Shimano Headset

On Tuesday, May 16, 2017 at 7:17:36 AM UTC-7, jbeattie wrote:

When I crashed in October and broke my hand, my head bounced along the pavement, and I was happy to have a helmet on -- which broke. I wasn't knocked out, but I probably avoided scalp injury, and when you're miserable post-surgery with pins sticking out of your hand and in agonizing back pain, not having a scalp injury is a small bright spot. It's the little things.

I think we've had maybe two days of dry weather since last summer. Right now, the greatest risk to cyclists is probably suicide. Crashing due to poor traction, however, is right up there too. Might as well wear a helmet -- so long as its not flushing sweat into my eyes. Note to helmet users -- wash your liners.

And this is a good reason to wear a helmet. Not to save your life but rather to reduce minor injuries.

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!

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

On Tuesday, May 16, 2017 at 8:07:49 AM UTC-7, Frank Krygowski wrote:
On 5/16/2017 9:59 AM, AMuzi wrote:

There is a window within which a helmet would decelerate the brain to
sub-damage impact forces and a range within which
abrasions/lacerations/contusions will be mitigated.

There are points below which a helmet wasn't necessary and above which
useless.

That said, people differ in their analyses of those risks, frequencies,
mitigation ranges etc. I cannot agree with you categorically that a
helmet is useless in every case.

The concept of a window of usefulness seems reasonable. I don't think
anyone doubts that under certain circumstances, a helmet can prevent
abrasions, lacerations and contusions.

However, I think the window of usefulness is much smaller than people
have been led to believe. At the lower end, it's made smaller by the
fact that it's preventing only minor surface injury. IOW, there must be
many helmet hits that would have been near misses, or at worst slight
bumps and scratches. Personally, I suspect those account for most of
the "My helmet saved me!!!" stories. (And many of those would have been
protected by Guy Chapman's "wooly hat," which he humorously claimed
"saved his life.")

At the upper end, of course there are linear impacts beyond a helmet's
protective capacity. But I think it's likely that helmets can impose
rotational acceleration which is more damaging than with a bare head. I
think there are very good evolutionary reasons that we have hair (well,
some of us still do!) and scalps which are loosely attached to the skull
and well lubricated. Yes, it can be messy and scary when that mechanism
gets activated by a glancing blow; but I suspect it's a protective
mechanism that to some degree is thwarted by a helmet.

As mentioned upthread, bicycle concussions are way up, not way down,
since the surge in helmet popularity. The increase is so large that I
can't believe it's due only to increased reporting. (And I've not heard
of a similar increase in reported pedestrian concussions during that
time span.) If the "window of usefulness" were very large, we'd see
significant drops in bike concussions and other TBI.

However, let's keep in mind that bike concussions have _never_ been very
common compared to other sources' concussions. Any objective look at
sources of TBI shows that the great risk that helmeteers portray is a
myth.

When I first returned to riding about four years ago I was looking back as I was riding under a tree near the road to see where the people I was riding were. The tree had lifted a bump in the pavement and my headset was set too tight. The combination was the the bike didn't self correct and dumped me on the ground. I landed on my left side - knee and shoulder.

When people helped me up they asked if my head was OK. I said that I didn't even hit my head. And believe me I'm MORE than sensitive to a head blow now.

They pointed out the back aero section of my Bell helmet and it was broken up. Now that just happens to be an area in which that model of helmet has very little support with them trying to save weight while having an aero design.

So that helmet broke up and my head could have BARELY touched the ground so little that I didn't even feel it.

My local bike shop gives you a new helmet at cost if you trade in a broken helmet so that they can mount these on the wall to advertise all of the lives saved by helmets. It's a real joke.

On Tuesday, May 16, 2017 at 11:14:50 AM UTC-7, Emanuel Berg wrote:

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!

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

http://www.vehicularcyclist.com/kunich.html

"This chart shows that despite an increase in bicycle helmet use from near zero to 30% or more during the period, the trend in fatalities is virtually the same for both groups. Somewhat disturbing is that the rate of reduction in cycling deaths has not been quite as rapid as for pedestrians."

The reduction in pedestrian and cyclist deaths per 1,000 was due to laws and more bicycles being on the road and hence they are noticed more.

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

Emanuel Berg writes:

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?

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.

If you want to know what effect helmet promotion or helmet use have on
public health, it makes sense to measure what happens when helmet use
changes, although that is not the only reasonable methodology.


--

On 5/16/2017 2:14 PM, 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?

To provide reasonable context.

It's probably still different in Europe. But in North America, 30 years
of propaganda have made many if not most people believe a lie: that
simply riding a bicycle imposes a big risk of serious brain injury and
death. This is not an exaggeration. I've had people say "Aren't you
wearing a helmet??" or "Where is your helmet!?" when riding my bike a
mile to a pharmacy.

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%.

So people here start with the false assumption that bicycling causes
hoards of serious brain injuries. That is the _only_ reason they
consider wearing or promoting helmets.

It would be stupid to propose a helmet for knitting or watching TV. But
if you did, you might eventually find "proof" that wearing a knitting
helmet helps prevent brain injury. Would that justify a mania for
knitting helmets?

Whether bike helmets do provide justifiable protection is still an open
question; but the first question should be whether there is enough risk
to even consider that question.


--
- Frank Krygowski

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.

--
- Frank Krygowski

On 5/16/2017 2:24 PM, Radey Shouman wrote:
Emanuel Berg writes:

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?

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.

If you want to know what effect helmet promotion or helmet use have on
public health, it makes sense to measure what happens when helmet use
changes, although that is not the only reasonable methodology.



+1 good analysis

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On 5/16/2017 12:15 PM, Duane wrote:
On 16/05/2017 7:56 AM, John B. wrote:
On Tue, 16 May 2017 00:16:10 -0400, wrote:

On Tue, 16 May 2017 10:18:48 +0700, John B.
wrote:

On Mon, 15 May 2017 14:48:09 -0700 (PDT), Sir Ridesalot
wrote:

On Monday, May 15, 2017 at 4:44:46 PM UTC-4, jbeattie wrote:
Snipped
That would do. I think Joerg is a special case and could use a
tool and some master links because he breaks chains. If you don't
break chains . . .

I've broken a couple of chains because I messed up reassembly or,
in one case, I had an odd shift on to the big ring and up-shift,
and the quick-link snapped open. I probably side-loaded the chain
in some odd way. I had no chain tool, but I was close enough to
home that I could scooter until my wife came to pick me up.

I broke one chain in the middle of nowhere, but I was on tour and
had a chain tool. Another mis-assembled chain broke on the way to
work, but I was close enough to work to scooter the last bit, and
then I bought a cheap chain tool at lunch. The bad part was
dealing with a greasy chain in my backpack.

-- Jay Beattie.

Indeed does Joerg appear to be a special case. However, if I
experienced the number of problems/reakages that he does then I'd
be carrying a pretty comprehensive repar kit with tools and parts
that I'd most likely need. MAybe what Joerg needs to do is fix up a
method of towing another bike behind the one that he rides and that
way when one bike breaks something major he can then rather than
having to walk 20+ miles back to civilization he could just ride
the extra bike back and tow the werecked one behind it.

Cheers

I can only say that although I rarely, based on distances cycled, have
a flat I carry a spare tube and patch kit and while I even less
frequently break a chain I still carry a chain tool and a couple of
chain links.

Strange though, although I've had far fewer bike crashes than flat
tires everyone says "wear a helmet" :-)
Generally speeking a flat or broken chain won't kill you.

Generally speaking neither will a bike accident.

While true that these numbers don't come from the U.S., I would
suggest that they are indicative of bicycle accidents. Their report
http://www.rospa.com/road-safety/adv...facts-figures/
Shows that in 2014 there were 21,287 reported bicycle accidents of
which some 17,773 were only slightly injured. Given that the numbers
are only the accidents that were reported the report estimates that
total accidents may well be twice the numbers shown.

In short it appears that the vast majority of bicycle accidents do not
result in death and the article seems to indicate that perhaps a half
of all bike accidents are so minor as to require no medical attention
at all.
--


I've had two bike crashes that resulted in my having to have medical
attention. One was a separated shoulder and one was some broken ribs.

In neither case was I transported by emts and in neither case did I go
immediately to the ER though I did have treatment. So how did that fit
in with the stats?

Exactly as do all the cases where people are injured by tripping while
walking. Or like my very good friend who was struck by a car and
knocked down when walking in a crosswalk. Or like the people who cut
themselves while working in their workshop.

But if you did go to ER eventually, you're probably in some database.
If you did not, your injury was considered minor and not recorded.

This is not a problem. Minor injuries are minor, no matter the activity.
Society can't and shouldn't try to keep track of every one - although
some "Danger! Danger!" bike safety people have actually tried to.


--
- Frank Krygowski