On Sun, 20 Dec 2015 11:26:09 -0800 (PST), wrote:

On Sunday, September 20, 2015 at 5:19:45 PM UTC-7, John B. wrote:
On Sun, 20 Sep 2015 16:34:38 -0700 (PDT), wrote:

On Sunday, September 13, 2015 at 6:41:45 AM UTC-7, Frank Krygowski wrote:
On 9/12/2015 5:00 PM, Phil W Lee wrote:
John B. considered Sat, 12 Sep 2015 08:54:40
+0700 the perfect time to write:


About 75% of all bicyclists who die each year die of head injuries.

I think you'll find (unless it's very different from the UK, which
seems unlikely given the common mechanism of injury) that it's 75%
that have a brain injury at the time of their death, which may well
have occurred anyway due to other injuries.
Not much point in keeping your head in one piece if you've bled out
anyway. And even a motorcycle helmet won't save your head if a heavy
truck drives over it, or even some much lighter vehicles. So the most
you can do is cite that 75% as an upper bound.

I suspect the origin of the overestimate was a propaganda statement that
"75% of bicyclist fatalities involve a head injury." At least, that's
the way I first saw it expressed years ago. (Sorry, no citation.)

That version may be literally true - as in, the dead cyclist may have
had his abdomen run over by a truck's wheels, and he also got a little
scratch on his head. But the phrasing was obviously intended to trick
the reader into believing that helmets might prevent something like 75%
of fatalities. And other helmet proselytizers missed the subtlety and
went for the straight-out lie.

Similarly, after the infamous Thompson & Rivara paper of 1989 claimed
that helmets prevent 85% of head injuries, another paper used that
number to claim universal helmet use would prevent 85% of American bike
fatalities. And astonishingly, that made it through peer review.
--
- Frank Krygowski

Helmets are designed to do one thing and one thing only. It was designed around the old coaster bike where you were trying to make an emergency stop you would stand up. That put your head about 2 meters above the ground. The helmet was designed not for a collision but for a sideways fall from that standing position.


Wherever did you get that idea?

I grew up in an era when there wasn't anything except coaster brakes
and I never, and I've never seen anyone, stand up to brake with a
coaster brake. And, I might add, I grew up in a rather mountainous
part of New Hampshire where one used the brake a great deal of the
time.

As an aside, the first mention I see to "bicycle helmets" dates back
to the 1880's, while the "coaster brake" seems to have been first made
in 1898.

Firstly you cannot stop with sufficient power without standing on the cranks using a coaster brake. This was commonly seen even on Re-Pack by the guys that started the mountain bike craze. I remember seeing them sliding almost the entire bottom of the run.

Kids especially didn't have the strength to operate the brake from a sitting position and the only way to cut a donut on a stop was to stand on the brake and lean forward to take your weight off of the rear tire. Moreover almost ALL coaster bikes had the saddles set far too low to allow any leverage on the coaster brake via the legs and not the body weight of the operator.

Utter bull****. I was a kid and I rode a coaster brake equipped
bicycle and I didn't stand on the brakes, nor did I ever see one of my
contemporaries stand on a brake.


Secondly the "helmets" before Bell's scientifically designed experiments were leather sometimes with extra leather padding in a roll around the edges. These were designed to act exactly as I stated as the only efficiency of the modern helmets - to prevent friction damage to the head on a track. They were sometimes but not usually worn on a road race. Cycling caps were derigor and have their distinct shape and size.

Nope. You prove once again that you don't know what you are talking
about. The Snell project was named for William "Pete" Snell who was
killed in the crash of a sports car. there are plenty of photos of
Pete showing him and his helmet certainly wasn't leather.

From a Snell published article,

"The English seem to have been the first with performance standards
for crash helmets. In the 1950's, British Standards Institute began
enforcing standards for crash helmets sold
in England...William "Pete" Snell was wearing an English auto racing
helmet on that day in August 1956 when he crashed in an amateur racing
event in Arcata, California, sustaining head injuries that would prove
fatal."



Almost all racing falls are sideways drops of relatively low height. The majority of the force of the fall is absorbed by the hip and knee and often the arm and shoulder. These are amateur races.

Pro racers put themselves in far more dangerous positions far more often. The real surprise is that they have so few serious injuries.
--
cheers,

John B.