski
wrote:

On 5/16/2017 2:26 PM, Emanuel Berg wrote:
Because you require a base line with which to
strike comparisons.

Shouldn't the comparison be helmet vs.
no helmet on biker in accident with
head injuries?

You have not explained why you think such a comparison should be made
ONLY for bicyclists. After all, it's not like bicyclists are a large
portion of TBI victims.
Dutch TRAUMATIC BRAIN INJURYINJURY data.

http://journals.plos.org/plosone/art...l.pone.0110905

Cyclists represent 10 times as many TBIs (56.9%) as pedestrians (only
5.3%), about 5 times as many as Mopeds (12.2%), more than 3 times as
many as motor vehicle occupants (16.5 for automobiles and 5.1% for
scooters), a total of 56.9% of all traffic related TBIs. Traffic TBIs
comprise 33.4 % of all TBIs in the Netherlands, with home and leisure
comprising 48%, sports other than cycling 8.2%,Occupoational injuries
2.9%, asaults 6.6, self mutilation .5% and other .5%.

I think that discountts Frank's assertions - particularly for the
VERY cycle-centric nation of the Netherlands, where cycle helmets are
not required.

http://journals.plos.org/plosone/art...l.pone.0110905
gives the costs incurred.


an outline of the study generating this data is as follows:


Methods

This study included data on all TBI patients who were treated at an
Emergency Department (ED - National Injury Surveillance System),
hospitalized (National Medical Registration), or died due to their
injuries in the Netherlands between 2010–2012. Direct healthcare costs
and indirect costs were determined using the incidence-based Dutch
Burden of Injury Model. Disease burden was assessed by calculating
years of life lost (YLL) owing to premature death, years lived with
disability (YLD) and DALYs. Incidence, costs and disease burden were
stratified by age and gender.


Results

TBI incidence was 213.6 per 100,000 person years. Total costs were
€314.6 (USD $433.8) million per year and disease burden resulted in
171,200 DALYs (on average 7.1 DALYs per case). Men had highest mean
costs per case (€19,540 versus €14,940), driven by indirect costs.
0–24-year-olds had high incidence and disease burden but low economic
costs, whereas 25–64-year-olds had relatively low incidence but high
economic costs. Patients aged 65+ had highest incidence, leading to
considerable direct healthcare costs. 0–24-year-olds, men aged 25–64
years, traffic injury victims (especially bicyclists) and home and
leisure injury victims (especially 0–5-year-old and elderly fallers)
are identified as risk groups in TBI.


Conclusions

The economic and health consequences of TBI are substantial. The
integrated approach of assessing incidence, costs and disease burden
enables detection of important risk groups in TBI, development of
prevention programs that target these risk groups and assessment of
the benefits of these programs


NOTE:: This is NOT a study of helmet use, or cycling, so there is no
reason for results to be skewed against cycling without helmets ....

Chew on that for a while, Frank - - - -

You seem to be promoting helmets for the Netherlands, a place where
cycling is perhaps the most common method of movement. You can feel
free to sell helmets to the Dutch, but so far, that effort has had very
limited success.

Perhaps that's because the bike TBI incidence was still ridiculously
low. 213.6 per 100,000 person years for _all_ TBI, so 121.5 per 100,000
person years due to bicycling. That's 0.122 incidents of ANY level of
treated bike TBI for 100 years of cycling; or an average person would
have to cycle for about 820 years to get one bike TBI, even a minor one.
I can see why the Dutch aren't scared.

But IIRC, both you and I live in North America. Did the American data
do an even worse job of supporting your view?

--
- Frank Krygowski

On 5/16/2017 11:06 PM, wrote:
On Tue, 16 May 2017 20:26:03 +0200, Emanuel Berg
wrote:

Because you require a base line with which to
strike comparisons.

Shouldn't the comparison be helmet vs.
no helmet on biker in accident with
head injuries?
ALL thatb information is available on different pages of the websites
I listed previously.

So? Where is it?


--
- Frank Krygowski

On 5/16/2017 11:36 PM, wrote:
On Tue, 16 May 2017 15:45:02 -0400, Frank Krygowski
wrote:

On 5/16/2017 1:06 PM, Duane wrote:
On 16/05/2017 12:54 PM, jbeattie wrote:
IMO, the fact that helmets
are proven to prevent certain injuries does not justify mandating
helmet use. It does justify the personal choice to wear a helmet,
particularly for those people who ride dirt trails, wet descents, in
snow, etc.


Or apparently those who ride with a group containing a member trying to
channel Chris Froome.

As I've written in articles for our club's newsletter, I think it's
important to stay well away from certain riders. I've seen bad riders
take out good riders.
I'm sure you've seen what you would have considered good riders, up
untill the incident, take out other good and not so good riders too.

Actually, no.


--
- Frank Krygowski

On Tue, 16 May 2017 20:14:47 +0200, Emanuel Berg
wrote:

Frank Krygowski wrote:

So, why do we not do studies of the number of
severe head injuries of pedestrians with and
without helmets?

Why involve anything else apart from
bike accidents?

If the question is "do helmets help", shouldn't
the data method be: in 2016, x bike accidents
occurred with head injuries as a consequence.
How many of these bikers had helmets at the
time of the accident?

Still, the pro-helmet side could say: "Yeah,
but if they didn't use helmets, the injuries
would be even worse". Perhaps, but if
a majority or a large proportion of the
affected bikers had helmets, it'd raise doubts
at the very least.

And conversely, if only a small proportion had
helmets, it would be clear that a helmet
DOES help!

One of the problems is gathering data. The usual method is by counting
the number of accidents that resulted in a visit to a medical
facility.

In other words all the people that hit the tree and went to a clinic
were counted while the people that hit the tree and elected not to go
to the clinic were not counted.

--
Cheers,

John B.

On Tue, 16 May 2017 23:02:04 -0400, Frank Krygowski
wrote:

On 5/16/2017 4:48 PM, wrote:
On Tuesday, May 16, 2017 at 11:26:05 AM UTC-7, Emanuel Berg wrote:
Because you require a base line with which to
strike comparisons.

Shouldn't the comparison be helmet vs.
no helmet on biker in accident with
head injuries?

--
underground experts united
http://user.it.uu.se/~embe8573

Exactly how do you do that? 98% of bicycle accidents are never reported since they have no severe injuries. And they do not list whether or not a serious injury was wearing a helmet and hospitals have enough to do without worrying about keeping statistics for someone else.

What we do know is that from zero helmet use to almost universal use by sports riders there has been no change in injuries. If that isn't good enough for you then perhaps you can gather the statistics.

I wonder if Emanuel has looked at TBI data for the Tour de France.
Roughly 100 years, typically hundreds of riders per year, doing
thousands of miles, in the most grueling conditions, and for almost its
entire history without helmets.

Where was the plague of serious brain injuries?

It might also be interesting that the bulk of the professional riders
participating in the major bicycle races in Europe resisted vigorously
the enforcement of the mandatory helmet rule.
--
Cheers,

John B.

On Tue, 16 May 2017 22:34:49 +0200, Emanuel Berg
wrote:

Frank Krygowski wrote:

Similarly, I've given talks to bike clubs and
community groups on the topic of bike safety.
I've asked "What percentage of America's
brain injury deaths do you think are caused
by bike crashes?" I've had an entire room
full of people agree that its about 30
percent. The actual figure is about 0.6%.

Every injury to the head following an accident
which involves a bike should be analyzed and
booked with some rough scale of graveness say
from 1-10 where 1 is a scratch and 4 is
a dislocated jaw and 10 is death (just
examples, the system would have to be agreed
upon by a group of experts). Then the data
would be analyzed. Also the helmet should be
analyzed, or what is left of it, to get an
estimate if it helped or not. All this
parameterized into a computer to do graphs
and charts.

But that isn't what happens. Every study I've seen is based on visits
to a medical facility.

If you, for example, fall over on your bike and scratch your head do
you hurry down to the clinic to get a band-aid? Probably not so you
had a head injury and didn't get counted.
--
Cheers,

John B.

On Tue, 16 May 2017 22:59:23 -0400, Frank Krygowski
wrote:

On 5/16/2017 4:35 PM, Emanuel Berg wrote:
Frank Krygowski wrote:

You have not explained why you think such
a comparison should be made ONLY for
bicyclists. After all, it's not like
bicyclists are a large portion of
TBI victims.

Isn't the question "do helmets help bikers
in accidents?"

That may be your question. To me, it misses a lot by accepting unstated
assumptions.

My question is "Should helmets be recommended for cyclists?" It's a
bigger question. Certainly, if helmets fail your test, they should not
be recommended. But if helmets are not needed simply because cycling's
risk is too low, then we don't even need to get around to your test.

And all the data I've found shows that cycling's risks are indeed too
low to worry about helmets.

I find the "Danger, Danger" argument somewhat misleading as I read
that helmet impact tests are done with a two meter drop where the
helmet, and head form, are traveling at 14 MPH (22 KPH) when it
impacts the test anvil, and I read here about people riding at
considerable higher speeds. One bloke says he "Usually rides" at 20
MPH, some 30% faster then his helmet is tested for. Others write of
considerably higher speeds.

If it is dangerious to ride a bike without a helmet isn't it
exceedingly foolhardy to ride 30% to perhaps 300% faster then the
helmet is rated to protect the wearer?
--
Cheers,

John B.

wrote:
On Tue, 16 May 2017 15:45:02 -0400, Frank Krygowski
wrote:

On 5/16/2017 1:06 PM, Duane wrote:
On 16/05/2017 12:54 PM, jbeattie wrote:
IMO, the fact that helmets
are proven to prevent certain injuries does not justify mandating
helmet use. It does justify the personal choice to wear a helmet,
particularly for those people who ride dirt trails, wet descents, in
snow, etc.


Or apparently those who ride with a group containing a member trying to
channel Chris Froome.

As I've written in articles for our club's newsletter, I think it's
important to stay well away from certain riders. I've seen bad riders
take out good riders.
I'm sure you've seen what you would have considered good riders, up
untill the incident, take out other good and not so good riders too.


Right. Only bad riders have accidents. Like Chris Froome. Ridiculous.

--
duane