|
|
Thread Tools | Display Modes |
#31
|
|||
|
|||
Thunked my helmet a fourth time
On Thu, 12 Nov 2015 12:08:48 -0800, The Real Bev
wrote: On 11/12/2015 04:40 AM, Andrew Chaplin wrote: The Real Bev wrote in news:n21drr$ejq$1@dont- email.me: A thing I remember especially is that hair alone provides significant protection from abrasion. Your mileage may vary--wildly! Indeed. But surprises happen sometimes. When I crashed on my motorcycle and slid along the ground the parts of my body protected by flimsy cloth were fine; my shirt rode up and exposed half a square foot of abdomen skin, which eventually formed a scab 1/4 inch thick in places and cracked AND HURT where I bent. I eventually got in the tub and soaked it off. I figure hair is about the same. Still, I wear a helmet. Not when I ski, though. You are perfectly correct. Hair, in certain areas of the body provides what is refereed to as "a dry lubricant that reduces friction". But I'm not sure that it actually provides adequate "lubrication" for sliding down an asphalt road :-) -- cheers, John B. |
Ads |
#33
|
|||
|
|||
Thunked my helmet a fourth time
On Tuesday, September 22, 2015 at 1:01:03 PM UTC-7, The Real Bev wrote:
On 09/20/2015 04:04 PM, wrote: I could go into great detail about helmets since I started learning about them as the Safety Director of the American Federation of Motorcyclists about the time Bell started and I had some long discussions with people at Bell. I am also an engineer and a scientist. I wrote one of the few peer reviewed papers on bicycle helmets. Long ago I had/read a USAF publication about helmet design which had a lot of useful/interesting information. I recently did a google etc. search for it and turned up nothing. Did you ever read that? I remember reading a paper long ago about helmet design but they were for fighter pilots and the helmets were designed to nestle the head securely into the headrest so that violent maneuvers couldn't bounce your head off of the canopy. Helmets are capable of VERY little and at the cost of setting you up for two other kinds of killer injuries. I wear one because they are good for one thing - keeping your head from getting gravel rash in a mild crash. In harder crashes they can cause severe concussions or broken necks. Funny thing - evolution didn't design your head like a helmet for a reason. I remember reading that they were designed to "protect" the head from a 6-foot fall straight down. An unlikely occurrence, I think... You are correct. Mind you that Bell ran their early experiments making a lot of assumptions such as that the reason for head injuries was a fractured skull which has since been shown to be inaccurate. Very serious head injuries occur far below the force that would break a skull while wearing a helmet that spreads the forces evenly over a larger area. This is the growth of knowledge and not some sort of mistake on their part. The majority of accidents to adults are the fault of the car. An approaching driver making a sudden left turn. And a car approaching from behind, accelerating to pass you and then suddenly turning right. The left turn danger is MUCH reduced if you wear bright clothing. This both makes you much easier to see to the approaching driver plus it makes it more difficult for the driver to guess your speed making him think you are faster than he might otherwise think. I favor as much neon-color as possible -- the guy who hits me is NOT going to be able to tell the judge he didn't see me. For awhile bright neon outerwear started becoming popular after I complained so loudly about the popularity of Sky's all black outfits and other teams combinations of black and white that made these riders effectively invisible in shade/sun areas such as tree lined roads. But it appears to have been a fad and more and more riders are falling back to dull, lifeless colors which make them a target on streets |
#34
|
|||
|
|||
Thunked my helmet a fourth time
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. |
#35
|
|||
|
|||
Thunked my helmet a fourth time
On Wednesday, September 2, 2015 at 7:04:44 AM UTC-4, John B. wrote:
On Wed, 02 Sep 2015 00:35:10 -0300, Joy Beeson wrote: I've had three helmet-thunking falls in the last fifty years. I think it was in the eighties that I touched wheels while on a multi-day tour. Got up and finished the ride. A couple of years ago I slipped on some rotten leaves concealed under what appeared to be a drift of dry leaves, and had the same exact fall. The muscles attached to my ribs were still feeling it two months later; I don't bounce like I uster. (I did ride home, but after stiffening up, I could just barely walk.) A couple of months ago I dropped a piece of paper while stopped to read a map, and thought I could pick it up without dismounting. Sense of balance ain't what it used to be; being tangled in the bike, I hit like a bag of wet cement and banged up the same ribs. But it was only one day before I could cough; the wet leaves took a week. Today -- clock just struck, make that yesterday -- I made a pit stop at a playground. It was the middle of a school day, so the place was deserted. I looked all around: yes, there are no witnesses. I climbed the spiral slide -- and failed to duck under a bar at the top that was meant for much shorter people. Worse, between my sweat-soaked clothes and my body occupying more degrees of the curve than the designer planned, I went down so slowly that I almost had to push. No fun at all. And the moral is? Wear a helmet on the slide ? :-) -- cheers, John B. Haha |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Less than 70 days until the fourth NAB Coffs Coast Cycle Challenge | Stephen | UK | 2 | May 29th 13 07:32 PM |
Bicycle accident = glad i had my Helmet on this time | Sir Ridesalot | Techniques | 524 | August 27th 10 08:18 AM |
Best Time Trial helmet? Giro vs. Garneau | John Crankshaw[_2_] | Techniques | 1 | March 30th 08 05:57 PM |
time trial helmet w/visor NIB | steve | Marketplace | 0 | November 24th 04 05:16 AM |
fourth post, first uni | steveyo | Unicycling | 9 | August 17th 04 05:38 PM |