wphamilton

I won't say either way about his post but if I may interject, our combat helmets have traditionally been designed primarily to stop penetration from shrapnel and grazing bullet strikes, and to a much lesser extent blunt force. For this reason they don't make very good bicycle helmets.

More recent designs seek to stop small caliber bullets and improve protection of blunt impact.

That a big point of contention, the deal-killer among combat troops, is making them bulkier or heavier sounds familiar. I hope that we're not being asked to pressure the military into forcing the use of equipment which they believe will impede their effectiveness in combat.

Joe Minton

joejack951:
My information must be old and is now incorrect. The Army helmet I tested only had a suspension system and no impact mitigation padding at all; it was standard issue at the time. Thank you for the link. I am very glad to be wrong here.

Still, though, the pads, if they are EPS, are not thick enough to provide the level of blunt impact protection of a motorcycle or even most bicycle helmets.

There was a small industry going here in the US supplying pad kits for the earlier version combat helmet. Like I said in another place, that helmet would not pass the CPSC standard or any helmet performance standard. If sold to the public, it would have been called a "bogus" helmet within the helmet industry. It would have been illegal for use in California and probably most other states.

Again, I am glad the government is doing something to make our soldiers safer. But --- the damned thing should never been put on a soldier's head without effective pads in the first place.

When I did my testing, I learned a little about the incredible politicking involved. There were folks who could provide effective padding but were afraid to push too hard so as not to get on the 'bad' side of those making supplier decisions. My expectation was that there would be no motion forward. I don't know how that changed but suspect loved ones' calls to Senators and Congressmen had something to do with it.

Joe

How would the Challenger investigation have gone if it had not been for Richard Feynman? Sometimes government really doesn't work very well.

Joe Minton

There is a new impact attenuation system available from 6D Helmets
That shows great promise.

6D’s liner system certainly is more complex than a carefully made hunk of Styrofoam and makes their helmets rather expensive at $270. The drop test charts shown in the linked page illustrate the superior performance of 6D’s design.

Those impacts that, in the past, were not considered very important turn out to be very important indeed for those who might get more than one or two. Mountain bikers and BMX riders might want to take a look at the link.

Joe

Joe Minton

Helmet fitment and children:

A few entries back (#2124), I talked about poor helmet fitment and children. I’ve had great fun and satisfaction in my neighborhood adjusting helmets for young people. They appreciate it and so do their parents; I’ve made some friends ;o). I figure that since the kids must wear one anyway, it might as well be in the right place on their precious little heads.

It is the law around here (California) that children must wear helmets while cycling. Parents often buy their kids’ helmets from their local superstore. They do not get instructions; they do not get a fitment by the seller they just get a receipt. And, probably, if there is a fitment brochure they don’t read it. Consequence: the helmet goes on the head as is. “As is” is normally wrong.

Now, here’s my pitch:
If you see what I see regarding helmet fitment on children and want to do something about the problem – hows about Y’all start doing what I’ve been doing. Engage your neighborhood parents and their kids. Go out and adjust helmets!

Bell/Giro has a brochure they send with each helmet they sell. It is mostly about fitting. Here’s a link: https://www.bellhelmets.com/bellsport...01074700-B.pdf
You can download this brochure, select appropriate parts of it, print those parts and hand them out to the parents who have no clue about how helmets work and why they should be ‘just so’ on their children’s’ heads. We, collectively, could make a small but very important difference in the safety of our children. ;o)

Joe

Joe Minton

Chinstrap problem with Bell/Giro helmets:

We have five helmets at our house. They were all made by either Bell or Giro, which is the same company.

They all have the same problem: the chinstraps loosen with use. This should not happen; a strap-length adjustment needs to be stable. Instead, the adjustment slips with usage and loosens the fit of the chin strap. In my experience, this slippage occurs slowly which means that the chin strap can become rather loose before being noticed. They must know this and I’d like to build a small fire under their corporate bellies/asses to correct the matter.

Here’s what I do: I either sew the adjusted straps together so they cannot slip, or, tighten a small Tie-Wrap around them. Sewing is more elegant but the 2.5” Tie-Wrap is quicker and easier.

Take a look at your helmet; check the chin strap adjustment; make sure it is snug per the instructions in the Bell brochure https://www.bellhelmets.com/bellsport...01074700-B.pdf


Joe

joejack951

Where are you getting this stuff from? Of course the pads aren't EPS. Why would the Army use cheap, one time use crap like that in their helmets that need to last and survive several impacts without falling apart? If you search for 'Team Wendy pads' you can find information about the pad system used.

Making the massive assumption that any of this is true, perhaps you might consider that the original combat helmet design was possibly (and likely) far more concerned with protecting against shrapnel and bullets than blunt force impacts. If they met that goal and that was the goal given to the designers (along with size, weight, and cost constraints and any other functionality that makes a combat helmet far different than a bicycle helmet), they were doing their job. Lessons were learned and the design has been iterated and improved. That's how product design goes.

Have you heard of MIPS? Does MIPS mean all other bike helmet designs should have never existed and are 'bogus'?

Joe Minton

joejack951:

I said: "-- if they are EPS,” I didn’t say they should be. Hell even the Riddell football helmet liner would have been yards better than nothing. The problem was that there was no impact protection. None! The padless combat helmet could not be dropped even a few feet onto the flat anvil without destroying the expensive accelerometer, so we didn’t.

I tested the SkyDex https://www.skydex.com/ pads which gave very, very low "g" loading numbers. The pads were ready to go (in 2004-5?) if they could sell them to the Pentagon. Which they could not do because of the politicking I earlier referred to.

Other manufacturers must have been working on a solution too. Maybe one or more of them had a solution. I don’t know that but I sure as hell know that SkyDex did.

Somewhere back there among my entries, I did clearly state that the early combat helmets, like the one I tested, were developed to stop an AK47 bullet fired from about 200 meters.

Even back then (actually 1960 or so), it was clear that blunt force impacts were important but the Pentagon did nothing. One knowledgeable helmet guy told me that cost was a factor, that it might cost an additional $10 to protect our soldiers against the very real and known threat of blunt force trauma in combat. The old helmet cost about $9, the new one - $47 (without blunt impact protection). They didn’t do it.

Go yell at them not me – I’m just trying to inform.

Joe

BTW: I tried to get "60 minutes" involved, with some help from Professor Hurt. They didn't seem to be interested. I should have called Morley Safer. ;o( --- JM

Joe Minton

Helmet protrusions: --- There shouldn’t be any. Really – there shouldn’t be any!

The problem: -- There are too many protrusions, both built-in and bolted on.

Anything that sticks out too far can catch things as you slide down the road and then give your head a mighty rotational acceleration which, in turn, might very well kill you. Or, even worse (my opinion based on experience) make you into an in-effective vegetable that your loved ones and/or our government has to care for until you unconsciously fade away.

DOT standards for motorcycle helmets prohibit hard bits sticking out more than 10 millimeters. This requirement is based on experience; hard things that stick out from a helmet can cause rotational brain injuries. The same considerations apply to bicycle helmets.

There are or have been two violations of this common-sense ‘standard’: helmet shape and things-that-get-bolted-on. Both the aftermarket and the helmet industry itself have and still do violate this experiential ‘standard’.

I, just the other day, saw a new MTB helmet being sold with a GoPro camera mount attached at the top. It stuck up the better part of an inch (25.4mm for my beloved Canadians). If that MTB biker crashes (isn’t that what they do?) and catches his/her GoPro mount on some tree/branch/pucker bush as it goes by, what do you think might happen? Well there is a better-than small chance that said theoretical rider would receive a potential rotationally-based closed-head injury.

The visor on my new $30 Bell helmet (Walmart Bell Adult Helmet Terrain, Black - Walmart.com) sticks out more than 10mm. It is also rather reasonably attached to the helmet itself. It can be popped off with a moderate sidewise force and I am sure (not certain) that Bell saw to it that this is so. I think I might take the visor off even though it looks rather cool.

Pointy-tailed helmets: Well – I’ll get that next time. This is long enough for now.

Joe ;o)

Joe Minton

Pointy-tailed (PT) bicycle helmets are a bad idea. A very bad idea.

Here’s why: In a crash where the rider is struck from behind by a car and rotates into said car’s windshield or, even worse, the upper windshield/roof support structure. A PT will rotate violently and twist the rider’s head violently. A TBI (Traumatic Brain Injury) is sure to follow. This is one of the more common bicycle/car collisions.

I invite you to watch this: https://www.youtube.com/watch?v=dNFaAqS2f18
Notice that at 24 seconds in the bike rider’s head strikes the asphalt. The helmet takes the blow as it was designed/developed to do. Notice also that his head was not violently twisted. This was a perfect example of the goal of the CPSC flat anvil drop test standard. Because of the height of the fall, that man would surely have been DRT (Dead Right There) had he not worn that helmet.

Now, if that helmet had been one of the popular boat-tailed helmets, the British guy would have received a violent twist as the damned PT helmet tried to get out of the way!

I viewed a video of a testing lab attempting to get a “g” number for a CPSC flat anvil drop on the rear of a PT helmet. They had to use the better part of a roll of duct tape to keep it pointed at the anvil as it struck same. It ‘wanted’ to get out of the way of what was coming. The test was connected with a lawsuit. They settled the case and all the evidence was therefore declared confidential. Still, if I had a copy of that test video, it would now be all over the internet.

Some physics: A bicycle helmet weighs 3-500 grams, it is very light. Heads typically weigh 11 pounds. Flat test anvils and cars weigh so much that it doesn’t matter. Now, if a 400 gram helmet gets between a fast-closing 5kg head and an anvil/earth/car, and that helmet is designed to get out of the way, what do you think is going to happen? Yep, the helmet gets out of the way, twisting its wearer's head as it goes, and then lets nature take its course. BTW: After that lawsuit was settled, the bike helmet manufacturer stopped making PT helmets. You’d have to go to eBay to find one these days.

At the top is an example of a “Pig Snout” helmet. It was meant to deflect pointy things aimed at its wearer’s head. Turn it around and it looks a lot like those ‘aerodynamic’ helmets we used to see in our LBS. That design might have saved some jousting knights but, in our world, it might kill you.


Joe

wphamilton

I'm more concerned about torque on the neck if you roll over the shoulder, or twisting if you go down more tangential to the direction of travel. That's where you're more at risk of rotational brain injury also. I am a little less impressed with the car-from-behind hitting the windshield example - you might or might not be as well served with one helmet as the other.

On the plus side, the pointy aero helmets protect about as well as the others against minor cuts and abrasions, which are evidently by a large margin the kinds of injuries usually mitigated by helmets

howsteepisit

All this, and totally ignoring the risk of any event actually happening

Joe Minton

I have ridden motorcycles a little more than one million kilometers. I’ve fallen a few times. I’ve always worn a helmet. I’ve never even scratched one of them. I could have ridden all those miles without a helmet at all. Not everyone has been so lucky.

Even the most skillful cyclists can get nailed in some way or other as I was by a self-involved, speeding, texting driver a couple of years ago while riding my bicycle. For the first time, in 50,000 kilometers of cycling, my head hit the ground. The fall was hard enough to crush the helmet, break two ribs and smash the end of my collar bone. Without the helmet I most likely wouldn’t be here, because, unlike ribs and clavicles, brains don’t come back stronger as bones often do.

Traumatic Brain Injuries (TBIs) are rare, most us ride a lifetime without one and may never even meet a person who’s had one. Most of us never smack our heads on the ground hard enough to need hospital care, or so we may think.

Contemporary studies show that almost any bell-ringing event does cause brain damage though and, as a sports-oriented society, we are beginning to take the matter more seriously. Heroic professional athletes, suffering with advanced CTE (Chronic Traumatic Encephalopathy) have been killing themselves in a way that preserves their brains so science may study those brains and hopefully help others. They got CTE by banging their heads against one thing or another as part of their sport.

Brain injuries are rare but they are also forever. We can train around brain damage, to some extent and sometimes wonderfully well. However, about half of those who suffer TBIs die in the hospital within hours.

Here a few, of many, factual and hopefully enlightening links:
AANS - Traumatic Brain Injury
Facts About Traumatic Brain Injury
Death rate is increased for at least 7 years after head injury: a prospective study | Brain

USC Professor Hugh “Harry” Hurt, did a three year “Death Study” (his words) whereby he personally followed fatal motorcycle crash victims literally from the location and time of the crash all the way through autopsy. He learned many interesting things and one of them was just how effective helmets could be. He gathered enough data to conclude that for every helmeted fatal head injury where the TBI was the sole cause of death, there are 250 such fatal head injuries when no helmet is worn. This was a study about motorcycle accidental deaths but the issues are the same for us; TBIs are deadly and helmets do much to prevent or mitigate them. Professor Hurt’s 250 to 1 conclusions give helmets a better success ratio than condoms.

You may ride all your life with no problem, but --- if you do then get a TBI and if you live at all, life is going to become very difficult.

I include links to a few of many YouTube videos regarding TBIs and recovery.
https://www.youtube.com/watch?v=9Wl4-nNOGJ0
https://www.youtube.com/watch?v=DkSPVRxDBnI
https://www.youtube.com/watch?v=BcY5eeXqt9E
https://www.youtube.com/watch?v=3pCiWDKA93s
https://www.youtube.com/watch?v=7kQf2G_DIJM

If you choose to not wear a helmet, fine; I really don’t care. You are responsible to and for your life. But, I do care that you make such a decision knowing what the facts are. TBIs are rare but horrible life ending/altering events that affect everyone who cares about the injured.

Joe

wphamilton

44 fatalities per billion kilometers traveled in the USA OECD Analysis of International Trends of Bicycle Use and Cyclist Safety. (if the link doesn't work, google the title) See Fig 3.12 That would be 67 per billion miles by our reckoning.**

To make that easier to grasp I like to personalize it. Say I generously estimate 4,000 miles commuting in a year, how many years does that represent for a fatal accident, assuming my riding had those same odds? That would be 67 deaths times my miles per year / one billion miles = .00027 deaths per year of my commutes. Inverting that for years for one death, I get 3,731 years.

So there in very broad strokes is the risk. Someone with a longer than average commute can expect a fatal accident after several millennia. That risk is in reality exaggerated in my case, and your's of course, since as has been often pointed out here a large fraction of these fatalities* involved intoxicated riders and other risky behaviors that we avoid.

* 21% of NY cyclists who died in three hours had alcohol in their bodies https://cityroom.blogs.nytimes.com/20...d-bike-deaths/

**caveat, estimates of bicycle miles vary widely
[TABLE]
[TR]
[TD]6.2 billion[/TD]
[TD]Bureau of Transportation Statistics[/TD]
[/TR]
[/TABLE]
[TABLE]
[TR]
[TD]6 to 21 billion[/TD]
[TD]U.S. Dept. of Trans. / Fed. Hwy Admin.[/TD]
[/TR]
[/TABLE]
[TABLE]
[TR]
[TD]150 billion[/TD]
[TD]Consumer Product Safety Commission[/TD]
[/TR]
[/TABLE]
from Bicycle Almanac

howsteepisit

I have looked at similar calculations as you WP, if I recall my thoughts were about the same. My complaint is that the latest helmet evangelist seems to 1) be all about motorcycle helmet and risk being the same or similar to bicycling, which I do not believe they are, and 2) J seems to be of the "if there is one injury/risk avoided there is no end to the costs that should be borne" school of thought.. I also disagree there. I was trying to egg JM into putting some context into his comments, he appears unable to do that.

wphamilton

I've learned from the other fellow that expresses that sentiment, that if they don't address the risk calculation when you confront them once, we might as well forget it. The interest remains with the other half of the question.

Joe Minton

I have made a lot of statements about helmets here these past few days and now I'm gonna take a rest. I’ve made some folks angry and am glad to have done so, it’s about time. Hopefully, I’ve also gotten more folks curious about helmets, how they work, what they’re made of and just how much is known for sure about how effective they can be and --- just how fragile our amazing brains are, how seldom they are injured and how bad it can be when they are.

My goal has been to say things about head injury and helmet performance that I know to be so. I've given a few links that might help y'all become better informed about the subject. I have invited you to do your own research --- There’s a lot of useful information out there, go after it.

As I expected, I've been attacked by trolls and self-important lazy people some of whom have reading comprehension difficulties and don’t seem to be capable of clear thinking. I have gone ahead anyway because, ultimately – they don’t matter beyond their ability to stop others from joining the conversation.

I believe that the helmet thread has been almost useless since its inception because of the trolls. I fault whoever is in charge for letting this happen.

Surely there are cyclists out there who would like to know more about TBIs and the risks of falling on one's head. A more open and supportive helmet forum would promote that; at this time it is not and does not.

Sophomoric trolls ought to feel shame for the way they suppress free exchange in this or any other forum. They attack and bully anyone who might ask useful questions and might to be a target for their venom. By their attempts to attack, criticize, destroy and 'win' arguments rather than encourage and promote inquiry, they do themselves and all of us a great disservice. I’d like to think that we are in this sport together, to help, support, encourage and enlighten. Clearly this is not so for some.

Joe

wphamilton

No one is angered by your posts Joe.

You've been operating under a misconception. The Helmet Thread is a quarantine space intended to contain the arguments that arise whenever helmets are mentioned.

If you really want to discuss TBI, there is no policy prohibiting you from starting a thread for that, as long you refrain from helmet advocacy (probably, though you could get away with advocacy if no one argued).

bobwysiwyg

So I should stop paying my homeowner's insurance?

howsteepisit

That's up to you. but a claim on your homeowners is probably 3 orders of magnitude more likely than needing a bicycle helmet.

Signed the troll

Joe Minton

Thank you wphamilton for your kind words, I truly do not deserve them.

I failed to see the helmet thread as a quarantine site but rather a failed one and I still do. Still, we are left with no way to shed light on the mechanisms and consequences of TBIs, which now know are much easier to come by than previously thought. Of course helmets are part of that discussion, how can they not be.

Another Subject:
A now closed thread started by skye in the middle this month led me to this website:
CDC - Hierarchy of Controls - NIOSH Workplace Safety and Health Topic

Take a look at the graphic on that site (copied below) showing the relative importance of injury factors in the workplace. It places things like headgear at the bottom of the inverted triangle expressing the relative effectiveness of the various things we can do to reduce total injuries. The helmet is the last resort: if nothing can fall on your head, you won’t need a helmet.
However, I am sure this Hierarchy does not equally apply to we cyclists riding on our roadways, especially our urban streets. Construction sites and other regulated and watched environments are better looked after than our streets, of that I am sure. I find it very hard to believe that a construction worker would be required to do his/her job while trucks, cars and busses fly by a meter away. Surely y’all are aware of how DOT workers are protected as they work on our highways; they sure are a bunch better off than we cyclists.



What dear old Copenhagen has done is pretty much apply this “Hierarchy of Controls” to their streets. Riding a bike there is about as safe as walking and walking there is very safe; they don’t need helmets for where and how they ride. It has taken them more than 40 years to get where they are in this regard.

They are not us (USA). In my opinion, they care more about one another than we do. In another place in this thread I implied and believe that I would probably be dead or terribly and permanently disabled were it not for my, now broken, Giro helmet. I like to believe that a Copenhagener would not text or cell-phone while driving 15mph over an already generous speed limit, clip a bike rider and not even seem to notice. That sort of thing happens often here.

So – I wear a helmet even though I only needed one once in over 50 years. I wouldn’t be here if I hadn’t done so.

Joe

BTW:
As a sometimes sporting rider, I’m sure I’d be bored to tears riding a bike around Copenhagen ;o)

350htrr

I think the "real problem" is the combination of perceived risk, and a perceived benefit ratio.. If you do 'riskier" type of riding maybe you need/should, wear a helmet... If your head actually does hit the ground, a helmet would/should, help with reducing injury, but "probably" wouldn't save your life... That is what I have gleaned from this "useless" thread... "expectations" need to be realigned with reality for most people, because of some propaganda from both sides...

I-Like-To-Bike

Correct.

CarinusMalmari

Actually, bicycle helmets are specifically designed for falling off of your bicycle, a type of accident that is stil common in countries like Denmark and the Netherlands. It's also a type of accident you would walk away from without clinically significant injuries; head or otherwise, but if your fall is less lucky, a helmet could save you some trouble.

If you're in a more severe crash, a bicycle helmet would not nearly be sufficient, and you would e in need of something more robust, A.K.A. a motorcycle helmet. Now I think of it, that's exactly what I wear when I take the moped, which is in NL typically a contraption with a top speed of 50 km/h. Not going to expect wonders from that helmet, in fact I basically ride as if I'm not wearing it, but the idea of using a bicycle helmet instead of a proper helmet, seems preposterous to me.

Joe Minton

TBI-related death statistics may not be reliable.

The problem is with how they are typically recorded, by whom they are recorded and what the immediate goal is with the documentation of the death.

Physicians fill out certificates of death. They are typically niether practicing scientists nor trained statisticians; they are practitioners whose paperwork job in this case is to assign a cause of death. I am not saying these folks aren’t smart, they certainly are. It’s just that, when filling in the cause of death on the certificate, they are not thinking about gathering possible information for some future statistical study.

Typically, they’ll pick a single obvious cause of death and give that the full weight of their conclusion. Nothing is a more obvious cause than an open head wound. A possible example: We all know that JFK died from a head wound. What we don’t know is whether it was the only fatal wound. He was first shot through his neck which did great damage to his throat. He might have died from that were there no fatal head wound. I’ve never been able to discover if that might have been so. We got the simple clear and correct conclusion that a bullet through his brain was fatal with no mention of the throat wound.

This is what happens most times when there is a fatal head injury; the other possible fatal injuries are ignored on the paperwork.

Part of the motivation for Prof. Hurt’s “Death Study” which I referred to a few entries back was to more thoroughly document causes of death in motorcycle crashes. He followed 139 crash fatalities from the crash scene through autopsy. This took almost three years and was a lot of work.

He found that the examining physicians were being lazy. If there was a fatal head injury, it was given the full weight as the cause of death even though there might be others. This laziness prejudiced conclusions about the effectiveness of helmets.
He found that for every fatal head injury of a rider who was wearing a helmet, that same rider had 3.1 other fatal injuries as well. On the other hand TBI fatalities for riders wearing no helmet seldom included other life threatening let alone fatal injuries.

The traditional cause of death declarations were being skewed against the efficacy of helmets. They probably still are and for the same reasons: folks are filling in blanks on paperwork and being somewhat simple minded about doing so. As soon as Prof. Hurt finished his study the MEs went back to the old practice.

So: --- I recommend that you not trust statistics about helmet effectiveness because they probably aren’t accurate or complete.

Joe

“There are three kinds of lies: Lies, Damned Lies and Statistics” – Mark Twain

howsteepisit

Or at least ignore those that do not support JM's view of the efficacy of bicycle helmets evaluated against the lens of motorcycle helmets.